The Surprising Link Between Gut Health And Brain Aging

Crossword puzzles, memory games, and Sudoku get all the credit for protecting our brains as we age—but emerging research suggests there’s a far less heady player in long-term brain health: your gut.

“Our brains and gut are deeply connected,” says certified nutritionist and personal trainer Lisa Schultz, C.N., C.P.T., creator of the Verdura Method for healthier eating. “It’s wild once you understand just how connected they are.” Case in point: A June 2025 review published in Archives of Gerontology and Geriatrics Plus found that as we age, changes in gut health—specifically increased gut imbalances and immune system activity—may contribute to a higher risk of neurodegenerative diseases like Alzheimer’s. The researchers concluded that supporting a healthy gut environment is one of the most effective ways to protect brain function and preserve cognitive health over time.

But how exactly does your gut influence your brain, and how can you preserve both? Let’s explore. 

• ABOUT OUR EXPERTS: Lisa Schultz, C.N., C.P.T., is a certified nutritionist, personal trainer, and creator of the Verdura Method for healthier eating. Jenna Volpe, R.D.N., L.D., C.L.T., is a functional registered dietitian and founder of Whole-istic Living.

The Gut-Brain Connection, Explained  

Though you’ve probably heard of the gut-brain connection by now, it can still be a pretty fuzzy concept. Here’s the deal: The gut and brain are connected through a two-way communication system known as the gut-brain axis, explains Schultz. This complex network consists of nerves (mainly the vagus nerve), hormones, immune messengers (called cytokines), and the trillions of bacteria in your digestive tract, all of which work together around the clock to keep your system in sync, she says. 

“This unique connection allows for our gut and digestive system to impact our nervous system and brain function—and vice versa,” says holistic and functional registered dietitian Jenna Volpe, R.D.N., L.D., C.L.T., founder of Whole-istic Living. When operating optimally, this system supports steady mood, smooth digestion, strong immunity, and sharp cognitive function, she says. 

Read More: How To Support A Fried Nervous System

Unfortunately, chronic stress, inadequate sleep quality or quantity, poor nutrient intake, and other lifestyle habits can all throw the gut-brain axis off balance. When that happens, symptoms can crop up in the belly and brain, says Volpe. 

“The gut-brain axis is why many people have a ‘chicken-or-the-egg’ experience with their gut and mental health,” Volpe explains. Someone struggling with irritable bowel syndrome (IBS), for example, might notice their symptoms spike during periods of emotional upheaval. Meanwhile, people with anxiety often also experience bloating or constipation. With that, “supporting the gut-brain axis can be a game-changer for most people with either mental health conditions or GI issues, or both,” she says. 

How The Gut Impacts Brain Aging

Our gut and brain are in constant communication, like two best friends who just got their first flip phones. However, the quality of conversation can decline as we age—and disruptions in gut health are the primary culprits. 

Stress, diet, aging, and underlying health conditions can throw off the gut’s natural balance, which may trigger a heightened immune response not just in the gut but throughout the body, including in the brain, says Schultz. That means these gut shifts impact more than digestion. “They’re also linked to brain fog, mood swings, and over time, can contribute to more serious issues like cognitive decline,” she says.

Research over the last decade backs this up, according to Volpe. “Chronic gut issues have been strongly linked to long-term brain health,” she says. In one Microorganisms study, gut-related immune activity increased brain stress responses that can contribute to cognitive challenges and mental health conditions. Meanwhile, a study published in Frontiers in Psychiatry reported a link between prolonged gut disruptions and changes in brain signaling. 

“It’s not a straight line from gut issue to cognitive disease, but it’s clear that when the gut isn’t well, the brain often shows signs of being unwell, too,” Schultz says. 

What To Eat To Support Your Gut and Brain 

Often, the first domino in this chain is a shift in gut bacteria. “In many cases, microbiome imbalances appear before other gut issues, setting off a cascade that eventually affects the brain,” Volpe explains. This is significant because low-grade, persistent immune activity in the brain is increasingly recognized as a factor in age-related cognitive decline and mood disorders, she says.

