Newborns are highly susceptible to pathogenic infections with significant worldwide morbidity possibly due to an immature immune system. Recently, we reported that Propionibacterium strain, P. UF1, isolated from the gut microbiota of preterm infants, induced the differentiation of bacteria-specific Th17 cells. Here, we demonstrate that P. UF1 significantly increased the number of protective Th17 cells and maintained IL-10⁺ regulatory T cells (Tregs) in newborn mice. In addition, P. UF1 protected mice from intestinal Listeria monocytogenes (L. m) infection. P. UF1 also functionally sustained the gut microbiota and induced critical B vitamin metabolites implicated in the regulation of T cell immunity during L. m intestinal infection. Transcriptomic analysis of P. UF1-induced Th17 cells revealed genes involved in the differentiation and regulation of these cells. These results illustrate the potency of P. UF1 in the enhancement of neonatal host defense against intestinal pathogen infection.

新生儿极易受到病原体感染，全球发病率很高，这可能是由于免疫系统不成熟所致。最近，我们报道了从早产儿肠道微生物群中分离出来的丙酸杆菌菌株 P. UF1 诱导了细菌特异性 Th17 细胞的分化。在这里，我们证明 P. UF1 显着增加了新生小鼠中保护性 Th17 细胞的数量并维持了 IL-10 ⁺调节性 T 细胞 (Tregs)。此外，P. UF1 保护小鼠免受肠道单核细胞增生李斯特菌( L. m ) 感染。P. UF1 还在功能上维持肠道微生物群并诱导关键的 B 族维生素代谢物，这些代谢物与L. m期间 T 细胞免疫的调节有关肠道感染。P. UF1 诱导的 Th17 细胞的转录组学分析揭示了参与这些细胞分化和调节的基因。这些结果说明了 P. UF1 在增强新生儿宿主防御肠道病原体感染方面的效力。