Darmmicrobioot-afgeleid IPA is lager bij T2D en gekoppeld aan glycemische variabiliteit

The gut microbiota influences host metabolism through diverse metabolites, many of which have been linked to glucose homeostasis and type 2 diabetes (T2D). Understanding microbial contributions to metabolite biosynthesis is essential for developing dietary and microbiota-targeted T2D prevention and treatment strategies. We performed targeted plasma metabolomics in individuals with T2D and healthy controls, all receiving histidine supplementation, before and after gut microbiota suppression using 7-day broad-spectrum antibiotic treatment. Associations between pre-antibiotic metabolite levels and fecal metagenomics-derived gut microbiota composition were examined using co-abundance network analysis and Random Forest modeling. Indole-3-propionic acid (IPA) was the only gut-derived metabolite differing between groups before antibiotics, with lower levels in T2D and higher levels associated with reduced T2D odds. Antibiotic treatment reduced IPA to near-undetectable levels in both groups, confirming its predominantly microbial origin. Beyond established inverse associations with BMI and glycemic markers, we found a novel inverse correlation between IPA and glycemic variability, consistent with a protective association with T2D. Plasma IPA was associated with gut microbiota beta diversity. IPA-associated species clustered within a single co-abundance module, but did not include known IPA producers, suggesting plasma IPA is influenced by broader microbial community composition rather than IPA-producing capacity of individual taxa alone. This study provides direct human evidence that plasma IPA is virtually exclusively gut microbiota-derived in individuals with T2D, extending prior findings in healthy populations. It highlights IPA's relevance to metabolic health and T2D, and guides future research on dietary and microbiota-targeted strategies to modulate IPA, advancing T2D prevention and treatment.