Inulin, gut bacteria and metabolic health in people
What it found
In people, inulin supplements were linked to better body weight, blood sugar, insulin and inflammation markers, mostly through changes in gut bacteria.
The studies were small and varied, so results were not always consistent.
What they found
Studies in people
Body weight and BMI
Some trials found that 16 g per day of inulin for 12 weeks lowered body weight and BMI in adults with obesity or metabolic disorder, and 10 g per day for 8 weeks gave similar results. But two studies using 21 g and 20 g per day for 6 weeks had conflicting results, one finding benefits and the other none.
Blood sugar and insulin
Inulin supplementation reduced insulin levels and improved insulin sensitivity in some studies. For example, 10 g per day for 8 weeks lowered blood glucose levels.
Gut bacteria changes
Most studies showed that inulin increased Bifidobacterium species, such as B. longum, B. adolescentis and B. angulatum, regardless of dose or source. It also increased Anaerostipes species, which were linked to better blood sugar and body measurements.
Inflammation markers
Inulin supplementation decreased proinflammatory cytokines and biomarkers like TNF-α and calprotectin, and increased anti-inflammatory IL-10.
Cholesterol and lipids
Some studies found that inulin reduced LDL cholesterol, total cholesterol and triglycerides, and increased HDL cholesterol with long-term use. But results were contradictory, especially with different inulin sources.
Animal and lab studies
Mechanisms in lab and animals
In lab tests and animal models, short-chain fatty acids produced from inulin fermentation were shown to improve glucose metabolism, reduce inflammation and affect lipid processing. These mechanisms are proposed to explain effects seen in people.
What the authors conclude
“In conclusion, the studies collected suggest that inulin intake produces positive metabolic effects through the improvement of the intestinal microbiota and through the metabolites produced by its fermentation.”
Also in their conclusions
- They conclude that inulin shows significant potential in improving human physiology, particularly through modulation of gut bacteria like Bifidobacterium and Anaerostipes, leading to better body measurements, glucose metabolism, insulin levels and inflammation.
- They state that further research is warranted to fully elucidate its therapeutic potential and optimize its clinical applications.
How it was done
The authors wanted to review how inulin affects obesity and the human gut bacteria, and to highlight the mechanisms that might explain its use in obesity and metabolic syndrome.
They collected clinical trials published between January 2009 and 28 June 2024 that tested inulin in people. The trials included adults and children, with the largest having 174 participants and the smallest 12, and inulin doses ranged from 3 g to 20 g per day.
What it can’t tell you
- The studies were small and used different doses, sources and durations, so results were not always consistent.
- Most studies cannot show cause and effect because they are not all randomised controlled trials, and some findings come from animal or lab studies.
- The long-term effects of inulin on health outcomes like disease prevention are not known from these studies.
Who paid
- Funding
- Funded by Gobierno de Navarra; MICINN; CIBER (from the PubMed record).
- Conflicts
- The authors declare that this study received funding from LABORATORIOS CINFA, S.A. and VISCOFAN, S.A. The funder was not involved in the study design, collection, analysis, interpretation of data, the writing of this article or the decision to submit it for publication.
- Authors work at
- University of Navarra, Spain; Navarra Institute for Health Research (IdiSNA), Spain; Instituto de Salud Carlos III, Spain
The paper
- Title
- Health Effects and Mechanisms of Inulin Action in Human Metabolism
- 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
- Alonso-Allende J, Milagro FI, Aranaz P (2024). Health Effects and Mechanisms of Inulin Action in Human Metabolism. Nutrients. doi:10.3390/nu16172935Free full textPubMed 39275251DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error