In vitro screening of probiotic characteristics of some Italian products.

Six commercial probiotic products produced and marketed Italy (containing Lactobacillus GG, Lactobacillus casei DG, Lactobacillus reuteri, Bacillus clausii spores, Bifidobacterium longum and Saccharomyces boulardii) were assayed for their stability during storage, acid, base and bile tolerance and adherence to human intestinal cells. Results indicate that storage, even at conditions established by manufacturers, affects the microbial content of products based on B. longum and partially of that containing L. casei GG. Differences in acid and bile tolerance were found for the products, S. boulardii being better able to survive acid and bile than bacteria. Vegetative cells of B. clausii and B. longum were more susceptible than lactobacilli to low pH values, while fewer differences were found for bile tolerance. Lactobacilli and only partially B. longum, were able to adhere to Caco-2 cells, while S. boulardii and B. clausii showed reduced adherence to human intestinal cells. In conclusion, the products did not completely fulfill all probiotic attributes.