The differences of bacteria and bacteria metabolites in the colon between fatty and lean pigs1

Overweight and obesity are growing global health problems. Recently, gut microbiota was found to affect energy balance by determining the efficiency of calories obtained from the diet and how that energy is utilized and stored. This study was conducted to compare the differences in colonic microbiota and their metabolites situated within the colon of two genotype pigs fed with diets formulated to meet NRC nutrient requirements. Forty-eight barrows, including 24 Bama mini-pigs (a fatty-type Chinese local pig strain) and 24 Landrace pigs (a lean-type pig strain), were fed individually from 5 wk of age to market weight. Colon tissue and its content were sampled (n= 8) at nursery, growing, and finishing phases according to their individual physiological stage. Results showed that the abundance of colon luminal bacteria, including Bifidobacterium, Lactobacillus, Clostridium coccoides–Eubacteria rectal, Faecalibacterium prausnitzii, Prevotella, Escherichia coli, and Pseudomonas aeruginosa, was greater (P< 0.05) in Bama mini-pigs compared with Landrace pigs. The colon luminal concentrations of bacteria metabolites, including short-chain fatty acids (SCFAs), polyamine, indole, and skatole, were lower (P< 0.05) in Bama mini-pigs compared with Landrace pigs. Moreover, the colon tissue of Bama mini-pigs also showed higher inflammation status and worse epithelial barrier function than that of Landrace pigs. These results suggest that the SCFA-producing bacteria may be the bacteria responsible for the obesity and the lipopolysaccharide-containing bacteria may be the bacteria responsible for the relatively terrible intestinal health status of Bama mini-pigs.