Identification of Enterotype and Its Effects on Intestinal Butyrate Production in Pigs

Gut microbiota is thought to play a crucial role in nutrient digestion for pigs, especially in processing indigestible polysaccharides in the diets to produce short-chain fatty acids (SCFAs). However, the link between microbiota community structure and phenotypic performances are poorly understood. In the present study, the fecal samples of 105 Jinhua pigs at 105 days of age were clustered into three enterotypes (ETs, ET1, ET2, and ET3) that are subpopulations of distinct bacterial community composition by using 16S rRNA high throughput sequencing. The α-diversity indices (the OTU number and Shannon index) were significantly different among the ETs ( < 0.001). At the genus level, the ET1 group was over-represented by (17.49%) and (11.78%), the ET2 group was over-represented by (17.49%) and (11.78%), and the ET3 group was over-represented by (18.17%). Significant differences in the fecal contents of butyrate were observed among ETs, with the highest level detected in ET3 and the lowest in ET2 ( < 0.05). Consistently, more copies of the terminal genes for butyrate synthesis, butyrate kinase (Buk) and butyryl coenzyme A (CoA): acetate CoA transferase (But) were detected by qPCR in the fecal samples of the ET3 group as compared to other two groups ( < 0.05). In addition, of the two genes, But was demonstrated to be more relevant to the butyrate content (R = 0.7464) than Buk (R = 0.4905) by correlation analysis. In addition, based on the taxonomic analysis, we found that was the most relevant butyrate-producing genera with fecal butyrate contents in Jinhua pigs, followed by , and all of which showed significantly higher richness in ET3 than as compared to ET1 and ET2 ( < 0.05). Collectively, this work presents a first overview of the enterotypes clustering in Jinhua pigs and will help to unravel the functional implications of ETs for the pig's phenotypic performance and nutrient metabolism.