Inulin and gut-brain compounds in children with obesity
What it found
In children with obesity, six months of inulin increased putrescine, spermine and tyrosine, compounds linked to gut-brain signalling.
The trial compared inulin with a placebo and with dietary fibre advice.
What they found
Studies in people
Putrescine rise
Inulin increased putrescine over the 6 months compared with the placebo group. Putrescine is a compound made by gut bacteria that the authors link to appetite and satiety signalling.
Spermine and tyrosine
Only the inulin group showed significant rises in spermine and tyrosine from the start to month 6. Tyrosine is a building block for dopamine, which is involved in appetite control.
Other groups unchanged
The placebo and dietary fibre advice groups showed no significant changes in these gut-brain related compounds over the 6 months.
Gut bacteria links
Changes in putrescine after inulin were linked to changes in Bacteroides and Olsenella. At the start, putrescine was linked to Bacteroides and Fusobacterium, and spermine to Bifidobacterium and Blautia.
Clinical links
At the start, several compounds were linked to clinical measures: histidine to GLP-1, glutamate to butyrate, and histidine, glutamine and tryptophan to lower levels of inflammatory cytokines. Dopamine was linked to less screen time and lower cytokines.
What the authors conclude
“In conclusion, inulin supplementation significantly enhanced putrescine, spermine, and Tyr over time, suggesting its potential influence on gut-brain communication and metabolic regulation in obesity.”
Also in their conclusions
- They conclude that inulin supplementation significantly enhanced putrescine, spermine, and tyrosine over time, suggesting its potential influence on gut-brain communication and metabolic regulation in obesity.
- They say these findings highlight the complexity of gut-brain interactions and that future studies should explore the specific mechanisms and therapeutic potential for managing childhood obesity.
How it was done
The authors say gut bacteria can affect appetite and energy balance through the gut-brain axis, and that this communication is disrupted in obesity. They wanted to see whether inulin could change compounds involved in that pathway.
They randomly assigned 165 Thai children aged 7 to 15 with obesity to three groups for 6 months: 13 g of inulin daily, 11 g of maltodextrin placebo daily, or dietary fibre advice. Blood and stool samples were analysed at the start and after 6 months; 154 children completed the study.
What it can’t tell you
- The study lasted only 6 months, so it cannot show the long-term effects of inulin on gut-brain communication or clinical outcomes.
- The authors did not directly explore the detailed biological pathways behind the changes they saw.
Who paid
- Funding
- Funded by Ratchadapiseksomphot Fund, Faculty of Medicine, Chulalongkorn University (from the PubMed record).
- Conflicts
- Declarations. Competing interests: The authors declare no competing interests.
- Authors work at
- Chulalongkorn University, Thailand; King Chulalongkorn Memorial Hospital, Thailand
The paper
- Title
- Inulin supplementation modulates gut microbiota derived metabolites related to brain function in children with obesity
- Type
- Randomised controlled trial
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Andriyas T, Sriswasdi S, Tansawat R, Uaariyapanichkul J, Chomtho S, Visuthranukul C (2025). Inulin supplementation modulates gut microbiota derived metabolites related to brain function in children with obesity. Scientific reports. doi:10.1038/s41598-025-21079-2Free full textPubMed 41057493DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error