Glucomannan

Considering dyslipidemia's impact on cardiovascular disease and even chronic illnesses and the beneficial effect of glucomannan on dyslipidemia, this study aimed to examine how glucomannan affects lipid profile parameters thoroughly. Using standard keywords, the databases Scopus, PubMed, Embase, Web of Science databases, and Google Scholar were searched from inception to December 2024. Based on our finding, glucomannan significantly reduced total cholesterol (TC) (SMD: -2.26; 95 % CI: -2.98, -1.55, p <0.001), low-density lipoprotein cholesterol (LDL-C) levels (SMD: -2.57; 95 % CI: -3.41, -1.74; p<0.001), but not effect on high-density lipoprotein cholesterol (HDL-C) (SMD: -0.33; 95 % CI: -0.70, 0.03, p=0.075), and triglyceride (TG) (SMD: -0.16; 95 % CI: -0.59, 0.27, p =0.473). However, these significant decreases are not clinically important. Therefore, glucomannan only can be considered as an adjunctive therapeutic approach in managing dyslipidemia.

BACKGROUND: Glucomannan has been studied for various health benefits, but its effects on lipid profile in adults are not well understood. This meta-analysis aims to evaluate the impact of glucomannan supplementation on serum/plasma levels of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), Apo B1, Apo A1, APO-B/ A1 ratio, and LDL-C/ HDL-C in adults. METHODS: A comprehensive search was conducted across Scopus, PubMed, Embase, and Web of Science from inception to June 2024 to identify randomized controlled trials (RCTs) assessing glucomannan supplementation on lipid profile in adults. Data were extracted and analyzed using random effects model to determine the standardized mean differences (SMDs) and 95% confidence intervals (CIs) for each biomarker. RESULTS: Glucomannan supplementation significantly decreased TC (SMD: -3.299; 95% CI: -4.955, -1.664, P < 0.001; I 2 = 95.41%, P-heterogeneity < 0.001), LDL-C (SMD: -2.993; 95% CI: -4.958, -1.028; P = 0.006; I 2 = 95.49%, P-heterogeneity < 0.001), and Apo B1 (SMD: -2.2; 95% CI: -3.58, -0.82; P = 0.01). However, glucomannan did not alter the levels of TG (SMD: -0.119; 95% CI: -1.076, 0.837, P = 0.789; I 2 = 91.63%, P-heterogeneity < 0.001), Apo A1 (SMD: -0.48; 95% CI: -6.27, 5.32; P = 0.76), APO-B/ A1 ratio (SMD: -1.15; 95% CI: -2.91, 0.61; P = 0.11), and LDL-C/ HDL-C ratio (SMD: -2.2; 95% CI: -7.28, 2.87; P = 0.2). CONCLUSIONS: Glucomannan supplementation has a beneficial effect on the level of TC and LDL-C. © 2024. The Author(s).

There is no research on the comparative effects of nutraceuticals on weight loss in adults with overweight or obesity. This study aimed at quantifying and ranking the effects of different nutraceuticals on weight loss. We searched PubMed, Scopus, and Web of Science to November 2022. We included randomized trials evaluating the comparative effects of two or more nutraceuticals, or compared a nutraceutical against a placebo for weight loss in adults with overweight or obesity. We conducted random-effects network meta-analysis with a Frequentist framework to estimate mean difference [MD] and 95% confidence interval [CI] of the effect of nutraceuticals on weight loss. One hundred and eleven RCTs with 6171 participants that investigated the effects of 18 nutraceuticals on body weight were eligible. In the main analysis incorporating all trials, there was high certainty of evidence for supplementation of spirulina (MD: -1.77 kg, 95% CI: -2.77, -0.78) and moderate certainty of evidence that supplementation of curcumin (MD: -0.82 kg, 95% CI: -1.33, -0.30), psyllium (MD: -3.70 kg, 95% CI: -5.18, -2.22), chitosan (MD: -1.70 kg, 95% CI: -2.62, -0.78), and Nigella sativa (MD: -2.09 kg, 95%CI: -2.92, -1.26) could result in a small improvement in body weight. Supplementations with green tea (MD: -1.25 kg, 95%CI: -1.68, -0.82) and glucomannan (MD: -1.36 kg, 95%CI: -2.17, -0.54) demonstrated small weight loss, also the certainty of evidence was rated low. Based on our findings, supplementations with nutraceuticals can result in a small weight loss in adults with overweight or obesity.

The hypoglycemic and lipid-lowering effects of glucomannan are widely known, and it is a potential effective treatment for type II diabetes. In this study, we evaluated the effects of glucomannan supplementation on blood-lipid-related indicators, blood-glucose-related indicators, blood pressure (BP), and body weight (BW) in patients suffering from type II diabetes. We searched databases including PubMed, Cochrane, the comprehensive biomedical research database (Embase), Web of Science, and China National Knowledge Infrastructure (CNKI) for literature on glucomannan and type II diabetes. Six randomized controlled trials (RCTs) were eligible (n = 440 participants) to be included in our analysis. Glucomannan not only reduced the total cholesterol (TC) (MD -0.38 [95% CI: -0.61, -0.15], p = 0.001) and low-density lipoprotein (LDL) levels (MD -0.35 [95% CI: -0.52, -0.17], p < 0.0001) compared with the control group, but also reduced the fasting blood glucose (FBG) (MD -1.08 [95% CI: -1.65, -0.50], p = 0.0002), 2 h postprandial blood glucose (P2hBG) (MD -1.92 [95% CI: -3.19, -0.65], p = 0.003), fasting insulin (FINS) (MD -1.59 [95% CI: -2.69, -0.50], p = 0.004), and serum fructosamine (SFRA) levels (SMD -1.19 [95% CI: -1.74, -0.64], p < 0.0001). Our analysis indicates that glucomannan is an effective nutritional intervention for type II diabetes.

