Konjac glucomannan: health uses, gut effects and new research
What it found
Konjac glucomannan, a soluble fibre from the konjac plant, is linked to weight loss, better blood sugar and cholesterol, and gut health in people, with some evidence from animals and lab tests.
The authors also flag possible gut discomfort and allergic reactions.
What they found
Studies in people
Weight and body fat
In people, adding konjac glucomannan to a low-calorie diet led to greater weight loss and fat loss than diet alone. One 8-week study found an average loss of 5.5 lbs, and a trial in children saw mean overweight drop from 49.5% to 41%.
Cholesterol and lipids
People taking konjac glucomannan saw lower total cholesterol and LDL cholesterol. In one controlled study, serum cholesterol fell by 32.0 mg/dl and LDL by 28.7 mg/dl.
Gut health and stool
Konjac glucomannan increased stool bulk and bowel movements in a dose-dependent way. A daily intake of 3 grams led to 0.5 more bowel movements per day and 3 more per week; 4 grams led to 0.9 more per day and 6 more per week.
Side effects and limits
Some people may get gastrointestinal discomfort when starting konjac glucomannan, and it can cause allergic reactions. The authors say purity and molecular consistency are hard to maintain.
Studies in people and animals
Blood sugar control
In people with type 2 diabetes, konjac glucomannan supplements were linked to a 23.2% drop in fasting glucose compared to placebo. In animals and lab settings, it reduced glucose by 55.37% at a dose of 1.5 g/kg.
Gut bacteria and inflammation
Konjac glucomannan acts as a prebiotic, boosting beneficial gut bacteria like Bifidobacterium and Lactobacillus. In mice, it reduced skin inflammation and suppressed hyper-IgE production.
What the authors conclude
“KGM is a versatile dietary fiber with extensive applications in functional foods, nutraceuticals, and therapeutic interventions.”
Also in their conclusions
- They say konjac glucomannan is a versatile dietary fibre with wide uses in foods and medicine.
- They advise that future research should focus on improving how well the body absorbs it, developing targeted delivery systems, and creating new formulations.
- They also call for population-based clinical trials and long-term studies to set evidence-based guidelines for konjac glucomannan consumption.
How it was done
The authors wanted to give a complete picture of konjac's traditional uses, its modern health applications, and the latest research on its main fibre, konjac glucomannan. They also wanted to point out the challenges and limits of what is known.
They pulled together and reviewed published studies on konjac glucomannan, covering its history, chemical makeup, health effects, and new research methods. The studies they looked at included people, animals, and lab tests.
What it can’t tell you
- Many of the findings come from animal or lab studies, so they may not apply to people.
- The review includes studies with different doses and lengths, so it cannot say what the best dose or long-term effects are.
- It cannot show whether konjac glucomannan prevents diseases like cancer in people.
Who paid
- Conflicts
- The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision.
- Authors work at
- Zunyi Medical University, China
The paper
- Title
- Amorphophallus konjac : traditional uses, bioactive potential, and emerging health applications
- Type
- ReviewThe authors read earlier studies and describe what they found. It isn’t a new study.
- Evidence
- Studies in people · animals · lab
- Summarised from
- Full text
- Cite
- Jain A, Sarsaiya S, Gong Q, Wu Q, Shi J (2025). Amorphophallus konjac : traditional uses, bioactive potential, and emerging health applications. Frontiers in plant science. doi:10.3389/fpls.2025.1530814Free full textPubMed 40061034DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error