Millions of Americans suffer from the malaise, fatigue, brain fog, pain, and other symptoms of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS)—a significant neurological disorder made all the worse by the fact that it’s still unexplained. Now researchers at Columbia University in New York have analyzed stool samples from a diverse group of 106 people with ME/CFS and 91 healthy controls and discovered differences in their gut microbiomes. Those who were most fatigued had the lowest levels of health-promoting Faecalibacterium prausnitzii bacteria, which are one of the abundant gut producers of butyrate, a short-chain fatty acid that helps aid digestion. The findings may help explain how ME/CFS symptoms emerge, the researchers say, and also “identify potentially actionable targets for disease classification and therapeutic testing.” Cell Host & Microbe

Telomeres—those capped, protective ends of DNA chromosomes that shrink as we age—have long been a bellwether for age-related disease. But we have a lot more to learn. Case in point is a new study from the Salk Institute in La Jolla, California, this week that shows how the body deals with danger when telomeres become too short and dysfunctional. Cells with very short telomeres are in crisis and at risk of “neoplastic transformations,” a series of changes that turn a cell cancerous. But the body pulls the plug before then by triggering a protective mechanism, signaling mitochondria in surrounding cells, initiating an innate immune inflammatory response, and destroying the falling Jekyll before it can raise its cancerous Hyde. In a statement to the press, the Institute announced the discovery “could lead to new ways of preventing and treating cancer as well as designing better interventions to offset the harmful consequences of aging.” Nature

In this illustration, shortened telomeres are represented as the ends of the two sparklers. The telomeres send off inflammatory communication signals, represented as sparkler paths, to mitochondria. The telomere-to-mitochondria communication activates the immune system, which destroys cells that might become cancerous. Salk Institute

Infant mortality is a major U.S. health problem. One in every 200 children born in the United States dies prematurely, placing us at the top of the list of industrialized, high-income nations—on average, 71 percent more babies die here than in other comparable countries. A new study from Rady Children’s Hospital in San Diego, California, finds that a surprisingly high number of these deaths may be associated with genetic diseases. Extrapolating based on an analysis of the whole-genome sequences of 112 infants who died from 2015–2020 and 434 infants who survived acute illness during that timeframe, they found single-locus genetic diseases associated with 41 percent of the infant deaths. Treatments are available for 30 percent of those genetic diseases, the doctors write, which suggests that we could use neonatal diagnosis to drive down infant mortality. JAMA Network Open

Juries in criminal trials are often instructed to consider what actions a “reasonable” person would take in a defendant’s shoes or whether the claims of the plaintiff in a civil suit are “reasonable.” Now researchers at the University of California, Berkeley are suggesting brain scans may be able to help courts cut through all those exasperatingly qualitative judgments in trademark or copyright infringement disputes. Such cases often hinge on asking juries how similar one brand is to another, but the researchers showed that an established fMRI brain-imaging technique called repetition suppression could reveal how people judge those questions in a more unbiased way. Science Advances

Just in time for Valentine’s Day, researchers at Peking University have discovered how sexual satisfaction is controlled in the brain. Scientists have long observed that after copulating, mice will be satisfied for days or even weeks afterwards—long after the time it would take for their bodies to be ready for Round II. According to the researchers, what accounts for this love pause are hyperexcited neurons in the bed nucleus of the stria terminalis. That doesn’t sound very sexy, but in both male and female mice, after a male ejaculated, these neurons adopted a persistently lower firing threshold for days or weeks. During that time, the mice were uninterested in further intercourse. Inhibiting the hyperexcited neurons, however, returned the rodents to their formerly eager state. Science

And speaking of Valentine’s Day, if your partner asks what you got them and you happened to forget, you could always say, “A lower risk of diabetes.” That’s according to a new study from the University of Luxembourg and the University of Ottawa, which looked at 3,335 adults aged 50–89 without previously diagnosed diabetes from the English Longitudinal Study of Aging. The researchers found that having a spouse or partner was significantly associated with lower average HbA1c blood glucose levels, even though the quality of a marriage or partnership generally was not. Interestingly, the work suggests that doctors could consider that older adults without pre-existing diabetes who are going through breakups or divorce may be at risk of worsening glycemic levels. BMJ Open Diabetes Risk and Care