Gut Bacterial Families Are Associated with Body Composition and Metabolic Risk Markers in School-Aged Children in Rural Mexico.

Background: Differences in gut microbiota composition have been associated with obesity and metabolic alterations in children. The aim of this study was to analyze the abundance of the main bacterial families of the gut among children according to their body composition and metabolic markers. Methods: A cross-sectional study was conducted with 93 school-aged children (8.4 +/- 1.6 years old). Anthropometric and body composition variables were measured and a blood sample was collected to determine glucose, insulin, lipid profile, C-reactive protein, leptin, and cytokines [interleukin 6, interleukin 10 (IL-10), tumor necrosis factor alpha (TNF alpha)]. DNA was extracted from stool samples and the abundance of bacterial families (Bacteroidaceae-Porphyromonadaceae-Prevotellaceae, Lactobacillaceae, Enterococcaceae, and Lachnospiraceae-Ruminococcaceae) was determined by qPCR assays. Results: Children with obesity and high waist/height ratio had lower Bacteroidaceae-Porphyromonadaceae-Prevotellaceae and higher abundance of Lactobacillaceae when compared with normal-weight children. TNF alpha was negatively associated and IL-10 was positively associated with Bacteroidaceae-Porphyromonadaceae-Prevotellaceae. Triglycerides showed a positive relationship with Lachnospiraceae-Ruminococcaceae whereas high-density lipoprotein-cholesterol was negatively associated with Lactobacillaceae. Conclusion: In rural Mexican school-aged children, a low abundance of Bacteroidaceae-Porphyromonadaceae-Prevotellaceae and a high abundance of Lactobacillaceae are associated with obesity and metabolic disturbances.