But on its own, “BMI [body mass index] remains a strong independent risk factor” for severe COVID-19, according to several studies that adjusted for age, sex, social class, diabetes, and heart conditions, says Naveed Sattar, an expert in cardiometabolic disease at the University of Glasgow. “And it seems to be a linear line, straight up.”
The impact extends to the 32% of people in the United States who are overweight. The largest descriptive study yet of hospitalized U.S. COVID-19 patients, posted as a preprint last month by Genentech researchers, found that 77% of nearly 17,000 patients hospitalized with COVID-19 were overweight (29%) or obese (48%). (The Centers for Disease Control and Prevention defines overweight as having a BMI of 25 to 29.9 kilograms per square meter, and obesity as a BMI of 30 or greater.)
Nature reviews: Engineering yeast to produce medicines, immunity to Covid-19, and the mechanism of anaesthetic action.
In this episode:
00:44 Making medicine with yeast
The tropane alkaloids are an important class of medicine, but they are produced agriculturally leaving them vulnerable to extreme weather and world events. Now, researchers have engineered yeast to produce these important molecules. Research Article: Srinivasan and Smolke
06:36 Coronapod
We discuss the complex story of immunity to COVID-19, and how this may affect vaccine development. News Feature: What the immune response to the coronavirus says about the prospects for a vaccine
16:33 Research Highlights
The neurological reason for overindulgence, and the bacteria that harness copper electrodes. Research Highlight: The brain circuit that encourages eating for pleasure; Research Highlight: Microbes with mettle build their own electrical ‘wires’
19:07 The molecular mechanisms of general anaesthetics
Despite over a century of use, there’s a lot we don’t know about how anaesthetics function. This week, researchers have identified how some of them they bind to a specific neuronal receptor. Research Article: Kim et al.
26:34 Briefing Chat
Whilst the Nature Briefing is on its summer holidays, we take a look at some other science from around the web. This time we discuss Elon Musk’s latest showcase of a brain-chip, and the physics behind how boats can float upside down on levitating liquid. New Scientist: Elon Musk demonstrated a Neuralink brain implant in a live pig; Business Insider: Elon Musk’s AI brain chip company Neuralink is doing its first live tech demo on Friday. Here’s what we know so far about the wild science behind it.; Research Article: Apffel et al.; Video: The weird physics of upside down buoyancy
As states grapple with the question of when it will be safe to reopen businesses and relax social distancing, there’s increasing urgency to better understand who’s immune to Covid-19. Does having the virus and recovering mean you can’t get it again, or at least that you can’t be reinfected for some time?No one yet has good answers to these questions. Kristen V. Brown looked into what we do, and don’t, know about the science of coronavirus immunity.
From a Science Magazine online article:
Antibiotic use diminished the gut microbiome composition and impaired the ability of the immune system to generate antibodies. Treatment with antibiotics also disturbed bile acid metabolism and caused inflammatory responses.
From the original findings the Journal “Cell.com”:
Emerging evidence indicates a central role for the microbiome in immunity. However, causal evidence in humans is sparse. Here, we administered broad-spectrum antibiotics to healthy adults prior and subsequent to seasonal influenza vaccination. Despite a 10,000-fold reduction in gut bacterial load and long-lasting diminution in bacterial diversity, antibody responses were not significantly affected. However, in a second trial of subjects with low pre-existing antibody titers, there was significant impairment in H1N1-specific neutralization and binding IgG1 and IgA responses.
In addition, in both studies antibiotics treatment resulted in (1) enhanced inflammatory signatures (including AP-1/NR4A expression), observed previously in the elderly, and increased dendritic cell activation; (2) divergent metabolic trajectories, with a 1,000-fold reduction in serum secondary bile acids, which was highly correlated with AP-1/NR4A signaling and inflammasome activation. Multi-omics integration revealed significant associations between bacterial species and metabolic phenotypes, highlighting a key role for the microbiome in modulating human immunity.
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