Modulation of Intestinal Inflammation by Yeasts and Cell Wall Extracts: Strain Dependence and Unexpected Anti-Inflammatory Role of Glucan Fractions

Abstract

Yeasts and their glycan components can have a beneficial or adverse effect on intestinal inflammation. Previous research has shown that the presence of Saccharomyces cerevisiae var. boulardii (Sb) reduces intestinal inflammation and colonization by Candida albicans. The aim of this study was to identify dietary yeasts, which have comparable effects to the anti-C. albicans and anti-inflammatory properties of Sb and to assess the capabilities of yeast cell wall components to modulate intestinal inflammation. Mice received a single oral challenge of C. albicans and were then given 1.5% dextran-sulphate-sodium (DSS) for 2 weeks followed by a 3-day restitution period. S. cerevisiae strains (Sb, Sc1 to Sc4), as well as mannoprotein (MP) and β-glucan crude fractions prepared from Sc2 and highly purified β-glucans prepared from C. albicans were used in this curative model, starting 3 days after C. albicans challenge. Mice were assessed for the clinical, histological and inflammatory responses related to DSS administration. Strain Sc1-1 gave the same level of protection against C. albicans as Sb when assessed by mortality, clinical scores, colonization levels, reduction of TNFα and increase in IL-10 transcription. When Sc1-1 was compared with the other S. cerevisiae strains, the preparation process had a strong influence on biological activity. Interestingly, some S. cerevisiae strains dramatically increased mortality and clinical scores. Strain Sc4 and MP fraction favoured C. albicans colonization and inflammation, whereas β-glucan fraction was protective against both. Surprisingly, purified β-glucans from C. albicans had the same protective effect. Thus, some yeasts appear to be strong modulators of intestinal inflammation. These effects are dependent on the strain, species, preparation process and cell wall fraction. It was striking that β-glucan fractions or pure β-glucans from C. albicans displayed the most potent anti-inflammatory effect in the DSS model.

Chemical composition of the cell wall of probiotic and brewer’s yeast in response to cultivation medium with glycerol as a carbon source

“…may also demonstrate biotherapeutic effect. Results of the latest study by Jawhara et al [16] confirm this line of thought. The authors screened a range of S. cerevisiae sp.…”

“…Results of this study may be a basis for obtaining bioactive b-glucans and mannoprotein preparations or elaboration of probiotic culture of increased content of cell wall structure polymers. The experimental data point that not only polymers isolated from cell wall of yeasts of Saccharomyces genus demonstrate health-promoting activity, but also the whole cells of these fungi [3,16,54].…”

“…boulardii yeasts were prepared via autolysis of yeasts cells. Autolysis is a common procedure used in obtaining yeast cell wall preparations, from which b-glucans and mannoprotein are isolated [16,20,35,48,50,51,56].…”

“…boulardii. The authors of this study [16] connect probiotic activity of both strains to the presence of bglucans in the cell wall.…”

Uric acid levels are independent of anti-Saccharomyces cerevisiae antibodies (ASCA) in Crohn’s disease: A reappraisal of the role of S. cerevisiae in this setting

“…Such studies have included in vitro analysis of physiological traits (i.e. the ability to grow at body temperature, pseudo-hyphal growth, protease and phospholipase secretion) [22] and in vivo analysis in experimental models of infection/colonization [23,24]. These studies demonstrated that there are obvious differences in pathogenic potential of strains although the reasons for this are not yet understood.…”