Looking for microbes on Mars, a retroviral connection to ALS, and dosing asthmatic children with probiotics. This week in Abstract Science.

Is Finding Life on Mars Rocket Science?

(Scientific American, 9/28/15, Lee Billings)

The news was filled this week with stories about the discovery of water on Mars. While this offers a good place to search for extra-terrestrials, probing these wetter parts of the Red Planet won’t be easy, says NASA. In what surely sounds like the stuff of science fiction movies, research suggests that the easiest way for us to find microorganisms on Mars is to import our own. However, if we do this we will also be subjecting Earth’s stubborn arsenal of bacteria o whatever fragile population exists on Mars.

Retroviruses and ALS

(Science, 9/30/15, Jon Cohen)

Amyotrophic Lateral Sclerosis (ALS) burns out motor neurons, causing the brain to lose its ability to control muscle movement. As with other neurodegenerative disorders, the mechanisms driving ALS are multi-faceted and not that well-understood but recent findings suggest, surprisingly, that an endogenous retrovirus might be responsible for a small subset of cases. A study published this week in Science Translational Medicine found elevated levels of human endogenous retrovirus K (HERV-K) in the brains of 11 people who died from the disease. ALS studies have never found outside retroviruses in the blood of ALS patients, but HERV-K is what is considered an endogenous retrovirus. Such viruses are very old and initially worm their way into the DNA of human sperm and eggs, where they are then passed down generation to generation.

Bacteria and Childhood Asthma

(Science, 9/30/2015, Sarah C. P. Williams)

We’ve been hearing a lot about the gut microbiome. Imbalances in this complex ecosystem of more than 1,000 intestinal microbiota have been linked to diseases that ostensibly have little do with the body’s microbiota, such as diabetes, cancer, and now asthma. A study published his week in Science Translational Medicine suggests that four types of gut bacteria in stool  seem to predict which children will develop asthma and which ones will not. The work was part of the Canadian Healthy Infant Longitudinal Development (CHILD) study; scientists collected stool and urine samples from more than 300 babies at 3 months and 1 year old and used high-throughput genetic sequencing to detect levels of gut microbes in each stool sample. Researchers also used stool samples from the asthma-prone 3-month-olds to colonize the guts of mice that had been raised in a bacteria-free environment. The animals went on to develop inflamed lungs indicative of asthma, but when researchers added a mixture of the four missing microbes to the mice’s digestive tracts along with the feces the mice no longer had asthma.

—Compiled by Senior Scientific Writer Regina McEnery