Gut Microbiome Reveals Specific Dysbiosis in Primary Osteoporosis.

Object: Primary osteoporosis (PO) is the most common bone disease, which is characterized by decreased bone mass, damage of bone tissue microstructure, increased bone fragility, and is prone to fracture. Gut microbiome may be involved in bone metabolism of PO through gut-brain axis regulation of immune system and endocrine system, however, the specific mechanism is still unclear. The purpose of this study was to characterize the gut microbiome of patients with PO and its possible role in the occurrence and development of the disease. Methods: Fecal samples were collected from 48 PO patients and 48 healthy controls (HC). The composition of gut microbiome community was analyzed by 16s rDNA amplification sequencing, and the difference of gut microbiome composition between PO patients and HC individuals was compared. PICRUSt was also used to predict the biological function of gut microbiome in patients with PO, and to explore its possible role in the occurrence and development of this disease. The classification model is constructed by random forest algorithm so as to screen the key biomarkers. Result: The diversity of gut microorganisms in PO patients was significantly higher than that in HC group (p < 0.05) and there was significant difference in microbial composition in PO group. The abundance of Dialister (0.036 vs. 0.004, p < 0.001) and Faecalibacterium (0.331 vs. 0.132, p < 0.001) were significantly enriched which were the key flora related to PO. Although no significant correlation between bone mineral density and the richness of microbial communities are found, PICRUST results show that there are a wide range of potential pathways between gut microbiome and PO patients, including genetic information processing, metabolism, environmental information processing, cellular processes, human diseases, and organic systems. Notably, the discriminant model based on dominant microflora can effectively distinguish PO from HC (AUC = 93.56). Conclusions: The findings show that PO is related to the change of gut microbiome, especially the enriched Dialister and Faecalibacterium genera, which give new clues to understand the disease and provide markers for the diagnosis and new strategies for intervention treatment of the disease.

PCR-dipstick DNA chromatography for profiling of a subgroup of caries-associated bacterial species in plaque from healthy coronal surfaces and periodontal pockets.

The onset of plaque-mediated disease, including dental caries and periodontal diseases, is highly associated with compositional change of the resident microflora from the ecological perspective. As specific bacterial profiles have been linked to different disease stages, microbial compositional measurements might therefore have great value for clinical diagnosis. Previously we have reported a dry-reagent strip biosensor-PCR-dipstick DNA chromatography, which utilized molecular recognition of oligonucleotides and biotin-streptavidin, and the optical property of colored microspheres, for semiquantifying a five-membered subgroup of caries-associated bacterial species in supragingival plaque from healthy coronal surfaces of teeth. The present study aimed to evaluate this technique's ability to differentiate microflora by comparing the subset profiles. Sixteen subgingival plaque specimens were pooled from periodontal pockets and analyzed for the composition of Streptococcus mutans, Streptococcus sobrinus, Scardovia wiggsiae, Actinomyces sp. and Veillonella parvula. Detection frequencies, relative abundance of each bacterial species, and the five-membered bacterial profiles were compared between supra- and subgingival groups. The supragingival plaque harbored significantly more of the tested species and higher amount of Actinomyces sp. and V. parvula. In subgingival plaque, the predominance was obscured, since several highly overlapped profiles were found at comparable frequencies. Thus, PCR-dipstick DNA chromatography using the same plaque sample enabled simultaneous profiling of multiple species at species level and facilitated discrimination between anticipated different microflora, making this technique a promising chair-side microbiota profiling method.

Rapid and sensitive PCR-dipstick DNA chromatography for multiplex analysis of the oral microbiota.

A complex of species has been associated with dental caries under the ecological hypothesis. This study aimed to develop a rapid, sensitive PCR-dipstick DNA chromatography assay that could be read by eye for multiplex and semiquantitative analysis of plaque bacteria. Parallel oligonucleotides were immobilized on a dipstick strip for multiplex analysis of target DNA sequences of the caries-associated bacteria, Streptococcus mutans, Streptococcus sobrinus, Scardovia wiggsiae, Actinomyces species, and Veillonella parvula. Streptavidin-coated blue-colored latex microspheres were to generate signal. Target DNA amplicons with an oligonucleotide-tagged terminus and a biotinylated terminus were coupled with latex beads through a streptavidin-biotin interaction and then hybridized with complementary oligonucleotides on the strip. The accumulation of captured latex beads on the test and control lines produced blue bands, enabling visual detection with the naked eye. The PCR-dipstick DNA chromatography detected quantities as low as 100 pg of DNA amplicons and demonstrated 10- to 1000-fold higher sensitivity than PCR-agarose gel electrophoresis, depending on the target bacterial species. Semiquantification of bacteria was performed by obtaining a series of chromatograms using serial 10-fold dilution of PCR-amplified DNA extracted from dental plaque samples. The assay time was less than 3 h. The semiquantification procedure revealed the relative amounts of each test species in dental plaque samples, indicating that this disposable device has great potential in analysis of microbial composition in the oral cavity and intestinal tract, as well as in point-of-care diagnosis of microbiota-associated diseases.