BACKGROUND/OBJECTIVES: A systematic review with meta-analysis was conducted to synthesise evidence on the efficacy of dietary supplements containing isolated organic compounds for weight loss. SUBJECTS/METHODS: Four electronic databases (Medline, Embase, Web of Science, Cinahl) were searched until December 2019. Sixty-seven randomised placebo-controlled trials of dietary supplements containing isolated organic compounds for weight loss were included. Meta-analyses were conducted for chitosan, glucomannan, conjugated linoleic acid and fructans, comparing mean weight difference post-intervention between participants receiving the dietary supplement or placebo. RESULTS: Statistically significant weight differences compared to placebo were observed for chitosan (-1.84 kg; 95% confidence interval [CI] -2.79, -0.88; p < 0.01), glucomannan (-1.27 kg; 95%CI -2.45, -0.09; p = 0.04), and conjugated linoleic acid (-1.08 kg; 95%CI -1.61, -0.55; p < 0.01). None met our threshold for clinical significance (≥2.5 kg). There was no statistically significant effect on weight for fructans compared to placebo (p = 0.24). For dietary supplements with an inadequate number of trials for meta-analysis, a statistically and borderline clinically significant weight difference compared to placebo was found for modified cellulose, manno-oligosaccharides (in males), blood orange juice extract, and three multiple-ingredient dietary supplements. These were only reported in one trial of each. Thus, more evidence is needed before recommending them for weight loss. CONCLUSIONS: While some dietary supplements containing isolated organic compounds warrant further investigation to determine efficacy and safety, there is currently insufficient evidence to recommend any of these dietary supplements for weight loss. © 2021. The Author(s), under exclusive licence to Springer Nature Limited.

OBJECTIVE: The increased prevalence of obesity has resulted in the current high popularity of dietary supplements marketed as weight reducing agents. The efficacy of most of these supplements is not established. The soluble fiber, glucomannan, is often recommended for weight loss. The aim of this systematic review is to evaluate the evidence for or against the efficacy of glucomannan in body weight reduction. METHODS: Electronic searches were conducted in Medline, Embase, Amed, and The Cochrane Library. Hand searches of bibliography were also conducted. Outcomes of interest were body weight and body mass index. Studies involving only overweight and/or obese participants were included. Two reviewers independently determined the eligibility of studies and assessed the reporting quality of included randomized controlled trials (RCTs), using the CONSORT and PRISMA guidelines. RESULTS: Eighteen trials were identified, and 9 were included. There was a variation in the reporting quality of the included RCTs. A meta-analysis (random effect model) of 8 RCTs revealed a nonstatistically significant difference in weight loss between glucomannan and placebo (mean difference [MD]: -0.22 kg; 95% confidence interval [CI], -0.62, 0.19; I(2) = 65%). Adverse events included abdominal discomfort, diarrhea, and constipation. CONCLUSION: The evidence from available RCTs does not show that glucomannan intake generates statistically significant weight loss. Future trials should be more rigorous and better reported.

PURPOSE: Athletes are at increased risk for functional constipation due to high-intensity training, irregular diets, and disrupted circadian rhythms. Soluble fibers, particularly konjac glucomannan (KGM), have shown potential in alleviating constipation, but clinical evidence, especially in athletes, is limited. This study aimed to assess the effects of an 8-week KGM intervention on gastrointestinal symptoms and gut microbiota in elite male Taekwondo athletes with functional constipation. METHODS: In this double-blind randomized controlled trial, we enrolled male elite Taekwondo athletes diagnosed with functional constipation according to Rome IV criteria. Participants were randomly assigned to receive either KGM supplementation (dietary intervention group, DG) or placebo (control group, CG) for 8 weeks. Primary outcomes included the Patient Assessment of Constipation Symptoms (PAC-SYM), Patient Assessment of Constipation Quality of Life (PAC-QoL), bowel movement frequency (BMF), Bristol Stool Scale, and the Bowel Function Index (BFI). Stool samples were collected for 16S rRNA gene sequencing to evaluate microbial composition and diversity. RESULTS: Compared to the placebo group, the KGM group exhibited significant improvements in PAC-SYM, PAC-QoL, BMF, and BFI scores (p < 0.05 for all). Microbial analysis revealed a marked increase in α-diversity and elevated relative abundances of Prevotella_9, Phascolarctobacterium, Lactobacillus, Bacteroides, and members of the Prevotellaceae family, alongside reduced levels of Alistipes and Desulfovibrio. Correlation analyses indicated a strong association between microbial shifts and symptom improvement. Functional predictions further suggested differential expression in microbial metabolic pathways, including upregulation of biotin biosynthesis I and nitrate reduction VI (assimilatory), and downregulation of L-methionine biosynthesis III (all p < 0.05). CONCLUSIONS: Konjac glucomannan significantly ameliorated gastrointestinal symptoms in elite athletes with functional constipation, potentially via modulation of the gut microbiota. © 2025. Springer-Verlag GmbH Germany, part of Springer Nature.

