Postbiotic (Heat-killed)

BACKGROUND: Recent research has highlighted the potential of postbiotics for addressing obesity and associated metabolic disorders. In this randomized, double-blind clinical trial, the efficacy of a postbiotic product in managing overweight and associated parameters was assessed. METHODS: Sixty individuals were randomized into two groups: one group (n = 30) received the Postbiotic (heat-killed L. fermentum strain K8-Lb1) and the other (n = 30) a Placebo control. Body weight, waist circumference, body composition, vital signs, blood biomarkers and questionnaires for quality of life, eating behavior, eating control and gastrointestinal symptoms were assessed. RESULTS: After a 12-week intervention, body fat mass (primary parameter) was significantly (p = 0.016) reduced in the Postbiotic group (98.15 ± 3.32% of baseline) compared to the Placebo group (100.41 ± 3.39%). In line with this, body weight (p = 0.047) and waist circumference (p = 0.034) were significantly reduced and visceral fat tended to be reduced (p = 0.053). Accordingly, the Postbiotic group tended (p = 0.066) to feel more in control of their body weight. Despite weight loss, muscle mass tended (p = 0.062) to increase. ALT, AST and GGT tended to be reduced, which may indicate an improvement in liver steatosis. Estimated average glucose (eAG) differed significantly between the groups in individuals with normal fasting glucose levels. The ability to concentrate significantly (p = 0.014) improved. CONCLUSIONS: Under an ad libitum diet, the postbiotic L. fermentum strain K8-Lb1 reduced body fat mass, body weight, and waist circumference, improved the ability to concentrate, and showed a trend towards an increase in muscle mass. The results of this pilot trial need confirmation by a pivotal trial.

BACKGROUND/OBJECTIVES: Skin aging is a multifactorial process driven by intrinsic and extrinsic factors. Orally administered postbiotics may support skin homeostasis; however, clinical validation of their efficacy remains limited. In this study, we aimed to examine the effect of oral supplementation with the heat-killed lactic acid bacterium Lactobacillus acidophilus IDCC 3302 (ID-ACT 3302) on skin aging-related markers in healthy adults with periorbital wrinkles. METHODS: In this 12-week, randomized, double-blind, placebo-controlled trial, 100 participants were assigned to receive either ID-ACT 3302 or a placebo. The prespecified primary endpoint was the change in crow's-feet wrinkles at week 12, assessed using investigator visual wrinkle grading and PRIMOSlite. Secondary endpoints included skin hydration, transepidermal water loss (TEWL), skin elasticity indices (including the overall elasticity index R2), and global improvement scores. RESULTS: In the full analysis set, wrinkle grade, hydration, TEWL, and elasticity improved over 12 weeks in both groups; however, ID-ACT 3302 exhibited no superiority over placebo for the primary wrinkle endpoints. The overall elasticity index R2 exhibited significant inter-group difference, whereas R5, R7, hydration, TEWL, and global assessment scores improved consistently in both groups. In the absence of multiplicity adjustments for secondary endpoints, the R2 finding is considered exploratory. Safety outcomes were comparable between the groups, with no serious adverse events. CONCLUSIONS: The 12-week supplementation with ID-ACT 3302 was safe and well tolerated. However, no placebo-adjusted benefit was observed for the prespecified primary wrinkle endpoints. An exploratory between-group difference was observed for the Cutometer overall elasticity index (R2), but because secondary endpoints were not multiplicity-adjusted and the effect size was small, this finding should be interpreted as hypothesis-generating and requires confirmation in adequately powered trials.

Osteoarthritis (OA) is a common cause of chronic pain and functional impairment in older adults. Evidence suggests a gut-joint axis, where gut dysbiosis and systemic low-grade inflammation may contribute to OA pathogenesis. Postbiotics, which are non-viable microbial products such as heat-killed bacteria, have been proposed as safe and stable alternatives to live probiotics. ID-CBT5101, a tyndallized Clostridium butyricum preparation, reduced inflammation and preserved cartilage in a rat OA model. We conducted a 12-week randomized, double-blind, placebo-controlled trial to assess ID-CBT5101 safety and efficacy in adults with mild-to-moderate knee OA. Ninety-six participants were randomized to receive either ID-CBT5101 (1.0 × 1010 CFU-equivalents/day) or placebo. The primary endpoint was the change from baseline in walking pain on a 100-mm visual analog scale (VAS). Secondary outcomes included WOMAC, Korean Knee Score (KKS), patient global assessment, and serum biomarkers. Both groups showed significant within-group improvements in VAS, WOMAC, and KKS over 12 weeks. However, no significant differences were observed between groups for any clinical endpoint. Serum interleukin-6 (IL-6), cartilage oligomeric matrix protein (COMP), prostaglandin E2 (PGE2), leukotriene B4 (LTB4), transforming growth factor-β (TGF-β), and high-sensitivity C-reactive protein (hs-CRP) showed no consistent changes favoring ID-CBT5101. Safety profiles were comparable between groups, with no treatment-related adverse events. ID-CBT5101 was safe and well-tolerated, but it did not demonstrate significant clinical efficacy compared with placebo.

It has been confirmed that Lacticaseibacillus paracasei (formerly designated as Lactobacillus paracasei: L. paracasei) K71, a lactic acid bacterium isolated from sakekasu (sake lees) has immunomodulatory and anti-obesity effects. This study aimed to investigate the effect of heat-killed L. paracasei K71 intake on reducing abdominal fat in a randomized, double-blind, placebo-controlled, parallel-group comparative trial. Eighty healthy male and female subjects with a BMI of ≥23 and <30 were selected and randomly assigned to one of two groups, a test food group and a placebo group. Subjects ingested either a test food containing 50 mg (approximately 1×1011 bacteria) of heat-killed L. paracasei K71 or a placebo for 12 wk. Abdominal fat area and volume, as calculated by computed tomography, body weight, BMI, body fat percentage, waist circumference, hip circumference, waist-to-hip ratio, and blood markers were evaluated. In PPS, no significant between-group differences were observed in any item. On the other hand, in subjects with no significant changes in lifestyle, compared with the placebo group, the test food group showed significant decreases in subcutaneous fat area, visceral fat volume, subcutaneous fat volume, body fat percentage, and hip circumference after 12 wk. Moreover, no adverse events due to the test food containing heat-killed L. paracasei K71 were observed during the test period. These results suggest that continuous intake of heat-killed L. paracasei K71 has the effect of reducing abdominal fat in healthy subjects with a high BMI. This trial was registered at UMIN-CTR (UMIN000051324).

