Higher consumption of sulfur microbial diet is associated with the increased risk of chronic kidney disease.

Background: Emerging evidence suggested that dietary patterns linked to sulfur-metabolizing bacteria in the stool may influence kidney health. We aimed to investigate the association between the sulfur microbial diet and chronic kidney disease (CKD). Methods: We included 192,282 participants from the UK Biobank. The sulfur microbial diet score was derived from a 24-h dietary assessment, calculated by summing the products of the β-coefficients and their corresponding portion sizes. CKD was defined using the International Classification of Diseases, 10th revision codes (ICD-10). Cox proportional hazard models were used to estimate the hazard ratio (HR) and 95% confidence interval (CI). Mediation analyses were employed to examine potential mediators, primarily focusing on indicators of metabolic disorders and systemic inflammation. Substitution analyses were performed to evaluate the impact of replacing one dietary component of the sulfur microbial diet with another. Results: After a median follow-up of 12.17 years, 4,739 incident CKD cases were identified. The fully adjusted HR of CKD for participants in the highest quartile was 1.15 (95% CI: 1.06, 1.24) compared with those in the lowest quartile. Substituting one serving per day of low-calorie drinks or sweets and desserts with an equal amount of other vegetables was significantly associated with a 7% or 5% reduction in CKD risk. In the mediation analyses, metabolic disorder factors accounted for 1.27-23.13% of the association between the sulfur microbial diet and CKD, while BMI explained 23.13% of the association. Conclusion: Higher sulfur microbial diet intake was associated with an increased risk of CKD, which was partially mediated by metabolic disorders. Replacing low-calorie drinks or sweets and desserts with other vegetables was related to a significant reduction in CKD risk. These findings highlighted the role of sulfur-metabolizing bacteria in the relationship between diet and CKD.