PURPOSE: To investigate the effects of a chromium-enriched glucomannan-fructooligosaccharide complex (SB) on glycaemic and insulin responses, satiation, and hunger biomarkers in healthy adults. METHODS: Using a double-blind, placebo-controlled, randomised crossover design, we assessed the acute impact of a single 3 g SB dose in 16 healthy adults (BMI 18.5-24.9 kg/m2) during a modified oral glucose tolerance test. On separate days, participants consumed 50 g dextrose or 50 g dextrose with 3 g SB (SBD). Blood glucose and insulin were analysed over 2.5 h. Hunger, fullness, and desire to eat were assessed via visual analogue scales. Additionally, the impact of SB on gastric viscosity was assessed in vitro. RESULTS: SBD intake significantly reduced the insulin concentration compared to dextrose alone at 45, 75, and 90 min post-intake. Additionally, SBD resulted in significantly greater fullness and a lower desire to eat at 75 min when compared to dextrose (p < 0.05). Although hunger increased over time for both interventions, SBD led to lower hunger, desire to eat, and food desire scores compared to dextrose at 150 min (p < 0.05). The viscosity of SB, even when combined with dextrose, was significantly higher compared to dextrose alone. CONCLUSIONS: These novel findings suggest that SB can modulate insulin response and influence appetite regulation, highlighting its potential use in weight management strategies. © 2025. The Author(s).

The complex interactions between intestinal microbiota and metabolic disorders are well-documented, with implications for glucose metabolism, energy expenditure, and intestinal permeability. Prebiotics induce beneficial changes in gut microbiota composition in prediabetes, while postbiotics can enhance gut barrier function, complementing each other to improve glucose metabolism and insulin sensitivity. This study investigated the effects of a 12-week dietary fibre (DF) supplement on gut health, metabolic function, and diet. The supplement contained konjac glucomannan (KGM), galacto-oligosaccharides (GOSs), and exopolysaccharides (EPSs) from Bifidobacterium breve. In a randomised, double-blind, placebo-controlled, parallel-group clinical trial, 53 prediabetic volunteers were randomly assigned to either a daily DF supplement (YMETA) or a placebo (cellulose microcrystalline) for 12 weeks, followed by a 4-week follow-up. Measurements included gut microbiota composition, glycated haemoglobin (HbA1c), fasting plasma glucose (FPG), plasma lipids, anthropometry, body composition, blood pressure, and dietary intake. The intervention group showed a significant increase in alpha diversity and butyrate-producing bacteria, with reductions in HbA1c and FPG levels below prediabetes thresholds. No significant changes were observed in the placebo group. This study suggests that manipulating the human gut microbiome through dietary interventions could be a promising therapeutic approach to managing prediabetes and preventing or delaying diabetes.

This study aimed to determine the impact of a fiber supplement on body weight and composition in individuals with obesity with specific genetic polymorphisms. It involved 112 adults with obesity, each with at least one minor allele in the FTO, LEP, LEPR, or MC4R polymorphism. Participants were randomized to receive either a fiber supplement (glucomannan, inulin, and psyllium) or a placebo for 180 days. The experimental group showed significant reductions in body weight (treatment difference: -4.9%; 95% CI: -6.9% to -2.9%; p < 0.01) and BMI (treatment difference: -1.4 kg/m2; 95% CI: -1.7 to -1.2; p < 0.01) compared to placebo. Further significant decreases in fat mass (treatment difference: -13.0%; 95% CI: -14.4 to -11.7; p < 0.01) and visceral fat rating (treatment difference: -1.3; 95% CI: -1.6 to -1.0; p < 0.01) were noted. Homozygous minor allele carriers experienced greater decreases in body weight (treatment difference: -3.2%; 95% CI: -4.9% to -1.6%; p < 0.01) and BMI (treatment difference: -1.2 kg/m2; 95% CI: -2.0 to -0.4; p < 0.01) compared to heterozygous allele carriers. These carriers also had a more significant reduction in fat mass (treatment difference: -9.8%; 95% CI: -10.6 to -9.1; p < 0.01) and visceral fat rating (treatment difference: -0.9; 95% CI: -1.3 to -0.5; p < 0.01). A high incidence of gastrointestinal events was reported in the experimental group (74.6%), unlike the placebo group, which reported no side effects. Dietary supplementation with glucomannan, inulin, and psyllium effectively promotes weight loss and improves body composition in individuals with obesity, particularly those with specific genetic polymorphisms.

