Probiotic GG Induces Alterations in Ileal Microbiota With Associated CD3CD19T-betIFNγ Cell Subset Homeostasis in Pigs Challenged With Serovar 4,[5],12:i:

serovar 4,[5],12:i:- ( 4,[5],12:i:-) is an emerging foodborne pathogen causing salmonellosis in humans and animals. Probiotic GG (LGG) is an effective strategy for controlling enteric infections through maintaining gut microbiota homeostasis and regulating the intestinal innate immune response. Here, LGG was orally administrated to newly weaned piglets for 1 week before 4,[5],12:i:- challenge. 4,[5],12:i:- challenge led to disturbed gut microbiota, characterized by increased levels of , and uncultured populations, as well as an aberrant correlation network in -centric species. The beneficial effect of LGG correlated with attenuating the expansion of . only found in the pigs treated with LGG was positively correlated with and . Administration of LGG induced the expansion of CD3CD19T-betIFNγ and CD3CD19T-betIFNγ cell subsets in the peripheral blood at 24 h after a challenge of 4,[5],12:i:-. 4,[5],12:i:- infection increased the population of intraepithelial CD3CD19T-betIFNγ and CD3CD19T-betIFNγ cells in the ileum; however, this increase was attenuated via LGG administration. Correlation analysis revealed that LGG enriched and populations, which were negatively correlated with intraepithelial CD3CD19T-betIFNγ and CD3CD19T-betIFNγ cells in the ileum. The present data suggest that probiotic LGG alters gut microbiota with associated CD3CD19T-betIFNγ cell subset homeostasis in pigs challenged with 4,[5],12:i:-. LGG may be used in potential gut microbiota-targeted therapy regimens to regulate the specific immune cell function and, consequently, control enteric infections.