People often talk about the microbiome in black-and-white terms, as if there’s a “good” one and a “bad” one when it comes to healthy aging.
However, each person’s microbiome is as unique as their fingerprint.
In other words, there’s no one best microbiome for healthy aging, says Purna C. Kashyap, M.B.B.S., a Mayo Clinic gastroenterologist.
Perhaps more surprisingly, keeping your microbiome healthy as you age is less complicated than you might think — and won’t cost you hundreds of dollars in tests, specialized foods or supplements.
What is a microbiome?
Trillions of microbes live on your skin and inside your body. These communities of bacteria, viruses, parasites and fungi make up your microbiome.
However, when most people refer to their “microbiome,” they’re talking about the many types of bacteria that live inside the GI tract.
These bacteria perform several important jobs, including:
- Breaking down fiber and starches.
- Synthesizing vitamins and amino acids, such as vitamins B and K.
- Producing short-chain fatty acids (SCFA) that play an essential role in disease prevention.
- Maintaining the intestinal barrier.
“When you eat an apple, your stomach and small intestine break down some of it. The rest of the apple goes to your colon, where bacteria do the rest of the work for you,” says Dr. Kashyap. “As the bacteria break down the apple’s fiber, they produce substances that are good for the cells of the colon and the body.”
Can my microbiome become damaged?
The gut microbiome is more resilient than many people think.
“If you take antibiotics, your microbiome might change for a short time, but it usually goes back to its original state,” says Dr. Kashyap. “The same thing can happen with other changes or behaviors, such as traveling or eating a lot of fast food. Think of your microbiome like a rubber band. You can stretch it a bit, and it bounces back. But if you stretch it too much, it might get disrupted.”
How far you can stretch your microbiome depends on many factors, including:
Your age
When you’re born, your microbiome is only partially developed. For this reason, during the first few years of life, “the microbiome is more vulnerable than during adulthood when the microbiome is more established,” says Dr. Kashyap.
How long the disruption lasts
Repeated courses of antibiotics taken for many months will affect your microbiome more severely than one course of antibiotics taken for several days.
Whether you have an underlying disease
Inflammatory intestinal diseases will affect which communities of bacteria can thrive in your gut — and which can’t.
Your lifestyle
Gut bacteria eat what you eat. Consume a diet rich in chips, sweets and highly processed foods, and you’ll starve bacteria. As a result, they will try to get nutrients from the lining of your gut and damage it in the process, says Dr. Kashyap.
On the other hand, consume a diet loaded with a diverse array of minimally processed foods and plant fibers, and you’ll nourish a diverse microbial community. The more diverse your gut microbes, the farther you can stretch things before you experience disruption.
“Happy bugs, happy life,” says Dr. Kashyap.
What happens when your microbiome gets disrupted?
In a healthy GI tract, many microbial communities compete, keeping each other in check.
However, if some healthy microbes get wiped out — such as through a poor diet or repeated courses of antibiotics — opportunists can thrive, says Dr. Kashyap.
For example, Clostridioides difficile (C. diff) lives in the gut of all people, yet it only becomes a problem when good bacteria aren’t around to keep it in check. When C. diff proliferates, it can lead to diarrhea, fever and gut inflammation.
In addition to gut infections like C. diff, microbial imbalances are thought to play a role in other diseases and symptoms, including:
- Fatigue.
- Metabolic diseases like diabetes.
- Depression and other mood disorders.
- Alzheimer’s and Parkinson’s diseases.
- Cardiovascular disease.
- Colon cancer.
How does aging affect the gut microbiome?
As you age, your microbiome changes.
However, it’s not clear why this happens.
It’s possible that other age-related changes, such as rising inflammation, lead to a shift in microbial composition. Another possibility: As some people age, their lifestyle changes. They might, for example, move less while consuming more processed food — both of which could influence gut bacteria.
Can you test your gut microbiome?
You’ve probably noticed ads for over-the-counter microbiome test kits. “These tests can tell you which microbes are high or low compared to some healthy people,” says Dr. Kashyap. “However, just because your microbiome differs from the microbiomes of healthy people doesn’t mean yours is abnormal. Everyone has a unique set of gut microbes.”
None of the tests have been approved by the Food and Drug Administration (FDA).
More importantly, you don’t need a microbiome test to understand your gut health.
“Your overall health status is reflected in your microbiome,” says Dr. Kashyap. “Generally, healthy people are likely to have a healthy gut microbiome.”
Let’s say your blood sugar, cholesterol levels, blood pressure, weight and other health indicators all fall within healthy ranges. In that case, it’s likely that your microbiome falls within the healthy range, too, he says.
How do you improve your gut microbiome?
The same lifestyle habits that slow overall aging also will help to protect the health of your gut. They include:
- Eating a wide variety of fruits, vegetables, beans and whole grains.
- Drinking plenty of fluids and limiting alcohol.
- Exercising for 30 minutes most days.
- Not smoking.
- Managing stress.
- Avoiding processed foods such as chips and candy and artificial sweeteners, such as diet soda and sugar-free gum.
What about probiotics? Can they reset my microbiome?
Probiotics are live bacteria found in some supplements and fermented foods.
“We used to think that probiotics could crowd out the bad bacteria and make your microbiome healthier,” says Dr. Kashyap.
However, research doesn’t support that initial belief. That doesn’t necessarily mean that probiotics don’t work at all. However, more research is needed to understand which bacteria are most beneficial, along with who benefits from them and who doesn’t.
On the other hand, prebiotics — a type of fiber supplement— may feed certain beneficial colonies of gut bacteria. “Some research has shown that prebiotics can help with certain conditions, but scientists are still learning about them,” says Dr. Kashyap.
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