Ultra-processed food intake and its associations with atherogenic dyslipidemia, glycemic control, and gut microbiome features in adults with type 1 diabetes from Southern Italy

Aims To examine the associations between ultra-processed food (UPF) intake, glycemic control, cardiovascular risk factors, and gut microbiome in adults with type 1 diabetes (T1D). Methods In 253 adults with T1D, diet was assessed using the EPIC food-frequency questionnaire, and UPFs classified according to NOVA. Evaluations included lipid profile, HbA1c, and continuous glucose monitoring metrics. In a subgroup (n = 103), gut microbiota composition/function was analyzed using shotgun metagenomic sequencing and beta-diversity assessed by PERMANOVA. Associations were examined using multivariable regression models adjusted for age and Mediterranean diet adherence. Results Mean UPF intake was 15.5 % of total food intake. Higher UPF intake was independently associated with higher triglycerides (β per 20 g/1000 kcal = 3.62 mg/dL; 95 %CI 1.16–6.08) and lower HDL-cholesterol (β = − 0.98 mg/dL; 95 %CI − 1.72 to − 0.24). Sugar/artificially sweetened beverages were positively associated with triglycerides and animal-based UPFs inversely associated with HDL cholesterol. In participants on multiple daily injections or open-loop systems, ready-to-eat mixed dishes were positively associated with HbA1c. Microbiome beta-diversity significantly differed according to UPF intake. Triglycerides positively associated with microbial pathways (ketogluconate, tetrapyrrole, and acetate metabolism). Conclusion Higher UPF intake was associated with atherogenic dyslipidemia, poorer glycemic control in selected groups, and gut microbiome alterations in adults with T1D. The study was registered at ClinicalTrials.gov with the identifier NCT05936242.