The oral microbiota is associated with oral diseases and digestive systemic diseases. Nevertheless, the causal relationship between them has not been completely elucidated, and colonisation of the gut by oral bacteria is not clear due to the limitations of existing research models. The aim of this study was to develop a human oral microbiota-associated (HOMA) mouse model and to investigate the ecological invasion into the gut. By transplanting human saliva into germ-free (GF) mice, a HOMA mouse model was first constructed. 16S rRNA gene sequencing was used to reveal the biogeography of oral bacteria along the cephalocaudal axis of the digestive tract. In the HOMA mice, 84.78% of the detected genus-level taxa were specific to the donor. Principal component analysis (PCA) revealed that the donor oral microbiota clustered with those of the HOMA mice and were distinct from those of specific pathogen-free (SPF) mice. In HOMA mice, OTU counts decreased from the stomach and small intestine to the distal gut. The distal gut was dominated by Streptococcus, Veillonella, Haemophilus, Fusobacterium, Trichococcus and Actinomyces . HOMA mice and human microbiota-associated (HMA) mice along with the GF mice were then cohoused. Microbial communities of cohoused mice clustered together and were significantly separated from those of HOMA mice and HMA mice. The Source Tracker analysis and network analysis revealed more significant ecological invasion from oral bacteria in the small intestines, compared to the distal gut, of cohoused mice. In conclusion, a HOMA mouse model was successfully established. By overcoming the physical and microbial barrier, oral bacteria colonised the gut and profiled the gut microbiota, especially in the small intestine.

ObjectivesEmerging evidence suggests that the microbiome plays an important role in the pathogenesis of osteoarthritis (OA). We aimed to test the two-hit model of OA pathogenesis and potentiation in which one ‘hit’ is provided by an adverse gut microbiome that activates innate immunity; the other ‘hit’ is underlying joint damage.MethodsMedical history, faecal and blood samples were collected from human healthy controls (OA-METS-, n=4), knee OA without metabolic syndrome (OA+METS-, n=7) and knee OA with metabolic syndrome (OA+METS+, n=9). Each group of human faecal samples, whose microbial composition was identified by 16S rRNA sequencing, was pooled and transplanted into germ-free mice 2 weeks prior to meniscal/ligamentous injury (MLI) (n≥6 per group). Eight weeks after MLI, mice were evaluated for histological OA severity and synovitis, systemic inflammation and gut permeability.ResultsHistological OA severity following MLI was minimal in germ-free mice. Compared with the other groups, transplantation with the OA+METS+ microbiome was associated with higher mean systemic concentrations of inflammatory biomarkers (interleukin-1β, interleukin-6 and macrophage inflammatory protein-1α), higher gut permeability and worse OA severity. A greater abundance of Fusobacterium and Faecalibaterium and lesser abundance of Ruminococcaceae in transplanted mice were consistently correlated with OA severity and systemic biomarkers concentrations.ConclusionThe study clearly establishes a direct gut microbiome-OA connection that sets the stage for a new means of exploring OA pathogenesis and potentially new OA therapeutics. Alterations of Fusobacterium, Faecalibaterium and Ruminococcaceae suggest a role of these particular microbes in exacerbating OA.

Our aims of the research were to study the antimicrobial effect of dimethylaminododecyl methacrylate (DMADDM) modified denture base resin on multi-species biofilms and the biocompatibility of this modified dental material. Candida albicans (C. albicans), Streptococcus mutans (S. mutans), Streptococcus sanguinis (S. sanguinis), as well as Actinomyces naeslundii (A. naeslundii) were used for biofilm formation on denture base resin. Colony forming unit (CFU) counts, microbial viability staining, and 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) array were used to evaluate the antimicrobial effect of DMADDM. C. albicans staining and Real-time PCR were used to analyze the morphology and expression of virulence genes of C. albicans in biofilm. Lactate dehydrogenase (LDH) array and Real-time PCR were conducted to examine the results after biofilm co-cultured with epithelial cell. Hematoxylin and eosin (HE) staining followed by histological evaluation were used to study the biocompatibility of this modified material. We found that DMADDM containing groups reduced both biomass and metabolic activity of the biofilm significantly. DMADDM can also inhibit the virulence of C. albicans by means of inhibiting the hyphal development and downregulation of two virulence related genes. DMADDM significantly reduced the cell damage caused by multi-species biofilm according to the LDH activity and reduced the expression of IL-18 gene of the cells simultaneously. The in vivo histological evaluation proved that the addition of DMADDM less than 6.6% in denture material did not increase the inflammatory response (p > 0.05). Therefore, we proposed that the novel denture base resin containing DMADDM may be considered as a new promising therapeutic system against problems caused by microbes on denture base such as denture stomatitis.

The objectives of this study were to investigate the effects of dental adhesives containing quaternary ammonium methacrylates (QAMs) with different alkyl chain lengths (CL) on ecological caries prevention in vitro. Five QAMs were synthesized with a CL = 3, 6, 9, 12, and 16 and incorporated into adhesives. Micro-tensile bond strength and surface charge density were used to measure the physical properties of the adhesives. The proportion change in three-species biofilms consisting of Streptococcus mutans, Streptococcus sanguinis, and Streptococcus gordonii was tested using the TaqMan real-time polymerase chain reaction. Lactic acid assay, MTT [3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay, exopolysaccharide staining, live/dead staining, scanning electron microscopy (SEM), and transverse microradiography (TMR) were performed to study the anti-biofilm and anti-demineralization effects of the dental adhesives. The results showed that incorporating QAMs with different alkyl chain lengths into the adhesives had no obvious effect on the dentin bond strength. The adhesives containing QAMs with a longer alkyl chain developed healthier biofilms. The surface charge density, anti-biofilm, and anti-demineralization effects of the adhesives increased with a CL of the QAMs from 3 to 12, but decreased slightly with a CL from 12 to 16. In conclusion, adhesives containing QAMs with a tailored chain length are promising for preventing secondary caries in an “ecological way”.

