Before we begin: a warning that changes everything Imagine you are the security system of a vast, breathtakingly complex factory. Your entire job is to ensure that every single product rolling off the assembly line is perfectly shaped, correctly folded, labelled accurately, and either put to work or, when broken, safely disposed of. Now imagine that one day, a rogue product starts coming out crumpled. It cannot do its job. It clogs the disposal system. It triggers every alarm

Picture a city at night, every window lit, the grid humming - and yet the streetlights flicker out one by one. There is no shortage of electricity; the cables are thick with it. The problem is that the lamps have stopped answering when the current calls. That, in a single image, is the paradox at the heart of one of the most intriguing ideas in modern neuroscience: a brain swimming in fuel and starving all the same. The brain is a famously expensive organ - roughly two percen

In the first article, the focus was the science. Parkinson’s disease has a real and measurable relationship with the gut microbiome, the trillions of bacteria and other microbes that live in the gut. That relationship shows up in gastrointestinal symptoms that often appear early, a vagus nerve route between belly and brain, abnormal α-synuclein, a protein that can misfold and build up in Parkinson’s, in gut tissue before diagnosis, recurring changes in which gut microbes are