Distinct distal gut microbiome diversity and composition in healthy children from Bangladesh and the United States - 16S rDNA Targeted Locus. human gut metagenome

Background: Much of our current understanding of the composition and stability of the human distal gut microbiota is based on studies of infants and adults living in developed countries. In contrast, little is known about the gut microbiota and its variation over time in older children and adolescents, especially in developing countries. Methods: In this study, we compared the diversity, composition, and temporal stability of the fecal microbiota of healthy children, ages 9 to 14 years, living in an urban slum in Bangladesh with that of children of the same age range in an upper-middle class suburban community in the United States. We analyzed >8,000 near full-length 16S rRNA gene sequences and over 845,000 pyrosequencing reads of the 16S rRNA V1-V3 region. Results: The distal gut of Bangladeshi children harbored significantly higher bacterial diversity than that of U.S. children, including novel lineages from several bacterial phyla. Bangladeshi and U.S. children had distinct fecal bacterial community membership and structure with Bangladeshi children enriched in Prevotella, Butyrivibrio, and Oscillospira and depleted in Bacteroides relative to U.S. children (although similar to Bangladeshi adults). Furthermore, community membership and structure in Bangladeshi children was significantly less stable on a month-to-month basis than U.S. children. Conclusions: Together, these results suggest that differing environmental or genetic factors may shape the microbiota of healthy children in the two countries. Further investigation is necessary to understand the mechanisms and factors that underlie these differences, and to incorporate these findings into new strategies for the prevention and treatment of childhood and adolescent diseases.