Metabolic syndrome (MetS) is associated with cardiovascular risk factors, such as insulin resistance, dyslipidaemia, hypertension and abdominal obesity. Given the growing need to investigate food supplements with positive health effects, this study was aimed at testing the benefits of a specific supplement for people with MetS. Fifty-eight subjects with MetS and T2DM or impaired glucose tolerance assuming metformin, were randomly assigned to take a food supplement of glucomannan, D-chiro-inositol, Cinnamomum zeylanicum blume and inulin at a daily fixed dose of 4 g orally for four months. Body weight, waist circumference, plasma lipid profile (total cholesterol, LDL, HDL and triglyc-erides), plasma glycaemic profile and visceral adiposity index (VAI) were measured at baseline and after four months of supplementation. After 16 weeks, in subjects with T2DM or insulin resistance who took the supplement (+ metformin), there was a significant reduction in body weight and BMI (p < 0.0001), serum insulin (p < 0.05) and the HOMA index (p < 0.01), as well as in the lipaemic pattern, with a significant improvement in total serum cholesterol (p < 0.005), triglycerides (p < 0.03) and LDL (p < 0.02). Our study shows that the food supplement tested is a valid and safe alternative therapeutic approach in the management of MetS and all its resulting risk factors, as its efficacy has been demonstrated across anthropometric, glucose, lipid and hepatic parameters.

Konjac glucomannan (KGM) is a herbal medicine with benefits in appetite control, body weight and biochemical parameters in overweight individuals. The objective of our work was to evaluate the effect of the consumption of gummy candy enriched with KGM on appetite, to evaluate anthropometric data, biochemical and oxidative stress markers in overweight individuals. Forty-two participants aged 18 to 45 years completed our randomized, double-blind, placebo-controlled clinical trial. Participants were randomly assigned to consume for fourteen days, 2 candies per day, containing 250 mg of KGM or identical-looking placebo candy with 250 mg of flaxseed meal, shortly after breakfast and dinner. As a result, we observed that there was a reduction in waist circumference and in the intensity of hunger/satisfaction of the participants who consumed KGM for fourteen days, and we believe that a longer consumption time as well as an increase dose of KGM contribute to even more satisfactory body results.

In a recent study, we showed that konjac glucomannan (KGM) inhibits rice gruel-induced postprandial increases in plasma glucose and insulin levels. To extend this research, we investigated the effects of KGM addition to rice gruel on pre- and postprandial concentrations of circulating lipoprotein lipase (LPL), glycosylphosphatidylinositol-anchored high-density lipoprotein-binding protein 1 (GPIHBP1), hepatic triglyceride lipase (HTGL), free fatty acids (FFA), and triglycerides (TG). A total of 13 Japanese men, without diabetes, dyslipidemia, or gastrointestinal diseases, interchangeably ingested rice gruel containing no KGM (0%G), rice gruel supplemented with 0.4% KGM (0.4%G), and rice gruel supplemented with 0.8% KGM (0.8%G), every Sunday for 3 weeks. Blood samples were obtained at baseline and at 30, 60, and 120 min after ingestion to measure the abovementioned lipid parameters. Lipid parameters showed small, but significant, changes. Significant reductions were found in circulating FFA levels among all participants. Circulating TG levels significantly declined at 30 min and then remained nearly constant in the 0.8%G group but exhibited no significant difference in the 0%G and 0.4%G groups. Although circulating levels of LPL and GPIHBP1 significantly decreased in the 0%G and 0.4%G groups, they increased at 120 min in the 0.8%G group. Participants in the 0%G and 0.4%G groups showed significant decreases in circulating HTGL levels, which was not observed in the 0.8%G group. Our results demonstrate the novel pleiotropic effects of KGM. Supplementation of rice gruel with KGM powder led to TG reduction accompanied by LPL and GPIHBP1 elevation and HTGL stabilization, thereby attenuating TG metabolism.

Effective management of acute wounds, particularly those caused by burns and trauma, remains a significant clinical challenge. Conventional formulations, such as ointments, creams, and hydrogels, often face challenges related to stability, portability, and patient compliance. To address these limitations, we developed a novel bi-layered skin tablet system using direct compression for immediate application to topical wounds. The upper protective layer contains konjac glucomannan as a gelling agent and oleic acid as a permeability enhancer. The lower therapeutic layer includes a synergistic combination of clindamycin hydrochloride (CLC), benzalkonium chloride (BKC), and recombinant human mitsugumin 53 (rhMG53), a membrane repair protein. rhMG53 was repurposed for acute wound healing at a reduced dosage to maintain therapeutic efficacy while improving cost efficiency. The formulation was optimized to achieve controlled release of rhMG53 for wound repair and of CLC and BKC for antibacterial activity. The synergistic interaction between CLC and BKC (Index 1.2) enhanced broad-spectrum antibacterial efficacy. The prepared tablets underwent in-vitro testing for hardness, swelling index, content uniformity, drug release, and stability. The rhMG53 containing formulation demonstrated consistent drug loading (98.5%, RSD < 6%), prolonged release, and effective wound healing in cell-based tests. The tablet form improves portability, stability, and ease of application compared with conventional remedies. This bi-layered skin tablet system represents a promising therapeutic strategy for acute wound management, particularly in emergency and military settings where lightweight, ready-to-use treatments are critically needed. © 2026. The Author(s), under exclusive licence to American Association of Pharmaceutical Scientists.

