Bifidobacteria is a key marker of a healthy gut flora in infants. A Brazilian study of 49 newborns — 24 full-term and 25 pre-term (31.2 weeks) — explored the prevalence and concentration of bifidobacteria in stools of one-month-old newborns using qPCR.

Bifidobacterium genus and B. longum species were present in all stool samples at one month of age. Counts were higher in full-term (8.3 log cells/g) than in pre-term (7.1), and prevalence of other species were different. Counts of B. longum species were also higher after vaginal (8.5) than after caesarean (6.9) delivery in full-term newborns.

The authors concluded that gestational age might influence bacterial numbers and species in a broad way, while mode of delivery might impact bifidobacteria specifically. They suggest that specific probiotics may compensate for the lower amount of bifidobacteria in some newborns.


Łukasz Grześkowiaka, et al.
Gut Bifidobacterium microbiota in one-month-old Brazilian newborns.
Anaerobe. Volume 35, Part B, October 2015, Pages 54–58. doi:10.1016/j.anaerobe.2015.07.004