Properties of Lactobacillus plantarum group strains isolated from two kinds of Japanese post-fermented teas, Ishizuchi-kurocha and Awa-bancha, were compared. Although lactic acid bacteria isolated from the fermented teas were identified as L. plantarum via homology comparison of 16S ribosomal RNA gene sequences, classification of L. plantarum based on ribosomal proteins showed that the strains isolated from Ishizuchi-kurocha and Awa-bancha were different. According to classification by the ribosomal protein typing, Ishizuchi-kurocha–derived strains belong to the same group as L. plantarum subsp. plantarum JCM 1149^T. Awa-bancha–derived strains were assigned to a different group. This pattern was also applicable to strains isolated more than 10 years ago. A further analysis based on recA and a dnaK gene showed that Awa-bancha-derived strains were closely related to L. pentosus. The interactions with cultured cells were different between strain JCM 1149^T and the Ishizuchi-kurocha–derived strains. The Ishizuchi-kurocha–derivedstrains showed strong adhesion to Caco-2 cells. In contrast, strain JCM 1149^T and the Awa-bancha–derived strains hardly adhered to Caco-2 cells. According to the ribosomal protein typing, sugar utilization, and interaction with Caco-2 cells, although these properties were dependent on the strain strictly speaking, the L. plantarum group strains in this study can be subdivided into two groups: (1) type strain JCM 1149^T and Ishizuchi-kurocha–derived strains and (2) Awa-bancha–derived strains. A regionally unique microorganism may persist in each traditional fermented drink.

The incidence of Clostridium difficile infection (CDI) is greater in elderly orthopedic patients. We conducted a retrospective case-control study by selecting elderly patients who underwent proximal femoral fracture surgery to investigate the effect of probiotics on CDI prevention. Cases were diagnosed with CDI by an enzyme-linked immunosorbent assay for C. difficile toxins using frozen stool specimens. The primary method of exposure was receipt of combination probiotics such as Streptococcus faecalis, Bacillus mesentericus, and Clostridium butyricum. The crude odds ratio between developing CDI and receiving combination probiotics was 0.074 (95% CI: 0.010–0.565; p=0.002). Adjunctive combination probiotics among elderly patients who undergo proximal femoral fracture surgery likely reduces the probability of CDI.

We aimed to determine whether the composition of the fecal microbiota changes under hyperbaric conditions. In this study, we collected fecal samples from 6 healthy divers at three points during deep diving training (before, 2.1 MPa, end). The frequency of Clostridium cluster XVIII tended to be increased after compression. The frequencies of Clostridium cluster IV and subcluster XIVa were inversely correlated with that of Bacteroides. The compositional changes in the fecal microbiota exhibited interindividual variability. These findings suggest that hyperbaric conditions affect the fecal microbiota.

The gastrointestinal tract is believed to be colonized rapidly with bacteria immediately from birth. The source of these intestinal microbes is an ongoing topic of interest because increasing evidence suggests that the composition of the initial intestinal bacterial colonization strongly affects health. In particular, the source of bifidobacteria has received marked attention because these bacteria are suggested to play a crucial role in protecting against susceptibility to diverse diseases later in life. However, the source of these microbes has remained unclear. Recently, it was confirmed that mothers transmit their unique bifidobacterial strains to their children shortly after birth. The transmitted strains predominate during early infancy, suggesting that maternal intestinal bifidobacteria are an important source of the infant gut microbiota. Accordingly, maintenance of a healthy, balanced gut microbiota during pregnancy has an important positive influence on the newborn gut microbiota.

Gut microbiota influences the host immune system and are associated with various diseases. In recent years, postmenopausal bone loss has been suggested to be related to gut microbiota. In the present study, we investigated the treatment effect of the probiotic Bacillus subtilis C-3102 (C-3102) on bone mineral density (BMD) and its influence on gut microbiota in healthy postmenopausal Japanese women. Seventy-six healthy postmenopausal Japanese women were treated with a placebo or C-3102 spore-containing tablets for 24 weeks. When compared with the placebo, C-3102 significantly increased total hip BMD (placebo = 0.83 ± 0.63%, C-3102 = 2.53 ± 0.52%, p=0.043). There was a significant group-by-time interaction effect for urinary type I collagen cross-linked N-telopeptide (uNTx) (p=0.033), a marker of bone resorption. Specifically, the C-3102 group showed significantly lower uNTx when compared with the placebo group at 12 weeks of treatment (p=0.015). In addition, in the C-3102 group, there was a trend towards a decrease in the bone resorption marker tartrate-resistant acid phosphatase isoform 5b (TRACP-5b) when compared with the placebo group at 12 weeks of treatment (p=0.052). The relative abundance of genus Bifidobacterium significantly increased at 12 weeks of treatment compared with the baseline in the C-3102 group. The relative abundance of genus Fusobacterium was significantly decreased in the C-3102 group at 12 and 24 weeks of treatment compared with the baseline. These data suggested that C-3102 improves BMD by inhibiting bone resorption and modulating gut microbiota in healthy postmenopausal women.