ABSTRACT
This chapter describes the generation of a pig model with human infant gut microbiota (HGM) to study 1) the effect of a probiotic on the composition of the transplanted microbiota following rotavirus vaccination and challenge and 2) the effect of healthy (HHGM) and unhealthy HGM (UHGM) on vaccine-induced immune responses and protection. The gut microbiota of vaccinated pigs were investigated for effects of Lactobacillus rhamnosus GG (LGG) supplement and virulent HRV challenge. HRV challenge caused a phylum-level shift from Firmicutes to Proteobacteria. LGG supplement prevented the changes in microbial communities caused by HRV challenge. The UHGM was from an infant with a high enteropathy score and no seroconversion following administration of oral rotavirus vaccine, while the converse was characteristic of the HHGM. Significantly more rotavirus-specific IFN-γ producing T cells were detected in HHGM than UHGM pigs after three vaccine doses, suggesting that HHGM promotes stronger cell-mediated immunity than UHGM. There were significant positive correlations between Collinsella and CD8+ and CD4+ T cells in the blood, whereas significant negative correlations between Clostridium and Anaerococcus and CD8+ and CD4+ T cells in the ileum. The correlations between certain microbial taxa and T cell responses highlight the role of gut microbiota, especially certain microbial species on enteric immunity.
