Impact of Food Matrix on L. rhamnosus CRL1505 survival

Scope: Probiotics survival is crucial for their beneficial effect but only few studies have assessed the impact of delivery format on probiotic viability after the passage through the gastrointestinal tract. Methods and Results: our study aimed to investigate the survival of Lacticaseibacillus rhamnosus CRL1505 through the gastrointestinal transit in healthy volunteers after a daily consumption of at least 1 billion CFUs per day administered as freeze-dried cells or incorporated into oat- and milk-fermented drinks. The probiotic's survival was evaluated combining culture-based and molecular techniques. Our findings revealed that L. rhamnosus CRL1505 survival was significantly higher when the probiotic was administered as oat- and as milk-fermented drink. The study allowed us to observe the persistence of CRL1505 in a subset of volunteers one week after the last administration. The metataxonomic analysis of fecal samples did not reveal significant changes in microbiota diversity among treatment groups. Conclusion: The survival of CRL1505 through the human gastrointestinal tract was demonstrated with and without the protection of food matrices, highlighting the strain's remarkable ability to withstand harsh conditions. Our findings emphasize the importance of food matrix selection for improving probiotic viability, with potential implications for improving probiotic efficacy in functional foods.