In brief (September 2015): saliva and radiotherapy, cold and insulin sensitivity, and a giant virus

Keeping saliva secretion up after radiotherapy, or how finding where stem cells crucial to salivary gland regeneration reside may help prevent irreversible tissue damage and loss of saliva production after head-and-neck cancer radiotherapy
Getting cold in type 2 diabetes, or how a protocol involving sitting in a cold room for several hours can improve insulin sensitivity in patients with type 2 diabetes
Another big, big, big virus, or how a new giant virus was recently discovered in a 30,000-year-old permafrost sample from Siberia Continue reading

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Four questions about the Ebola virus

In its 30 October issue, the journal Nature published a news feature about some of the scientific questions surrounding the Ebola virus and more generally the family of viruses it belongs to. If you are interested in knowing more about Ebola, I recommend reading the whole article (free access). Alternatively, here are the main points: Continue reading

Pediatric respiratory tract infections and antibiotics: overprescribing?

10344775_815628761791470_2583354142570698374_nAntimicrobial resistance is a serious threat to human health. As the WHO global report published in April 2014 highlighted, it is no longer a concern for the future but happening right now, in every part of the world. It threatens to undo many of the achievements of modern medicine that allow people to live longer and healthier.

A number of concerted actions are needed to tackle the resistance problem, and one of them is to improve the way antibiotics are currently used, both in agriculture and in medicine. Mostly, this means curbing antibiotics use.

A study published in the journal Pediatrics in October tried to assess how often antibiotics were prescribed in cases of acute respiratory tract infections in children in the US in relation to how often these infections actually involved bacteria (many of these infections are indeed caused by viruses). Continue reading

Of the placental microbiome

fetusA study published last week in Science Translational Medicine shows that low amounts of DNA from diverse bacterial phyla are found in the placenta even in healthy pregnancies, and that the bacterial phyla present in the placenta are more similar to those found in the mouth than to those present in other body tissues such as the gut, the skin, or the vagina.

Many news outlets reported the findings; unfortunately, it seems that (perhaps characteristically) the speculations developed by the authors of the study in the discussion section of their article received more attention than the actual results of the study, leading to misleading comments on the importance of oral hygiene in women and on the relative importance of the placental microbiome and the mode of delivery (C-section or vaginal birth) regarding the infant’s own microbiota. Continue reading

What regulation for fecal transplantations?

A year ago, I wrote about the first randomized controlled trial investigating the medical use of human feces. The trial evaluated the efficacy of fecal transplantations to treat recurrent infections with Clostridium difficile. The results revealed a success rate of 94% for fecal transplantations, by contrast to a 27% success rate for a conventional antibiotics treatment.

Interest in the potential benefits of manipulating the gut microbe population (microbiota) has increased a lot over the past 5 years, as more and more research has shown how the bacteria living in the human gut can affect their host physiology (for example, by participating in the “education” of the immune system). Continue reading

GMO sent to kill the pathogenic bacteria P. aeruginosa

Photo Credit: Janice Haney Carr/CDC

Pseudomonas aeruginosa is a common bacterium that can be found in many places, from soil and water to the surface of your skin or medical equipment. It is also a common nosocomial pathogen that can for example infect the lungs, burns or wounds and lead to pneumonia, sepsis or other infections with life-threatening consequences, especially in immunodepressed individuals. Unfortunately, P. aeruginosa is resistant to many antibiotics (and pretty good at developing resistance to new treatments), can survive and even thrive on many surfaces, and can organize in biofilms that are particularly difficult to destroy.

Synthetic biologists at Nanyang Technological University in Singapore have now created an Escherichia coli bacterium that specifically seeks out and kills P. aeruginosa. Continue reading

In brief (August 2013, part II) – microbiome and speciation, and more viruses

Picks for this month, second part:
gut bacteria keeping species apart, or how the microbiota may promote speciation by contributing to offspring lethality when two species are interbred,
new genera of ocean-dwelling phages, or how analysis of an aquatic bacterium led to the discovery of twelve new genera of bacteria-infecting viruses. Continue reading

In brief (August 2013, part I) – prions and giant viruses

Picks for this month, first part:
prions, alcohol and yeast, or how an environmentally responsive prion protein may help yeast to cope with high concentrations of ethanol,
giant viruses, or how the discovery of viruses larger in size and DNA content than any virus known so far challenges the way scientists think of viruses. Continue reading

Red meat, cardiovascular risk and gut bacteria

In a study published in April in Nature Medicine, US researchers show that the intestinal microflora can process L-carnitine, a nutrient abundant in red meat, to produce a compound linked to the risk of developing cardiovascular disease.

Nowadays, many people are aware that the high level of meat consumption in developed countries is linked to the risk of developing cardiovascular diseases (CVD). However, it is also generally assumed that this is due to the high content in saturated fats and cholesterol of red meat. But what about other factors associated with meat consumption? Is there more to it than saturated fat and cholesterol? Continue reading