Effect of Probiotics on the Gut-Mammary Pathway: Implications on Infant Microbiota Transfer and Development

Transfer of microbiota from the maternal gut, during lactation, takes place via breastmilk, which establishes an intricate beneficial microbial ecosystem in the gut of the newborn. A healthy gut microbiota influences and enhances the neonatal health, and aids in multidimensional development-metabolically, immunologically, neurologically, and hormonally. Several microorganisms like Lactobacillus and Bifidobacterium get transferred to the infant gut and play a key role in its colonization and programming. Administration of such microbes, or probiotics, to the mother can assist in improving the benefits imparted by breastmilk to the infant, and can also provide health benefits to the mother. In recent years, there has been a focus on related metagenomic studies and the immunological effects of individual genera have also been studied in detail. In this review, we observe the gut-mammary pathway and the different roles played by probiotics in prenatal and postnatal scenarios. We also analyze the level of evidence of potential of some promising probiotic strains in the transfer, establishment, and development of infant gut microbiota based on recently conducted studies.

The analysis of recent metagenomic studies proved that strains like Bifidobacterium infantis, Lactobacillus rhamnosus, and Limosilactobacillus reuteri exibit a high level of evidence in benefitting the microbiota transfer as well as establishment, diversification, and development of the infant gut ecosystem. Hence, these strains in particular, can be given as supplements to mothers during pregnancy and lactation, in order to improve their inherent immunity and the overall health of the mother-infant dyad. With the advent of metagenomics, the roles, functions and effects of microbes in the gut-mammary pathway have been re-examined. This review, critically evaluates the recent studies related to gut-mammary pathway and the different roles played by probiotics in prenatal and postnatal scenarios with particular emphasis on the strength and quality of their evidence.