Although type 2 diabetes (T2D) is a major comorbidity of novel coronavirus disease 2019 (COVID-19), the impact of blood glucose control on the degree of medical interventions required and on all-cause mortality of patients with COVID-19 and pre-existing T2D remains unclear. Here, Zhu et al. report that among $7,300 individuals with COVID-19 (among which nearly 1,000 had T2D) in Hubei Province, China, those with T2D had significantly increased medical interventions and mortality risk. But among the patients with T2D, those with well-controlled blood glucose regulation (upper limit % 10 mmol/L) fared much better than those with poorly controlled blood glucose (upper limit > 10 mmol/L). These findings provide clinical evidence correlating more proper blood glucose control with improved outcomes in patients with COVID-19.

Highlights d Statin treatment among 13,981 patients with COVID-19 was retrospectively studied d Statin use in this cohort was associated with a lower risk of all-cause mortality d Adding an ACE inhibitor or an ARB did not affect statinassociated outcome in the cohort d The benefit of statins among this cohort may be due to immunomodulatory benefits

BackgroundSystemic lupus erythematosus, characterized by persistent inflammation, is a complex autoimmune disorder with no known cure. Immunosuppressants used in treatment put patients at a higher risk of infections. New knowledge of disease modulators, such as symbiotic bacteria, can enable fine-tuning of parts of the immune system, rather than suppressing it altogether.ResultsDysbiosis of gut microbiota promotes autoimmune disorders that damage extraintestinal organs. Here we report a role of gut microbiota in the pathogenesis of renal dysfunction in lupus. Using a classical model of lupus nephritis, MRL/lpr, we found a marked depletion of Lactobacillales in the gut microbiota. Increasing Lactobacillales in the gut improved renal function of these mice and prolonged their survival. We used a mixture of 5 Lactobacillus strains (Lactobacillus oris, Lactobacillus rhamnosus, Lactobacillus reuteri, Lactobacillus johnsonii, and Lactobacillus gasseri), but L. reuteri and an uncultured Lactobacillus sp. accounted for most of the observed effects. Further studies revealed that MRL/lpr mice possessed a “leaky” gut, which was reversed by increased Lactobacillus colonization. Lactobacillus treatment contributed to an anti-inflammatory environment by decreasing IL-6 and increasing IL-10 production in the gut. In the circulation, Lactobacillus treatment increased IL-10 and decreased IgG2a that is considered to be a major immune deposit in the kidney of MRL/lpr mice. Inside the kidney, Lactobacillus treatment also skewed the Treg-Th17 balance towards a Treg phenotype. These beneficial effects were present in female and castrated male mice, but not in intact males, suggesting that the gut microbiota controls lupus nephritis in a sex hormone-dependent manner.ConclusionsThis work demonstrates essential mechanisms on how changes of the gut microbiota regulate lupus-associated immune responses in mice. Future studies are warranted to determine if these results can be replicated in human subjects.Electronic supplementary materialThe online version of this article (doi:10.1186/s40168-017-0300-8) contains supplementary material, which is available to authorized users.