Influence of dietary fiber fermentability on DSS-induced colitis severity and muscle wasting via gut microbiota.

Dietary fiber may improve dysbiosis and contribute to the management of intestinal inflammation and muscle wasting. We examined whether low- and high-fermentable fibers differently influence dextran sulfate sodium (DSS)-induced colitis severity and muscle wasting. Male C57BL/6 J mice were assigned to four groups: nonfiber control (N), nonfiber with DSS (ND), cellulose with DSS (CD), and partially hydrolyzed guar-gum with DSS (GD), then subjected to a 27-day DSS protocol. Colitis severity was attenuated in the CD group, accompanied by increased Lactobacillus and Lactococcus lactis and decreased Clostridium innocuum group. These microbial changes were associated with maintenance of gastrocnemius muscle mass through mitochondrial biogenesis. Conversely, the GD group exhibited exacerbated colitis, associated with increased cecal succinate and expansion of Bacteroides, Blautia, and Enterococcaceae. These alterations correlated with muscle wasting accompanied by mitochondrial dysfunction. These results suggest that fiber fermentability plays a pivotal role in colitis management via gut microbiota alterations, also associated with muscle wasting.