I’ve heard people call the gut a ‘second brain’ but I don’t get how bacteria in our stomach could influence our thoughts, moods, or mental health.
I’ve heard people call the gut a ‘second brain’ but I don’t get how bacteria in our stomach could influence our thoughts, moods, or mental health.
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So thoughts and emotions are ultimately just chemicals. When the body is happy, it releases and transports certain chemicals to the brain, and when it is sad, it does the same thing but with different chemicals.
So the bacteria in your gut have the ability to make those same chemicals. Certain bacteria species will make the same chemicals that make you happy, while other species will make the same chemicals that make you sad or mad.
These “foreign” chemicals will then be transported by the body up to the brain, where you will experience the chemical as an emotion.
So if you have too much of the bacteria that make the sad chemical, you can be depressed even if you’re fine otherwise.
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It’s a downstream effect. Let’s start upstream so understand!
Brain needs hormones and neurotransmitters to work.
Many/most of these are produced in the digestive system.
If it’s not produced in the digestive system, a lot of the necessary ingredients are.
The digestive system breaks things down differently based on the bacteria in it.
Different combinations of bacteria encourage better or worse outcomes.
Now let’s follow it from the start!! You have bad bacteria in your gut. This means you aren’t breaking down food properly or completely. This limits your body’s stash of important ingredients. Without those ingredients it can’t make all the neurotransmitters and hormones your brain needs. Without those neurotransmitters and hormones, your brain is forced to process and function differently. This difference in function results in a change in mood, thoughts, etc
This is of course SUPER simplified and there’s a lot of different pathways and overlapping elements. It’s not such a direct relationship but this is the general idea and principles
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It’s a very, very scary thought how many different species of bacteria live symbolically both inside and outside our bodies. I don’t know the exact number – but it isn’t small. And, worse still, we’d die, very quickly, without them.
Also everyone’s gut biome is unique and can change drastically with the food we choose to eat.
I did hear somewhere once that something like the stomach lining contain cells that look and behave suspiciously like Brian cells.
So if you’ve ever had a bad case of diarrhoea or the butterflies, now you know why!
Through our hormones, endorphins in particular.
You know how people say there’s chemicals in vaccines and there’s chemicals in your food and all that stuff. Turns out there’s chemicals in everything including your brain.
The bacteria in your gut produce chemicals as a waste product. They consume chemicals. Their consumption and excretion both prevents you from absorbing some chemicals that you might not want, and provides from you some chemicals you might need or in fact might not want.
Vitamins. Binding metals. Absorbing excess dosage of something that you might need a little bit of but not too much.
One of the most important things about the bacteria in your gut is that you poop them out constantly. They absorb things in your digestive system. Sometimes things that they have absorbed from the liquids that have passed from your blood back into your digestive system.
Plants produce caffeine and psilocybin and psychoactive chemicals and all that stuff as insecticides. We don’t know the half of what’s actually being produced in our gut and we don’t know the half of what our gut is absorbing from our bloodstream and carrying away after having had it be eaten by the bacteria and turned into whatever the bacteria need.
There are only so many stable simple chemicals available in the universe. So the most stable tend to show up in a lot of strange places and do different things in different contexts.
Over the eons we meaning every species have simply been repeatedly exposed to one another.
So we have evolved to scavenger off one another. We literally function on the basis of “hey you’re just going to throw that out? That’s a perfectly good enzyme. I could do something with that!”
Animals in particular are very good at harboring other animals and when they’re not good at that they’re really good at hiding in other animals and taking advantage of them in the best case it’s a symbiosis and the case is only go downhill from there.
One of the best things that your gut Flora can do is outcompete the harmful floor that would like to live in your gut and the fact that they do that keeps you from feeling ill and not feeling ill is great for your personal mental outlook.
And we have recently learned that some of the molecules they create and discard as useless to them include neurotransmitters that we need all throughout our body. And having the right number of neurotransmitters is bad. Having too few and having too many are both problematic.
That all goes back to the fact that there are only so many small useful chemicals that are stable and easy to produce in the living systems so one bacteria is poop is another organisms serotonin balance.
https://youtu.be/VzPD009qTN4?si=vJ5idvZLcTHAATxH
Kurzgesagt – In A Nutshell does a decent job of covering this topic in this video. I really like their video format, and they do a good job of explaining things in an ELI5 fashion on a lot of topics.
We now know there are as many or more neurons in the gut as in the brain.
The majority of mood affecting neurotransmitters are made in the gut; dopamine, seratonin, norepinephrine, oxytocin.
Like any resource reliant system, the more demands in an area the more scarce those resources. So when bad guy bacteria cause inflammation, use up resources, or prevent proper absorption, there’s fewer resources from which to create the needed transmitters, and interruptions to the overall system.
There’s more, that’s all most of us really need to know about it. Take a probiotic daily. Try different brands or formulations until you find the list of organisms that your gut needs. It WILL change your life.
What probiotics are actually beneficial and actually work? Because I’ve read that yogurt is useless and it and a lot of bottled probiotics are inert and destroyed by the stomach acid