Young gut bacteria restore an aging brain, and solar just topped coal

Normally this is only possible in early childhood, when the brain's visual cortex is still flexible. In adults, that window has closed. But the old mice with young gut microbiomes responded to the treatment as if they were young animals again. Their brains had regained plasticity. The mechanism, as best as the researchers can tell, involves bacterial families like Lachnospiraceae that produce short-chain fatty acids with neuroprotective properties. Mice whose gut microbiomes had been disrupted by antibiotics showed dramatically altered gene expression in their visual cortex, more than 1,000 genes switched on or off differently, including genes related to myelination, the protective sheathing of nerves, and the integrity of the blood-brain barrier [16].

For the first time in American history, the sun beat coal [128]. That made solar the third-largest source of electricity in the US, behind only natural gas and nuclear. To put the trajectory in numbers: five years ago, coal was at 19.7 percent and solar at 5.4 percent. Today those positions have essentially traded places. Solar hit an all-time monthly high of 45.5 terawatt-hours in May, up 17 percent from the same month the year before, according to data from the energy think tank Ember [128].

Here is the context that makes this meaningful. Microglia are the brain's immune cells. In a healthy brain, they patrol for threats, surround amyloid plaques, and contain them. In Alzheimer's disease, they progressively lose this ability. They stop clearing plaques and can begin contributing to neuronal damage instead. Most Alzheimer's therapies have tried to target amyloid from the outside. OLE takes a different approach: it gives the brain's own cleanup cells their instructions back. After OLE treatment in animal models, microglia moved toward amyloid plaques, surrounded them, and created physical barriers limiting contact between the plaques and nearby neurons. In mice, three months of treatment reduced plaque buildup and produced better performance on memory tests. In genetically modified worms that produce amyloid, OLE reduced protein aggregates and improved movement [5]. The work was published in Cell Death and Disease.

Scientists had long assumed those ancestors went through a tadpole-like phase before becoming land animals, as frogs and salamanders do today. But the new fossils, from ancient crocodile-like creatures called embolomeres that ruled river and swamp habitats 350 to 280 million years ago, show no external gills or any tadpole features. The hatchlings are miniature adults. Days to a couple of weeks old, and already built like the grown animals. Looking at other fossils from the fin-to-limb transition, the researchers found no evidence of an amphibian-like life cycle there either. The study was published in Science [11].

The mycelium, the dense thread-like root network of the mushroom, did the work. The results were good enough that England's water regulator OFWAT gave local utility Anglian Water nearly two million dollars to scale the approach immediately. The application is simpler than it sounds: a bag of woodchips impregnated with spores, left in the river. No infrastructure, no chemicals, nothing to maintain.

Burn surgeon Dr. Marc Jeschke decided to try something that had never been done in humans for burns: exosomes [151]. Exosomes are tiny particles released by cells that carry the molecular signals triggering powerful healing responses. Normally they are studied in animal models. Jeffrey needed a trillion of them. Health Canada approved the treatment on compassionate grounds. By April 29th, her face had healed entirely. The burns first appeared December 2nd [151]. She will still need grafts for remaining scarring on her neck, but the outcome was far beyond what anyone expected.