Could fecal microbiota be a useful indicator of serum cholesterol levels among men?

Trepidation with blood tests among men may result in fewer routine screening and examination of their cardiovascular risk factors. Associations between fecal microbiota and serum cholesterols have not been well-established. The aim of this study was to explore such association in order to determine the potential of fecal microbiota as a non-invasive alternate predictor of serum cholesterols. Secondary data from a cross-over trial were analyzed. Associations between fecal microbiota, mainly Bifidobacterium and Clostridial group, of healthy men (n = 16) and their total cholesterols, low and high-density lipoprotein cholesterols (LDL-C and HDL-C) were assessed using generalized estimating equations, adjusted for diet intervention, diet order, frequency of defecation and flatulence level. For every two-fold increase in fecal Bifidobacterium, geometric mean of LDL-C increases by a factor of 1.23 (95% CI: 1.01, 1.49) whilst that of HDL-C increases by a factor of 1.07 (95% CI: 1.03, 1.10). For every two-fold increase in Clostridial group (C. ramosum, C. spiroforme and C. cocleatum), geometric mean of HDL-C decreases by a factor of 1.10 (95% CI: −1.16, −1.03). No association was found between total bacteria and serum cholesterols. Fecal Bifidobacterium spp. and Clostridium spp., are potential non-invasive surrogate markers of men’s serum cholesterols.