Survival of potential probiotic lactobacilli used as adjunct cultures on Pecorino Siciliano cheese ripening and passage through the gastrointestinal tract of healthy volunteers.

In the present study, two lactobacilli strains, Lactobacillus rhamnosus H25 and Lactobacillus paracasei N24, used asadjunct cultures, were evaluated for their heat resistance both with and without prior heat adaptation and fortheir survival, at industrial scale, during the production and ripening of the Pecorino Siciliano cheese. Inaddition, the viability and persistence of the lactobacilli strains after passage through the gastrointestinal tract ofhealthy volunteers were evaluated by using rep-PCR analysis of viable cells. Both strains exhibited good heatresistance and survival throughout cheese production and ripening, and positively influenced the physicochemical,the microbiological and the sensorial characteristics of the final product. In addition, the moleculartyping of the lactobacilli isolates, retrieved from fecal samples of healthy volunteers during and after 15 days ofthe experimental cheese administration, revealed a high survival of the strains, highlighting their persistenceduring passage into the GI tract. In conclusion, this study proposes the two adjunct cultures as potential probioticcandidate deliverable by cheese.