Characterization of the Probiotic Yeast Saccharomyces boulardii in the Healthy Mucosal Immune System

Abstract

The probiotic yeast Saccharomyces boulardii has been shown to ameliorate disease severity in the context of many infectious and inflammatory conditions. However, use of S. boulardii as a prophylactic agent or therapeutic delivery vector would require delivery of S. boulardii to a healthy, uninflamed intestine. In contrast to inflamed mucosal tissue, the diverse microbiota, intact epithelial barrier, and fewer inflammatory immune cells within the healthy intestine may all limit the degree to which S. boulardii contacts and influences the host mucosal immune system. Understanding the nature of these interactions is crucial for application of S. boulardii as a prophylactic agent or therapeutic delivery vehicle. In this study, we explore both intrinsic and immunomodulatory properties of S. boulardii in the healthy mucosal immune system. Genomic sequencing and morphological analysis of S. boulardii reveals changes in cell wall components compared to non-probiotic S. cerevisiae that may partially account for probiotic functions of S. boulardii. Flow cytometry and immunohistochemistry demonstrate limited S. boulardii association with murine Peyer’s patches. We also show that although S. boulardii induces a systemic humoral immune response, this response is small in magnitude and not directed against S. boulardii itself. RNA-seq of the draining mesenteric lymph nodes indicates that even repeated administration of S. boulardii induces few transcriptional changes in the healthy intestine. Together these data strongly suggest that interaction between S. boulardii and the mucosal immune system in the healthy intestine is limited, with important implications for future work examining S. boulardii as a prophylactic agent and therapeutic delivery vehicle.

Application ofSaccharomyces cerevisiae var. boulardiiin food processing: a review

“…Moreover, S. boulardii can effectively induce immune response by increasing IgA and IgG levels (Hudson et al . ).…”

“…Some of its probiotic properties which include resistance to stress due to changes in regular and simulated gastrointestinal pH conditions can be explained by these cell wall properties (Hudson et al . ). In addition, S. boulardii has a great resistance to a body temperature of 37°C (Czerucka et al .…”

“…Moreover, S. boulardii regulates the cytokines pro and anti-inflammatory factors (interleukins IL-10, IL-1b, IL-23A, tumour necrosis factor (TNF)-a, IL-12b, interferonc (INF-c), and IL-17A) in the colonized intestinal mucosa (Kelesidis and Pothoulakis 2012;Łukaszewicz 2012). Moreover, S. boulardii can effectively induce immune response by increasing IgA and IgG levels (Hudson et al 2016).…”

“…The cell wall of S. boulardii is thicker in comparison with other yeasts. Some of its probiotic properties which include resistance to stress due to changes in regular and simulated gastrointestinal pH conditions can be explained by these cell wall properties (Hudson et al 2016). In addition, S. boulardii has a great resistance to a body temperature of 37°C (Czerucka et al 2007), exposure to gastric acid and bile (Ivanova et al 2012), good adhesion to the gastric wall (Diosma et al 2014), and, therefore, high viability (Bastos et al 2014).…”

Establishing ProbioticSaccharomyces boulardiias a Model Organism for Synthesis and Delivery of Biomolecules

“…S. boulardii is a non-pathogenic yeast that was originally isolated from lychee and mangosteen in 1923 and has since been used to treat ulcerative colitis, diarrhea, and recurrent Clostridium difficile infection 1, 31 . S. boulardii is closely related to the famous budding yeast Saccharomyces cerevisiae , indicating that it may be similarly amenable to engineering for the production of biomolecules, including biologics requiring post-translational modifications 2, 32 . Supporting this, S. cerevisiae expression vectors can be transformed and propagated in S. boulardii , and CRISPR/Cas9-mediated genome editing is functional in both strains 33 .…”