Fortunately, there are actionable steps you can take to support your gut microbiome, starting with your diet. A lack of bacterial diversity and too much of the “bad” kinds of gut bacteria can lead to gut imbalances, says Schultz. The former is primarily caused by eating too few fruits and vegetables, while the latter is caused by allowing processed foods to be a mainstay in your regimen, she suggests.

Read More: These Foods Spell Disaster For Weight Loss And Long-Term Health

Your move: “Eat more plants. Real ones, not just crackers labeled ‘plant-based,’” says Schultz. “Fruits, vegetables, legumes, nuts, seeds, herbs, and spices are rich in antioxidants and fiber that your gut bacteria love.” Aim to eat at least five different vegetables, alongside other colorful fare, daily. Since each color offers a different nutrient benefit, variety supports your microbiome and helps calm overactive gut and brain signals, she explains. Avoiding packaged foods as much as possible is also a good move.

In addition to what you eat, be mindful of how you eat, too. “Chew your food well,” Schultz says. “Slowing down eating during meals helps with digestion, prevents bloating, and sends signals to your brain that you’re nourished and safe.” It might seem like a small thing, but the quality of your eating experience really does have a downstream effect on that gut-brain communication channel.

The Best Supplements For Gut and Brain Health

Diet and lifestyle may be your healthy gut-brain foundation, but enlisting the help of supplements can certainly level up your microbiome, digestive health, and brain function—especially over time.

1. Probiotics

Probiotic supplements deliver strains of beneficial bacteria to your gut microbiome, says Volpe. “This can help improve digestion while supporting a balanced gut environment, which may reduce brain fog or mental health,” she suggests. While most people can honestly benefit from a daily probiotic supplement these days, “people prone to gut issues, depression or anxiety, cognitive decline, and/or who have taken many rounds of antibiotics throughout their lifetime are especially likely to benefit,” Volpe notes. Look for a supplement with at least 10 billion CFUs and multiple strains to support microbial diversity.

2. Prebiotics

Probiotics feast on types of fiber called prebiotics. So, “supplementing with prebiotics can help to further fuel and sustain the growth of healthy probiotic microbes, which have been shown to support a balanced immune response in both the gut and brain,” shares Volpe. Consider starting with a lower dose for the first week as your body adjusts to the increased fiber intake, Schultz adds. 

3. Omega-3 Fatty Acids

Omega-3 fatty acids are a scientifically-proven must-have for long-term brain health—and since the body cannot produce them on its own, we need to obtain them from food and/or supplements, says Volpe. Supplementation has been shown to promote cognitive function and preserve neural function, while supporting nervous system balance (read: a calm baseline mood). Volpe recommends supplementing with 1,000 milligrams of both EPA and DHA from purified fish or algae sources. 

4. L-glutamine

The amino acid l-glutamine is famous for its gut health benefits, as it supports the cells lining our small intestine. “Supplementing with glutamine has been shown to help reduce the gaps between intestinal cells through which substances can enter if gut barrier integrity is lacking,” explains Volpe. This lackluster gut barrier integrity, commonly called “leaky gut,” contributes to excess inflammation throughout the body and often impacts cognitive function. By helping repair the gut lining, l-glutamine can reduce symptoms associated with leaky gut, Volpe says. Most supplements offer two to five grams per serving. 

Other Ways To Support Your Gut and Brain 

Naturally, there’s more to good gut and brain health than the kitchen and medicine cabinet. Logging quality sleep, managing your stress, moving your body, and getting outside regularly also make a huge difference in both, according to Schultz. “These all support the gut-brain loop in some way, whether through hormone regulation, oxygen flow, or simply giving the nervous system a chance to reset,” she explains.

When To See A Doctor 

Because your gut and brain profoundly impact your overall health and everyday function, don’t hesitate to call for professional backup if you’re having trouble in either area.

If you’re experiencing new or worsened gastrointestinal symptoms like excess gas, abdominal bloating, unexplained weight loss, constipation, abdominal pain, excessive burping, or loose stools, check in with a holistic healthcare practitioner, Schultz says. The same goes if you notice any psychological or cognitive changes, such as mood swings, brain fog, memory loss, difficulty concentrating, unexplained sadness, apathy, or anxiety, adds Volpe. Gut issues could be part of the picture, but these symptoms might also signal that something beyond a microbial imbalance or gut disruption is at play.