BACKGROUND: Preterm infants discharged from the neonatal intensive care unit (NICU) have a risk of severe viral respiratory tract infections (RTIs). Researchers have recently reported the potential use of postbiotics to decrease RTIs in young children. However, the safety and efficacy of postbiotics for preventing RTIs in preterm infants is not yet established. METHODS: We conducted a pilot double-blind, randomized, placebo-controlled study of the heat-killed lactic acid bacterium Pediococcus acidilactici K15 in 41 preterm infants born at <36 weeks of gestation and discharged from the NICU at Chiba University Hospital. RESULTS: Following once-daily K15 or placebo treatment for one year, no significant differences were found in the mean number of febrile days (4.5 [1.5-7.4] days vs. 6.6 [2.6-10.5] days). The subgroup analysis showed that the effect of treatment on the number of febrile days was more prominent in the K15 group than in the placebo group, among children with older siblings. The 16S rRNA gene sequencing of fecal samples illustrated that the genus Faecalimonas was enriched in the K15 group, potentially promoting butyrate production by butyrate-producing bacteria. No adverse events were found to be associated with K15 intake. CONCLUSION: There were no clear data to show the effectiveness of K15 in preventing fever and RTIs in preterm babies during infancy. A larger clinical trial is warranted.

A randomized, placebo-controlled, double-blind, parallel-group clinical study was conducted to examine the effects of ingesting a heat-killed lactic acid bacterium, Lactobacillus johnsonii No. 1088 (LJ88) on temporal gastroesophageal reflux-related symptoms in healthy volunteers. A total of 120 healthy Japanese volunteers of both sexes, aged between 21 and 63 years, whose Frequency Scale for the Symptoms of Gastroesophageal Reflux Disease (FSSG) total score was 8 or greater, but who were not diagnosed with functional dyspepsia according to the Rome IV classification, were enrolled. They were randomly assigned to either the LJ88 or placebo group and instructed to ingest the test food (1 billion heat-killed LJ88 or placebo) once a day for six weeks. Gastroesophageal reflux-related symptoms were evaluated using FSSG scores as a primary endpoint. The Gastrointestinal Symptoms Rating Scale (GSRS), stomach state questionnaire, and serum gastrin concentration were used as secondary endpoints. In the FSSG evaluation, the heartburn score was significantly improved at 6 weeks in the LJ88 group compared to the placebo group. No severe adverse events related to the test food were observed. In conclusion, daily ingestion of heat-killed LJ88 improved temporal heartburn symptoms in non-diseased individuals.

Previous clinical studies have shown that heat-killed Lacticaseibacillus paracasei MCC1849 suppresses subjective symptoms among healthy adults. However, the mechanism underlying this beneficial effect remains unclear. This clinical study aimed to investigate the effects of MCC1849 on immune functions in humans. In this randomized, double-blind, placebo-controlled, parallel-group study, 100 healthy adults were randomly divided into MCC1849 or placebo groups. Participants ingested test powder with 5 × 1010 MCC1849 cells or placebo powder for 4 weeks. Immune functions were evaluated using expression levels of CD86 and HLA-DR on dendritic cells (DCs), neutrophils, and natural killer cells. The expression levels of interferon (IFN)-α, -β, and -γ in peripheral blood mononuclear cells incubated with Cpg2216 in vitro were quantified. Efficacy analysis was performed on participants in the per-protocol set (placebo group; n = 47, MCC1849 group; n = 49). The expression level of CD86 on pDCs and the gene expression levels of IFN-α, -β, and -γ upon TLR9 agonist stimulation were significantly higher in the MCC1849 group at 4 weeks. No side effects were observed. This is the first report to show the positive effects of MCC1849 on human immune cells. These findings reveal one possible mechanism of how MCC1849 suppresses subjective symptoms.

Consumption of Lactiplantibacillus plantarum TWK10 (TWK10) has beneficial probiotic effects, improves exercise endurance performance, regulates body composition, and mitigates aging-related problems in mice and humans. Here, we investigated the effects of heat-killed TWK10 on exercise endurance performance, muscle weight and strength, fatigue, and body composition in a double-blind, placebo-controlled clinical trial. Thirty healthy males aged 20-40 years were assigned to the Control group or heat-killed TWK10 group (TWK10-HK) in a balanced order according to each individual's initial maximal oxygen uptake. After 6-week administration, the exercise endurance time in the TWK10-HK was significantly increased (p = 0.0028) compared with that in the Control group. The grip strength on the right and left hands of the subjects was significantly increased (p = 0.0002 and p = 0.0140, respectively) in the TWK10-HK compared with that in the Control group. Administration of heat-killed TWK10 resulted in a significant increase (p = 0.0275) in muscle weight. After 6-week administration, serum lactate, and ammonia levels were significantly lower in the TWK10-HK group than in the Control group during the exercise and recovery periods. These findings demonstrate that heat-killed TWK10 has significant potential to be used as a postbiotic for humans. © 2023 Synbio Tech Incorporation and The Authors. Physiological Reports published by Wiley Periodicals LLC on behalf of The Physiological Society and the American Physiological Society.

We previously reported that the intake of heat-killed Lacticaseibacillus paracasei MCC1849 suppressed the onset of cold-like symptoms in healthy young women who were susceptible to colds. This study aimed to investigate the effects of MCC1849 on subjective symptoms of physical condition in healthy adults of a wide age range. In this randomized, double-blind, placebo-controlled, parallel-group study, 200 healthy adults were randomly divided into the MCC1849 group or placebo group. The participants received test powder with 50 billion MCC1849 cells or placebo powder without MCC1849 for 24 weeks. Subjective symptoms were assessed by diary scores. Analysis was performed on 183 participants (MCC1849 group; n = 91, placebo group; n = 92) in the per-protocol set. The number of days of stuffy nose and cold-like symptoms was significantly reduced in the MCC1849 group compared with the placebo group. In addition, the duration of stuffy nose, sore throat and cold-like symptoms was significantly lower in the MCC1849 group. No side effects were observed. Therefore, oral intake of MCC1849 suppressed subjective symptoms in healthy adults of a wide age range. These data suggest that MCC1849 may help maintain physical condition.

Oral microbial dysbiosis is the primary etiologic factor for halitosis and may be the critical preventive target for halitosis. This study included randomized controlled trials (RCTs) assessing the effects of Lactobacillus paracasei ET-22 live and heat-killed bacteria on halitosis and the related oral microbiome. 68 halitosis subjects were divided into placebo, ET-22 live (ET-22.L) and ET-22 heat-killed (ET-22.HK) groups. Subjects took different lozenges three times a day for 4 weeks and underwent saliva collection and assessment of breath volatile sulfur compound (VSC) levels at the beginning and end of the intervention. Salivary volatile organic compounds were measured using HS-SPME-GC/MS, and the microbiome profile was determined by 16S rRNA gene amplicon sequencing. A positive decrease in breath volatile sulfur compound (VSC) levels was observed in the means of both ET-22.L and ET-22.HK groups after 4 weeks of intervention, being more marked in the ET-22.L group (p = 0.0148). Moreover, ET-22.L and ET-22.HK intervention remarkably changed the composition of total salivary volatile organic compounds (VOCs) and aroma-active VOCs. Key undesirable VOCs, such as indole, pyridine, nonanoic acid, benzothiazole, and valeric acid, were significantly reduced. Meanwhile, ET-22.L or ET-22.HK also altered the taxonomic composition of the salivary microbiome. The halitosis pathogens Rothia and Streptococcus were significantly reduced in the ET-22.HK group and the pathogenic Solobacterium and Peptostreptococcus were significantly inhibited in the ET-22.L group. Collectively, our study suggests that both ET-22.L and ET-22.HK can significantly inhibit the production of undesirable odor compounds in subjects with halitosis, which may be related to the changes of the oral microbiome.

