Modulating effects of microbiota on synbiotic intervention outcomes for microbiota-derived trimethylamine, trimethylamine N-oxide and indoxyl sulfate in healthy young medical students: insights from a 12-week randomized clinical trial

In this randomized, placebo-controlled trial in healthy young adults, the synbiotic did not produce a significant arm-wide effect on post-challenge serum TMA, TMAO, or indoxyl sulfate over 12 weeks. Exploratory moderation analyses suggest that baseline gut-microbiota features, taxonomic and functional, may modulate individual responses, particularly for IS and TMA, supporting a precision-nutrition framework. The translational significance of this study stems from the observation that primary prevention, which is particularly important in metabolic diseases, should be individualised based on the function of the microbiota.