Aims: Lactobacilli strains with probiotic effects have been widely used in dairy products such as yoghurts as well as in food additives and pharmaceuticals. Despite their successful commercial application, the current species identification and quantification methods of the genus Lactobacillus are timeconsuming and labour-intensive. Methods and Results: To fulfil the requirements of a robust quality management, we have developed a quantitative real-time PCR assay based on the heat shock protein 60 gene (hsp60) for accurate identification and quantification of five commercially important Lactobacillus species. The developed assay allows an unambiguous species-specific detection of the species Lact. acidophilus, Lact. brevis, Lact. delbrueckii subsp. bulgaricus, Lact. helveticus and Lact. reuteri from bacterial cultures as well as directly from dairy products for instance yoghurt. Conclusions: With the assay, we were able to specifically detect lactobacilli strains down to 10 5 CFU ml À1 directly from yoghurt, which is a sufficient detection limit as commercial products usually contain 10 6 -10 12 CFU ml À1 of probiotic strains. Significance and Impact of the Study: The real-time PCR assay developed here might become a convenient tool enabling an accurate, fast and sensitive detection of probiotic lactobacilli commercially used in food.

Commensal microbes critically regulate skeletal homeostasis, yet the impact of specific microbiota communities on osteoimmune response mechanisms is unknown. To discern osteoimmunomodulatory effects imparted by the commensal oral microbiota that are distinct from the systemic microbiota, osteoimmunology studies were performed in both alveolar bone and nonoral skeletal sites of specific-pathogen-free (SPF) vs. germ-free (GF) mice, and SPF mice subjected to saline vs. chlorhexidine oral rinses. SPF vs. GF mice had reduced cortical/trabecular bone and an enhanced pro-osteoclastic phenotype in alveolar bone. Toll-like receptor signaling and TH17 cells that have known pro-osteoclastic actions were increased in alveolar, but not long-bone marrow, of SPF vs. GF mice. MHC class II antigen presentation genes and activated dendritic cells and CD4 + T-cells were elevated in alveolar, but not long-bone marrow, of SPF vs. GF mice. These findings were substantiated by in vitro allostimulation studies demonstrating increased activated dendritic cells derived from alveolar, but not long-bone marrow, of SPF vs. GF mice. Chlorhexidine antiseptic rinse depleted the oral, but not gut, bacteriome in SPF mice. Findings from saline-vs. chlorhexidine-treated SPF mice corroborated outcomes from SPF vs. GF mice, which reveals that the commensal oral microbiota imparts osteoimmunomodulatory effects separate from the systemic microbiome.

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