Inulin
Also known as: chicory inulin, fructan, oligofructose (related)
Human trials and a systematic review report that oral inulin (commonly 5–20 g/day) increases bifidobacteria and other beneficial taxa and can modify microbial diversity and function; randomized trials in adults with overweight/obesity found improvements in insulin sensitivity versus low-fermentable control, and recent paediatric RCTs show microbiota and metabolite changes in children with obesity. One pilot study in COPD patients suggested benefit when combined with microbiome modulation.
Last reviewed: 2026-10-14 · 5 indexed studies
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Overview
Inulin is a naturally occurring fermentable dietary fibre composed of β(2→1) fructosyl chains used as a prebiotic. Clinical trials show it consistently alters gut microbiota composition (notably increasing Bifidobacterium) and has been tested for effects on metabolic markers in people with overweight, obesity and COPD.
Mechanism & Function
Mechanism of Action
Inulin reaches the colon where it is fermented by saccharolytic bacteria, increasing short-chain fatty acid production and selectively stimulating growth of taxa such as Bifidobacterium and butyrate-producers, thereby altering microbial metabolites and downstream host metabolic and immune signalling.
Physiological Role
Serves as a fermentable substrate for colonic microbiota, promoting production of microbially derived metabolites (eg, SCFAs) that can influence host metabolism, immune function and gut-brain signalling.
Primary Pathways
Performance / Health Relevance
Not a performance ergogenic; relevance is to gut health and host metabolic regulation via microbiota-mediated metabolite changes rather than direct effects on exercise capacity.
Evidence Review
Practical Use & Dosage
- Minimum Effective Dose
- Approximately 5 g/day (based on reviewed trials)
- Optimal Range
- 5–20 g/day as used in trials; 20 g/day commonly studied in adult trials
- Upper / Caution Level
- Not established from provided abstracts
- Timing
- Daily, with meals where tolerated
- Best Format
- Powder or incorporated into food
- Bioavailability
- Not absorbed systemically; acts in the colon where it is fermented by resident microbes
- Absorption Considerations
- Fermentation can increase gas production and cause bloating or flatulence in some individuals
Safety & Interactions
Side Effects
- •Gastrointestinal symptoms such as bloating, flatulence and abdominal discomfort (commonly reported with fermentable fibres)
Contraindications
- Known intestinal obstruction or severe motility disorders
Drug Interactions
- •No specific drug interactions reported in the provided abstracts
Who Should Avoid
- •Individuals with severe gastrointestinal disease without medical advice
Monitoring
Monitor gastrointestinal tolerance when initiating or increasing dose; observe metabolic markers if used for metabolic health goals.
Frequently Asked Questions
Auto-generated from indexed evidence — dosage, safety, interactions, and more.
When is Inulin typically used or indicated?
Inulin is most commonly used for: Prebiotic to support gut microbiota, Support for metabolic health (insulin sensitivity), Adjunct for management of obesity-related gut dysbiosis. Serves as a fermentable substrate for colonic microbiota, promoting production of microbially derived metabolites (eg, SCFAs) that can influence host metabolism, immune function and gut-brain signalling.
How does Inulin work?
Inulin reaches the colon where it is fermented by saccharolytic bacteria, increasing short-chain fatty acid production and selectively stimulating growth of taxa such as Bifidobacterium and butyrate-producers, thereby altering microbial metabolites and downstream host metabolic and immune signalling.
What is the recommended dose of Inulin?
The optimal range is 5–20 g/day as used in trials; 20 g/day commonly studied in adult trials. with a minimum effective dose of Approximately 5 g/day (based on reviewed trials). Best taken: Daily, with meals where tolerated. Upper / caution level: Not established from provided abstracts.
What are the side effects of Inulin?
Reported side effects include: Gastrointestinal symptoms such as bloating, flatulence and abdominal discomfort (commonly reported with fermentable fibres). Monitoring: Monitor gastrointestinal tolerance when initiating or increasing dose; observe metabolic markers if used for metabolic health goals.
Does Inulin interact with medications?
Known or theoretical interactions: No specific drug interactions reported in the provided abstracts. Always check with a clinician before combining with prescription medication.
Who should avoid Inulin?
Inulin is generally not recommended for: Individuals with severe gastrointestinal disease without medical advice; and Known intestinal obstruction or severe motility disorders.
How strong is the evidence for Inulin?
Evidence level: Moderate (overall score 74/100), based on 5 indexed studies on SuppIndex.
Research & References (5)
The effects of inulin on gut microbial composition: a systematic review of evidence from human studies.
Systematic review of human studies assessing inulin effects on gut microbiome composition; included randomized placebo-controlled trials using 5–20 g/day. Most consistent finding was an increase in Bifidobacterium; other increases reported in Anaerostipes, Faecalibacterium and Lactobacillus, with decreases in Bacteroides. Taxonomic changes were not uniformly linked to increased short-chain fatty acids.
Dietary supplementation with inulin-propionate ester or inulin improves insulin sensitivity in adults with overweight and obesity with distinct effects on the gut microbiota, plasma metabolome and systemic inflammatory responses: a randomised cross-over trial.
Randomized, double-blind, placebo-controlled crossover in 12 non-diabetic adults with overweight/obesity comparing 20 g/day inulin, an inulin-propionate ester and cellulose over 42 days each. Both inulin and propionate-delivering ester improved insulin resistance versus cellulose; inulin altered gut bacterial classes (increased Actinobacteria, decreased Clostridia) but did not change the systemic inflammatory markers measured.
Faecal microbial transfer and complex carbohydrates mediate protection against COPD.
Pilot randomised double-blind placebo-controlled study component in 16 patients with COPD assessing inulin supplementation as part of investigations into complex carbohydrates and faecal microbial transfer; supplementation improved disease-related outcomes in combination with microbiome interventions in the overall study context.
Enhancing gut microbiota and microbial function with inulin supplementation in children with obesity.
Randomized, double-blind, placebo-controlled trial in 143 children with obesity comparing inulin from Jerusalem artichoke, maltodextrin placebo and dietary fibre advice over 6 months. Inulin increased alpha diversity and abundance of Bifidobacterium and several butyrate-producing bacteria; changes in microbial functional pathways correlated with clinical and metabolic outcomes in the inulin group.
Inulin supplementation modulates gut microbiota derived metabolites related to brain function in children with obesity.
Randomized trial in children with obesity (part of same clinical trial registry) assessing plasma gut–brain-axis related amino acids and bioactive molecules over 6 months. The inulin group showed marked increases in putrescine, spermine and tyrosine and a significant upregulation of putrescine versus placebo, with changes associating with gut microbiota shifts.
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Research Overview
Moderate EvidenceCite this ingredient
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Stable URL
https://thesuppindex.com/ingredients/inulin
SuppIndex. (2026). Inulin: Evidence summary, dosage and clinical studies. Retrieved October 16, 2026, from https://thesuppindex.com/ingredients/inulin
Based on 5 indexed studies · Evidence level: Moderate.
Goal Ratings
Stack Compatibility
Generally compatible with probiotics and other fermentable fibres but may increase gas when combined with other fermentable substrates