Beneficial effect of a symbiotic preparation with S. boulardii lysate in mild stress-induced gut hyper-permeability

Increased intestinal permeability has been advocated as one of the likely causes of various pathologies, such as allergies and metabolic or even cardiovascular disturbances. Thus, the aim of the present study was to test a symbiotic preparation containing microbial lysates (KC-1317, Named, Italy) against stress-induced derangement of gut mucosa permeability. Sprague Dawley rats were allocated into control (n=20) and stress (n=20) group. Stress was implemented by 1h of water avoidance stress daily for 10 days. Body weight, food and water intake and passage of stool pellet during stress session were recorded throughout the experiment. On the 11th day, fluorescent iso-thiocyanate dextran solution was injected into small intestinal loops. One hour after the injection, rats were sacrificed. Jejunum and ileum were taken for histopathology. Blood was collected from the abdominal aorta to measure intestinal permeability. In stress group, stool pellets during stress session was significantly higher than control group (p < 0.01). Villus height (p < 0.01), crypt depth (p < 0.01), number of goblet cells in villus (p < 0.01) and crypt (p < 0.05) decreased significantly in jejunum as compared to control. These phenomena were significantly prevented by KC-1317 (p < 0.05). Ileum also showed atrophy but villus height and the number of goblet cells in the villi did not significantly differ. Plasma-concentration of brain-gut peptides (substance P, thyrotropin-releasing hormone, cholecystokinin and motilin) were affected by stress (p < 0.001) and this effect did not change during supplementation with KC-1317. Polymorphonuclear neutrophil counting was significantly higher in stress group as compared to control (p < 0.01) but this phenomenon was abolished in the ileum (p < 0.01) or partly but significantly reduced by KC-1317 supplementation (p < 0.05). Accordingly, intestinal permeability was significantly enhanced in stress group as compared to control (p < 0.01) and prevented by KC-1317 (p < 0.01) in both intestinal segments examined. While confirming that chronic mild stress in rats compromises small intestinal morphology and permeability, we showed that a symbiotic microbial lysate can partly counteract this phenomenon.