Obesity changes the human gut mycobiome

Abstract

The human intestine is home to a diverse range of bacterial and fungal species, forming an ecological community that contributes to normal physiology and disease susceptibility. Here, the fungal microbiota (mycobiome) in obese and non-obese subjects was characterized using Internal Transcribed Spacer (ITS)-based sequencing. The results demonstrate that obese patients could be discriminated by their specific fungal composition, which also distinguished metabolically “healthy” from “unhealthy” obesity. Clusters according to genus abundance co-segregated with body fatness, fasting triglycerides and HDL-cholesterol. A preliminary link to metabolites such as hexadecanedioic acid, caproic acid and N-acetyl-L-glutamic acid was also found. Mucor racemosus and M. fuscus were the species more represented in non-obese subjects compared to obese counterparts. Interestingly, the decreased relative abundance of the Mucor genus in obese subjects was reversible upon weight loss. Collectively, these findings suggest that manipulation of gut mycobiome communities might be a novel target in the treatment of obesity.

The Fungal Mycobiome and Its Interaction with Gut Bacteria in the Host

“…The most abundant genera found in obese patients were Mucor and Nakaseomyces . In line with this finding, the relative abundance of Mucor increased after diet-induced weight loss in the obese subjects [19]. In addition there were correlations between High-density lipoprotein (HDL)-cholesterol and the relative abundance of class Eurotiomycetes, family Aspergillaceae and genus Penicillium , and negative correlations from the classes Saccharomycetes, Tremellomycetes, Cystobasidiomycetes and family Erythrobasidiaceae amongst other metabolic parameters studied [19].…”

The Gut Bacteria-Driven Obesity Development

“…A recent study analyzed the modifications in the gut fungal species of obese humans and described no differences in the richness of the gut mycobiome between obese and non-obese subjects but identified a lower family biodiversity in obese individuals [48]. More in detail, the authors found decreased levels of Mucor racemosus and Mucor fuscus in obese mycobiome, and interestingly, this effect was reversible after weight loss [48].…”

“…More in detail, the authors found decreased levels of Mucor racemosus and Mucor fuscus in obese mycobiome, and interestingly, this effect was reversible after weight loss [48]. …”

Host–microbe interactions: commensal fungi in the gut

“…as well as Cladosporium , Wallemia , and Malassezia spp. [4,7–15]. Some reports also include robust detection of fungi such as Phoma , Alternaria , Sclerotinia and others which are primarily plant pathogens and are likely to be carried by food or other environmental sources.…”

“…Further, we are still in early stages of understanding “normal” fungal diversity, time- and diet-based fluctuations, and the contributions of environmental exposures to definitions of the fungal microbiota [3]. Nevertheless, growing numbers of studies are suggesting that the intestinal mycobiome is skewed in the context of diseases including obesity, asthma, cirrhosis, and autism [4–6]. The potential for fungal dysbiosis to influence disease progression will be an active area of research in coming years.…”