Gm8.5

Glucomannan Research

39 peer-reviewed studies · Evidence score: 8.5/10

Comparative effects of nutraceuticals on body weight in adults with overweight or obesity: A systematic review and network meta-analysis of 111 randomized clinical trials

Shahinfar H et al. • Pharmacological research (2023)

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.

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.
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.

Meta-Analysisn=6,171

DOI

Effects of Glucomannan Supplementation on Type II Diabetes Mellitus in Humans: A Meta-Analysis

Zhang Z et al. • Nutrients (2023)

Our analysis indicates that glucomannan is an effective nutritional intervention for 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.
Our analysis indicates that glucomannan is an effective nutritional intervention for type II diabetes.

Meta-Analysisn=440

DOI

Konjac glucomannan as an emerging nutritional strategy for obesity control via gut microbiota and metabolic regulation

Zhang Y et al. • Discover Food (2025)

KGM supplementation (≥5g/day for ≥12 weeks) associated with reductions in BMI (1.49 kg/m²) and weight (3.18 kg).

BMI reduction of 1.49 kg/m² average
Weight reduction of 3.18 kg average
Waist circumference reduction of 2.11 cm

Systematic Review

DOI

A systematic review and meta-analysis of randomized controlled trials of the effect of konjac glucomannan, a viscous soluble fiber, on LDL cholesterol and the new lipid targets non-HDL cholesterol and apolipoprotein B

Ho HVT et al. • The American journal of clinical nutrition (2017)

This study was registered at clinicaltrials.gov as NCT02068248.

Data were pooled by using the generic inverse-variance method with random-effects models and expressed as mean differences (MDs) with 95% CIs.
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.

Meta-Analysisn=370

DOI

The effect of glucomannan supplementation on lipid profile in adults: a GRADE-assessed systematic review and meta-analysis

Musazadeh V et al. • BMC cardiovascular disorders (2024)

Glucomannan supplementation has a beneficial effect on the level of TC and LDL-C.

Glucomannan supplementation has a beneficial effect on the level of TC and LDL-C.
Further research warranted to confirm findings

Meta-Analysis

DOI

Effects of glucomannan supplementation on weight loss in overweight and obese adults: A systematic review and meta-analysis

Mohammadpour S et al. • Obesity Medicine (2020)

Glucomannan resulted in significant reduction in weight (-0.96 kg; 95% CI: -1.81 to -0.11).

Significant weight reduction vs placebo
Greater effects in females (-1.86 kg)
6 RCTs with 225 subjects analyzed

Meta-Analysisn=225

DOI

Effect of glucomannan on functional constipation in children: a systematic review and meta-analysis of randomised controlled trials

Han Y et al. • Asia Pacific journal of clinical nutrition (2017)

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.

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.

Meta-Analysisn=122

DOI

A Systematic Review on Polysaccharides from Dendrobium Genus: Recent Advances in the Preparation, Structural Characterization, Bioactive Molecular Mechanisms, and Applications

Li X et al. • The American journal of Chinese medicine (2022)

We hope that this review will lay a solid foundation for further development and applications of Dendrobium polysaccharides.

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.

Systematic Review

DOI

Efficacy of dietary supplements containing isolated organic compounds for weight loss: a systematic review and meta-analysis of randomised placebo-controlled trials

Bessell E et al. • International journal of obesity (2005) (2021)

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.

There was no statistically significant effect on weight for fructans compared to placebo (p = 0.24).
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.
Further research warranted to confirm findings

Meta-Analysis

DOI

The effect of glucomannan on body weight in overweight or obese children and adults: a systematic review of randomized controlled trials

Zalewski BM et al. • Nutrition (Burbank, Los Angeles County, Calif.) (2015)

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.

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.
Further research warranted to confirm findings

Systematic Review

DOI

The efficacy of glucomannan supplementation in overweight and obesity: a systematic review and meta-analysis of randomized clinical trials

Onakpoya I et al. • Journal of the American College of Nutrition (2014)

The evidence from available RCTs does not show that glucomannan intake generates statistically significant weight loss.

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%).
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.

Meta-Analysis

DOI

Effect of glucomannan on plasma lipid and glucose concentrations, body weight, and blood pressure: systematic review and meta-analysis

Sood N et al. • The American journal of clinical nutrition (2008)

Glucomannan appears to beneficially affect total cholesterol, LDL cholesterol, triglycerides, body weight, and FBG, but not HDL cholesterol or BP.

