(P20-053-23) Bile Acid Modulating Nutrients Are Significantly Associated With Bacterial Secondary Bile Acid Derivatives

Objectives: Hydrophobic bile acid accumulation is linked with cancer risk, however bacterial production of secondary bile acid derivatives  may mitigate the proinflammatory and cytotoxic effects of hydrophobic bile acids. To our knowledge, the impact of diet on secondary bile acid derivative production has not been determined. Therefore, associations between bile acid modulating nutrients and the composition of secondary bile acids and their derivatives was investigated.

Methods: Stool was collected from 134 subjects between 45-75 years of age living in the Chicago metropolitan area. Bile acids were extracted from stool and quantified using LC/ESI-MS/MS. Energy, macronutrients, micronutrients, and specific dietary nutrients (e.g., fatty acids, dietary fiber, and calcium) were estimated from two 24-hour diet recalls using the Nutrition Data System for Research software. To determine associations between bile acid categories and select energy adjusted dietary variables (alcohol, calcium, coffee, fiber, fat, protein), Kendall’s tau correlation was performed, and P-values were corrected using False Discovery Rate. Regression-based models were used to test differences in bile acid categories and specific nutrients using backwards elimination to control for relevant covariates.

Results: Deoxycholic acid (DCA) and lithocholic acid (LCA) negatively correlated with fiber and calcium intake and positively correlated with intake of total fat (q < 0.007, 0.05, and 0.05, respectively). Fiber intake was also negatively correlated with high abundant derivatives of DCA (q < 0.05). High abundant derivatives of LCA were positively associated with alcohol consumption (β= 0.13, p < 0.04) and negatively associated with fiber intake (β= -0.03, p < 0.04) when adjusting for covariates including race, body mass index, and smoking status. Coffee intake was positively associated with low abundant derivatives of LCA when adjusting for race, NSAID use, and smoking status (β= 0.01, p < 0.03).

Conclusions: Dietary covariates were significantly associated with secondary bile acids and their derivatives. Given that race and smoking status were significant predictors of these associations, future work should account for social and structural influences on dietary intake and its relationship with bile acid elicited cancer risk.

Funding Sources: NCI, NIMHD, and UIUC Vision 2020 Grant