...you can see the changes in brain scans
https://bgr.com/science/fasting-rewires-your-brain-and-you-can-see-the-changes-in-brain-scans/
That relatively new idea that gut bacteria influences out brains and decision making doesn't sit well with me. A single cell organisms controlling my actions is a bit disconcerting.
I remember 40 years ago when a friend of mine with a really broad range of interests (PHD in physics, taught environmental sciences, reads broadly) said that he thought we would eventually discover that many things we think of as normal, like greed and anxiety would be traced back to microbes and viruses in the body.
Now, as all this info on the microbiome and such comes out, it seems like he might be right.
>> single cell organisms controlling my actions
But we've know this for years with other mammals, so we shouldn't expect humans to be immune.
We know that Toxoplasmosis gondii causes mice to be more active in open spaces and less afraid of the smell of cat urine. What is it doing then to humans? Unclear, but it causes inflammation which is linked with ADHD for example.
https://theconversation.com/is-the-brain-parasite-toxoplasma-manipulating-your-behavior-or-is-your-immune-system-to-blame-116718
Ophiocordyceps unilateralis - Wikipedia
https://en.wikipedia.org/wiki/Ophiocordyceps_unilateralis