Impact of Gut Microbiome Modulation on Gut Inflammation

Abstract

Direct fed microbial products have been the focus of considerable scientific and public interest as we learn how the gut microbiome impacts host health and immune function. Previous research in our lab has demonstrated supplementation with a lactic acid bacteria (LAB) product results in an anti‐inflammatory host phenotype. It is also associated with an anti‐inflammatory cytokine profile in the ileum (↑ IL‐10, ↓ IL‐12RB2). However, the mechanisms behind this effect remain unknown. We hypothesized that the LAB product would stimulate the presence of bacteria with an anti‐inflammatory effect on the gut mucosa and/or suppress inflammatory species. Following supplementation with 3x105 CFU LAB (Lactobacillus acidophilus, Lactobacillus casei, Enterococcus faecium, and Bifidobacterium bifidium)/g feed from day of hatch, we evaluated the gut microbiome of 28‐day old chickens at 5 gastrointestinal locations. Microbial DNA was isolated from 5 samples/treatment x location and sequenced using Illumina MiSeq paired end sequencing. The sequence reads were processed and analyzed with Qiime and Primer‐E. Analysis of intestinal samples revealed upward shifts in Lactobacillus following supplementation, as well as a sharp decline in segmented filamentous bacteria (SFB) in the ileum. Though they have been observed in the ileum of many species for decades, the taxonomic identification of these bacteria is relatively recent, as is understanding of their role in stimulating gut inflammation through TH17 cells. These data suggest this LAB consortium works to decrease levels of SFM in the ileum, which may result in less ileal inflammation. This could reduce gut inflammation, reducing irritation and improving digestive efficiency.