Tired and down? Bloated? Struggling to concentrate? These are signs that your gut is talking to your brain and you need to listen.
As I explained in last week’s Good Health, your gut, specifically your gut microbiome (the community of bacteria, fungi and microbes that live there) is key to every aspect of your health, from your immune defenses to your likelihood of gaining weight.
And we now know that the gut microbiome is also key to brain health, in addition to influencing our mood and how well we think.
For centuries, our medical system separated the mind from the body. But while brain problems are still often treated separately from the rest of the body, fortunately there is now a growing understanding of the importance of the gut-brain connection for both health and disease.
For example, up to 80 percent of people with Parkinson’s also suffer from constipation, a symptom that can appear up to 20 years before other warning signs. And one-third of those with irritable bowel syndrome also suffer from depression and anxiety.
If your microbiome is unhealthy, you’re likely to feel the same way, from feeling sluggish to moody and often experiencing digestive issues, too.
Gut bacteria and the brain communicate in many different ways. When gut bacteria break down food, they produce metabolites, small molecules that play a crucial role in health.
For example, short-chain fatty acids are a type of metabolite produced when gut bacteria ferment fiber. Aside from the few that remain in the gut, almost all short-chain fatty acids are absorbed into the bloodstream and travel throughout the body.
They are potent anti-inflammatory molecules that can help combat excess inflammation in the brain. Lower levels of short-chain fatty acids have been found in brain diseases such as Parkinson’s and in mouse studies of Alzheimer’s and chronic stress.
These metabolites are linked to health benefits including mood and appetite.
Some bacteria produce metabolites that act as chemical messengers that send signals to the brain via the immune system and the vagus nerve. These signals travel from the brain to the gut, where the gut lining is located, where the gut microbiome is located. How well does the connection between the gut and the brain work?
If your microbiome isn’t healthy, you probably feel the same way, from lethargic to down, and often with digestive issues, too. Aside from how you feel, there’s a free and easy way to monitor the health of your gut: lift the toilet seat.
Don’t feel shy about it: the shape and color of your stool and how often you go to the bathroom are a great way to see if your gut and gut microbiome are in good shape.
Let me explain. Your poop is made up of about one-quarter solid matter and three-quarters of it is water, which helps keep it nice and soft.
Dr Emily Leeming explained on last week’s Good Health that your gut microbiome (the community of bacteria, fungi and microbes) is key to every aspect of your health, from your immune defences to your likelihood of gaining weight.
The solid part consists of: 25–50 percent intestinal bacteria (live and dead); undigested food remains in the form of protein, fiber, fat, and a little carbohydrate; some dead body cells; and dried digestive juices.
If all goes well, your poop will likely be solid brown and easy to pass. It will look like a smooth sausage or one with a few cracks in it. Good poop tends to sink, though floating poop can sometimes be a sign of a high-fiber or high-fat diet. As for color, healthy poop is brown, thanks to a pigment called stercobilin. Without it, poop would be a pale beige color.
To help digest fats from food, the liver secretes bile into the small intestine – some of the bile is broken down into stercobilin, which turns everything brown when it mixes with the food being digested. When stool moves too quickly through the body, such as when you have diarrhea, the bile doesn’t have time to break down into stercobilin and your stool may look more yellow or green.
In addition to color, signs of an unhealthy bowel include a sudden change in the frequency of bowel movements that lasts more than three or four days; stools that are loose and liquid or come in hard pellets; discomfort or pain when going to the bathroom; even when you do go, feeling like you haven’t expelled all the stool or taking a long time to go.
If your stool looks red or black and you haven’t eaten beets, it could be because they contain blood. This is a warning sign and you should consult a doctor.
Of course, there are also the obvious digestive symptoms that can reveal the state of your gut health. These include bloating. It’s a very common and normal reaction that most people experience from time to time, so it’s not necessarily something to worry about.
Your gut microbiome is also key to brain health, as well as influencing your mood and how well you think.
Dr. Leeming recommends that half your plate should contain fruits and vegetables for good gut health.
You’re more likely to bloat, for example, after a large meal, when you’re feeling stressed or anxious, or just before your period (due to changes in estrogen and progesterone levels that cause smooth muscles to contract and shed the lining of the uterus; for some people, this can slow down the digestive tract and cause constipation and bloating, or speed it up and make you need to go to the bathroom more often).
Swelling can be a sign of a problem when it doesn’t go away (and you should see a doctor).
Another sign of poor gut health is gas: When you eat or drink, you may swallow small amounts of air that build up in your gut.
Once the gas is inside you, most of it must be released somehow, such as a burp or a fart.
The average person produces the equivalent of one to four large glasses of gas and farts between 12 and 25 times a day, mostly in the hour after each meal.
You also fart when you’re sleeping in bed, as the anal sphincter muscle relaxes and makes it easier for gas to pass. Farting is normal and is often a sign of a healthy digestive system and, in particular, happy gut bacteria.
When you feed your gut bacteria the foods they like the most, they produce gas as a side effect. Think of this like a cat bringing you a dead mouse as a gift. Most farts don’t smell, but 1 percent do. More often than not, this is usually due to the foods you eat.
A compound called sulfur, found in foods such as meat, eggs, cauliflower and sprouts, is broken down by some intestinal bacteria into a gas, hydrogen sulfide, which smells like rotten eggs.
If you naturally have more of these types of gut bacteria, you’ll produce more of this stinky gas than someone else. But if you’re regularly throwing up big stink bombs, it could be a sign of an unbalanced gut microbiome. Armed with this information, now take my gut health quiz to see how you’re doing.
The good news, as I explained last week, is that there are simple, scientifically proven ways to improve gut health, feel happy and energized, and boost your brain.
Here’s a quick reminder of some of my tips on the gut-brain diet (you’ll find more in my new book):
- Eat more fiber.
- Make half of your plate fruits and vegetables: they provide a double benefit: fiber and polyphenols, antioxidants that act as fuel for intestinal bacteria.
- Have a regular bedtime.
- Get your hands dirty: A teaspoon of dirt contains more microbes than there are humans on Earth. One small study showed that when people rubbed their hands with dirt for 20 seconds three times a day (rinsing only afterwards, without soap), the diversity of gut bacteria increased in just two weeks.
- Eat oily fish twice a week.
- Have a coffee or two a day (if you don’t have a sensitive gut): Coffee drinkers tend to have a more diverse gut microbiome.
- Exercise regularly.
Genius Gut by Dr Emily Leeming (Penguin, £18.99) is published on 25 July. © Emily Leeming 2024. To order a copy for £17.09 (offer valid until 21 July 2024; free UK delivery on orders over £25), visit mailshop.co.uk/books or call 020 3176 2937.
