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® System; CAVI and ba-PWV were determined by Vasera 2000® 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.

Gut microbiota composition and arterial stiffness measured by pulse wave velocity: case-control study protocol (MIVAS study).

INTRODUCTION: Intestinal microbiota is arising as a new element in the physiopathology of cardiovascular diseases. A healthy microbiota includes a balanced representation of bacteria with health promotion functions (symbiotes). The aim of this study is to analyse the relationship between intestinal microbiota composition and arterial stiffness. METHODS AND ANALYSIS: An observational case-control study will be developed. Cases will be defined by the presence of at least one of the following: carotid-femoral pulse wave velocity (cf-PWV), Cardio-Ankle Vascular Index (CAVI), brachial ankle pulse wave velocity (ba or ba-PWV) above the 90th percentile, for age and sex, of the reference population. Controls will be selected from the same population as cases. The study will be developed in Primary Healthcare Centres. We will select 500 subjects (250 cases and 250 controls), between 45 and 74 years of age. Cases will be selected from a database that combines data from EVA study (Spain) and Guimarães/Vizela study (Portugal). MEASUREMENTS: cf-PWV will be measured using the SphygmoCor system, CAVI, ba-PWV and Ankle-Brachial Index will be determined using VaSera device. Gut microbiome composition in faecal samples will be determined by 16S ribosomal RNA sequencing. Lifestyle will be assessed by food frequency questionnaire, adherence to the Mediterranean diet and IPAQ (International Physical Activity Questionnaire). Body composition will be evaluated by bioimpedance. ETHICS AND DISSEMINATION: The study has been approved by 'Committee of ethics of research with medicines of the health area of Salamanca' on 14 December 2018 (cod. 2018-11-136) and the 'Ethics committee for health of Guimaraes' (Portugal) on 15 October 2019 (ref: 67/2019). All study participants will sign an informed consent form agreeing to participate in the study, in compliance with the Declaration of Helsinki and the WHO standards for observational studies. The results of this study will allow a better description of gut microbiota in patients with arterial stiffness. TRIAL REGISTRATION DETAILS: ClinicalTrials.gov, identifier NCT03900338.