BACKGROUND: The growing prevalence of obesity has become a major concern worldwide, therefore a great number of studies are conducted every day in the field of obesity. Since postbiotics are a newly introduced term, there is not much systematic evidence about their function and impact on obesity. We designed this study to systematically review the effect of different types of postbiotics on obesity. METHODS: A systematic search was conducted using PubMed, SCOPUS, and Web of Science databases up to August 2023. Both human and animal interventional studies that investigated the effects of any type of postbiotic on obesity and obesity-related factors were eligible. Screening, data extraction, and quality assessment were conducted independently by two researchers. The quality of the studies was appraised using Cochrane and Systematic Review Centre for Laboratory Animal Experimentation (SYRCLE's) risk of bias tool. RESULTS: Of the 19373 retrieved studies, finally, 49 studies were included (9 human studies and 40 animal studies). Short-chain fatty acids and heat-killed (inactivated) bacteria were the most used postbiotics. In human clinical trials, inactivated Lactobacillus amylovorus (CP1563), Bifidobacterium animalis subsp. lactis (CECT 8145) and Pediococcus pentosaceus (LP28) were administered orally as postbiotics which improved body composition and anthropometric indices. Animal studies evaluated other types of postbiotics including muramyl dipeptide, cell-free extracts, urolithin A&B, extracellular Vesicles, exopolysaccharides, and surface Layer Proteins, supporting the anti-obesity effects of postbiotics. CONCLUSION: Postbiotics seem to be a safe intervention and the results were in favor of a reduction in adipogenesis as well as an increase in energy expenditure. Further high-quality studies are required in this relatively new topic.

In recent years, postbiotics have increased in popularity, but the potential relevancy of postbiotics for augmenting exercise performance, recovery, and health is underexplored. A systematic literature search of Google Scholar and PubMed databases was performed with the main objective being to identify and summarize the current body of scientific literature on postbiotic supplementation and outcomes related to exercise performance and recovery. Inclusion criteria for this systematic review consisted of peer-reviewed, randomized, double-blind, and placebo-controlled trials, with a population including healthy men or women >18 years of age. Studies required the incorporation of a postbiotic supplementation regimen and an outcome linked to exercise. Search terms included paraprobiotics, Tyndallized probiotics, ghost biotics, heat-killed probiotics, inactivated probiotics, nonviable probiotics, exercise, exercise performance, and recovery. Only investigations written in English were considered. Nine peer-reviewed manuscripts and two published abstracts from conference proceedings were included and reviewed. Supplementation periods ranged from 13 days to 12 weeks. A total of 477 subjects participated in the studies (n = 16-105/study) with reported results spanning a variety of exercise outcomes including exercise performance, recovery of lost strength, body composition, perceptual fatigue and soreness, daily logs of physical conditions, changes in mood states, and biomarkers associated with muscle damage, inflammation, immune modulation, and oxidative stress. Early evidence has provided some indication that postbiotic supplementation may help to support mood, reduce fatigue, and increase the readiness of athletes across several weeks of exercise training. However, more research is needed to further understand how postbiotics may augment health, resiliency, performance, and recovery. Future investigations should include longer supplementation periods spanning a wider variety of competitive athletes and exercising populations.

Atopic dermatitis (AD) is a prevalent chronic skin disease affecting all age groups. The connection with the gut microbiome led to oral probiotics as a therapeutic strategy. However, being viable microorganisms, probiotics might present risks. Thus, non-viable postbiotics have been considered as an alternative. We aimed to evaluate the efficacy of oral Lactobacillus postbiotics for managing symptoms of AD in pediatric and adult patients. A systematic review was conducted following PRISMA guidelines. Nine randomized controlled trials assessing the effects of non-viable Lactobacillus spp. administered orally to patients diagnosed with AD were included in the review, in which 512 subjects were evaluated after the intervention. Most studies allowed the concomitant usage of corticosteroids. Three studies focused on adults and indicated symptom improvement. In contrast, three out of six trials evaluating pediatric patients did not report postbiotics-favoring results. The dosage seems to be relevant for outcome determination. Two trials compared postbiotics with their viable analogs, and only one reported positive results in both groups. Postbiotics-associated shifts in gut microbial communities were reported in one trial. Mild adverse effects were detected by a single study. The overall results suggested that Lactobacillus postbiotics might be successfully used as adjuvant AD therapy in adults. Thus far, data do not indicate efficacy in pediatric patients. Standardizing nomenclatures and experimental procedures, as well as expanding the studies to more geographic locations and assessing comprehensively the effects on the gut microbiome would provide better perspectives of postbiotics as a therapeutic option for AD. Plain Language Summary: The usage of oral probiotics has been driven by the recognized connection between atopic dermatitis (AD) and the gut microbiome.Probiotics might offer risks as they are viable microorganisms and non-viable postbiotics have been considered as an alternative. However, their effectiveness and safety in AD patients is not totally clear.This systematic review of clinical trials evaluated the effects of non-viable Lactobacillus spp. admin

Postbiotics have recently been tentatively defined as bioactive compounds produced during a fermentation process (including microbial cells, cell constituents and metabolites) that supports health and/or wellbeing. Postbiotics are currently available in some infant formulas and fermented foods. We systematically reviewed evidence on postbiotics for preventing and treating common infectious diseases among children younger than 5 years. The PubMed, Embase, SpringerLink, and ScienceDirect databases were searched up to March 2019 for randomized controlled trials (RCTs) comparing postbiotics with placebo or no intervention. Seven RCTs involving 1740 children met the inclusion criteria. For therapeutic trials, supplementation with heat-killed Lactobacillus acidophilus LB reduced the duration of diarrhea (4 RCTs, n = 224, mean difference, MD, -20.31 h, 95% CI -27.06 to -13.57). For preventive trials, the pooled results from two RCTs (n = 537) showed that heat-inactivated L. paracasei CBA L74 versus placebo reduced the risk of diarrhea (relative risk, RR, 0.51, 95% CI 0.37-0.71), pharyngitis (RR 0.31, 95% CI 0.12-0.83) and laryngitis (RR 0.44, 95% CI 0.29-0.67). There is limited evidence to recommend the use of specific postbiotics for treating pediatric diarrhea and preventing common infectious diseases among children. Further studies are necessary to determine the effects of different postbiotics.

