Supplementation with a cranberry extract favors the establishment of butyrogenic guilds in the human fermentation SHIME system

Background: Proanthocyanidins (PAC) and oligosaccharides from cranberry exhibit multiple bioactive health properties and persist intact in the colon post-ingestion. They display a complex bidirectional interaction with the microbiome, which varies based on both time and specific regions of the gut; the nature of this interaction remains inadequately understood. Therefore, we aimed to investigate the impact of cranberry extract on gut microbiota ecology and function. Methods: We studied the effect of a cranberry extract on six healthy participants over a two-week supplementation period using the ex vivo artificial fermentation system TWIN-M-SHIME to replicate luminal and mucosal niches of the ascending and transverse colon. Results: Our findings revealed a significant influence of cranberry extract supplementation on the gut microbiota ecology under ex vivo conditions, leading to a considerable change in bacterial metabolism. Specifically, Bifidobacterium adolescentis (B. B. adolescentis) ) flourished in the mucus of the ascending colon, accompanied by a reduced adhesion of Proteobacteria. . The overall bacterial metabolism shifted from acetate to propionate and, notably, butyrate production following PAC supplementation. Although there were variations in microbiota modulation among the six donors, the butyrogenic effect induced by the supplementation remained consistent across all individuals. This metabolic shift was associated with a rise in the relative abundance of several short- chain fatty acid (SCFA)-producing bacterial genera and the formation of a consortium of key butyrogenic bacteria in the mucus of the transverse colon. Conclusion: These observations suggest that cranberry extract supplementation has the potential to modulate the gut microbiota in a manner that may promote overall gut health.