In this research, simultaneous contribution of konjac-mannan (0.3%), xanthan (0.3%), and tragacanth (0.3%) gums in tomato ketchup was investigated comparing the physicochemical, rheological, texture, and sensory properties with the control sample containing 0.3% xanthan gum. Samples selected through viscosity and syneresis evaluation of the nine prepared samples were analyzed by color, flow behavior, frequency sweep, particle size, texture, and sensory experiments. Results indicated that increasing xanthan concentration did not have any significant effect on the apparent viscosity while considerable improvement was observed in the physical stability of ketchups containing konjac-mannan/xanthan ascribed to smaller particles with larger contact surfaces encouraging gel network formation. Highest a* and a*/b* was observed for konjac-mannan/xanthan (0.075%/0.225%) in which formation of hydrated gel granules of gums intensifies light diffraction due to the decreased particle size. This synergistically formed viscous three-dimensional gel network is responsible for the highest cohesiveness and gumminess of the same sample between the ketchup formulations containing two gums. Organoleptic properties of ketchup samples containing konjac-mannan/xanthan showed no significant difference with the control sample. PRACTICAL APPLICATIONS: Development of modern food technologies along with the lifestyle changes over the past few decades and grown public awareness of the relevance between health and nutrition have considerably increased the consumption of ready meals containing low-fat and fiber-rich functional condiments. Ketchup is a popular sauce thickened with tomato pulp powder, potato or corn starch, modified starch, and severally available hydrocolloids such as carboxymethyl cellulose, xanthan, guar, and locust bean gum. In this research work, mixtures of konjac-mannan and xanthan/tragacanth hydrocolloids are used to produce new ketchups with improved physical and rheological properties and lower prices. © 2018 Wiley Periodicals, Inc.

An in vitro model simulating the intestinal barrier for efficacy and drug interaction testing of mycotoxin detoxifying agents was developed using Transwell® cell culture inserts. Intestinal porcine epithelial cells derived from the jejunum of piglets were exposed to DON and a mycotoxin binder (efficacy testing) or exposed to tylosin and a mycotoxin binder (drug interaction testing). Active carbon and bentonite were used in the efficacy and drug interaction trials, respectively, to validate the developed model. The evaluated parameters were passage of DON and tylosin through the epithelial monolayer, the integrity of the monolayer by measurements of the trans-epithelial electrical resistance and the viability of the monolayer using the neutral red assay. In the efficacy model it was shown that active carbon effectively bound DON at both non-cytotoxic and cytotoxic concentrations of DON, respectively 0.5 and 1 μg/mL. Moreover, the negative effects of DON at cytotoxic concentrations on cellular viability and integrity were completely offset. A commercially available modified gluco-mannan binder was also tested and it was able to partly reduce the negative effects on these latter parameter. Moreover, it reduced the transepithelial passage of DON with 37% to 57% compared to active carbon, at both cytotoxic and non-cytotoxic concentrations of DON. In our drug interaction model, the interaction between tylosin and mycotoxin binders was investigated as some authors suggest binding of macrolide antibiotics to bentonite clays. Indeed, a bentonite clay showed decreased passage of tylosin through the epithelial monolayer, indicating binding of tylosin by bentonite. This indicates that the combined use of bentonite and tylosin in the feed could lead to therapy failure. The modified gluco-mannan binder did not alter the passage of tylosin significantly, indicating safe combined use.

118. Prikl Biokhim Mikrobiol. 2011 Nov-Dec;47(6):699-706. [Effect of polysaccharides on biological activity of human lactoferrin]. [Article in Russian] Mestechkina NM, Bezborodova OA, Il'ina AV, Levov AN, Kleĭmenov SIu, Nemtsova ER, Iakubovskaia RI, Shcherbukhin VD, Varlamov VP. The influence of neutral and ionic polysaccharides on the antioxidant (AOA) and detoxifying activities of lactoferrin (LF) and the duration of its circulation in the body was studied. In addition to natural polymers, we studied artificial chitosan derivatives with different functional groups. On the basis ofAOA test, five polysaccharides were selected. The study of the detoxifying effect of LF in two models of induced toxicity revealed polysaccharides that maintained or increased the detoxifying activity of LF. We established that the formation of a complex of lactoferrin with two galactomannans and succinyl chitosan caused positive changes in LF properties: the detoxifying activity of the protein remained unchanged or increased, whereas its elimination from the body was decelerated.

OBJECTIVE: The purpose of this study was to determine whether supplements of plant sterols and/or glucomannan improve lipid profile and cholesterol biosynthesis in mildly hypercholesterolemic type II diabetic and non-diabetic subjects and to compare the response of these two subject groups to the treatments. DESIGN: A randomized, crossover study consisting of four phases of 21 days, with each phase separated by a 28-day washout. SETTING: The Mary Emily Clinical Nutrition Research Unit of McGill University. SUBJECTS: Eighteen non-diabetic individuals and 16 type II diabetic individuals aged 38-74 years. INTERVENTIONS: Subjects were supplemented with plant sterols (1.8 g/day), glucomannan (10 g/day), a combination of glucomannan and plant sterols, and a placebo, provided in the form of bars. RESULTS: Overall plasma cholesterol concentrations were lowered (P<0.05) after combination treatment (4.72+/-0.20 mmol/l) compared to control (5.47+/-0.18 mmol/l). Plasma low-density lipoprotein (LDL) cholesterol concentrations were decreased (P<0.05) after glucomannan (3.16+/-0.14 mmol/l) and combination treatments (2.95+/-0.16 mmol/l) compared to control (3.60+/-0.16 mmol/l). The results of lipid profiles did not differ between subject groups. Overall plasma lathosterol concentrations, an index of cholesterol biosynthesis, were lowered (P<0.05) after the combination treatment compared to the plant sterol treatment. CONCLUSIONS: The results suggest that glucomannan and a combination of glucomannan and plant sterols substantially improves plasma LDL cholesterol concentrations. SPONSORSHIP: Forbes Medi-Tech Inc., Vancouver, British Columbia, Canada.