The host immune system forms its first line of defense. Its innate effectors, including natural killer (NK) cells and macrophages, cooperate with adaptive lymphocytes to preserve immune competence. Aging, chemotherapy, and physiological stress erode this competence, creating a demand for safe dietary immunostimulants. Lactic acid bacteria are leading candidates because their cell-envelope structures engage host pattern recognition receptors. Interest has recently expanded from live probiotics to include postbiotics (inanimate cells that retain immunostimulatory activity without the constraints of live delivery). We evaluated heat-killed Lactiplantibacillus plantarum DRC2509 isolated from Korean kimchi. Ex vivo profiling of splenocytes and peritoneal macrophages (PMs) exposed to DRC2509 subjected to two heat-killing regimens identified 80 °C for 90 min as associated with dose-dependent enhancement of NK cell cytotoxicity with sustained phagocytic receptor and cytokine expression. This preparation was given orally for two weeks before cyclophosphamide challenge in mice, with β-glucan as a positive control. DRC2509 preserved body weight, thymus, and spleen indices, and restored lymphocyte and white blood cell counts. Splenic NK cytotoxicity, serum immunoglobulins A and G, mitogen-driven T and B cell proliferation, and splenocyte interleukin (IL) 2, IL6, and interferon γ secretion recovered, and PMs restored Il1β, Il6, Nos2, Cd14, Marco, and Msr1 expression. These benefits encompass both innate and adaptive immunity and manifest once host defenses are suppressed. Since heat killing preserves the strain in a stable, non-viable form without abolishing its bioactivity, DRC2509 is a food-grade candidate for supporting compromised or dysregulated immune function. © 2026. The Author(s).

BACKGROUND: Overweight is linked to gut microbiota dysbiosis and gastrointestinal (GI) symptoms that impair quality of life. METHODS: This 84-day randomized, double-blind, placebo-controlled study evaluated the gut-health effects of heat-killed Lactiplantibacillus plantarum (beLP1®) in otherwise healthy adults (aged 18-45 years) within the BMI range of 25-35 kg/m2 and a ≥3-month history of mild-to-moderate GI discomfort, confirmed by Gastrointestinal Symptom Rating Scale (GSRS). In this trail 140 adults were allocated in a 1:1 ratio to receive either daily beLP1® (>30 billion cells) (n = 70) or placebo (n = 70). A total of 103 participants completed the study without protocol deviations and were included in the primary per-protocol (PP) analysis (beLP1®: n = 49; Placebo: n = 54). This predefined analysis directly compares the beLP1® and placebo arms using analysis of covariance (ANCOVA), supplemented by two independent-sample Student's t-tests. The primary endpoint was change in gastrointestinal symptoms via the GSRS, secondary endpoints included the Perceived Stress Scale (PSS), the Digestion-associated Quality of Life Questionnaire (DQLQ), Tumor Necrosis Factor-alpha (TNF-α), lipid parameters, Dual-Energy X-ray Absorptiometry (DEXA), and gut microbiome diversity by metagenomic Next-Generation Sequencing (NGS). RESULTS: Compared to placebo, beLP1® significantly reduced total Gastrointestinal Symptom Rating Scale (GSRS) scores at Day 42 (p = 0.0215) and Day 84 (p = 0.0394), with prominent improvements in abdominal pain (p = 0.0205) and dyspeptic syndrome (p = 0.0303) domains. Significant reductions in perceived stress (p = 0.0004) and improvements in digestion-associated quality of life (p = 0.0008) were concurrently achieved. Metagenomic analysis revealed a favorable modulation of the gut microbiota, characterized by an enrichment of several short-chain fatty acid-producing bacteria and a significant reduction in multiple opportunistic pathogens. No significant changes occurred in serum TNF-α, lipid profiles, or DEXA body composition metrics. CONCLUSION: Overall, beLP1® safely and progressively alleviates GI symptoms, reduces stress, and optimizes microbiome co

BACKGROUND: Low-grade inflammation (LGI) and increased infection susceptibility are common under sustained stress. We investigated whether daily consumption of hydrolyzed milk protein (HMP), alone or combined with heat-killed Lacticaseibacillus rhamnosus GG (HK-LGG), reduces LGI in healthy young Finnish conscripts, with serum high-sensitivity C-reactive protein (hs-CRP) as the primary outcome. Secondary outcomes included additional inflammatory biomarkers (calprotectin, haptoglobin, suPAR), sick days, stress, fitness, and recovery metrics. METHODS: In this eight-week randomized, double-blinded, placebo-controlled pilot trial, 160 conscripts (157 male) received milk beverages containing either maltodextrin (Control; 9.5g protein; n = 53), HMP (19.5g protein; n = 53), or HMP (19.3g protein; n = 54) with HK-LGG (2 × 109 cells) daily, administered in two 250 ml portions. We assessed the following factors: fasting serum markers of LGI, anthropometrics, smartwatch-based activity, recovery, fitness test metrics, self-reported sick days, and stress and fatigue questionnaire scores. RESULTS: Between-group differences in changes over the intervention period were observed for hs-CRP (p = 0.02) and calprotectin (p = 0.04). Over time the increase in hs-CRP from baseline was lower in the HMP vs HMP + HK-LGG group (ratio of geometric means 0.45; 95% CI 0.21-0.95; p = 0.03), whereas post hoc comparisons for calprotectin showed no between-group differences. No differences were observed between the treatment groups in haptoglobin (p = 0.53) or suPAR (p = 0.14). Infection prevalence was highest in the HMP + HK-LGG group (60.5%) compared with the HMP group (34.1%; p = 0.045), whereas the Control group (45.2%) did not differ from either group. The interventions did not impact body weight, activity, recovery, or fitness test outcomes. CONCLUSION: HMP may help stabilize immune responses during physical and infectious stress in conscripts, although these effects did not extend to fitness or recovery outcomes. The potential postbiotic HK-LGG showed no additional benefit when combined with HMP, calling for further evaluation of its efficacy in high stress and infection risk populations.

Background/Objectives: Exploiting the metabolic properties of postbiotics is a novel strategy for managing metabolic disorders, including diabetes. Inactivated microorganisms, a major class of postbiotics, improve glycemic control in preclinical and clinical studies. Here, we examined whether heat-killed (HK) Mycobacterium aurum (M. aurum) exerts prophylactic or therapeutic anti-hyperglycemic effects in diabetic mice. Methods: Diabetes was induced in male BALB/c mice by streptozotocin (STZ; 150 mg/kg) injection. HK M. aurum (1 mg) was given orally (three prophylactic doses before STZ) or intradermally (six weekly therapeutic doses after STZ). We assessed glycemic parameters, serum C-peptide/insulin (ELISA), and tissue protein expression (Western blot). Results: Neither route altered body weight or glucose homeostasis in non-diabetic mice. In STZ-diabetic mice, oral prophylactic treatment significantly attenuated hyperglycemia (39-60% reduction weeks 5-8 post-STZ) and showed a trend toward improved serum C-peptide, but did not affect dysregulated expression of skeletal muscle (SM), hepatic, pancreatic and renal proteins involved in glucose transport (GLUT2, GLUT4, and SGLT2), glycolysis (α-LDH), mitochondrial uncoupling (UCP2 and UCP3), and antioxidant defense (CAT). Therapeutic intradermal administration significantly decreased blood glucose (~30% at week 5, ~40% at week 6) and modestly enhanced insulin secretion. Hepatic UCP2 and α-LDH and SM UCP3 protein levels were normalized toward non-diabetic levels, whereas hepatic GLUT2 and SM GLUT4 remained largely unchanged. These correlative findings suggest effects independent of insulin-dependent glucose transport, but do not demonstrate direct functional improvement in mitochondrial or redox status. Conclusions: HK M. aurum exerts partial anti-hyperglycemic effects in STZ-induced diabetic mice, but the associated protein changes require functional validation before its role as a postbiotic in β-cell dysfunction can be established.

