Association between oral microbiome diversity and kidney stones: a cross-sectional study

Zufa Zhang^1,2Fengze Jiang^1,3Sheng Guan^1,3Li Chen⁴Huqiang Dong⁵Zuyi Chen^1,3Long Lv^1,3Hongxuan Song^1,3Weibing Sun^1,3Danni He^1,3Feng Tian^1,3*Sixiong Jiang^1,3*

• ¹Affiliated Zhongshan Hospital of Dalian University, Dalian, China
• ²Zhongshan Clinical Collage of Dalian University, Dalian, Liaoning Province, China
• ³Key Laboratory of Microenvironment Regulation and Immunotherapy of Urinary Tumors of Liaoning Province, Dalian, Liaoning Province, China
• ⁴Fuzhou Children's Hospital, Fujian Medical University, Fuzhou, China
• ⁵School of Public Health, Ningxia Medical University, Ningxia, China

Background: Kidney stones are a common urologic disorder that imposes a significant burden on global public health. This study aimed to determine the association between oral microbiome diversity and kidney stones.The data for this study came from the NHANES 2,009-2,012 survey cycle. Use of alpha diversity to assess oral microbiome diversity. Multivariate logistic regression modeling was used to assess the association between different alpha-diversity indicators and kidney stones. Subgroup analyses and interaction tests were used to assess the stability of the association between alphadiversity and kidney stones. Restricted cubic spline plots were used to assess nonlinear associations and dose-response relationships.The study included 5,870 eligible participants with a mean age of 43.74 years at baseline. After adjusting for all covariates, the observed oral microbiome diversity was significantly negatively associated with the risk of kidney stones (P < 0.05). Subgroup analyses showed that oral microbiome diversity was negatively associated with the risk of kidney stones in certain populations, particularly among those aged 40-60 years, men, obese, with moderate to high cardiovascular health scores, smokers, and those without hypertension. Restricted cubic spline analysis suggested a significant nonlinear negative correlation between the Shannon and Simpson diversity indices and the risk of kidney stones (p for nonlinear < 0.05). Since our study was a cross-sectional design, the main limitation was the inability to prove causality.In this study, we found an inverse relationship between oral microbiome diversity and kidney stone risk observed in alpha diversity. This reveals the complexity of host-microbiome interactions, and further mechanistic studies are necessary to elucidate these complex roles in the future.