The synergistic interaction between xanthan and glucomannan in solution and in the gel phase has been studied by circular dichroism spectroscopy and differential scanning calorimetry. The study in solution of the polysaccharidic mixture indicates a preferred stoichiometry of the interaction corresponding to a weight fraction of xanthan around 0.55. This finding is in reasonable agreement with the differential scanning calorimetry measurements carried out on the gel phase. Models from conformational analysis based on these results were formulated in terms of 1:1 and 2:1 Konjac glucomannan/xanthan molecular assemblies. The experimental and calculation results clearly indicate the involvement of the side chains of xanthan and suggest that the ordered portions of the macromolecular complex in solution act in the gel phase as junction zones. Effect of deacetylation on the synergistic interaction of acetan with locust bean gum or konjac mannan. Ojinnaka C(1), Brownsey GJ, Morris ER, Morris VJ. Author information: (1)Cranfield University, Silsoe College, Bedford, UK. It has been discovered that deacetylation of the bacterial polysaccharide acetan promotes synergistic interactions with either locust bean gum (LBG) or konjac mannan (KM). Acetan is similar in structure to xanthan, and adopts a similar 5-fold conformation in the solid state. Like xanthan, it shows a thermally reversible order (helix)-disorder (coil) transition in solution. Both polymers have a cellulosic backbone with charged (anionic) sidechains attached at O-3 of alternate glucosyl residues, but the sidechains in acetan are longer (pentasaccharide rather than trisaccharide) and do not contain pyruvic substituents. Acetan has two sites of acetylation, one at O-6 of the inner mannosyl residue of the carbohydrate sidechains (as in xanthan) and the other on the polymer backbone (believed to be at O-6 of the branched glucosyl residues). Solutions of acetan or deacetylated acetan were equilibrated against 10 mM potassium chloride (to stabilise the ordered conformation) and were mixed (at 25 degrees C) with solutions of LBG or KM, also equilibrated against 10 mM potassium chloride. Unlike xanthan, native ac

42. Carbohydr Res. 1997 Dec;305(1):101-8. doi: 10.1016/s0008-6215(97)00277-2. Effect of deacetylation on the synergistic interaction of acetan with locust bean gum or konjac mannan. Ojinnaka C(1), Brownsey GJ, Morris ER, Morris VJ. Author information: (1)Cranfield University, Silsoe College, Bed

BACKGROUND AND AIMS: In a recent open trial we have shown the efficacy of long term intermittent administration of a poorly absorbable antibiotic (rifaximin) in obtaining symptomatic relief in uncomplicated diverticular disease of the colon. The aim of this double-blind placebo-controlled trial was to test our previous observations. METHODS: One hundred and sixty-eight outpatients with symptomatic uncomplicated diverticular disease were treated with fibre supplementation (glucomannan 2 g/day) plus rifaximin 400 mg b.d. for 7 days every month (84 patients), or with glucomannan 2 g/day plus placebo two tablets b.d. for 7 days every month (84 patients). Clinical evaluation was performed at admission and at three-month intervals for 12 months. RESULTS: After 12 months, 68.9% of the patients treated with rifaximin were symptom-free or mildly symptomatic, compared to 39.5% in the placebo group (P = 0.001). Symptoms such as bloating and abdominal pain or discomfort were primarily affected by antibiotic treatment when compared with placebo (P < 0.001). CONCLUSION: Rifaximin appears to be of some advantage in obtaining symptomatic relief in diverticular disease of the colon when compared with fibre supplementation alone.

Chemical mutagenesis has been used to produce mutants of Acetobacter xylinum NRRL B42 that are cellulose-negative and that produce variants of the acetan structure deficient in the side-chain sugar residues. The product of A. xylinum strain CR1/4 has been shown to possess a tetrasaccharide repeat unit with the side chain terminating in glucuronic acid. X-ray diffraction studies of oriented fibres suggest that the polysaccharide CR1/4 forms a fivefold helix with a pitch of 4.8 nm. Light-scattering studies on CR1/4 solutions suggest a molecular weight of 1.2 x 10(6) with radii of gyration values of 86 nm (aqueous solution) and 67 nm (0.1 M NaCl solution). The magnitude of the measured radii of gyration and the shape of the Holtzer plots suggest that CR1/4 can be described as a stiff coil. Preliminary differential scanning calorimetry data show melting behaviour consistent with order-disorder transitions of a charged helical structure. Rheological studies have revealed new synergistic interactions of CR1/4 with locust bean gum. Comparative studies of acetan and CR1/4 show that decreasing the length of the side chain enhances the solution viscosity.

