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

Abstract 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.