Inulin supplementation modulates gut microbiota derived metabolites related to brain function in children with obesity.

The gut microbiota plays a key role in regulating energy balance via gut-brain axis (GBA). Dysbiosis can disrupt this communication, contributing to obesity. This study aimed to assess the effects of inulin supplementation on GBA-related amino acids and bioactive molecules in children with obesity. Children aged 7-15 were randomly assigned to 3 treatment groups for 6 months: inulin supplementation, isocaloric maltodextrin (placebo), or dietary fiber advice. Plasma amino acids and bioactive molecules were analyzed using LC-MS/MS at baseline and month 6. Relationships of changes in GBA-related compounds with changes in gut microbiota were evaluated. By month 6, principal component analysis trajectories showed clustering across all groups, involving 154 children, but indicated potential metabolic shifts, particularly in the inulin group. S-plots identified significant changes in GBA-related compounds, with only the inulin group showing marked increases in putrescine, spermine, and tyrosine from baseline (all P < 0.0001). Inulin supplementation significantly upregulated putrescine over time compared to the placebo group (P = 0.021), suggesting enhanced GBA communication. Changes in specific GBA-related compounds in the inulin group were significantly associated with gut microbiota changes. These findings indicate that inulin effectively modulates GBA-related bioactive molecules, potentially mediating its effect on childhood obesity management through putrescine, spermine, and tyrosine.Clinical Trial Registry number: NCT03968003. Registered 30/05/2019.