PURPOSE: Type 2 diabetes (T2DM) is increasing, particularly in South-East Asia. Intake of high-glycaemic foods has been positively associated with T2DM, and feasible routes to reduce the glycaemic response to carbohydrate-rich staple foods are needed. The research question was whether different fibre and legume flour mixes in flatbreads lower postprandial glucose (PPG) responses. METHODS: Using a balanced incomplete block design, we tested the inclusion of guar gum (GG), konjac mannan (KM) and chickpea flour (CPF) in 10 combinations (2/4/6 g GG; 2/4 g KM; 15 g CPF, and 10 or 15 g CPF plus 2 or 4 g GG) in 100 g total of a control commercial high-fibre flatbread flour mix ("atta") on PPG in 38 normal-weight adults. Self-reported appetite was an additional exploratory outcome. An in vitro digestion assay was adapted for flatbreads and assessed for prediction of in vivo PPG. RESULTS: Flatbreads with 6 g GG, 4 g KM, and 15 g CPF plus 2 or 4 g GG reduced PPG ≥30 % (p < 0.01), while no other combinations differed significantly from the control. A statistical model with four in vitro parameters (rate of digestion, %RDS, AUC, carbohydrate level) was highly predictive of PPG results (adjusted R 2 = 0.89). Test products were similar to the control for appetite-related measures. CONCLUSIONS: The results confirm the efficacy of specific additions to flatbread flour mixes for reducing PPG and the value of the in vitro model as a predictive tool with these ingredients and product format. This trial is registered at ClinicalTrials.gov with identifier NCT02671214.

Polyactin A is a polysaccharide extracted from cultured alpha-Streptococcus No. 33 in the mouth. It is also known as alpha-glucomannan. According to clinical reports, Polyactin A is considered to be an immunological adjuvant with significant curative effect in chemotherapy of tumors. Immunological activities of Polyactin A were studied. When injected into mice at the dosage of 100 mg/kg for 4-5 consecutive days, Polyactin A can cause a marked increase in spleen weight and RFC in spleen, and it can antagonize the immunosuppressive actions of cyclophosphamide. Polyactin A can also increase phagocytosis of macrophages in the peritoneal cavity of mice. Phagocytotic ratio and phagocytotic index in the experimental group were greater than those in the control group. Phagocytotic ratio and phagocytotic index were respectively 63.5 +/- 8.3% and 1.02 +/- 0.05% in the Polyactin A treated group but were respectively 21.0 +/- 5.7% and 0.3 +/- 0.03% in the control group. The differences were significant (p < 0.05, < 0.01). Polyactin A had definite influence on the transformation test of lymphocytes and increased the transformation ratio of lymphocytes in vitro. The ability of Polyactin A to induce the transformation of lymphocytes into lymphoblasts was almost the same as that of PHA. These results suggest that polyactin A has a marked immunological activity, which is not entirely due to the role of large molecular weight polysaccharide. They provide direct evidence for the assumption that Polyactin A may be an immunological adjuvant, and it is experimentally confirmed that Polyactin A can protect the immunity of the organism.

Dendrobium polysaccharides (DPSs) have aroused people's increasing attention in recent years as a result of their outstanding edible and medicinal values and non-toxic property. This review systematically summarized recent progress in the different preparation techniques, structural characteristics, modification, various pharmacological activities and molecular mechanisms, structure-activity relationships, and current industrial applications in the medicinal, food, and cosmetics fields of DPSs. Additionally, some recommendations for future investigations were provided. A variety of methods were applied for the extraction and purification of DPSs. They possessed primary structures (e.g., glucomannan, rhamnogalacturonan I type pectin, heteroxylan, and galactoglucan) and conformational structures (e.g., random coil, rod, globular, and a slight triple-helical). And different molecular weights, monosaccharide compositions, linkage types, and modifications could largely affect DPSs' bioactivities (e.g., immunomodulatory, anti-diabetic, hepatoprotective, gastrointestinal protective, antitumor, anti-inflammatory, and anti-oxidant activities). It was worth mentioning that DPSs were significant pharmaceutical remedies and therapeutic supplements especially due to their strong immunity enhancement abilities. We hope that this review will lay a solid foundation for further development and applications of Dendrobium polysaccharides.

BACKGROUND AND OBJECTIVES: Constipation, a common complaint in children, considerably affects the quality of life. This systematic review assessed the treatment effects of glucomannan on children with constipation by summarising evidence from previous randomised controlled trials (RCTs). METHODS AND STUDY DESIGN: A comprehensive electronic literature search was conducted for identifying eligible RCTs that evaluated the effectiveness of glucomannan. The results were reported as mean differences (MDs), standardised mean differences (SMDs), and risk ratios (RRs) with 95% confidence intervals (CIs). The primary outcome was the defecation frequency per week; the secondary outcomes were stool consistency and the rate of successful treatment. A metaanalysis was conducted using the random effects model. RESULTS: Three RCTs evaluating 122 participants were identified. Glucomannan use was associated with an increased frequency of defecation (3 trials; MD=1.40; 95% CI: 0.36-2.44, p=0.008); however, there were no significant differences in the outcomes of stool consistency (3 trials; SMD=0.48; 95% CI: -0.44 to 1.40, p=0.300) or the rate of successful treatment (2 trials; RR=1.36; 95% CI: 0.48-3.81, p=0.110). CONCLUSIONS: Glucomannan moderately increases the defecation frequency of children with constipation but is not associated with a reduction in stool consistency or overall improvement in the rate of successful treatment. However, these results should be cautiously interpreted because of the small sample size and the risk of products containing glucomannan need to be considered. Additional large-scale and well-designed RCTs are necessary to evaluate the efficacy and long-term safety of glucomannan.

