Sex Differences in Gut Microbiota and Their Relation to Arterial Stiffness (MIVAS Study)

Background: Recent research highlights the potential role of sex-specific variations in cardiovascular disease. The gut microbiome has been shown to differ between the sexes in patients with cardiovascular risk factors. Objectives: The main objective of this study is to analyze the differences between women and men in the relationship between gut microbiota and measures of arterial stiffness. Methods: We conducted a cross-sectional study in Spain, selecting 180 subjects (122 women, 58 men) aged between 45 and 74. Subjects with arterial stiffness were identified by the presence of at least one of the following: carotid-femoral pulse wave velocity (cf-PWV) above 12 mm/s, cardio-ankle vascular index (CAVI) above nine, or brachial-ankle pulse wave velocity (ba-PWV) above 17.5 m/s. All other cases were considered subjects without arterial stiffness. The composition of the gut microbiome in fecal samples was determined by 16S rRNA sequencing. Results: We found that women have a more diverse microbiome than men (Shannon, p < 0.05). There is also a significant difference in gut microbiota composition between sexes (Bray-Curtis, p < 0.01). Dorea, Roseburia, and Agathobacter, all of them short-chain fatty-acid producers, were more abundant in women's microbiota (log values > 1, p-value and FDR < 0.05). Additionally, Blautia was more abundant in women when only the subjects with arterial stiffness were considered. According to logistic regression, Roseburia was negatively associated with arterial stiffness in men, while Bifidobacterium and Subdoligranulum were positively related to arterial stiffness. Conclusions: In the Spanish population under study, women had higher microbiome diversity and potentially protective genera. The host's gender determines the influence of the same bacteria on arterial stiffness.