Effects of Bile acid levels on gut microbial community metabolic processes, microbiome diversity and human metabolism and nutrition status

Introduction & Methods Both Bile Acids (BAs) and nutrition are important factors in the mediation of microbial effects on the human metabolism and metabolic diseases like T2 D. We aim to explore the BA-Host-Microbiome intersection by determining metabolic processes in the gut microbial community (GMC) and their interaction with BA levels.

A cross-sectional cohort (N = 434) was investigated regarding their BA status, gut microbiome (16s), clinical biomarkers and nutrition patterns (FFQ). Analysis was stratified by BMI and T2 D status. Metabolic models of the GMC were constructed based on microbiome composition data and nutrition data to predict metabolite exchanges and bacterial growth. Predicted GMC traits were then tested for association with BA levels by Kruskal-Wallis tests and hurdle models. BA levels of two obesity intervention cohorts (diet and bariatric surgery) were also analyzed.

Results BA levels were significantly associated with diversity of the microbiome and nutrition data, with primary BAs being mostly associated with nutrition and clinical features, while secondary BAs were primarily associated with microbiome traits. Analysis of GMC interactions in relation to secondary BA levels revealed, among others, significant changes in the predicted Pyruvate and Glycerinaldehyde exchange of the GMC with the host. We also identified changes in the predicted GMC interchange (metabolites that are exchanged between bacteria) of 32 metabolites. A general increase of BAs levels after weight loss was observed in both intervention cohorts.

Conclusion In a potential microbiome therapy for the treatment of T2 D, symbiotic effects of BAs and GMC metabolism need to be carefully considered.

Interessenskonflikt

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Publication History

Article published online:
06 May 2021