The gut microbiota is a central regulator of metabolic function, and its disruption by a high-fat diet (HFD) is strongly linked to obesity and metabolic impairment. This study evaluated the potential of heat-killed Lactiplantibacillus plantarum beLP1 (beLP1®) in alleviating HFD-induced metabolic and microbial imbalances in mice. Male C57BL/6N mice were fed an HFD for 10 weeks, with or without daily oral supplementation of beLP1 (≥3 × 1010 cells). Compared with untreated HFD mice, beLP1 supplementation reduced serum triglycerides by 35% and lowered liver enzymes AST and ALT by 17% and 36%, respectively. Blood glucose levels remained similar to the HFD group throughout the study period. Shotgun metagenomic analysis revealed that beLP1 restored gut microbial diversity, increased beneficial taxa such as Akkermansia and Faecalibaculum high. and reduced pro-inflammatory species including Streptococcus sp., Mucispirillum schaedleri and Clostridium cocleatum. These microbial changes were associated with partial normalization of the Firmicutes/Bacteroidota ratio and improvements in antibiotic resistance gene (ARG) profiles. Specifically, in silico analysis of the short-chain fatty acid (SCFA) synthesis pathways indicated that the potential for acetate and propionate production was maximized in the beLP1 group, resulting in the highest relative abundance among all groups. This functional enhancement directly correlated with the enrichment of key SCFA-producing taxa, particularly Akkermansia muciniphila, confirming that increased bacterial abundance suggests an enhanced functional potential for SCFA production. Furthermore, beLP1® induced a selective modulation of gut ARGs, significantly reducing specific subtypes such as tetracycline and multidrug efflux genes, despite a slight increase in vancomycin resistance markers. Overall, our findings suggest that beLP1® attenuated the rate of body weight gain during the initial weeks of HFD exposure and significantly improved markers of hepatic stress and lipid metabolism.

INTRODUCTION: With growing evidence of clinical efficacy of probiotics in various diseases, safety concerns have arisen regarding the therapeutic use of live probiotic bacteria, especially in critically ill, immunocompromised, and pediatric populations. Serious probiotic-related adverse effects have been reported in these patients, including bloodstream infection and sepsis. This has led to an increased interest in developing postbiotics (non-viable bacterial products) that may exert beneficial effects on the host without the risks associated with administration of live microorganisms. The aim of this study was to explore postbiotic potential of recombinant Lactococcus lactis bacteria that have been engineered to display interleukin 6 (IL6)-targeting affibody (ZIL6) on their surface and are intended for treatment of inflammatory intestinal diseases. METHODS: Five different killing treatments were applied to kill bacteria (heat, ethanol, sonication, UV, and gamma irradiation) and their effect on bacterial viability, morphology and functionality was examined in vitro using a combination of different techniques, including microscopy, flow cytometry, immunoassays and cell-based reporter assay. RESULTS: The results showed that ZIL6 affibody displayed on L. lactis via non-covalent anchoring withstood the treatments applied to kill bacteria and remained functional after the loss of microbial viability. The degree of functionality was dependent on the type of treatment. Heat-killed cells retained 50% of the activity of live strain, while most of the activity was preserved after exposure of bacteria to ethanol, sonication, UV and gamma irradiation. The applied treatments varied in killing efficacy, whereby ethanol and heat rendered bacteria non-viable, UV and gamma irradiation yielded non-replicative cells, whereas sonication was ineffective in killing L. lactis. Among non-viable cells, ethanol-killed bacteria exhibited the greatest activity and showed high maximum binding capacity of 200 ng IL6 per mg dry cell weight, possessed strong nanomolar affinity for IL6, and inhibited up to 78% of IL6-induced STAT3 signaling. CONCLUSION: The study demonstrates that functional no

Sarcopenia is characterized by a reduction in muscle function and skeletal muscle mass relative to that of healthy individuals. In older adults and those who are less resistant to sarcopenia, glucocorticoid secretion or accumulation during treatment exacerbates muscle protein degradation, potentially causing sarcopenia. This study assessed the preventive effects and mechanisms of heat-killed Lactobacillus plantarum postbiotic beLP-K (beLP-K) against dexamethasone (DEX)-induced sarcopenia in C2C12 myotubes and Sprague-Dawley rats. The administration of beLP-K did not induce cytotoxicity and mitigated cell damage caused by DEX. Furthermore, beLP-K significantly reduced the expression of forkhead box O3 α (FoxO3α), muscle atrophy f-box (MAFbx)/atrogin-1, and muscle RING-finger protein-1 (MuRF1), which are associated with muscle protein degradation. DEX induced weight loss in rats; however, in the beLP-K group, weight gain was observed. Micro-computed tomography analysis revealed that beLP-K increased muscle mass, correlating with weight and grip strength. beLP-K alleviated the DEX-induced reduction in grip strength and increased the mass of hind leg muscles. The correlation between beLP-K administration and increased muscle mass was associated with decreased expression levels of muscle degradation-related proteins such as MAFbx/atrogin-1 and MuRF1. Therefore, beLP-K may serve as a treatment for sarcopenia or as functional food material.

Background: Exercise-induced fatigue arises primarily from energy substrate depletion and the accumulation of metabolites such as lactate and ammonia, which impair performance and delay recovery. Emerging evidence implicates gut microbiota modulation-particularly via probiotics-as a means to optimize host energy metabolism and accelerate clearance of fatigue-associated by-products. Objective: This study aimed to determine whether live or heat-inactivated Lacticaseibacillus paracasei NB23 can enhance exercise endurance and attenuate fatigue biomarkers in a murine model. Methods: Forty male Institute of Cancer Research (ICR) mice were randomized into four groups (n = 10 each) receiving daily gavage for six weeks with vehicle, heat-killed NB23 (3 × 1010 cells/human/day), low-dose live NB23 (1 × 1010 CFUs/human/day), or high-dose live NB23 (3 × 1010 CFUs/human/day). Forelimb grip strength and weight-loaded swim-to-exhaustion tests assessed performance. Blood was collected post-exercise to measure serum lactate, ammonia, blood urea nitrogen (BUN), and creatine kinase (CK). Liver and muscle glycogen content was also quantified, and safety was confirmed by clinical-chemistry panels and histological examination. Results: NB23 treatment produced dose-dependent improvements in grip strength (p < 0.01) and swim endurance (p < 0.001). All NB23 groups exhibited significant reductions in post-exercise lactate (p < 0.0001), ammonia (p < 0.001), BUN (p < 0.001), and CK (p < 0.0001). Hepatic and muscle glycogen stores rose by 41-59% and 65-142%, respectively (p < 0.001). No changes in food or water intake, serum clinical-chemistry parameters, or tissue histology were observed. Conclusions: Our findings suggest that both live and heat-treated L. paracasei NB23 may contribute to improved endurance performance, increased energy reserves, and faster clearance of fatigue-related metabolites in our experimental model. However, these results should be interpreted cautiously given the exploratory nature and limitations of our study.

