Background: Although recent studies have indicated that gut microbiome dysbiosis was significantly associated with the onset of type 2 diabetes mellitus (T2DM), information on the role of blood microbiome in T2DM development is scarce.Methods: Fifty incident T2DM cases and 100 matched non‐T2DM controls were selected from a prospective cohort study of “135.” The composition of the blood microbiome was characterized using bacterial 16S ribosomal RNA (16S rRNA) gene sequencing from pre‐diagnostic blood sample. The amplicons were normalized, pooled, and sequenced on the Illumina MiSeq instrument using a MiSeq Reagent Kit PE300 v3 kit.Results: Totally, 3 000 391 and 6 244 227 high‐quality sequences were obtained from T2DM patients and non‐T2DM controls, respectively. The mean diversity of the blood microbiome (Simpson, Chao1 and Shannon indices) was not different between two groups at baseline. At genus level, the Aquabacterium, Xanthomonas, and Pseudonocardia were presented with lower abundance, while Actinotalea, Alishewanella, Sediminibacterium, and Pseudoclavibacter were presented with higher abundance among T2DM cases compared to those in non‐T2DM controls. As the results shown, participants carried the genus Bacteroides in blood were significantly associated with a decreased risk for T2DM development, with 74% vs 88% (adjusted OR: 0.367, 95% CI: 0.151‐0.894). However, participants carried the genus Sediminibacterium have an increased risk for T2DM, with adjusted OR (95% CI) being 14.098 (1.358, 146.330).Conclusions: Blood microbiome may play an etiology role in the development of T2DM. These findings would be useful to develop microbiota‐based strategies for T2DM prevention and control.

Hypertension is a common comorbidity in COVID-19 patients. However, the association of hypertension with the severity and fatality of COVID-19 remain unclear. In the present meta-analysis, relevant studies reported the impacts of hypertension on SARS-CoV-2 infection were identified by searching PubMed, Elsevier Science Direct, Web of Science, Wiley Online Library, Embase and CNKI up to 20 March 2020. As the results shown, 12 publications with 2389 COVID-19 patients (674 severe cases) were included for the analysis of disease severity. The severity rate of COVID-19 in hypertensive patients was much higher than in non-hypertensive cases (37.58%vs19.73%, pooled OR: 2.27, 95% CI: 1.80–2.86). Moreover, the pooled ORs of COVID-19 severity for hypertensionvs.non-hypertension was 2.21 (95% CI: 1.58–3.10) and 2.32 (95% CI: 1.70–3.17) in age <50 years and ⩾50 years patients, respectively. Additionally, six studies with 151 deaths of 2116 COVID-19 cases were included for the analysis of disease fatality. The results showed that hypertensive patients carried a nearly 3.48-fold higher risk of dying from COVID-19 (95% CI: 1.72–7.08). Meanwhile, the pooled ORs of COVID-19 fatality for hypertensionvs.non-hypertension was 6.43 (95% CI: 3.40–12.17) and 2.66 (95% CI: 1.27–5.57) in age <50 years and ⩾50 years patients, respectively. Neither considerable heterogeneity nor publication bias was observed in the present analysis. Therefore, our present results provided further evidence that hypertension could significantly increase the risks of severity and fatality of SARS-CoV-2 infection.

Objective: Hepatitis B vaccine is regarded as the most effective method for the prevention of hepatitis B virus (HBV) infection. However, several factors such as age, body mass index and immunocompetent state have been reported to be associated with reduced immunization responses. The present commentary was aimed to discuss the influences of obesity on the immunogenicity of hepatitis B vaccines. Data sources: Available peer-reviewed literatures, practice guidelines, and statistics published on hepatitis B vaccine in obesity between 1973 and 2015. Conclusions: Obesity was significantly associated with non-response to hepatitis B vaccine immunization. The risk of nonresponsiveness of hepatitis B vaccine among obese people increased with BMI. Moreover, the obesity might lead to an increased risk of HBV vaccine-escape mutations. The mechanism responsible for decreased immunization responses in obesity included leptin-induced systemic and B cell intrinsic inflammation, impaired T cell responses and lymphocyte division and proliferation. Therefore, more studies should be performed to analyze the influences of obesity on the immunogenicity of hepatitis B vaccines to improve the immunoprotecive effect of hepatitis B vaccines in future.

Although previous studies have reported the gut microbiome is closely related to hypertension development, whether the change in blood microbiome is associated with the risk of hypertension remains unclear. One hundred and fifty incident hypertension cases and 150 age (± 2 years) and gender (1:1) matched nonhypertension controls included in this nested case–control study were recruited from a prospective cohort study of “135.” The composition of the blood microbiome was characterized using bacterial 16S ribosomal RNA gene sequencing. The relative abundance of detected bacteria was converted to a negative logarithm of 10 for the statistical analysis. Totally, 10,689,961 high-quality sequences were acquired. The Chao1 index of the blood microbiome in nonhypertension controls was significantly higher than in hypertensive group (2,302.08 ± 752.78 vs. 1,598.21 ± 500.88, P < 0.001). Compared with the nonhypertension controls, the relative abundance of Proteobacteria phylum was significantly increased (P < 0.001), whereas the relative abundance of phyla Firmicutes and Bacteroidetes were significantly reduced in the hypertensive cases (P < 0.001 and P = 0.039, respectively). At genus level, the risk of hypertension was directly associated with the relative abundance of Acinetobacter (odds ratio [OR]: 1.43, 95% confidence interval [CI]: 1.01–2.03), Sphingomonas (OR: 1.84, 95% CI: 1.32–2.56), and Staphylococcus (OR: 0.51, 95% CI: 0.36–0.73), respectively. In addition, the relative abundance of Pseudomonas was minor positively correlated with the total cholesterol level. However, the relative Staphylococcus level was minor positively correlated with high-density lipoprotein cholesterol level. The composition of the blood microbiome is significantly associated with the development of hypertension.