Fiber-enriched Centella asiatica longitudinally suppresses proteolytic fermentation and reprograms microbe–metabolite networks

Human microbiome intervention studies often focus on taxonomic shifts, whereas longitudinal changes in functional metabolic outputs remain less defined. In this randomized trial, dietary fiber enrichment of a traditional Centella asiatica beverage selectively suppressed branched short-chain fatty acids (BSCFAs), markers of proteolytic fermentation, in healthy adults. Integrating microbiome profiling, targeted metabolomics, and microbe–metabolite network analysis, we show that fiber availability acts as a dominant driver of metabolic reprogramming, favoring saccharolytic over proteolytic pathways without major compositional restructuring. These findings provide longitudinal evidence that targeted fiber supplementation modulates BSCFAs as functional indicators of microbial metabolic plasticity in urban dietary settings.Human microbiome intervention studies mostly emphasize on taxonomic and computational changes, while functional microbial metabolic outputs and their longitudinal dynamics remain less well characterized. Our longitudinal randomized trial demonstrates that dietary fiber enrichment of a traditional Centella asiatica beverage selectively suppresses branched short-chain fatty acids (BSCFAs), key markers of proteolytic microbial fermentation, in healthy adults. By integrating gut microbiome profiling with targeted metabolomics, and microbe–metabolite network analysis, we show that fiber availability can acts as a dominant driver of microbial metabolic reprogramming, favoring saccharolytic over proteolytic pathways even in the absence of overt clinical changes. This study provides high-resolution longitudinal evidence that dietary fiber supplementation modulates BSCFAs as functional readouts of microbial metabolic reprogramming in healthy adults, offering mechanistic insight into how targeted fiber interventions influence the metabolic profile of the gut microbiota in urbanized dietary contexts.