Heat-killed Fructobacillus fructosus OS-1010 reportedly enhance the number and membrane potential of mitochondria in muscle cell C2C12 in vitro. However, there are no reports on the effects of this strain on mitochondria or the resulting effects on the body in animal models. In this study, we investigated the effects of heat-killed F. fructosus OS-1010 on obesity and other metabolic abnormalities and muscle weakness in mice with high-fat diet (HFD)-induced sarcopenic obesity. C57BL/6 mice were fed HFD supplemented with heat-killed F. fructosus OS-1010 for 13 weeks. The HFD-induced body weight gain was significantly reduced. Additionally, there was a significant decrease in alanine aminotransferase levels, improvement in serum lipid profiles, and a reduction in non-alcoholic fatty liver disease (NAFLD) progression. Skeletal muscle weakness was also mitigated, with changes in gene expression in the quadriceps indicating suppression of intramuscular fat accumulation, and enhancement of mitochondrial density. The findings of this study suggest that heat-killed F. fructosus OS-1010 functions as an anti-obesity postbiotic, potentially benefiting both NAFLD and muscle weakness associated with obesity. © 2025. The Author(s).

Background/Objectives: Sarcopenia is an age-related disease resulting in muscle mass deterioration and declining strength and functional ability. Muscle protein degradation pathways are activated through the ubiquitin-proteasome system, which is integral to the pathogenesis of sarcopenia. This study examined the capability of Lactobacillus plantarum beLP1 as a postbiotic ingredient of kimchi that prevents sarcopenia. Methods: We evaluated cell viability and measured diameters in a C2C12 myotube damage model and muscle volume, muscle weight, muscle strength, and the expression of muscle degradation proteins MuRF1 and Atrogin-1 in dexamethasone-induced sarcopenic model rats using a heat-killed beLP1 strain. Results: beLP1 had no cytotoxic effects on C2C12 and prevented dexamethasone-induced cellular damage, suggesting its role in muscle protein degradation pathways. beLP1 treatment significantly prevented the dexamethasone-induced reduction in myotube diameter. In a dexamethasone-induced sarcopenic rat model, oral beLP1 significantly mitigated muscle mass decline and prevented grip strength reduction. Microcomputed tomography demonstrated that beLP1 reduced dexamethasone-induced muscle volume loss. beLP1 treatment reduced Atrogin-1 and Muscle RING-finger protein-1 (MuRF1) and the transcription factor Forkhead box O3 alpha (FoxO3α), which triggers muscle protein breakdown. beLP1 exerts protective effects by inhibiting the ubiquitin-proteasome system and regulating FoxO3α signaling. It increased AKT (Ser473) phosphorylation, which affected muscle protein synthesis, degradation, and cell survival, suggesting its potential to prevent sarcopenia. Conclusions: Heat-killed Lactobacillus plantarum beLP1 alleviates muscle mass wasting and weakness in a dexamethasone-induced sarcopenia model by regulating muscle protein degradation pathways and signaling molecules. Thus, postbiotics may be functional ingredients in sarcopenia prevention.

BACKGROUND: At present, Bacillus subtilis has been reported as a probiotic to be used as a feed additive to improve the production performance of broilers. However, the relevant reports on its derived postbiotics are still limited. METHODS: In this study, a total of 480 day-old Arbor acre broiler chicks with an initial body weight of 52.8 ± 1.4 g were used in this study to investigate the effects of dietary supplementation of graded levels of heat-killed B. subtilis on growth performance, cecal morphology, and cecal bacteria and fungus composition. Birds were assigned into four groups with six replicates of 20 birds each. The experiment was designed to last for 42 days. B. subtilis was supplemented with 0.000, 0.015, 0.030, or 0.045% heat-killed Bacillus subtilis (HKB). RESULTS: Our data indicate that body weight gain, gain to feed ratio, cecal villus height, and cecal villus to crypt ratio dose-dependently improved, while cecal crypt depth dose-dependently reduced, by HKB supplementation. Additionally, dietary supplementation of graded levels of HKB dose-dependently reduced cecal bacteria Chao1 index. Cecal bacteria identified by 16S rRNA and cecal fungus identified by ITS revealed that the supplementation of HKB regulate the composition of bacteria and fungus in cecum. CONCLUSION: Therefore, dietary supplementation of HKB is an effective measure to improve cecal morphology by regulating cecal bacteria and fungus composition, and therefore improved growth performance.

Previous research shown that live probiotics have immunomodulatory effects, however the effectiveness of heat-inactivated bacteria and their immune-related components require further study. This study evaluated the immunomodulatory effects of heat-inactivated BBMN68 in BALB/c mice and explored immunomodulatory postbiotic components in vitro. Cyclophosphamide-induced immunosuppressed mice were orally administered heat-inactivated BBMN68 for 15 days. Postbiotic components from heat-inactivated BBMN68 were utilized to stimulate RAW264.7 cells for 24 h. In vivo, heat-inactivated BBMN68 significantly mitigated body weight decline, improved immune organ index and enhanced hematopoietic function in immunosuppressed mice. Additionally, it promoted delayed-type hypersensitivity responses and increased serum hemolysin and immunoglobulin (IgA, IgG, and IgM) levels. Oral administration of heat-inactivated BBMN68 increased serum cytokine (IL-2, TNF-α, IFN-γ, IL-4 and IL-6), while reducing IL-1β and IL-10. It also boosted beneficial microbiota (Lachnospiraceae_NK4A136_group and Dubosiella) and reduced harmful microbiota (Clostridium_sensu_stricto_1, Faecalibaculum and Romboutsia) by altering the Firmicutes/Bacteroidetes ratio. Unlike live probiotics, heat-inactivated BBMN68 is safer and has stronger immunomodulatory effects than Levamisole. It uniquely modulated gut microbiota compared to other heat-inactivated probiotics. In vitro, peptidoglycan from heat-inactivated BBMN68 cell wall suppressed TNF-α and IL-1β mRNA in RAW264.7 cells. These results suggest BBMN68 and its postbiotics can enhance immune responses, offering potential as safe immunomodulatory agents.

This study was performed to evaluate the effects of dietary supplementation with viable Bacillus subtilis, inactivated Lactobacillus plantarum, and their combination on growth and slaughter performance, immune organ and small intestine development, and cecal microbiota of broilers. A total of 480 one-day-old broilers were used across a 42-day feeding experiment and were fed a basal diet, a basal diet + 300 mg/kg viable B. subtilis (probiotic), 320 mg/kg heat-killed L. plantarum (postbiotic), or their mixtures (combination). Each diet had six replicates, and each replicate had 20 broilers. Compared to the control group, the final body weight and average daily gain increased, and the feed conversion ratio decreased in the probiotic and postbiotic groups, while the combination group showed parameters comparable to those of the postbiotic group. Feeding broilers with probiotic, postbiotic, and their combination increased the dressing-out percentage, indices of the spleen and bursa of Fabricius, and lengths and weights of the small intestine. In addition, the villus height/crypt depth ratio of both the duodenum and jejunum was increased in the probiotic and postbiotic groups. Broilers in the combination group had a lower abundance of Proteobacteria, while those in the probiotic and postbiotic groups had a higher abundance of Desulfovibrio in the cecum. Overall, we concluded that dietary supplementation with viable B. subtilis and inactivated L. plantarum could improve growth and slaughter performance, organ development, intestinal morphology, and cecal microbiota of broilers. However, their combination had not yielded a synergistic and additive effect on broilers. © 2025. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.

