Like in stool, 16S rDNA assessment

Like in stool, 16S rDNA assessment of mucosal gut surfaces did not detect a significant elevation in the RA of any of the probiotics genera in any of the regions (Figures S1E–S1H). A pooled qPCR analysis for all administered probiotic species indicated significantly higher abundance in the lumen of the lower GI (LGI), but not the LGI mucosa (Figure 1D) or the upper GI (UGI; Figure 1E). The species that were significantly elevated in the lumen of the LGI tissues and the stomach were consistent with those shed in stool, while only BBR, LRH, and STH were significantly elevated in the LGI mucosa (Figure 1F). In comparison, mice that received probiotics using the same experimental design but without antibiotics pre-treatment featured a significantly lower aggregated probiotics load of all targets in the GI lumen, but not the mucosa (Figure S2A). These results indicate that resistance to the presence of probiotic species in the murine GI lumen is contributed by the resident microbiome. This