Rivera-Chavez, F. | bioRxiv Science

bioRxiv2026

Early-life acquisition of Lactobacillaceae protects against experimental cholera

Cholera causes severe diarrheal illness in young children, but the mechanisms underlying age-dependent susceptibility remain unclear. Experimental cholera in neonatal mice recapitulates age-dependent susceptibility: suckling mice are susceptible to Vibrio cholerae colonization and cholera toxin (CT)-dependent disease, whereas adult mice are not readily colonized and do not develop cholera-like disease. Here, we define a developmental window in which susceptibility declines sharply over the first two postnatal weeks. Maternal antibiotic exposure disrupted vertical transmission of maternal microbiota to offspring and altered distal small intestinal microbiota assembly, extending the window of susceptibility to CT-dependent V. cholerae colonization and disease. Pups born to antibiotic-treated dams exhibited reduced Lactobacillaceae and increased Enterobacteriaceae, and reintroduction of an endogenous Lactobacillus isolate restored offspring lactobacilli levels and reestablished resistance to experimental cholera at two weeks of age. Consistent with a direct protective role, increasing lactobacilli in susceptible neonatal mice reduced experimental cholera burden, and cultures of the endogenous Lactobacillus isolate as well as spent culture media acidified the in vitro growth environment and rapidly eliminated recoverable V. cholerae. Together, these findings identify vertical transmission of maternal microbiota to offspring and lactobacilli-associated antagonism as determinants of early-life resistance to cholera.

microbiology↗

bioRxiv2025

CT-induced disease generates epithelial cell-derived L-lactate that promotes Vibrio cholerae growth in the small intestine

Cholera toxin (CT) promotes Vibrio cholerae colonization by altering gut metabolism to favor pathogen growth. We have previously found that CT-induced disease leads to increased concentrations of L-lactate in the lumen of the small intestine during experimental cholera. Here, we show that CT-induced disease leads to the upregulation of mammalian lactate dehydrogenase A (LDHA), an enzyme that catalyzes the conversion of pyruvate to L-lactate, in small intestinal epithelial cells. In a suckling mouse model, the bacterial L-lactate dehydrogenase (LldD) conferred a fitness advantage to V. cholerae but not to the {Delta}ctxAB mutant incapable of producing CT. Finally, the fitness advantage conferred by LldD was significantly reduced in mice lacking epithelial-cell specific LDHA, demonstrating that epithelial-derived L-lactate is a major contributor to CT-dependent pathogen expansion. These findings identify L-lactate as a host-derived metabolite generated by intestinal epithelial cells produced during cholera disease that directly fuels V. cholerae growth during infection, uncovering a mechanism by which CT confers a fitness advantage to the pathogen during disease.

microbiology↗