The preterm gut microbiota and administration routes of different probiotics: a randomized controlled trial

Background Preterm children with their aberrant gut microbiota and susceptibility to infections and inflammation constitute a considerable target group for probiotic therapy to generate the age-appropriate healthy microbiota. Methods 68 preterm neonates were randomized into five intervention groups: Beginning from the median age of 3 days, 13 children received Lactobacillus rhamnosus GG (LGG) directly orally, and 17 via the lactating mother. 14 children received LGG with Bifidobacterium lactis Bb-12 (Bb12) orally, and 10 via the lactating mother. 14 children received placebo. The children’s faecal microbiota was assessed at the age of 7 days by 16S rRNA gene sequencing. Results The gut microbiota compositions of the children directly receiving the probiotic combination (LGG + Bb12) were significantly different from those of the children receiving the other intervention modes or placebo ( p = 0.0012; PERMANOVA), the distinction being due to an increase in the relative abundance of Bifidobacterium animalis ( P