Fungal Diversity of Human Gut Microbiota Among Eutrophic, Overweight, and Obese Individuals Based on Aerobic Culture-Dependent Approach

Abstract

Fungi have a complex role in the intestinal tract, influencing health and disease, with dysbiosis contributing to obesity. Our objectives were to investigate fungal diversity in human gut microbiota among eutrophic, overweight, and obese. Epidemiological and nutritional information were collected from adult individuals, as well as stool samples processed for selective fungi isolation and identification by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (yeasts) or microculture (filamentous fungi). Further 18S rDNA sequencing was performed to confirm identification. The mean count of fungi was 241 CFU/g of feces. Differences in the population level of the filamentous fungi were observed within eutrophic and obese groups. Overall, 34 genera were identified. The predominant phylum was Ascomycota with 20 different genera, followed by Basidiomycota and Zygomycota. As for Ascomycota, the most prevalent species were Paecilomyces sp., Penicillium sp., Candida sp., Aspergillus sp., Fonsecaea sp., and Geotrichum sp. (76.39, 65.28, 59.72, 58.33, 12.50, and 9.72%, respectively). As for Basidiomycota, Trichosporon sp. and Rhodotorula sp. were the most prevalent (30.56 and 15.28%, respectively), and for Zygomycota, Rhizopus sp. and Mucor sp. were the most numerous (15.28 and 9.72%, respectively). As expected there is a mycobiota shift towards obesity, with slightly higher diversity associated to eutrophic individuals. This mycobiota shift seems also to be related to the nutritional behavior of the individuals, as observed that the macronutrients intake may be positively related to the different fungi occurrences. Other studies are needed to better understand relationships between mycobiota and obesity, which could be used in future obesity treatments.

Candida Administration Worsens Cecal Ligation and Puncture-Induced Sepsis in Obese Mice Through Gut Dysbiosis Enhanced Systemic Inflammation, Impact of Pathogen-Associated Molecules From Gut Translocation and Saturated Fatty Acid

“…in mouse feces, but the abundance of fecal fungi in mouse feces is not high enough to be detectable by culture (10). Indeed, C. albicans in mouse intestine are lesser than human intestine (25) as fungi in human stool are easily detectable by culture in comparison with mouse feces (26). Hence, oral administration of C. albicans is necessary to increase mouse fecal fungi.…”

“…Characteristics of mice fed a high-fat diet (HFD) treated with phosphate buffer solution (PBS) or Candida with or without Lactobacillus rhamnosus L34 (L34) that were subjected to sham or cecal ligation and puncture (CLP) surgery as determined by survival analysis (A), kidney and liver injury (B,C), serum cytokines(D-F), gut leakage by FITC-dextran (G), endotoxemia (H), serum (1→3)-β-D-glucan (I), cytokines from ascending colon (J-L), fecal fungal burdens and fecal pH (M, N; n = 6-8/group for B-N) are demonstrated. # p < 0.05.the human condition(26), the influence of C. albicans is evaluated through C. albicans administration. Here, Candida pretreatment in obese mice worsened sepsis through enhanced systemic inflammation induced by LPS and BG from gut translocation which implies the importance of gut fungi toward sepsis in obesity.…”

Rhodotorula spp. in the gut – foe or friend?

“…The fact that increased numbers of Rhodotorula spp. in stool specimen of sick patients after various medical interventions are found rather often [1], [4], [8] indicates, however, a definite alteration of the milieu and a disturbed balance in the microbial population in the gut of those individuals. Obviously, these fungi can survive and multiply in the extreme, unfavorable conditions in the gut.…”

“…They may induce not only infections, but they may trigger metabolic disturbances [4], [19] and engender allergy [35], [36], [37], [38]. It can be assumed that Rhodotorula spp.…”

“…has been discussed extensively [2], [3] whereas the relevance of Rhodotorula spp. is hardly acknowleged although they are often found in stool specimen of humans [1], [4]. Intestinal colonization in healthy children is found in up to 5% and in young adults even in 12% [5].…”