Lactation and the Gut Microbiota

Fecal Bacterial Communities Differ by Lactation Status in Post-Partum Women and Their Infants Eliot Haddad, 3rd year

Abstract:

Breastfeeding has numerous benefits for both the mother and her infant after birth. The gut microbiota, the collection of microorganisms inhabiting the human gastrointestinal tract, has been shown to be modulated in infants by human milk exposure.

For lactating women, it has yet to be examined whether the gut microbiota differs by lactation status. As such, we aimed to determine whether gut microbial diversity differs by breastfeeding status in both women and their infants. By collecting and analyzing the fecal samples of N=24 women and their infants at 6 weeks after birth, we were able to perform statistical analyses of gut microbial diversity using the vegan package in the R software. Of the participants, n=14 were exclusively breastfeeding. Alpha diversity, or microbial diversity within an individual, was significantly lower in exclusively breastfed infants. Maternal breastfeeding status and alpha diversity were associated in univariate analysis, but this relationship disappeared when factoring BMI category in multivariate analysis. Beta diversity, or differences in microbial diversity between groups, differed by breastfeeding status for both the women and infants. Of n=6 infants with Bifidobacterium longum subsp. longum in their fecal samples, all had mothers sharing the same species, suggesting vertical microbial transfer. In summary, maternal gut microbiotas differ by lactation status, a relationship that is likely mediated by BMI category. These associations between breastfeeding practices and the gut microbiotas of both women and their infants is critical to enhancing our understanding of the mediating role of the gut microbiota on maternal and child health.