The bidirectional biological interplay between microbiome and viruses in periodontitis and type-2 diabetes mellitus.

Periodontitis was an inflammatory disease associated with a dysbiosis of the oral flora characterized by a chronic sustained inflammation inducing the resorption of alveolar bone and leading to tooth loss. Type 2 diabetes mellitus (T2D) was a metabolic disease caused by impaired insulin action. The oral microbiome played a crucial role in modulating both the innate and adaptive immune system during the trigger and exacerbation of periodontitis and T2D. The bidirectional relationship of T2D and periodontitis had been the focus of intensive research, but those were not well explored. In this commentary, an in-depth analysis of the changes of microbiome and bacterial metabolites in periodontitis with or without diabetes was described. The promotion of periodontitis to T2D might involve inflammatory factors/receptors, oxidative stress, microRNA and so on. The effect of diabetes on periodontitis might involve adipose factor pathway, AGE/RAGE and RANK/RANKL pathway etc. Generally, periodontitis and diabetes are closely related to the microecological-epithelial interaction, soft tissue degradation, bone coupling disorder, immune regulation and gene transcription. The viruses, including HBV, HCV, HSV-1, Coronavirus, HCMV, EBV, HIV, phageome and so on, played an important role in the development of T2D and periodontitis. An in-depth understanding of the relationship between microbiome and host was of great significance to clarify the bidirectional mechanisms, suggesting that the periodontitis or T2D remission will have a positive impact on the other.

Beware of pharyngeal Fusobacterium nucleatum in COVID-19.

BACKGROUND: Fusobacterium nucleatum (F. n) is an important opportunistic pathogen causing oral and gastrointestinal disease. Faecalibacterium prausnitzii (F. p) is a next-generation probiotic and could serve as a biomarker of gut eubiosis/dysbiosis to some extent. Alterations in the human oral and gut microbiomes are associated with viral respiratory infection. The aim of this study was to characterise the oral and fecal bacterial biomarker (i.e., F. n and F. p) in COVID-19 patients by qPCR and investigate the pharyngeal microbiome of COVID-19 patients through metagenomic next-generation sequencing (mNGS). RESULTS: Pharyngeal F. n was significantly increased in COVID-19 patients, and it was higher in male than female patients. Increased abundance of pharyngeal F. n was associated with a higher risk of a positive SARS-CoV-2 test (adjusted OR = 1.32, 95% CI = 1.06 ~ 1.65, P < 0.05). A classifier to distinguish COVID-19 patients from the healthy controls based on the pharyngeal F. n was constructed and achieved an area under the curve (AUC) of 0.843 (95% CI = 0.688 ~ 0.940, P < 0.001). However, the level of fecal F. n and fecal F. p remained unaltered between groups. Besides, mNGS showed that the pharyngeal swabs of COVID-19 patients were dominated by opportunistic pathogens. CONCLUSIONS: Pharyngeal but not fecal F. n was significantly increased in COVID-19 patients, clinicians should pay careful attention to potential coinfection. Pharyngeal F. n may serve as a promising candidate indicator for COVID-19.

The preparation of N-IgY targeting SARS-CoV-2 and its immunomodulation to IFN-γ production in vitro.

Specific antibodies against SARS-CoV-2 structural protein have a wide range of effects in the diagnose, prevention and treatment of the COVID-19 epidemic. Among them, egg yolk immunoglobulin Y (IgY), which has high safety, high yield, and without inducing antibody-dependent enhancement, is an important biological candidate. In this study, specific IgY against the conservative nucleocapsid protein (NP) of SARS-CoV-2 was obtained by immunizing hens. Through a series of optimized precipitation and ultrafiltration extraction schemes, its purity was increased to 98%. The hyperimmune IgY against NP (N-IgY) at a titer of 1:50,000 showed strong NP binding ability, which laid the foundation of N-IgY's application targeting NP. In an in vitro immunoregulatory study, N-IgY (1 mg/mL) modulated NP-induced immune response by alleviating type II interferon secretion stimulated by NP (20 µg/mL). In summary, N-IgY can be mass produced by achievable method, which endows it with potential value against the current COVID-19 pandemic.

[Biological Product Development Strategies for Prevention and Treatment of Coronavirus Disease 2019].

Coronavirus disease 2019 (COVID-19) caused by the novel coronavirus, also known as severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2), has become a Public Health Emergency of International Concern. Due to the large infection population, broad transmissibility and high mortality, it is urgent to find out the efficient and specific methods to prevent and treat COVID-19. As biological products have broadly applied in the prevention and treatment of severe epidemic diseases, they are promising in blocking novel coronavirus infection. According to the research advances of severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS), we reviewed the potential application of biological products such as interferon, convalescent plasma, intestinal micro-ecological regulators, vaccines and therapeutic antibodies, etc. , on prevention and treatment of COVID-19. May this review be helpful for conquering COVID-19 in the near future.