Time-course effects on digestible energy, gut microbiota composition, and SCFA profile for growing pigs fed different fiber-rich ingredients

The objective of this study was to investigate the time-course effects of different types of dietary fiber on the energy values, fecal microbiota, and SCFAs production in growing pigs.The results showed that the fiber inclusion decreased the digestible (DE) and metabolizable energy (ME) of diets (P < 0.05). No time effects on DE and ME of fibers were found. Distinct microbial community on the DFRB diet or SBH diet among different time points was observed (P < 0.05). And the fecal microbiota of the four diet groups demonstrated distinct cluster at each time point (P < 0.05).With time increased from 7d to 21d, cellulose-degrading bacteria and SCFA-producing bacteria (eg., Ruminococcaceae_UCG-014, Rikenellaceae_RC9_gut_group, and Bifidobacterium) were increased, and pathogenic genera (eg., Streptococcus and Selenomonas) were decreased in fiber inclusion diets. Besides, gut microbiota of growing pigs more easily and quickly adapted to SBP diet (rich in SDF) compared to DFRB diet (rich in IDF), as reflected by the concentration of propionate, butyrate, isovalerate, and total SCFA increased with time for pigs fed DFRB diet (P < 0.05).