Medical Bulletin 2/November/2022

Infection with the pandemic virus, SARS-CoV-2, can reduce the number of bacterial species in a patient's gut, with the lesser diversity creating space for dangerous microbes to thrive, a new study finds.

The study builds on the realization that widespread use of antibiotics to fight infections with disease-causing bacteria in recent decades, by killing off species most vulnerable to available drugs, has left in place more species that are resistant to antibiotics. In addition, disruptions in gut bacterial ratios have previously been linked to more severe COVID-19.

However, researchers say, it has remained unclear until now which came first, the coronavirus infection disrupting the gut microbiome or an already weakened gut making the body more vulnerable to the virus. The new study appears to favor the former explanation. The new investigation also revealed that antibiotic-resistant species can escape into the bloodstream, putting patients at greater risk for life-threatening secondary infections.

Reference:

Ken Cadwell et al,Gut microbiome dysbiosis in antibiotic-treated COVID-19 patients is associated with microbial translocation and bacteremia, Nature Communications, DOI 10.1038/s41467-022-33395-6

Poor quality sleep and irreversible glaucoma risk linked: UK Biobank study

Glaucoma is a leading cause of blindness and will likely affect an estimated 112 million people worldwide by 2040.

Characterised by progressive loss of light sensitive cells in the eye and optic nerve damage, its causes and contributory factors are still poorly understood. But if left untreated, glaucoma can progress to irreversible blindness.

Poor quality sleep, including too much or too little shut eye, daytime sleepiness, and snoring, may be linked to a heightened risk of developing irreversible sight loss (glaucoma), suggests a large UK Biobank study published in the open access journal BMJ Open.

The findings underscore the need for sleep therapy in people at high risk of the disease as well as eye checks among those with chronic sleep disorders to check for early signs of glaucoma, conclude the researchers.

Reference:

Association of sleep behaviour and pattern with the risk of glaucoma: a prospective cohort study in the UK Biobank,BMJ Open, DOI 10.1136/bmjopen-2022-063676

Scientists find new ways in which reproduction permanently alters females' bones

A rceent discovery sheds new light on how giving birth can permanently change the body.

"A bone is not a static and dead portion of the skeleton," notes NYU anthropologist Shara Bailey, one of the study's authors. "It continuously adjusts and responds to physiological processes."explains Paola Cerrito, who led the research as a doctoral student in NYU's Department of Anthropology and College of Dentistry.

"Our findings provide additional evidence of the profound impact that reproduction has on the female organism, further demonstrating that the skeleton is not a static organ, but a dynamic one that changes with life events,"

Specifically, the researchers found that calcium, magnesium, and phosphorus concentrations are lower in females who have experienced reproduction. These changes are linked to giving birth itself and to lactation.

Reference:

Paola Cerrito et al,PLoS ONE, DOI 10.1371/journal.pone.0276866

Physical activity in the afternoon linked to better control of blood sugar: Study

Timing of physical activity is a relatively unexplored field in human biology and the mechanisms underlying the potential benefits of timing of physical activity remain unclear. Earlier studies have shown that metabolic responses to high-intensity exercise differed based on the time of day the exercise was performed. In addition, muscular strength as well as the metabolic function of skeletal muscle cells show a peak in the late afternoon, suggesting that being most active during this period may result in a more pronounced metabolic response than activity earlier in the day.

A new study published in Diabetologia (the journal of the European Association for the Study of Diabetes [EASD]) finds that afternoon or evening physical activity is associated with reduced insulin resistance (and thus better blood sugar control) when compared with an even distribution of physical activity through the day. Morning physical activity offered no advantages, concluded the study by Dr Jeroen van der Velde and colleagues at Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, the Netherlands.

Reference:

https://doi.org/10.1007/s00125-022-05813-3, JOURNAL Diabetologia, ARTICLE TITLE Timing of physical activity in relation to liver fat content and insulin resistance