The mycobiotic component of the microbiota comprises an integral, yet 
under-researched, part of the gastrointestinal tract. Here, we present a 
preliminary study of the possible contribution of gut mycobiota to sub-clinical 
atherosclerosis in a well-characterised group of obese and non-obese subjects in 
association with the Framingham Risk Score (FRS) and carotid intima-media 
thickness (cIMT). From all taxa identified, the relative abundance of the phylum 
Zygomycota, comprising the family Mucoraceae and genus Mucor, was negatively 
associated with cIMT and this association remained significant after controlling 
for false discovery rate. Obese subjects with detectable Mucor spp. had a 
similar cardiovascular risk profile as non-obese subjects. Interestingly, the 
relative abundance of Mucor racemosus was negatively associated both with FRS 
and cIMT. Partial least square discriminant analyses modelling, evaluating the 
potential relevance of gut mycobiota in patients stratified by mean values of 
cIMT, showed that even a 1 component model had a high accuracy (0.789), with a 
high R2 value (0.51). Variable importance in projection scores showed that M. 
racemosus abundance had the same impact in the model as waist-to-hip ratio, 
high-density lipoprotein-cholesterol, fasting triglycerides or fasting glucose, 
suggesting that M. racemosus relative abundance in the gut may be a relevant 
biomarker for cardiovascular risk.