rumen micribiota Metagenome

We used the goat as a model to study the effects of the rumen microbial composition and epithelial TLR signalling on maintaining rumen stability during exogenous butyrate interference. Six cannulated goats received a rapid intraruminal infusion of 0.1 mol/L potassium phosphate buffer with (BT, n = 3) or without (CO, n = 3) 0.3 g/kg·BW·d sodium butyrate for 28 days. The ruminal pH and the concentration of total SCFA were not affected by the interference. 16S amplicon sequencing revealed a change of the microbial composition after the butyrate infusion. LEfSe analysis showed a shift of the biomarker species from butyrate-producing bacteria to acetate- and propionate-producing bacteria. Quantitative PCR-based comparisons showed that the significant increases of TLR2, TLR5 and MyD88 expression were accompanied by a significant decrease of IL-1ß and IFN-? expression in the ruminal epithelium. Constrained correlation analysis showed that the relative abundance of Roseburia was positively correlated to the expression of TLR5. Taken together, our study shows that microbial composition plays an important role in maintaining the stability of the microbial ecosystem in rumen, and reports, for the first time, that the microbe-TLR-cytokine axis was involved in maintaining the stability of the GI ecosystem.