Alterations in the mucosa-associated fungal microbiota in patients with ulcerative colitis

Abstract

BackgroundFungi colonize the human gut and might play a key role in the pathogenesis of ulcerative colitis (UC). However, studies on the fungal composition in the gut (especially adhering to the intestinal mucosa) of UC patients is limited.ResultsThe number of fungi decreased significantly in inflamed mucosa compared with that in HS mucosa. Fifteen major genera were examined, among which Wickerhamomyces, unidentified genus of Saccharomycetales, Aspergillus, Sterigmatomyces, and Candida showed increasing trends, whereas Exophiala, Alternaria, Emericella, Epicoccum, Acremonium, Trametes, and Penicillium showed decreasing trends in UC patients compared to the HS. The pro-inflammatory cytokines (IL-Iβ, TNF-α, INF-γ, IL-6, IL-17A, and IL-23) were up-regulated in the UC group. The genera Wickerhamomyces, Nigrospora, and Penicillium were positively correlated, while Sporobolomyces and Trametes were negatively correlated with the expression of several colonic pro-inflammatory cytokines and the Baron and/or Mayo score.ConclusionsOur study confirms the alteration of the colonic fungal microbiota in the UC patients, which might be associated with mucosal inflammation and pathogenesis of UC. Further studies need to identify the roles of different intestinal fungi in detail, and to determine the mechanism of the host-fungal interaction underlying the development of UC.MethodsMucosal samples of inflamed descending colon from 14 active UC patients and 15 healthy subjects (HS) were analyzed by high-throughput sequencing to compare the fungal microbiota. The expressions of pro-inflammatory cytokines (IL-Iβ, TNF-α, INF-γ, IL-6, IL-17A, and IL-23) in intestinal mucosal tissues were examined. The Baron and Mayo scores of UC patients were evaluated, and the correlation between intestinal fungal composition and intestinal inflammatory status was analyzed.

Gut microbiota in ulcerative colitis: insights on pathogenesis and treatment

“…In IBD there is a distinctive disorder of the fungal flora characterized by changes in their biodiversity and composition . It has been confirmed that there are alterations in the colonic mucosa‐associated fungal microbiota in patients with UC and this may be related to the mucosal inflammation of UC . The characteristics of the fungal community change with the growth of Candida spp .…”

“…94 It has been confirmed that there are alterations in the colonic mucosa-associated fungal microbiota in patients with UC and this may be related to the mucosal inflammation of UC. 95 The characteristics of the fungal community change with the growth of Candida spp. 48 Moreover, the abundance of viruses (bacteriophages) differs between patients with IBD and the control groups.…”

Cervicovaginal Fungi and Bacteria Associated With Cervical Intraepithelial Neoplasia and High-Risk Human Papillomavirus Infections in a Hispanic Population

“…Sporidiobolaceae were significantly associated with low-risk HPV-infections and ASCUS in the introitus and cervix. Sporidiobolaceae are anamorphic yeasts, including Sporobolomyces , that has been associated with ulcerative colitis and Crohn’s disease ( Ott et al, 2008 ; Liguori et al, 2016 ; Qiu et al, 2017 ). Other abundant fungi enriched in ASCUS included Sacharomyces and Cladosporium .…”

The mammalian mycobiome: A complex system in a dynamic relationship with the host

“…Changes in the mycobiome, like those described for the bacterial microbiome, have been associated with the penetrance and expressivity of IBD in people (Iliev & Leonardi, ; Limon et al, ; Table ). In particular, an overgrowth of C. albicans and related Candida species is often observed in mice and humans afflicted with IBD (Chehoud et al, ; Hoarau et al, ; Lewis et al, ; Li et al, ; Liguori et al, ; Ott et al, ; Qiu et al, , ; Sokol et al, ). On the other hand, S. cerevisiae was found to decline in abundance in IBD patients and during active flare (Liguori et al, ; Sokol et al, ), a result that has been reproduced in mice (Iliev et al, ).…”

“…On the other hand, S. cerevisiae was found to decline in abundance in IBD patients and during active flare (Liguori et al, ; Sokol et al, ), a result that has been reproduced in mice (Iliev et al, ). Of note, fungal communities likely differ between the mucosa and the lumen, and along different sections of the intestines (Liguori et al, ; Qiu et al, , ), and it remains a challenge to determine where the predictive or causative fungal symbionts in IBD reside.…”