How your gut bacteria keep you healthy (or sick)

This is entirely fascinating, from the always excellent Emily Deans. 

Lactobacillus and Bifidobacterium species are known to produce GABA.  Escherichia, Bacillus, and Saccharomyces produce norepinephrine.  Candida, Streptococcus, Escherichia, and Enterococcus produce  serotonin.  Bacillus and Serratia produce dopamine, and Lactobacillus species produce acetylcholine.  That's pretty much the entire hit parade of major neurotransmitters (there's histamine and glutamate and a few others - and histamine is known to be produced by some bacteria that infect shellfish, for example, causing food poisoning).   

What's clear is that gut bacteria affect our brain and vice versa. It's also clear that there are millions of other species of bacteria whose functions are entirely unknown to us. That's a scary thought.

Whenever someone talked about depression or other mental health issues as the result of "chemical imbalances" it used to make me cringe, since that sounds so appealingly pseudoscientific. But it's actually true.

Depression is largely unheard of in "primitive" cultures, and diet (as it affects gut bacteria) is one major pathway by which depression is modulated. Of course, having a great community, lots of sunshine exposure, etc. etc. etc. all helps, too.