Dysbiosis caused by dietary changes can alter the intestinal bacterial species and is closely associated with inflammatory bowel disease (IBD). Among the possible treatment options, postbiotics, which act to balance the constituent intestinal microflora, have gained substantial attention. Herein, we investigated the anti-inflammatory effects of heat-killed Lactiplantibacillus argentoratensis (hk-LA) BBLB001 isolated from a marine environment using both cell (Caco2/RAW264.7 cell co-culture) and animal (dextran sodium sulfate [DSS]-induced colitis in mice) models. hk-LA BBLB001 markedly reduced IL-8 secretion in Caco-2 cell culture medium after lipopolysaccharide-mediated stimulation of RAW264.7 cells by enhancing the expression of cell adhesion factors.The body weight loss, reduced inflammatory cytokine levels in the serum and colon tissues, colon shortening, and myeloperoxidase activation caused by DSS in mice were alleviated by hk-LA BBLB001. Similar to that in the intestinal cell model, the gene and protein expressions of cell adhesion molecules in the colon tissue were increased upon hk-LA BBLB001 treatment in DSS-induced colitis mice. We observed increased mucin expression and secretory IgA concentration in colon tissues, suggesting that hk-LA BBLB001 intake may benefit pathogen defense and the regulation of intestinal commensal bacteria. Thus, hk-LA BBLB001 may serve as an instrumental postbiotic material in IBD treatment.

There is significant interest in using postbiotics as an intervention strategy to address obesity. This study assesses the efficacy of postbiotics derived from different sourdough strains (Lactiplantibacillus plantarum LP1, LP25, and Pediococcus pentosaceus PP18) in mitigating intestinal injury in zebrafish fed on a high-fat diet. We screened postbiotics for their anti-colon cancer cell effects and compared various preparation methods applied to live bacterial strains, including heat-killing at different temperatures, pH adjustments, and ultraviolet radiation exposure. Heat-killing at 120 °C proved to be the most effective preparation method. A marked variation in health effects was observed in the heat-killed microbial cells, as evidenced by their hydrophobicity and self-aggregation ability. A five-week high-fat dietary intervention study in zebrafish demonstrated that diets supplemented with 108 CFU g-1 K-LP25 significantly attenuated weight gain and body fat, along with reductions in FASN, Leptin, and SREBF1 mRNA expression. However, diets supplemented with 107 CFU g-1 K-PP18 only reduced Leptin and SREBF1 mRNA expression. K-PP18 was more effective at mitigating gut barrier damage, promoting colonic Occludin, ZO-1, and Claudin-1 levels. Additionally, K-LP25 supplementation markedly downregulated the pro-inflammatory cytokines TNF-α, IL-6, and IL-1β, reducing intestinal inflammation. Supplementation with K-LP1 and K-PP18 increased the abundance of Acinetobacter spp., whereas K-LP25 increased the abundance of Cetobacterium and Plesiomonas. Collectively, these findings suggest that inactivated strains confer protective effects against high-fat diet-induced intestinal damage in zebrafish, with variation observed across different species. Studying the effects of sourdough-derived postbiotics on gut health may open new avenues for dietary interventions to manage gut-related diseases.

Capsular polysaccharide (CPS) as a probiotic component has the ability to regulate the function of the host's immune system. However, how the structure and function of heat-killed CPS are altered remains unclear. In the present study, CPS were isolated and purified from live (LCPS) and heat-killed (HCPS) Lacticaseibacillus paracasei 6235. The differences in structure and immunomodulation between LCPS and HCPS were compared and analyzed. The results demonstrate that after heat killed, the molecular weight of CPS decreased from 23.4 kDa to 17.5 kDa, with the disappearance of galactosamine in the monosaccharide composition, and changes in the microstructure. Methylation analysis and nuclear magnetic resonance analysis revealed that the LCPS and HCPS are similar in structure, which main units of →3,4)-α-D-Glcp-(1→4)-α-D-Galp-(1→3)-β-L-Rhap-(1→6)-β-D-Galp-(1→, and repeating units of →3,4)-α-D-Glcp-(1→, →3)-β-L-Rhap-(1→, and →4)-α-D-Galp-(1→ residues. Furthermore, both LCPS and HCPS significantly downregulated the expression of pro-inflammatory cytokines in RAW264.7 cells induced by LPS. Specifically, HCPS reduced the levels of IL-6 and IL-1β by 79.38 % and 88.42 %, respectively, compared to LCPS. Concurrently, both LCPS and HCPS effectively mitigated inflammatory responses through the NF-κB and MAPK signaling pathways. Moreover, compared to LCPS, HCPS increased the protein expression levels of NF-κB/p-NF-κB and IκB/p-IκB by 26.14 % and 28.92 %, respectively. These results suggest that CPS has a role in modulating immune responses and that HCPS is more effective. This study can be further developed into new products related to postbiotics.

In view of the safety concerns of probiotics, more and more attention is paid to the beneficial effects of dead probiotics cells. Herein, we investigated and compared the alleviation effects of viable Bifidobacterium longum subsp. infantis B8762 (B. infantis B8762) and its heat-killed cells on dextran sodium sulfate (DSS)-induced inflammatory bowel disease (IBD) rats. Four groups of rats (n = 12 per group) were included: normal control, DSS-induced colitis rats without bacterial administration (DSS), DSS-induced colitis rats with viable B. infantis B8762 administration (VB8762), and DSS-induced colitis rats with dead B. infantis B8762 administration (DB8762). Our results showed that both VB8762 and DB8762 administration exerted significant protective effects on DSS-induced IBD rats, as evidenced by a reduction in mortality, disease activity index score, body weight loss, as well as decreased histology score, which were companied by a significant decrease in serum pro-inflammatory factors compared with DSS group, and a stronger effect on modulating the fecal microbiota alpha-diversity and beta-diversity compared with DSS group. Additionally, the fecal metabolome results showed that both VB8762 and DB8762 interventions indeed altered the fecal metabolome profile and related metabolic pathways of DSS-induced IBD rats. Therefore, given the alleviation effects on colitis, the DB8762 can be confirmed to be a postbiotic. Overall, our findings suggested that VB8762 and DB8762 had similar ability to alleviate IBD although with some differences. Due to the minimal safety concern of postbiotics, we propose that the postbiotic DB8762 could be a promising alternative to probiotics to be applied in the prevention and treatment of IBDs.IMPORTANCEInflammatory bowel disease (IBD) has emerged as a global disease because of the worldwide spread of western diets and lifestyles during industrialization. Up to now, many probiotic strains are used as a modulator of gut microbiota or an enhancer of gut barrier to alleviate or cure IBD. However, there are still many issues of using probiotics, which were needed to be concerned about, for instance, safety issues in certain groups like ne

