A decrease in anaerobic bacteria promotes Candida glabrata overgrowth while β-glucan treatment restores the gut microbiota and attenuates colitis

Abstract

BackgroundThe intestinal microbiota plays a crucial role in the maintenance of gut homeostasis. Changes in crosstalk between the intestinal epithelial cells, immune cells and the microbiota are critically involved in the development of inflammatory bowel disease. In the experimental mouse model, the development of colitis induced by dextran sulfate sodium (DSS) promotes overgrowth of the opportunistic yeast pathogen Candida glabrata. Conversely, fungal colonization aggravates inflammatory parameters. In the present study, we explored the effect of C. glabrata colonization on the diversity of the gut microbiota in a DSS-induced colitis model, and determined the impact of soluble β-glucans on C. glabrata-host interactions.ResultsMice were administered a single inoculum of C. glabrata and were exposed to DSS treatment for 2 weeks in order to induce acute colitis. For β-glucan treatment, mice were administered with soluble β-glucans purified from C. glabrata (3 mg per mouse), orally and daily, for 5 days, starting on day 1. The number of C. glabrata colonies and changes in microbiota diversity were assessed in freshly collected stool samples from each tagged mouse, using traditional culture methods based on agar plates. An increase in Escherichia coli and Enterococcus faecalis populations and a reduction in Lactobacillus johnsonii and Bacteroides thetaiotaomicron were observed during colitis development. This decrease in L. johnsonii was significantly accentuated by C. glabrata overgrowth. Oral administration of β-glucans to mice decreased the overgrowth of aerobic bacteria and IL-1β expression while L. johnsonii and B. thetaiotaomicron populations increased significantly. β-glucan treatment increased IL-10 production via PPARγ sensing, promoting the attenuation of colitis and C. glabrata elimination.ConclusionsThis study shows that the colonic inflammation alters the microbial balance, while β-glucan treatment increases the anaerobic bacteria and promotes colitis attenuation and C. glabrata elimination.

Candida spp./Bacteria Mixed Biofilms

“…Charles and colleagues [123] revealed that the in vivo decrease in anaerobic bacteria helps C. glabrata overgrowth (with a decrease IL-1β expression). Notably, at the same time, β-glucan treatment reestablishes the gut microbiota, mitigates colitis (increasing IL-10 production via PPARγ sensing) and, thus, C. glabrata elimination.…”

“…During colitis development, a proliferation of E. coli and E. faecalis populations and a decline in Lactobacillus johnsonii and Bacteroides thetaiotaomicron was noted. The reduction in L. johnsonii was stressed by C. glabrata overgrowth [123]. Interactions between the gut-associated Bacteroides fragilis NCTC 9343, Bacteroides vulgatus ATCC 8482, and C. albicans were also explored [124].…”

The gut mycobiome: The overlooked constituent of clinical outcomes and treatment complications in patients with cancer and other immunosuppressive conditions

“…promoters of Candida gut colonization [15], it has been shown that high-intensity chemotherapy results in reduced diversity of the GI microbiota, reduction of anaerobes [16], and a shift in the Firmicutes to Bacteriodetes ratio [17]. Given that decreases of anaerobic bacteria have been shown to promote Candida overgrowth [18], and Bacteroidetes have been shown to be negatively associated with fungi [19,20], it stands to reason that the gut mycobiome is altered during cytotoxic chemotherapy.…”

How to boost the immune defence prior to respiratory virus infections with the special focus on coronavirus infections

“…It has been reported that soluble β-glucans are recognized by dendritic cells (DCs) and macrophages present in Peyer's patches and contributed to maturation of DC through the dectin-1 pathway [30]. In addition, we showed that administration of β-glucans derived from yeasts to mice diminished the overgrowth of Enterococcus faecalis and Escherichia coli populations, and modulated the production of inflammatory mediators [31]. β-glucan administration increased the production of IL-10 via activation of PPARγ, favouring the clearance of Candida glabrata from the gut and the reduction of diarrhoea and colitis [31].…”