In this study, Texas researchers investigated the structure, function, and variation of the gut microbiota in healthy children, aged 7-12 years (n = 37). They compared the children’s data with that from healthy adults (n = 43) of the same region.

Researchers found differences in composition and functional potential of the gut microbiota between these groups. Children had greater abundances of Bifidobacterium, Faecalibacterium, and Lachnospiraceae spp., while adults showed more Bacteroides spp.

The relative abundances of genes involved in functions such as vitamin synthesis, amino acid degradation, oxidative phosphorylation, and mucosal inflammation differed between children and adults. Children’s gut microbiota functions seemed to support ongoing development, while adults’ gut microbiota functions had more to do with inflammation and obesity.

Previous research has suggested that a child’s microbiota become adult-like by age 3; the results of this study show that, even in pre-adolescence, the gut microbiota of healthy children have compositional and functional qualities that differ from the microbiota of healthy adults. Authors say their work shows the human gut microbiome may develop more gradually than previously suspected.


Hollister EB, et al. (2015) Structure and function of the healthy pre-adolescent pediatric gut microbiome. Microbiome Aug 26;3:36. doi: