Prenatal administration of Lactobacillus rhamnosus has no effect on the diversity of the early infant gut microbiota.

We have recently shown that maternal administration of Lactobacillus rhamnosus GG (LGG) during late pregnancy can have beneficial effects on the early development of infant gut microbiota, promoting a bifidobacteria profile similar to that of a healthy breastfed infant. It is uncertain, however, whether such probiotic supplementation could influence the diversity of infant gut microbiota. We investigated the effect of pre-natal LGG on gut microbial diversity in the early post-natal period. Day-7 faecal samples were collected from 98 infants at high risk of allergic disease, whose mothers participated in a pre-natal probiotic eczema prevention study. Faecal microbial diversity was assessed by terminal restriction fragment length polymorphism using restriction enzymes Sau96I and AluI. A greater number of peaks represent greater diversity of bacterial communities. Administration of LGG to mothers during late pregnancy had no effects on the mean number of peaks in faecal samples from 1-wk-old infants as compared to placebo (AluI 14.4 vs. 15.5, p = 0.17, 95% CI -0.4, 2.5; Sau96I 17.3 vs. 15.8, p = 0.15, 95% CI -3.5, 0.5). Prenatal LGG failed to modulate diversity of early infant gut microbiota despite promoting a beneficial bifidobacteria profile.