The functional food industry requires an improvement of probiotic strain stability during storage, especially when they are stored at room temperature. In this study, the viability of freeze-dried Lactobacillus rhamnosus IMC 501^® and Lactobacillus paracasei IMC 502^® using different protective agents (i.e., glycerine, mannitol, sorbitol, inulin, dextrin, Crystalean^®) was determined and compared with semi skimmed milk (SSM) control. No significant differences were observed between the tested protectants and the control (SSM) during storage at refrigerated conditions. During storage at room temperature, only glycerine was found to stabilize viability better than other tested substances.

Aims The aim of this work was to refine the taxonomy and the functional characterization of publicly available Lactiplantibacillus plantarum complete genomes through a pan-genome analysis. Particular attention was paid in depicting the probiotic potential of each strain. Methods and Results Complete genome sequence of 127 L. plantarum strains, without detected anomalies, was downloaded from NCBI. Roary analysis of L. plantarum pan-genome identified 1,436 core, 414 soft core, 1,858 shell and 13,203 cloud genes, highlighting the “open” nature of L. plantarum pan-genome. Identification and characterization of plasmid content, mobile genetic elements, adaptative immune system and probiotic marker genes (PMGs) revealed unique features across all the L. plantarum strains included in the present study. Considering our updated list of PMGs, we determined that approximatively 70% of the PMGs belongs to the core/soft-core genome. Conclusions The comparative genomic analysis conducted in this study provide new insights into the genomic content and variability of L. plantarum. Significance and Impact of Study This study provides a comprehensive pan-genome analysis of L. plantarum, including the largest number (N=127) of complete L. plantarum genomes retrieved from publicly available repositories. Our effort aimed to determine a solid reference panel for the future characterization of newly sequenced L. plantarum strains useful as probiotic supplements.

Changes in functionality and composition of gut microbiota (GM) have been associated and may contribute to the development and maintenance of obesity and related diseases. The aim of our study was to investigate for the first time the impact of Lactiplantibacillus (L.) plantarum IMC 510 in a rat model of diet-induced obesity, specifically in the cafeteria (CAF) diet. This diet provides a strong motivation to voluntary overeat, due to the palatability and variety of selected energy-dense foods. The oral administration for 84 days of this probiotic strain, added to the CAF diet, decreased food intake and body weight gain. Accordingly, it ameliorated body mass index, liver and white adipose tissue weight, hepatic lipid accumulation, adipocyte size, serum parameters, including glycemia and low-density lipoprotein levels, in CAF fed rats, potentially through leptin control. In this scenario, L. plantarum IMC 510 showed also beneficial effects on GM, limiting the microbial imbalance established by long exposure to CAF diet and preserving the proportion of different bacterial taxa. Further research is necessary to better elucidate the relationship between GM and overweight and then the mechanism of action by which L. plantarum IMC 510 modifies weight. However, these promising results prompt a clear advantage of probiotic supplementation and identify a new potential probiotic as a novel and safe therapeutic approach in obesity prevention and management.