No abstract

The influence of the industrial process on the properties of probiotics, administered as complex manufactured products, has been poorly investigated. In the present study, we comparatively assessed the cell wall characteristics of the probiotic strain Lactobacillus rhamnosus Lcr35® together with three of its commercial formulations with intestinal applications. Putative secreted and transmembrane-protein-encoding genes were initially searched in silico in the genome of L. rhamnosus Lcr35®. A total of 369 candidate genes were identified which expressions were followed using a custom Lactobacillus DNA chip. Among them, 60 or 67 genes had their expression either upregulated or downregulated in the Lcr Restituo® packet or capsule formulations, compared to the native Lcr35® strain. Moreover, our data showed that the probiotic formulations (Lcr Lenio®, Lcr restituo® capsule and packet) showed a better capacity to adhere to intestinal epithelial Caco-2 cells than the native Lcr35® strain. Microbial (MATS) tests showed that the probiotic was an electron donor and that they were more hydrophilic than the native strain. The enhanced adhesion capacity of the active pharmaceutical ingredients (APIs) to epithelial Caco-2 cells and their antipathogen effect could be due to this greater surface hydrophilic character. These findings suggest that the manufacturing process influences the protein composition and the chemical properties of the cell wall. It is therefore likely that the antipathogen effect of the formulation is modulated by the industrial process. Screening of the manufactured products' properties would therefore represent an essential step in evaluating the effects of probiotic strains.

The vaginal microbiota balance is quite fragile and susceptible to the development of vaginosis and candidiasis. The current diagnostic method for bacterial vaginosis relies on the evaluation of different bacterial morphotypes using the Nugent score. This method is only partially in correlation with a DNA sequencing-based diagnostic or Amsel criteria used by clinicians, suggesting the need for new molecular approaches dedicated to the diagnosis of BV. The objective of this study was to develop and validate a quantitative polymerase chain reaction (qPCR) assay for the specific and rapid detection of three vaginal pathogens, i.e. Candida, Gardnerella and Atopobium and the commensal Lactobacillus genera. For this purpose, four oligonucleotide primer pairs were designed and tested to obtain optimal amplification of the four target genera. The qPCR assay was also tested on the non-target genera and on human DNA. The designed primers allowed specific amplification of the target organisms in vitro and in clinical vaginal samples. The qPCR assay designed in this study is effective to specifically detect these genera in clinical samples as a molecular technique complementary to the Nugent score. It can be used in epidemiological studies for understanding the role of these pathogens and to follow their abundance in the microbiota in disease processes such as the development of vulvovaginal candidiasis and bacterial vaginosis.