Discovery of Novel Probiotic Species to Improve Infant Health 2349

Abstract Description Selecting the right infant formula can be challenging for parents due to the wide range of options, often resulting in suboptimal choices or frequent changes. Our recent studies in mice have shown that the maternal microbiota, particularly Limosilactobacillus reuteri found in breast milk, plays a critical role in shaping the neonatal immune system by promoting the production of immunoglobulin A (IgA), an antibody essential for protecting against gut pathogens. To extend these findings to human health, we analyzed fecal samples from healthy breastfed infants using shotgun sequencing and whole-bacterial-cell ELISA to explore associations between specific bacteria and pathogen-specific IgA levels. Our results showed that the genera Oscillibacter and Fusobacterium were strongly correlated with anti-Salmonella and anti-Shigella IgA, while anti-EHEC IgA was associated with different genera, including Staphylococcus. Interestingly, Lactobacillus was linked to increased anti-Salmonella and anti-Shigella IgA but showed no correlation with anti-EHEC IgA. We also observed a positive correlation between anti-Salmonella IgA and formula use containing prebiotic fiber or Human Milk Oligosaccharides (5-HMO), even with 1-2 times use. These findings highlight a novel group of commensal bacteria that could serve as probiotic candidates, providing valuable insights into supporting infant health. We are currently working on identifying these probiotic candidates at the species level. Funding Sources Supported by NIH UL1 TR003015 Topic Categories Mucosal and Regional Immunology (MUC)