The dietary inflammatory index is associated with gastrointestinal infection symptoms in the national health and nutrition examination survey.

Inflammation influences many aspects of health including gastrointestinal illnesses. Associations between the Dietary Inflammatory Index (DII®) and gastrointestinal symptoms were examined using cross-sectional data from the National Health and Nutrition Examination Survey (years 2005-2014, n = 25,553). Outcomes included self-reported presence of mucus or liquid in bowel leakage and stomach illness in the past month, diarrhoea in the past year and number of weekly bowel movements. Energy-adjusted DII (E-DII) scores were estimated from one 24-h dietary recall. Analyses included survey design-appropriate logistic and linear regression. Compared to E-DII quartile 1 (anti-inflammatory), E-DII quartile 4 (pro-inflammatory) had elevated odds of mucus in leakage: 71% (95% confidence interval [95%CI] = 1.01-1.20); liquid in leakage: 74% (95%CI = 1.30-2.33); stomach illness: 43% (95%CI = 1.18-1.72); and diarrhoea: 65% (95%CI = 1.21-2.26). Those with more anti-inflammatory diets had more bowel movements. Future questions should address whether anti-inflammatory diets provide protective effects against gastrointestinal infections and if these relationships are modified by other health behaviours.