Dietary assessment from inflammation and gut microbiota perspectives in urban Chinese adults aged 40-69 years: Association with chronic diseases.

BACKGROUND AND OBJECTIVES: Current evidence suggests that gut microbiota dysbiosis accelerates aging and aging-related diseases through pro-inflammatory pathways. This study aimed to evaluate dietary quality in relation to inflammation and gut microbiota, and to explore their relationship with chronic diseases among urban Chinese adults aged 40-69 years. METHODS AND STUDY DESIGN: A cross-sectional study was conducted among urban Chinese adults aged 40-69 years. Dietary quality was assessed by dietary intake, dietary inflammation index (DII), and dietary index for gut microbiota (DI-GM). Log-binomial regression was per-formed to examine the associations between DII, DI-GM and chronic diseases. RESULTS: An excessive energy proportion from fat (37.4%) and an insufficient contribution from carbohydrates (44.7%) indicated an imbalance in macronutrient intake. The medians and interquartile ranges for DII and DI-GM of the participants were 1.3 (0.2, 2.5) and 3.0 (2.0,5.0), respectively, suggesting a pro-inflammatory and gut microbiota-unfavorable dietary tendency. Livestock contributed most to dietary inflammation in the population (standardized β = 0.251), whereas vegetables showed the strongest inverse effect (standardized β = -0.500). A higher DI-GM score was suggested to be a protective factor against self-reported dysglycemia (OR = 0.311; 95%CI: 0.118, 0.818). CONCLUSIONS: The participants exhibited an imbalance in macronutrient intake and a dietary tendency that was pro-inflammatory and unfavorable to gut microbiota. Notably, this study revealed a negative relationship between DI-GM and dysglycemia in middle-aged and elderly population, which under-scores the potential of targeting gut microbiota through diet for chronic disease prevention in this population.