Glucomannan appears to beneficially affect total cholesterol, LDL cholesterol, triglycerides, body weight, and FBG, but not HDL cholesterol or BP.
Further research warranted to confirm findings

Meta-Analysisn=531

DOI

The Impact of Glucomannan, Inulin, and Psyllium Supplementation (Soloways(TM)) on Weight Loss in Adults with FTO, LEP, LEPR, and MC4R Polymorphisms: A Randomized, Double-Blind, Placebo-Controlled Trial

Pokushalov E et al. • Nutrients (2024)

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.

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.

RCTn=112

DOI

Effects of konjac glucomannan on gastrointestinal symptoms and gut microbiota in athletes with functional constipation: a double-blind randomized controlled trial

Zhu Y et al. • European journal of nutrition (2025)

Konjac glucomannan significantly ameliorated gastrointestinal symptoms in elite athletes with functional constipation, potentially via modulation of the gut microbiota.

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).
Konjac glucomannan significantly ameliorated gastrointestinal symptoms in elite athletes with functional constipation, potentially via modulation of the gut microbiota.
Further research warranted to confirm findings

RCTn=66

DOI

Impact of Combined Prebiotic Galacto-Oligosaccharides and Bifidobacterium breve-Derived Postbiotic on Gut Microbiota and HbA1c in Prediabetic Adults: A Double-Blind, Randomized, Placebo-Controlled Study

Beteri B et al. • Nutrients (2024)

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.

The intervention group showed a significant increase in alpha diversity and butyrate-producing bacteria, with reductions in HbA1c and FPG levels below prediabetes thresholds.
Measurements included gut microbiota composition, glycated haemoglobin (HbA1c), fasting plasma glucose (FPG), plasma lipids, anthropometry, body composition, blood pressure, and dietary intake.
No significant changes were observed in the placebo group.

RCT

DOI

Impact of a mineral enriched, fiber complex on glycaemic response and satiation in healthy adults: a double-blind, crossover intervention study

Ancu O et al. • European journal of nutrition (2025)

These novel findings suggest that SB can modulate insulin response and influence appetite regulation, highlighting its potential use in weight management strategies.

SBD intake significantly reduced the insulin concentration compared to dextrose alone at 45, 75, and 90 min post-intake.
These novel findings suggest that SB can modulate insulin response and influence appetite regulation, highlighting its potential use in weight management strategies.
Further research warranted to confirm findings

Crossovern=16

DOI

Effectiveness of a Food Supplement Based on Glucomannan, D-Chiro-Inositol, Cinnamomum zeylanicum Blume and Inulin in Patients with Metabolic Syndrome

Citarrella R et al. • Nutrients (2024)

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.

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.
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.

RCTn=58

DOI

Gummies candy enriched with Konjac glucomannan reduces hunger intensity and waist circumference of overweight individuals

Fernandes ACS et al. • International journal of biological macromolecules (2023)

Forty-two participants aged 18 to 45 years completed our randomized, double-blind, placebo-controlled clinical trial.

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.

RCTn=42

DOI

Glucomannan for abdominal pain-related functional gastrointestinal disorders in children: a randomized trial

Horvath A et al. • World journal of gastroenterology (2013)

In our setting, GNN, as dosed in this study, was no more effective than the placebo in achieving therapeutic success in the management of FGIDs in children.

In our setting, GNN, as dosed in this study, was no more effective than the placebo in achieving therapeutic success in the management of FGIDs in children.
Further research warranted to confirm findings

RCTn=41

DOI

No Effect of Glucomannan on Body Weight Reduction in Children and Adolescents with Overweight and Obesity: A Randomized Controlled Trial

Zalewski BM et al. • The Journal of pediatrics (2019)

Glucomannan supplementation compared with placebo had no effect on weight reduction in children with overweight and obesity.

Compared with the placebo, glucomannan had no effect on the BMI-for-age z score at 12 weeks (mean difference: 0.0, 95% CI -0.1 to 0.1).
Glucomannan supplementation compared with placebo had no effect on weight reduction in children with overweight and obesity.
Further research warranted to confirm findings

RCTn=96

DOI

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