The therapeutic relevant effects of S. boulardii
Antimicrobial actions
The effect of S. boulardii in the intestine is based, amongst other things, on an antagonistic effect towards pathogenic bacteria and yeasts which are ‘undesired’ in the intestines of human beings. Mycocins are made partially responsible for this effect, which are excreted from S. boulardii and have a growthinhibiting effect on these harmful microorganisms.
Furthermore, S. boulardii binds pathogens such as Salmonella and certain Escherichia coli which carry fimbriae on their surface, reduces the adherence to the intestinal epithelium and eliminates them from the gut. Bacterial toxins, for example secreted by Clostridium difficile, are neutralised by proteolytic enzymes from S. boulardii. S. boulardii also protects against enteroinvasive pathogenic bacteria, such as Salmonella and Yersinia.
Strengthening the barrier function of the intestinal epithelium
S. boulardii has a protective effect on the damaged intestinal barrier caused by pathogenic microorganisms by increasing the transepithelial resistance of intestinal cells.1 In addition, S. boulardii reduces the number of intracellular infective agents and prevents the breakdown of tight junction proteins.2 The increased intestinal permeability observed in patients with Crohn's disease is lowered in the presence of S. boulardii.3
Antisecretory effect
S. boulardii has an antisecretory effect which normalises the water and electrolyte balance. The uptake of carbohydrates can be improved through the stimulation of disaccharidases.
Effect on intestinal epithelia and immune system
S. boulardii activates the gut-associated immune system; this is demonstrated by an increased level of protective secretory immunoglobulin A (slgA).
1) Dahan S, Dalmasso G, Imbert V, Peyron JF, Rampal P, Czerucka D. Saccharomyces boulardii interferes with enterohemorrhagic Escherichia coli-induced signaling pathways in T84 cells. Infect Immun. 2003;71(2):766–773.
2) Czerucka D, Dahan S, Mograbi B, Rossi B, Rampal P. Saccharomyces boulardii Preserves the Barrier Function and Modulates the Signal Transduction Pathway Induced in Enteropathogenic Escherichia coli-Infected T84 Cells. Kaufmann SHE, ed. Infection and Immunity. 2000;68(10):5998–6004.
3) Garcia Vilela E, De Lourdes De Abreu Ferrari M, Oswaldo Da Gama Torres H, Guerra Pinto A, Carolina Carneiro Aguirre A, Paiva Martins F, Marcos Andrade Goulart E, Sales Da Cunha A. Influence of Saccharomyces boulardii on the intestinal permeability of patients with Crohn’s disease in remission. Scand J Gastroenterol. 2008;43(7):842–848.