Background: Evidence from randomized controlled trials (RCTs) suggests the consumption of konjac glucomannan (KJM), a viscous soluble fiber, for improving LDL-cholesterol concentrations. It has also been suggested that the cholesterol-lowering potential of KJM may be greater than that of other fibers. However, trials have been relatively scarce and limited in sample size and duration, and the effect estimates have been inconsistent. The effect of KJM on new lipid targets of cardiovascular disease (CVD) risk is also unknown.Objective: This systematic review and meta-analysis aimed to assess the effect of KJM on LDL cholesterol, non-HDL cholesterol, and apolipoprotein B.Design: Medline, Embase, CINAHL, and the Cochrane Central databases were searched. We included RCTs with a follow-up of ≥3 wk that assessed the effect of KJM on LDL cholesterol, non-HDL cholesterol, or apolipoprotein B. Data were pooled by using the generic inverse-variance method with random-effects models and expressed as mean differences (MDs) with 95% CIs. Heterogeneity was assessed by the Cochran Q statistic and quantified by the I2 statistic.Results: Twelve studies (n = 370), 8 in adults and 4 in children, met the inclusion criteria. KJM significantly lowered LDL cholesterol (MD: -0.35 mmol/L; 95% CI: -0.46, -0.25 mmol/L) and non-HDL cholesterol (MD: -0.32 mmol/L; 95% CI: -0.46, -0.19 mmol/L). Data from 6 trials suggested no impact of KJM on apolipoprotein B.Conclusions: Our findings support the intake of ∼3 g KJM/d for reductions in LDL cholesterol and non-HDL cholesterol of 10% and 7%, respectively. The information may be of interest to health agencies in crafting future dietary recommendations related to reduction in CVD risk. This study was registered at clinicaltrials.gov as NCT02068248. © 2017 American Society for Nutrition.

OBJECTIVE: Glucomannan (GM), a soluble fiber derived from the plant Amorphophallus konjac, is marketed as being helpful in reducing body weight. However, the data supporting this claim are scarce. The aim of this review was to systematically evaluate the effects of GM on body weight (BW) and body mass index (BMI) in otherwise healthy obese or overweight children and adults. METHODS: MEDLINE, EMBASE, CENTRAL, and Google Scholar databases were systematically searched up to June 2014 for randomized controlled trials (RCTs) assessing the effectiveness of GM versus placebo. The primary outcome measures were BW and BMI. RESULTS: Six eligible RCTs, only one of which performed in children, were included. In adults, three RCTs reported a significant reduction in BW in the GM group compared with the control group at the following different points during the intervention: At week 2 (mean difference [MD], 0.21 kg; 95% confidence interval [CI], 0.13-0.29); at week 4 (MD, 2.04; 95% CI, 0.52-3.56); at week 5 (MD, 1.3; 95% CI, 0.89-1.71); and at week 8 (MD, 3.17; 95% CI, 1.29-5.05). Only one RCT reported a beneficial effect at more than one point. None of the RCTs reported a favorable effect of GM on BMI. CONCLUSIONS: In otherwise healthy overweight or obese adults, there is some evidence that in the short term GM may help to reduce BW, but not BMI. Data in children are too limited to draw any conclusions.

BACKGROUND: Several clinical trials have investigated the impact of glucomannan on plasma lipids, body weight, fasting blood glucose (FBG), and blood pressure (BP), but have yielded conflicting results and had only modest sample sizes. OBJECTIVE: The objective was to perform a meta-analysis of randomized controlled trials of glucomannan to better characterize its impact on plasma lipids, FBG, body weight, and BP. DESIGN: A systematic literature search of MEDLINE, EMBASE, CINAHL, Web of Science, the Cochrane Library, and the Natural Medicines Comprehensive Database was conducted from the earliest possible date through November 2007. A random-effects model was used to calculate the weighted mean difference (WMD) and 95% CIs as the difference between the mean for the glucomannan and control groups. Standard methods for assessing statistical heterogeneity and publication bias were used. RESULTS: Fourteen studies (n = 531) met the inclusion criteria. The use of glucomannan significantly lowered total cholesterol [weighted mean difference (WMD): -19.28 mg/dL; 95% CI: -24.30, -14.26], LDL cholesterol (WMD: -15.99 mg/dL; 95% CI: -21.31, -10.67), triglycerides (WMD: -11.08 mg/dL; 95% CI: -22.07, -0.09), body weight (WMD: -0.79 kg; 95% CI: -1.53, -0.05), and FBG (WMD: -7.44 mg/dL; 95% CI: -14.16, -0.72). The use of glucomannan did not appear to significantly alter any other study endpoints. Pediatric patients, patients receiving dietary modification, and patients with impaired glucose metabolism did not benefit from glucomannan to the same degree. CONCLUSIONS: Glucomannan appears to beneficially affect total cholesterol, LDL cholesterol, triglycerides, body weight, and FBG, but not HDL cholesterol or BP.