Gut microbiota and its relationship with early vascular ageing in a Spanish population (MIVAS study)

Background: Gut microbiota and its by-products are increasingly recognized as having a decisive role in cardiovascular diseases. The aim is to study the relationship between gut microbiota and early vascular ageing (EVA). Methods: A cross-sectional study was developed in Salamanca (Spain) in which 180 subjects aged 45-74 years were recruited. EVA was defined by the presence of at least one of the following: carotid-femoral pulse wave velocity (cf-PWV), cardio-ankle vascular index (CAVI) or brachial-ankle pulse wave velocity (ba-PWV) above the 90th percentile of the reference population. All other cases were considered normal vascular ageing (NVA). Measurements: cf-PWV was measured by SphygmoCor (R) System; CAVI and ba-PWV were determined by Vasera 2000 (R) device. Gut microbiome composition in faecal samples was determined by 16S rRNA Illumina sequencing. Results: Mean age was 64.4 +/- 6.9 in EVA group and 60.4 +/- 7.6 years in NVA (p < .01). Women in EVA group were 41% and 53% in NVA. There were no differences in the overall composition of gut microbiota between the two groups when evaluating Firmicutes/Bacteriodetes ratio, alfa diversity (Shannon Index) and beta diversity (Bray-Curtis). Bilophila, Faecalibacterium sp.UBA1819 and Phocea, are increased in EVA group. While Cedecea, Lactococcus, Pseudomonas, Succiniclasticum and Dielma exist in lower abundance. In logistic regression analysis, Bilophila (OR: 1.71, 95% CI: 1.12-2.6, p = .013) remained significant. Conclusions: In the studied Spanish population, early vascular ageing is positively associated with gut microbiota abundance of the genus Bilophila. No relationship was found between phyla abundance and measures of diversity.