Multi omics reveals that dietary fiber affects growth and slaughter performance by altering intestinal microbial composition and metabolomic profiles in Durco and Bamei crossbred pig

Dietary fiber (DF) is an important nutrient component in pigs diet that remarkably influences their growth and slaughter performance. The ability of pigs to digest DF depends on the microbial composition of the intestinal tract, particularly in the hindgut. However, studies on how DF alters the growth and slaughter performance of pigs by shaping the gut microbial composition and metabolites are still limited. Therefore, this study aimed to investigate the effects of DF on microbial composition, functions, and metabolites, ultimately altering host growth and slaughter performance using Durco Bamei crossbred pigs with supplemented with 0%, 10%, 17% and 24% broad bean silage in the basic diet. We found the final weight, average daily gain, fat, and lean meat weight significantly decreased with increasing DF. Pigs with the lowest slaughter rate and fat weight were observed in the 24% fiber supplemented group. Gut microbial communities with the highest alpha diversity were formed in the 17% fiber group. The relative abundance of fiber degrading bacteria, bile acid, and succinate-producing bacteria, including Prevotella, Bacteroides, Ruminococcus and Parabacteroides, and functional pathways, including the butanoate metabolism and the tricarboxylic acid [TCA] cycle significantly increased in the high-fiber groups. The concentrations of several bile acids significantly decreased in the fiber supplemented groups, whereas the concentrations of succinate and longchain fatty acids increased. Our results indicate that a highfiber diet may alter the growth and slaughter performance of Durco Bamei crossbred pigs by modulating the composition of Prevotella, Bacteroides, Ruminococcus and Parabacteroides, and metabolite pathways of bile acids and succinate.