Low Gut Bifidobacterium Relative Abundance and Low Intake of Zinc, Omega-3 Fatty Acids, and Vitamin D Are Associated With Inflammation in Children.

Maintaining optimal health in childhood is essential for proper physical, motor, and neurological development. A balanced gut microbiota and adequate micronutrient intake support immune regulation, preservation of the intestinal barrier, and reduction of chronic inflammation. In contrast, unhealthy diets are linked to lower nutrient intake and disruptions in gut microbial composition. In this cross-sectional study of 209 children aged 6-12 years in Mexico City, we evaluated the interaction between the relative abundance of B. longum, B. adolescentis, and B. breve and the intake of zinc, omega-3 fatty acids, and vitamin D, and their association with serum cytokines (IL-6, IL-10, tumor necrosis factor-alpha, and adiponectin) using logistic regression models. We observed that children with low B. adolescentis abundance and low zinc intake had higher odds of elevated IL-6 levels. Similarly, low B. adolescentis abundance combined with low vitamin D intake was associated with increased odds of elevated IL-6. Low B. breve abundance with low zinc intake also showed higher odds of elevated IL-6. Conversely, low B. longum abundance with low vitamin D and omega-3 intake was associated with higher odds of elevated IL-10 levels. These findings suggest that reduced Bifidobacterium abundance, combined with low micronutrient intake, is associated with altered cytokine profiles, contributing to immune dysregulation and inflammation in children.