Gut microbiota formation is affected by hydrogen peroxide levels in breast milk generated from amino acid metabolism

The development of gut microbiota during infancy is an important event that affects the health status of the host; however, the mechanism governing this is not fully understood. L-amino acid oxidase 1 (LAO1) is a flavoprotein that catalyzes the oxidative deamination of particular L-amino acids and converts them into keto acids, ammonia, and H2O2. Our previous study showed that LAO1 was present in the mammary gland and exerted protection against bacteria by its production of H2O2. The data led us to consider whether LAO1 and/or H2O2 could impact infant gut microbiota development via breast milk consumption. Therefore, gut microbiota profiles in the wildtype (WT) and LAO1-knockout pups. were investigated in this study.