The influence of ultra‐processed foods on gut microbiome and inflammatory markers in schoolchildren from Northeastern Brazil

OBJECTIVE: This study investigated the relationship between the consumption of ultra-processed foods (UPF), dietary profile, and inflammation on the intestinal microbiome in children. METHODS: A cross-sectional study was conducted using data from a community-based controlled trial involving 82 children aged 7-11 years enrolled in public schools in João Pessoa, Paraíba, Brazil. The gut microbiome was assessed by 16S rRNA gene sequencing. Dietary intake was assessed by a 24-h food recall and UPF intake was estimated using the NOVA system. Anthropometry, socio-economic variables, and cytokines (IL-2, IL-4, IL-6, IL-10, IL-17a, IFN-γ, and TNF-α) were also assessed. RESULTS: Children in the third tertile (higher consumption of UPF) had a higher intake of calories from UPF (p < 0.01), trans-fatty acids (p = 0.01), thiamine (p = 0.02), while the intake of protein (p = 0.01), and copper (p = 0.04) was lower. Children in the third tertile had lower abundance of Ruminococcaceae (p = 0.04) and Barnesiellaceae (p = 0.02) and higher abundance of the Monoglobaceae and Erysipelotrichaceae (p = 0.04). Several bacterial genera showed significant correlations with inflammatory cytokines. Dorea and Subdoligranulum were associated with IL-17A and IL-10; Agathobacter with IL-6, IL-10, and IFN-γ; Faecalibacterium with IL-10, IFN-γ, and TNF-α; Fusicatenibacter and Bifidobacterium with IL-10; and Roseburia with TNF-α (all q < 0.05). CONCLUSIONS: A high UPF intake was associated with a poorer-quality diet and changes in the composition of the gut microbiome, suggesting potential interactions between diet, microbial communities, and immune responses.