Short-Term Supplementation of Pectin Alters Substrate Dynamics and Modulates Microbial Carbohydrate Metabolism in the Gut of a Pig Model

The interaction of pectin and gut microbiota plays animportantrole in maintaining animal and human health, but this interactionis not fully understood. Here, the impact of pectin supplementationon substrate dynamics and gut microbiota (in the terminal ileum andfeces) was integrally investigated in a fistula pig model. Our resultsshowed that a pectin-supplemented diet (PEC) decreased the concentrationsof starch, cellulose, and butyrate in feces but not in the terminalileum. Metagenomic sequencing revealed that PEC had a low impact onthe ileal microbiota but significantly increased plant polysaccharide-degradinggenera (e.g., Bacteroides, Alistipes, and Treponema) in feces. Additionally, CAZymeprofiling indicated that PEC reduced GH68 and GH8 for oligosaccharidedegradation in the ileal microbiome, while it enriched GH5, GH57,and GH106 for degradation of carbohydrate substrates in feces. Metabolomicanalysis confirmed that PEC increased metabolites involved in carbohydratemetabolism including glucuronate and aconitate. Collectively, pectincould promote complex carbohydrate substrate degradation in the hindgutvia modulating the gut microbiota.