You Should Know

Neurotransmitters in the gut cannot reach the brain due to the blood brain barrier (or very limited at best). Reuptake proteins and breakdown enzymes also prevent outside neurotransmitters from interfering. Your gut already produces large amounts of serotonin and it was first identified in the gut. 90% of the serotonin in the body is made in the lining of the stomach where it modulates smooth muscle contractions. About 50% of the dopamine is produced in the gut also.

However, microbes could affect gut behavior and that could effect mood simply by feeling poorly or well. There is also the matter of inflammatory responses and signaling (i.e. cytokines) that could affect one's general sense of health. The small intestine is packed with immune cells that will also react to changes in the gut biome.

Finally there is the vagus nerve, a highway running from the gut, lungs and heart straight to the hindbrain, bypassing the spine. More here. We are still learning about how much this ancient nerve controls and influences. I've even wondered if it is related to dementia and Parkinson's because of its physical proximity to locations such as the substantia nigra (Parkinson's) and areas that show the first signs of dementia, possibly due to influences traveling up the nerve similar to the way rabies viruses travel. People who have had their vagus nerve cut, in an effort to stop severe stomach ulceration, showed a significant drop in Parkinson's. More here, and here.

Important to note: fast food and sweets are NOT what make your gut bacteria happy even if you think you are happier by eating them.

Gut health is important and well worth talking about. Note, though, that the serotonin and dopamine produced there will never cross the blood–brain barrier, so the effects that the gut has on mental health (which are very real) come about differently.

Honestly your gut is more central to your existence than your brain. There's plenty of organisms out there that are just a tube, and not all of them even have two ends!

YSK that this is just plain wrong for serotonin at least. Serotonin can't cross the blood brain barrier.

How do you make happy guts?

YSK the idea that the "self" or "consciousness" is centered in the brain is called Duality and it's a philosophical position, not a scientific one. It's the same idea that "mind" and "body" are separate things and it's most common iteration is the idea of the "soul".

You probably can't upload yourself to a computer or be preserved in a frozen brain.

jfc

DEA is used in industrial, agricultural, and consumer products.

“We knew that micropollutants can be incorporated into fatty molecules in the body, but we didn’t know how this occurs or what happens next,” Clardy said. “DEA’s metabolism into an immune signal was completely unexpected.”

The team proposes that DEA could be added to the growing list of biomarkers used to detect some cases of major depressive disorder.

The study also strengthens arguments that major depressive disorder, or a subset of cases, could be considered an autoinflammatory or autoimmune disease and be successfully treated with immune modulator drugs, Clardy said.

Oh yeah? I give my gut all the vodka and fast food it wants, and I'm still not happy! Checkmate, liberals!

"Bacteria" is already plural

My wife had an overgrowth of candida bacteria in her stomach, and it caused irritability and exhaustion. When she starved it out, it was wild. If she had any sugars or yeast she would have almost stroke like symptoms. Like she had just drank a ton of alcohol that hit her all at once. She had 1 bite of ice cream (she had been good for months and wanted to try it), and she literally started slurring her words and getting dizzy. Our stomach colony has way more control over us than we think.