Yong, Ed. I Contain Multitudes: The Microbes Within Us And A Grander View Of Life. Harpercollins, 2018. http://www.vlebooks.com/vleweb/product/openreader?id=none&isbn=9780062368621. [[2020-06-05]] 1822 - Fur trader by name of Alexis St Martin gets a musket shot to his side. An army surgeon named William Beaumont attended to his injuries. His stomach attached itself to the hole in his side ("an accidental orifice", in Beaumont's words), giving Beaumont a perfect means to study the stomach. Beaumont became the father of gastric physiology. One of the things he noticed was that St Martin's mood affected the functioning of his gut. This was the first clue to a "gut-brain axis". In the 1970s, a trickle of studies show that stress can change a mouse's gut microbiome, and vice versa. In 2011, this trickle became a flood. Perhaps alchohol makes people depressed because it makes the gut's linings more porous, allowing microbes access to the brain? Highly speculative, but intriguing. [[2020-06-09]] >Most microbes are not pathogens. They do not make us sick. There are fewer than 100 species of bacteria that cause infectious diseases in humans; by contrast, the thousands of species in our guts are mostly harmless. At worst, they are passengers or hitchhikers. At best, they are invaluable parts of our bodies: not takers of life but its guardians. They behave like a hidden organ, as important as a stomach or an eye but made of trillions of swarming individual cells rather than a single unified mass.