A Potential Probiotic Candidate Heyndrickxia ginsengihumi W1 is Associated with Increased Intestinal Stem Cell-Mediated Proliferation and Altered Barrier-Related Parameters: Potential Involvement of the Wnt/β-Catenin Pathway

Probiotic properties of the rumen-derived strain Heyndrickxia ginsengihumi W1 were evaluated by whole-genome analysis, in vitro assays, and a short-term mouse model. Genome analysis preliminarily indicated no acquired antimicrobial resistance genes or virulence factors. In mice, W1 administration showed no obvious adverse effects under the present short-term experimental conditions, and was associated with Lactobacillus enrichment and elevated lactate in the jejunum. W1 administration was also associated with changes in selected jejunal barrier-related parameters and with increased intestinal stem cell (ISC)-mediated epithelial proliferation, potentially through the Wnt/β-catenin pathway. Jejunal lactate correlated positively with crypt depth, PCNA, ISC markers, and Wnt/β-catenin components. In vitro, purified lactate and W1 cell-free supernatant, but not heat-killed W1, promoted sheep intestinal epithelial cell proliferation, and lactate upregulated Axin2, Ctnnb1, and PCNA, but this lactate–Wnt/β-catenin mechanism remains a hypothesis requiring further validation. These results indicate that W1 may be a promising rumen-derived probiotic candidate.