“Effects of Exclusive Breastfeeding on Infant Gut Microbiota: a Meta-Analysis across Studies and Populations”, Nhan T. Ho, Fan Li, Kathleen A. Lee-Sarwar, Hein M. Tun, Bryan Brown, Pia S. Pannaraj, Lianna F. Wood, Jeffrey M. Bender, Joanne E. Sordillo, Meghan B. Azad, Amanda L. Thompson, Scott T. Weiss, M. Andrea Azcarate-Peril, Augusto A. Litonjua, Anita L. Kozyrskyj, Heather B. Jaspan, Grace M. Aldrovandi, Louise Kuhn2018-03-31 (; similar)⁠:

Literature regarding the differences in gut microbiota between exclusively breastfed (EBF) and non-EBF infants is meager with large variation in methods and results. We performed a meta-analysis of 7 studies (a total of 1825 stool samples from 684 infants) to investigate effects of EBF compared to non-EBF on infant gut microbiota across different populations.

In the first 6 months of life, overall bacterial diversity, gut microbiota age, relative abundances of Bacteroidetes and Firmicutes and microbial-predicted pathways related to carbohydrate metabolism were consistently increased; while relative abundances of pathways related to lipid, vitamin metabolism, and detoxification were decreased in non-EBF vs. EBF infants. The perturbation in microbial-predicted pathways associated with non-EBF was larger in infants delivered by C-section than delivered vaginally. Longer duration of EBF mitigated diarrhea-associated gut microbiota dysbiosis, and the effects of EBF persisted after 6 months of age.

These consistent findings across vastly different populations suggest that one of the mechanisms of short and long-term benefits of EBF may be alteration in gut microbes.