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Yes, Your Gut Changes As You Age: Here Are 4 Ways To Keep It Healthy

Will Bulsiewicz, M.D., MSCI
November 9, 2019
Will Bulsiewicz, M.D., MSCI
By Will Bulsiewicz, M.D., MSCI
Dr. Will Bulsiewicz, M.D., MSCI is a gastroenterologist and internationally recognized gut health expert. He completed a bachelor’s degree from Vanderbilt University, a medical degree from Georgetown University, and a master's in clinical investigation from Northwestern University.
Image by Nicole Mason / Stocksy
November 9, 2019

Getting older has its ups and its downs, but if there is one key to staying healthy as you age, I would argue it is the gut microbiome. In fact, I would say the gut microbiome is the most important organ for human health (at any age), and—unlike some of your joints and reflexes—microbes don't decline or lose function with age. In fact, they procreate, multiply, and continue to live, generation after generation. What I'm saying is that it's possible to keep your gut "Forever Young."

There's one caveat: In order to accomplish this, we need to actively support the friendly microbes inside us as we age. Let's take a deep dive into the gut microbiome and how to keep it young. But first, inflammation.

What's inflammation got to do with it?

Well, everything, to be honest. If forced to summarize a complex topic in one word, my one word for aging would be inflammation. To put it simply, inflammation is a localized response that occurs when the immune system is activated with the intention of trying to restore normal function. It wasn't always the case—humans have evolved to have inflammation as a protective mechanism, such as to fight an infection or to heal a bodily wound. Consider that for most of human history, the top causes of death were infections or bodily injury, and it makes sense that we needed this immune response.

But now it's the 21st century, and our life expectancy is a multiple of what it used to be. Not to mention that we have antibiotics for infections and bandages for skinned knees. It's not that we don't need inflammation. We just don't need so dang much of it.

However, today's way of life proves a challenge when it comes to keeping inflammation at bay. In fact, the average American lifestyle creates a constant state of low-grade inflammation that is no longer localized—it's systemic and it's constant. Chronic inflammation has been associated with heart disease, insulin resistance and diabetes, cognitive decline and dementia, and cancer. Given this list, it's no surprise that chronic inflammation is also associated with early death1.

The microbiome-inflammation connection.

Which brings us back to the gut microbiome. What you may not realize is how closely tied inflammation is to our gut microbiome. In case you haven't heard, 70% of your immune system actually lives in your gut2 and in proximity to your gut microbiome. There is constant communication3 between the gut and the immune system. For example, short-chain fatty acids produced when our microbes consume prebiotic fiber are known to help regulate—and even optimize4—our immune system to do its job properly.

So to put it simply: Inflammation, which is an immune response, is at the root of aging. And if we want to control inflammation, the best place for us to start is by taking care of our gut microbiome5, which is besties with the immune system.

How the gut microbiome changes as you age.

While it would seem that your gut microbiome (which is completely capable of regenerating itself) would simply never age, it is unfortunately not the case. In the same way that a 30-something person's knees don't creak like those of a centenarian's, the gut microbiome changes with age3.

In a study comparing the gut microbiome of Northern Italian centenarians to young adults (30-somethings), they found that the elders had a loss of generally healthy microbes and an increase in inflammatory microbes6. The genetic makeup of the elder microbiome was less capable of processing fiber and producing short-chain fatty acids (SCFAs). As you might know, SCFAs are the currency of gut health and critical to health throughout the body. So to be less capable of producing them is a sign of diminished health or, in other words, aging.

In a different study out of Ireland7, researchers showed that aging was associated with a decline in diversity in the gut. Diversity is important to gut health, and when we lose diversity, we tend to make ourselves vulnerable to disease. And once again, they saw a loss of the microbes that produce SCFAs.

Taken together, it appears that the gut microbiome does, in fact, decline with age and that these changes may help to explain the emergence of disease that occurs as we age. For example, a 2017 study8 found that brain amyloid, the thing that causes Alzheimer's disease, was associated with an increased level of pro-inflammatory microbes in cognitively impaired elderly.

How to maintain a healthy gut as you age.

Maintaining a healthy gut as we age doesn't happen by accident. Frankly, good health doesn't happen by accident for any of us, does it? After all, our 21st-century lifestyle is largely working against us when it comes to gut health.

In considering the changes that occur with age, it comes as no surprise that diet and antibiotic use appear to be the driving factors in shifting microbiomes. For example, rates of antibiotic prescriptions are actually rising9 in the elderly, and even more so among those 80 years of age or living in a residential care facility. Regarding dietary choices, bear in mind that as we age there can be altered dentition, salivary function, taste, and smell, all of which may contribute to changes in eating habits.

So how do we take control of our gut microbiome as we age? Here are a few approaches:

  1. Ditch the Western diet, with excessive amounts of processed foods, animal protein, and saturated fat, and instead focus on a plant-based, minimally processed, high-fiber diet that maximizes a diversity of plants.
  2. Consider a daily probiotic or prebiotic supplement for additional gut support.
  3. Stay active! Physical exercise is known to improve gut fitness in addition to maintaining muscle mass, an important thing as we age.
  4. Proceed cautiously with antibiotics. The last thing we need is unnecessary antibiotic use. Always ask whether it is necessary and what the risks are of not using the antibiotic.

Also important? Embrace aging. It turns out that with the right outlook (and a healthy gut) getting older doesn’t have to be a downward slide and, in fact, can be quite the ride.

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Will Bulsiewicz, M.D., MSCI author page.
Will Bulsiewicz, M.D., MSCI

Dr. Will Bulsiewicz, M.D., MSCI is a gastroenterologist and internationally recognized gut health expert who wants to help you tap into the incredible healing power that lives inside you—your gut microbiota. His medical training involved 16 years at America's elite institutions. He completed a bachelor’s degree from Vanderbilt University, a medical degree from Georgetown University, and a master's in clinical investigation from Northwestern University. Bulsiewicz was also the chief medical resident at Northwestern and the chief gastroenterology fellow at UNC, and received the highest award given by both his residency and fellowship. He also completed an epidemiology fellowship at UNC's prestigious Gillings School of Global Public Health.