As studied by Associate Professor Kentaro NAGAOKA and colleagues at Tokyo University of Agriculture and Technology in mouse experiments, hydrogen peroxide produced in breast milk via amino acid oxidases acts as a gatekeeper for bacteria which gradually form the baby’s microbiome. Microorganisms such as lactic acid bacteria which have catalases preferentially enter the baby’s intestine.

https://www.fasebj.org/doi/10.1096/fj.201801462R

RIKEN news release, November 16, 2018