How Your Gut Bacteria Controls Your Mood

Your gut and your brain talk to each other, and when the gut talks, the brain listens. I'm Dr Tracy Marks, a psychiatrist and I make mental health education videos. Your intestines has about 39 trillion microorganisms in it.

And yes, I said, trillion. We call this collection of organisms, the microbiome, and it consists mostly of bacteria, but it also contains viruses and fungi. Collectively it weighs about three pounds, which is the same way as your brain.

We feed these organisms and they produce chemicals that we need. They send messages to the brain through the vagus nerve. The vagus nerve is cranial nerve number 10 that originates in the brain stem, and then it travels down your neck and alongside your carotid arteries, and then into your chest, and then branches out and sends out feelers to control your internal organs in your abdomen and your chest including your intestines.

It's the longest nerve that originates in the brain, and not only controls the contractions of your gut, which is called Peristalsis, but it also controls your heart rate. So it's a super important nerve, and that's what the microbiome uses to send messages directly to your chief operating officer, your brain. That's probably more than you wanted to know about the vagus nerve but I couldn't help myself.

The vagus nerve is an important in triggering a relaxation response more on that in another video. We know that people who are depressed and anxious have very different microbiomes and people who are not depressed. With depression you have a higher number of bad bacteria that produce inflammatory chemicals, they send these inflammatory chemicals back to the brain and they get distributed in the body.

So the ideal scenario is to have a diverse population of bacteria strains. Yes, even the microbiome values diversity, even though the microbiome contains viruses and fungi, it's mostly bacteria, so I will refer to it as your gut bacteria. What makes you have good versus bad bacteria?

Several things, diet and medications. Diets high in processed foods, sugar, red meat, and fast food promote the bad bacteria, and lots of medications and not just antibiotics can change the population of your gut. Your age, as you get older, your bacteria population becomes less diverse.

Your sleep, bacteria are sensitive to circadian rhythm changes, so poor sleep promotes bad bacteria and increases inflammation And then activity level, aerobics activity improves the diversity of your microbiome. The connection between having poor microbiome health and depression is so strong that research has shown that transplanting feces containing the bacteria from a non-depressed individual to a depressed individual treated the depression. So we know that this is a real thing that matters, but unfortunately it's not practical to do fecal transplants because of the risk of transmitting infection.

Plus there's just something about having someone else's feces injected into your body that just doesn't right, no pun intended. So until we have maybe an artificial option, you have to boost your own gut health. And here's some suggestions.

The first thing is to clean up your diet by eliminating or reducing processed foods, sugar and red meat. The Mediterranean diet is a good choice for this kind of diet. And I talk about this diet as a treatment for depression in this video.

Then you want to eat prebiotics. Prebiotics are the fiber that feeds the bacteria and keeps them in circulation. These are foods that are high in inulin, fruit, sugars, polyphenols, and polyunsaturated fatty acids.

Some examples of prebiotics are onion, garlic, bananas, walnuts, wine, oily fish, and oats. I have a handy guide that you can download from my website. If you're already part of my email community, you got this when the video first published, you can get it from my website without leaving your email address, but then you'll have to go back to my website every time I give away something.

Then there's probiotics. Probiotics contain the actual bacteria that you ingest to increase the good population of bacteria. You can get them from your diet, or you can take capsules.

It's always best to get important nutrients from your food rather than supplements. Some examples of dietary probiotics are yogurt, sauerkraut, pickles, and kombucha, because these foods contain live bacteria you should check with your doctor. If you are severely immunocompromised.

The more good bacteria that you have the better, and you can increase the diversity by taking probiotic supplements along with eating probiotic food. The probiotic capsules contain freeze dried bacteria, that reconstitute once they get past the stomach and into the gut. And by the way, because of the positive effect on your mental health, some people refer to probiotics as psychobiotics.

It matters when you take your probiotic supplements you need to take them on an empty stomach before for your meal. Why? Because your stomach secretes acid as part of the digestive process to break down your food.

Some bacteria are very resistant to acid, like certain strains of E Coli that cause food poisoning. These bacteria survive the stomach acid and then secrete toxins causing vomiting and diarrhea. The most common good bacteria strains are Bifidobacteria and Lactobacilli, and they can also survive the stomach acid if they're not exposed to the acid for too long.

So the bacteria containing food or pills need to move through your stomach as fast as possible so the bacteria isn't killed off by the acid. Movement through the stomach is fast when it's empty, but when you eat a heavy meal there's a backup as the food gets processed, it's like waiting in line to go through airport security. In that case, the bacteria can get killed off while it sits in the stomach.

So probiotics work best on an empty stomach or with a very light meal. The next thing you want to do is increase your aerobic exercise. The department of health and human services recommends 150 minutes of moderate exercise a week.

This could be 30 minutes of brisk walking or swimming five days a week, and then running would be vigorous exercising, with this you would only need 75 minutes a week. As for sleep set a consistent bedtime that allows you to get seven to nine hours of sleep each night. Even if you've never been depressed or anxious, good gut health begets good overall health including maintaining a proper weight.

Have you ever wondered what makes some people naturally thin while others large? Even when the two people eat the same amount of food, you may say it's genetic, well, guess what? That population of 39 trillion organisms house a lot of genetic material in their cells, and that influences a lot of our body functions.

Some people refer to the microbiome as the second brain or the secondary immune system. So it would be who view to take care of your microbe community and then it will take care of you. Thanks for watching.

See you next time.