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Bacterial vaginosis is one of the most common urogenital diseases affecting women in reproductive age. The administration of probiotics as vaginal suppository has been proposed as a strategy to cure this condition and reduce its recurrence. Nonetheless, also oral consumption of probiotics, which is a more practical route of administration, proved to be an efficient strategy. In this perspective, we studied Lactobacillus paracasei LPC-S01 (DSM 26760), a human vaginal isolate included in commercial probiotic preparations for topical use, in order to assess if this bacterium can also perform as gastrointestinal probiotic. Comparative genomics revealed the presence of several accessory genes suggesting that LPC-S01 is a niche-generalist member of its species. According to a procedure conventionally used to predict the probiotic potential, we demonstrated that the probiotic properties of strain LPC-S01, with respect to those of the well-known probiotic references L. paracasei Shirota and DG, are equal for the bile tolerance and the reduction of NF-κB activation in Caco-2 cells, or superior for the tolerance to gastric juice and the adhesion to Caco-2 epithelial cells. We then demonstrated that LPC-S01 is susceptible to antibiotics indicated by EFSA and does not produce biogenic amines. Finally, a double-blind cross-over pilot intervention trial on healthy human volunteers showed that, after a 7-days oral consumption of capsules containing about 24 billion live cells, the fecal cell concentrations of strains LPC-S01 and DG (evaluated by qPCR) were not dissimilar. Specifically, both probiotics' cell concentrations were above the detection limit for an average of 5 days from the end of the treatment, corresponding to a mean number of evacuations of 7 ± 2. Taken together, these data demonstrate that the vaginal isolate L. paracasei LPC-S01 possesses safety and functional properties that may support its use as probiotic to be administered per os for potential intestinal as well as vaginal applications.

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-Pannerone cheese is a cow raw milk cheese obtained without starter and salt addition, which can be classified as a semi-soft cheese with a high fat content. Prolonged holding of moulded curds at warm room temperatures (~30°C) was identified as having a key role in the cheese microbiological and chemical composition. Microbial populations were numerous and diverse with high numbers of lactic acid bacteria and coliforms. Pathogenic bacteria were not detected, while propionic bacteria and spores of lactate-fermenting clostridia were detected in all samples. Changes in microbial populations corresponded with key changes in chemical composition. During the first 2 days in the warm room at 30°C, pH decreased to 4.9 and lactose was completely fermented to lactic acid. Over the next 4 days, metabolism of lactate to butyric (7.5 g·kg −1 ) and propionic (1.7 g·kg −1 ) acids with a consequent increase in pH to 5.7 occurred. The importance of the warm room temperature was demonstrated. The incubation of moulded curd had to be carried out at temperatures of about 30°C to obtain the typical fermentation profile. The addition of lysozyme to the vat milk prevented the formation of high level of butyric acid typical of Pannerone cheese, thus demonstrating the involvement of lactate-fermenting clostridia in the production of butyric acid.Pannerone cheese / clostridia / butyric acid / propionic acid / cheese-making technology Résumé -Caractéristiques technologiques, microbiologiques et chimiques du Pannerone, un fromage italien traditionnel au lait cru. Le Pannerone est un fromage au lait de vache cru obtenu sans ajout de levain ni de sel, qui peut être classé comme fromage à pâte mi-molle à teneur élevée en matière grasse. Le maintien prolongé des caillés moulés en chambre chaude (~30°C) a été identifié comme ayant un rôle clé sur la composition microbiologique et chimique du fromage. Les populations microbiennes étaient nombreuses et diverses avec des nombres élevés de bactéries lactiques et de coliformes. Les bactéries pathogènes n'étaient pas détectées alors que les bactéries propioniques et les spores de clostridia fermentant le lactate étaient détectés dans tous les échan-tillons. Les changements dans les populations microbiennes correspondaient à des changements clés dans la composition chimique. Au cours des 2 premiers jours en chambre chaude à 30°C, le pH descendait à 4,9 et le lactose était complètement fermenté en acide lactique. Les 4 jours suivants, le métabolisme du lactate en acide butyrique (7,5 g·kg −1 ) et en acide propionique (1,7 g·kg −1 ) et une augmentation conséquente du pH à 5,7 avaient lieu. L'importance de la température en chambre chaude était démontrée. L'incubation du caillé moulé devait se faire à des températures d'environ 30°C afin d'obtenir le profil de fermentation typique. L'addition de lysozyme au lait de fabrication empêchait la formation de niveaux élevés d'acide butyrique typique du fromage Pannerone, démontrant ainsi l'implication des clostridia fermentant le lactate dans la produc...

Milk and dairy products play an important role in a healthy diet because of their high nutritional value, even if they represent a source of lipids and cholesterol. Nowadays, some commercially hypocholesterolemic products are available, which contain lactic acid bacteria (LAB). Therefore, the aims of this study were to test and compare the cholesterol removal abilities of different LAB species and to investigate the capacity of the cholesterol to change the cellular fatty acid composition of microorganisms. Fifty-eight strains of dairy LAB were studied for their ability to remove cholesterol during 24 h of growth. Two of them, L. plantarum 885 and L. acidophilus LA-5®, showed the higher reduction capability. For these strains, the cellular fatty acid composition was studied. They showed a different behaviour, which appeared related to the needs of the cells to maintain the characteristics of membrane fluidity, but was dependent upon their original fatty acid composition. Further studies are required to better characterise the LAB strains to be used to develop fermented dairy products with reduced cholesterol content or be able to induce hypocholesterolemic effects. It will also be interesting to investigate the possible modifications of the cell membrane caused by cholesterol and its possible involvement in cell metabolism.

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