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

- Pecorino ripened cheese was made at industrial scale using two adjunct cultures.
- The adjunct strains were detected through the ripening till 180 days.
- The strains survived through the passage on the GI tract of healthy volunteers.
- The potential probiotic strains survived also after stopping cheese administration.
- The adjunct strains could be proposed as new probiotics for dairy use.

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