BackgroundLimited therapeutic options are available for triple-negative breast cancer (TNBC), emphasizing an urgent need for more effective treatment approaches. The development of strategies by targeting tumor-associated macrophages (TAMs) to stimulate their ability of Programmed Cell Removal (PrCR) provides a promising new immunotherapy for TNBC treatment.MethodsCD47 is a critical self-protective “don’t eat me” signal on multiple human cancers against macrophage immunosurveillance. Using human and mouse TNBC preclinical models, we evaluated the efficacy of PrCR-based immunotherapy by blocking CD47. We performed high-throughput screens on FDA-approved anti-cancer small molecule compounds for agents potentiating PrCR and enhancing the efficacy of CD47-targeted therapy for TNBC treatment.ResultsWe showed that CD47 was widely expressed on TNBC cells and TAMs represented the most abundant immune cell population in TNBC tumors. Blockade of CD47 enabled PrCR of TNBC cells, but the efficacy was not satisfactory. Our high-throughput screens identified cabazitaxel in enhancing PrCR-based immunotherapy. A combination of CD47 blockade and cabazitaxel treatment yielded a highly effective treatment strategy, promoting PrCR of TNBC cells and inhibiting tumor development and metastasis in preclinical models. We demonstrated that cabazitaxel potentiated PrCR by activating macrophages, independent of its cytotoxicity toward cancer cells. When treated with cabazitaxel, the molecular and phenotypic signatures of macrophages were polarized toward M1 state, and the NF-kB signaling pathway became activated.ConclusionThe combination of CD47 blockade and macrophage activation by cabazitaxel synergizes to vastly enhance the elimination of TNBC cells. Our results show that targeting macrophages is a promising and effective strategy for TNBC treatment.

(1) secondary caries was successfully produced in rats; (2) there was a correlation between the modified Keyes scoring method and micro-CT in the evaluation of the secondary caries; (3) the adhesive containing DMADDM significantly reduced both LD and ML (according to micro-CT), and also lowered the scores (based on the modified Keyes scoring method). This suggests that the novel DMADDM adhesive could perform an anticaries function in vivo via the secondary caries animal model which was also developed and testified in research. Secondary caries is one of the major reasons leading to the failure of caries restoration treatment. As a solution, anticaries adhesives perform well in biofilm inhibition in vitro. However, the lack of secondary caries animal models limits the evaluation of anticaries adhesives in vivo. Secondary caries is one of the main reasons for restoration failure with a heavy economic burden [Sakaguchi, 2005;Kasraei et al., 2017]. While many factors facilitate the development of secondary caries, oral bacteria and acid production are the initiators of dental caries [Mjor Keywords Antibacterial material · Bonding system · Dimethylaminododecyl methacrylate · Keyes animal model · Micro-CT · Tooth restoration AbstractWe investigated the anticaries properties of an adhesive containing dimethylaminododecyl methacrylate (DMADDM) in vivo via a secondary caries animal model. Cavities were prepared in the maxillary first molars of Wistar rats. DMADDM-containing adhesives were applied on one side and commercial adhesives on the opposite side as a control. After a 3-week feeding period to induce secondary caries, the molars were harvested for the evaluation of the secondary caries. Lesion depth (LD) and mineral loss (ML) were measured via a micro-CT method, and a modified Keyes scoring method yielded scores for the caries lesions. Statistical analysis was divided into 2 parts: a correlation analysis between 2 evaluations with one-way ANOVA and a least-significant differences (LSD) test, and an evaluation of anticaries adhesives with a paired samples t test. The results showed that:

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IntroductionThe oral squamous cell carcinoma (OSCC) is detrimental to patients’ physical and mental health. The prognosis of OSCC depends on the early diagnosis of OSCC in large populations.ObjectivesHere, the present study aimed to develop an early diagnostic model based on the relationship between OSCC and oral microbiota.MethodsOverall, 164 samples were collected from 47 OSCC patients and 48 healthy individuals as controls, including saliva, subgingival plaque, the tumor surface, the control side (healthy mucosa), and tumor tissue. Based on 16S rDNA sequencing, data from all the five sites, and salivary samples only, two machine learning models were developed to diagnose OSCC.ResultsThe average diagnostic accuracy rates of five sites and saliva were 98.17% and 95.70%, respectively. Cross-validations showed estimated external prediction accuracies of 96.67% and 93.58%, respectively. The false-negative rate was 0%. Besides, it was shown that OSCC could be diagnosed on any one of the five sites. In this model, Actinobacteria, Fusobacterium, Moraxella, Bacillus, and Veillonella species exhibited strong correlations with OSCC.ConclusionThis study provided a noninvasive and inexpensive way to diagnose malignancy based on oral microbiota without radiation. Applying machine learning methods in microbiota data to diagnose OSCC constitutes an example of a microbial assistant diagnostic model for other malignancies.