Utilization of pectin with various degress of esterification by Bacteroides xylanisolvens

The intricate relationship between the human intestinal microbiota and polysaccharides has a profound and direct impact on health outcomes. Our previous research has shown that pectin possesses beneficial properties that can combat colitis and metabolic disorders, which may be facilitated by the dominant gut commensals such as the Bacteroides genus. This study aims to delve deeper into how pectin with varying esterification degrees is utilized by ten distinct Bacteroides strains. Among the tested strains, Bacteroides xylanisolvens Bt-17 demonstrated a remarkable capacity for efficiently utilizing pectin L102, as indicated by its growth rate, sugar consumption, pH changes, and production of short-chain fatty acids. The fermentation of pectin L102 by B. xylanisolvens Bt-17 potentially led to the production of novel substrates, which in turn promoted the growth of Bacteroides stercoris Bt-8. Furthermore, we observed significant regulatory changes in multiple genes encoding glycoside hydrolases and glycosyltransferases in B. xylanisolvens Bt-17 during the degradation of pectin L102. These insights deepen our understanding of the interplay between pectin polysaccharides and the gut microbiota, and they may offer evidence for a gut microbiota-targeted mechanism underlying pectin's functional benefits.