Gut Microbiome Diversity and Uric Acid in Serum and Urine

An increasing body of evidence has shown the importance of the gut microbiota in modulating serum uric acid (SUA) levels. In this study, we aimed to determine the association between gut microbiome diversity, diet, SUA, and fractional excretion of uric acid (FEUA) in the kidney.

A cross-sectional study was conducted in 53 adults with normal or elevated SUA and estimated glomerular filtration rate (eGFR) range from 37 to 124 ml/min per 1.73 m². Fecal microbiome composition was analyzed using 16S ribosomal RNA sequencing; and alpha diversity was expressed as reverse Simpson, Shannon, and Richness indices. Dietary data were collected, and dietary patterns were identified using principal component analysis. Unadjusted linear regression and models adjusted for sex, waist-hip ratio (WHR), and eGFR were used to study the association between gut microbial diversity, dietary pattern scores, and SUA/FEUA.

Shannon index was negatively associated with SUA after multiple adjustment (β -36.4, 95% CI [-66.2 to -6.7], P = 0.017; adjusted R² = 0.62, P < 0.001). Sex (standardized β = 0.52) and WHR (standardized β = 0.35) had the highest effect on SUA, followed by Shannon diversity index (standardized β = -0.22). We found that Shannon index (standardized β = 0.49, P < 0.001) was positively associated with FEUA after adjustment for sex and "sweet" dietary pattern. This model explained 40% of the variability in FEUA (P < 0.001). None of the dietary patterns were associated with SUA or FEUA.

A higher gut microbial diversity was associated with lower SUA and more efficient elimination of uric acid by the kidneys. There is a need for studies assessing efficacy and safety of interventions on the gut microbiome as a treatment of hyperuricemia.