Relative bacterial abundances and gene expression levels in the fermentation experiment for each group. A Relative abundances of Odoribacter splanchnicus and Bacteroides fragilis NCTC9343 in each group. The relative abundances of the LC, LT, HB, HC, and HT groups are shown compared to that of the LB group (set as 1). B Relative expression levels of the genes Odosp_3416 and BF9343_2953 in each group. The relative abundances of the LC, LT, HB, HC, and HT groups are shown relative to that of LB group (set as 1). Different letters in different groups indicate a significant difference, and significant differences among the means were determined by Tukey’s test (P < 0.05).