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:

James Versalovic
James Versalovic
Dr. James Versalovic received his M.D. with Honors at Baylor College of Medicine (BCM) in 1995 and his Ph.D. in Cellular and Molecular Biology at BCM in 1994. He pursued clinical pathology/medical microbiology residency training at the Massachusetts General Hospital and Harvard Medical School. He also received postdoctoral research training in the Division of Comparative Medicine at the Massachusetts Institute of Technology (MIT). Dr. Versalovic joined the medical staff as a clinical pathologist at the Massachusetts General Hospital and served as Assistant Professor of Pathology at Harvard Medical School from 1999-2001. He is board-certified in clinical pathology, molecular genetic pathology, and molecular diagnostics. Dr. Versalovic currently serves as Pathologist-In-Chief, Head of the Department of Pathology, and as member of the Board of Directors at Texas Children’s Hospital. He also serves as Vice Chair of Molecular Pathology and Omics at BCM, and Director of the Texas Children’s Microbiome Center. He holds the Milton J. Finegold endowed chair as Professor of Pathology & Immunology, and Professor of Pediatrics, Molecular and Human Genetics, and Molecular Virology & Microbiology at Baylor College of Medicine. He is Co-Director of the Medical Scientist (MD/PhD) Training Program at Baylor. He served as Editor-in-Chief of the Manual of Clinical Microbiology and Editor of Therapeutic Microbiology: Probiotics and Related Strategies. As a Principal Investigator, his primary research interests include the human microbiome, probiotics, medical and molecular microbiology, innate immunity, digestive diseases, and gastrointestinal physiology. His research program has been supported by the U.S. National Institutes of Health, Department of Defense, and Crohn’s and Colitis Foundation of America. Dr. Versalovic has authored 131 primary manuscripts, 34 book chapters, and 2 patents. He received the Lansky Award as a national leader in pathology under the age of 45 from the College of American Pathologists Foundation. He also received the BioGaia Ivan Casas Probiotics Research Award and the BCM Graduate School of Biomedical Sciences Distinguished Alumnus Award.