The prebiotic and targeted regulatory effects of konjac glucomannan on gut microbiota via multi-omics analysis

Konjac glucomannan (KGM), a common food hydrocolloid widely used in the food industries, has broad biological activities, but its targeted effects on gut microbiota remain unclear. In this study, we used feces microbiota from 30 healthy volunteers, conducted an in vitro fermentation, employed multi-omics analysis to characterize the effect of KGM on the gut microbiota, and performed a stepwise culture system to investigate its microbial interactions. KGM suppressed the opportunistic pathogen (unclassified Enterobacteriaceae) and the accumulation of branched-chain fatty acids, p-cresol, sulfides, and indole. In contrast, KGM enriched the proliferation of some potentially beneficial bacteria ( Faecalibacterium and Parabacteroides ) and the accumulation of short-chain fatty acids, as well as volatile organic metabolites, such as butanoic acid propyl ester. Notably, F. prausnitzii and P. distasonis were specifically enriched, but neither could utilize KGM directly. The primary degrader, such as Bacteroides ovatus , can degrade KGM and promote the growth of F. prausnitzii and P. distasonis . Our findings offer novel insights into KGM-microbiota interactions while establishing a scientific foundation for developing KGM-based functional foods targeting gut health enhancement.