In this study, researchers characterized the gut microbiota of breastfeeding mothers after collecting fecal samples from 2 days to 6 months postpartum. They found that the women’s gut bacterial communities were similar to those found in other adults; the gut communities were also relatively stable over the postpartum period.

Researchers also found associations between dietary components and the relative abundances of certain bacterial taxa: Increased Prevotella and decreased Bacteroides were associated with higher intakes of pantothenic acid, riboflavin, vitamin B6, and vitamin B12 in this group of women, while increased Firmicutes and decreased Bacteroidetes were correlated with higher intakes of copper, magnesium, manganese, and molybdenum.

Results showed that, overall, a diet higher in nutrients and calories was associated with more Firmicutes in the gut. Causality remains unclear, however, and scientists know little about the relationship between women’s health and the relative abundances of different bacteria.


Carrothers JM, et al. (2015) Fecal Microbial Community Structure Is Stable over Time and Related to Variation in Macronutrient and Micronutrient Intakes in Lactating Women. Journal of Nutrition doi: 10.3945/​jn.115.211110

Kristina Campbell
Kristina Campbell
Science writer Kristina Campbell (M.Sc.), from British Columbia (Canada), specializes in communicating about the gut microbiota, digestive health, and nutrition. Author of the best selling Well-Fed Microbiome Cookbook, her freelance work has appeared in publications around the world. Kristina joined the Gut Microbiota for Health publishing team in 2014.  Find her on: GoogleTwitter