Changes in bacterial diversity and composition in the faeces and colon of weaned piglets after feeding fermented soybean meal.

PURPOSE:The microbiota composition of faeces and colonic contents were analysed to investigate the mechaninsm by which fermented soybean meal improves intestinal microbial communities, growth and immunity in weaning piglets. METHODOLOGY:Microbiota were investigated using16S rRNA gene sequencing and systematical bio-information Operational Taxonomic Units; α-diversity analyses indicated that fermented soybean meal increased bacterial species diversity. RESULTS:The levels of Actinobacteria and Proteobacteia in faeces, and Firmicutes and Tenericutes in the colon, increased significantly in piglets fed fermented soybean meal (P<0.05). The relative abundance of Clostridium sensu stricto1, Lachnospira and Bacteoides had positive correlations with diarrhoea in the piglets. Lactobacillus, Blautia and Clostridium sensu stricto1 levels were correlated with increases in the average daily feed intake of piglets. Lactobacillus and Lachnospira also had positive relationships with IgM levels, and lymphocytes levels were increased relative to Clostridium sensu stricto1. Lymphocyte numbers also increased with higher levels of Blautia and decreased with Clostridium sensu stricto1. Increased levels of Blautia were also correlated with significant increases in white blood cells. CONCLUSION:The significant differences in faecal and colonic bacteria were correlated with enhanced immunity and overall improved health in the weaning piglets.