Gut Microbiota Composition in Adolescents From Mexico City, Associations With Nutritional and Socioeconomic Factors: Results From a Pilot Study

Abstract

The gut microbiota is a key determinant of metabolic health in adolescence, a critical period for the onset of obesity. Understanding its associations with body mass index (BMI), diet, and socioeconomic status (SES) helps identify early determinants of metabolic risk. We analyzed stool samples from 95 Mexican adolescents (11–15 years) using 16S rRNA V3–V4 sequencing. The main phyla were Bacteroidetes, Firmicutes, and Proteobacteria, with. At the genus level Azobacteroides Candidatus, Parabacteroides, Bacteroides, and Prevotella being the most abundant. Overweight and obese adolescents showed lower diversity and more Bacteroidetes, while normal-weight peers had more Firmicutes and beneficial taxa. Lactobacillus was enriched in normal-weight individuals, while Parabacteroides and Prevotella were more abundant in adolescents with low SES. A diet high in sugar-sweetened beverages and low in whole grains was associated with a predominance of Bacteroides and lower diversity. Low SES was also associated with potential pathogens, including Escherichia and Salmonella, and gastrointestinal symptoms. In particular, Vibrio and Salmonella were inversely associated with cholesterol and triglycerides, while Clostridiodes was positively correlated with triglycerides. Diet and SES influenced the adolescent gut microbiome, by shaping diversity, potentially pathogenic taxa, and their associations with metabolic health indicators. © 2026 The Author(s) Molecular Nutrition & Food Research published by Wiley-VCH GmbH.