Ulcerative colitis (UC) is a global intestinal disease, and conventional therapeutic drugs often fail to meet the needs of patients. There is an urgent need to find efficient and affordable novel biological therapies. Saccharomyces boulardii has been widely used in food and pharmaceutical research due to its anti-inflammatory properties and gut health benefits. However, there is still a relatively limited comparison and evaluation of different forms of S. boulardii treatment for UC. This study aimed to compare the therapeutic effects of S. boulardii, heat-killed S. boulardii, and S. boulardii β-glucan on UC, to explore the potential of heat-killed S. boulardii as a new biological therapy. The results demonstrate that all three treatments were able to restore body weight, reduce the disease activity index (DAI), inhibit splenomegaly, shorten colon length, and alleviate histopathological damage to colonic epithelial tissues in DSS-induced colitis mice. The oral administration of S. boulardii, heat-killed S. boulardii, and S. boulardii β-glucan also increased the levels of tight junction proteins (Occludin and ZO-1), decreased the levels of pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6) in the serum, and suppressed the expressions of TNF-α, IL-1β, and IL-6 mRNA in the colon. In particular, in terms of gut microbiota, S. boulardii, heat-killed S. boulardii, and S. boulardii β-glucan exhibited varying degrees of modulation on DSS-induced dysbiosis. Among them, heat-killed S. boulardii maximally restored the composition, structure, and functionality of the intestinal microbiota to normal levels. In conclusion, heat-killed S. boulardii showed greater advantages over S. boulardii and S. boulardii β-glucan in the treatment of intestinal diseases, and it holds promise as an effective novel biological therapy for UC. This study is of great importance in improving the quality of life for UC patients and reducing the burden of the disease.

The efficacy of postbiotics on the immune-related gene expression and gut microbiota of white shrimp, Penaeus vannamei remains unexplored. A commercial heat-killed postbiotic Pediococcus pentosaceus PP4012 was used to evaluate the growth performance, intestinal morphology, immunological status, and microbial community of white shrimp after dietary administration in this study. White shrimp (0.040 ± 0.003 g) were divided into three treatments; a control, inanimate P. pentosaceus (105 CFU g feed-1) at low concentration (IPL) and inanimate P. pentosaceus (106 CFU g feed-1) at high concentrations (IPH). The diets of IPL and IPH significantly increased final weight, specific growth rate and production compared to the control group. Shrimp fed with IPL and IPH significantly utilized feed more efficiently than those fed the control diet. The IPH treatment significantly lowered the cumulative mortality rate compared to the control and IPL diet following Vibrio parahaemolyticus infection. No significant difference was observed for Vibrio-like and lactic acid bacteria in intestine of shrimp fed with the control diet and the experimental diets. Adding inanimate P. pentosaceus significantly improved immune responses such as lysozyme and phagocytic activity compared to the control group. However, the total hemocyte count, phenoloxidase activity, respiratory burst, and superoxide dismutase activity were not significantly different among treatments. The immune-related genes alf, pen3a, and pen4 expression were significantly higher in shrimp fed IPL diet compared with control and IPH. Taxonomic identification of bacterial genera in all dietary groups belonged to two predominant phyla, Proteobacteria and Bacteroidota. An abundance of Photobacterium, Motilimonas, Litorilituus, and Firmicutes bacterium ZOR0006 were identified in the intestine of shrimp fed postbiotic diets. Unique microbes such as Cohaesibacter was discovered in the shrimp fed IPL while Candidatus Campbellbacteria, uncultured Verrucomicrobium DEV114 and Paenalcaligenes were discovered in the intestines of shrimp fed IPH diet. Collectively, these data suggest that including heat-killed P. pentosaceus, particularly

Inflammatory bowel disease (IBD) is a chronic inflammatory disease associated with gut dysbiosis. This study aimed to investigate the effects of heat-killed Bifidobacterium bifidum B1628 (HB1628) in dextran sulfate sodium (DSS)-induced colitis in mice. The following three mouse groups were included (n = eight per group): NC (normal control), DSS (colitis), and HB1628 (colitis and postbiotic). The mice in the DSS group showed significant weight loss and histological damage, developed bloody diarrhea, scored high in the disease activity index (DAI), and exhibited increases in pro-inflammatory cytokines (interleukin [IL]-1β, IL-6, and tumor necrosis factor [TNF]-α) and decreases in an anti-inflammatory cytokine (IL-13) in the serum. These changes were accompanied by gut microbiota modulation in colitis mice (decreases in Rikenellaceae and Eubacterium; increases in Peptostreptococcaceae, Bacteroides vulgatus, and Parasutterella excrementihominis). The HB1628 group had lower DAIs, histology scores, and serum levels of pro-inflammatory cytokines (IL-1β and TNF-α), but higher levels of an anti-inflammatory cytokine (IL-13), compared with the DSS group, suggesting a less severe inflammatory state after the HB1628 intervention. Additionally, HB1628 improved DSS-induced gut dysbiosis, which is evidenced by increases in intestinal beneficial bacteria, such as Lactobacillus, and decreases in known unfavorable taxa in IBD, e.g., Porphyromonadaceae, Subdoligranulum, Lachnospiraceae bacterium 3_1_46FAA, and Alistipes indistinctus. Functional metagenomics revealed three significantly enriched metabolic pathways in the HB1628 group (namely, the aerobic respiration I [cytochrome c] pathway and the superpathways of L-phenylalanine biosynthesis and L-tryptophan biosynthesis, respectively). In conclusion, our results showed that HB1628 effectively improved the inflammation state and tissue damage in DSS-induced colitis mice, and the symptom relief effect was accompanied by obvious gut microbiota remodulation.

Postbiotics are the inactive bacteria and/or metabolites of beneficial microbes which have been recently found to be as effective as their live probiotic. This study aimed to evaluate the benefits of Lactobacillus plantarum (LP)-derived postbiotics on ameliorating Salmonella-induced neurological dysfunctions. Mice were pretreated with LP postbiotics (heat-killed bacteria or the metabolites) or active bacteria, and then challenged with Salmonella enterica Typhimurium (ST). Results showed that LP postbiotics, particularly the metabolites, effectively prevented ST infection in mice, as evidenced by the inhibited weight loss, bacterial translocation, and tissue damages. The LP postbiotics markedly suppressed brain injuries and neuroinflammation (the decreased interleukin (IL)-1β and IL-6, and the increased IL-4 and IL-10). Behavior tests indicated that LP postbiotics, especially the metabolites, protected mice from ST-induced anxiety and depressive-like behaviors and cognitive impairment. A significant modulation of neuroactive molecules (5-hydroxytryptamine, gamma-aminobutyric acid, brain-derived neurotrophic factor, dopamine, acetylcholine, and neuropeptide Y) was also found by LP postbiotic pretreatment. Microbiome analysis revealed that LP postbiotics optimized the cecal microbial composition by increasing Helicobacter, Lactobacillus and Dubosiella, and decreasing Mucispirillum, norank_f_Oscillospiraceae, and Eubacterium_siraeum_group. Moreover, LP postbiotics inhibited the reduction of short-chain fatty acids caused by ST infection. Pearson's correlation assays further confirmed the strong relationship of LP postbiotics-mediated benefits and gut microbiota. This study highlights the effectiveness of postbiotics and provide a promising strategy for preventing infection-induced brain disorders by targeting gut-brain axis.