Want to lower dementia risk? Grow good gut bacteria

gut bacteria dementia

With rates of dementia rising dramatically, you’re not alone in wondering how to avoid becoming another casualty. Although lowering the risk of dementia depends on dietary and lifestyle changes, one little known approach involves cultivating your garden. Not the garden in your yard, but the one in your gut.

A team of Harvard-affiliated researchers discovered gut bacteria influence brain inflammation, a mechanism behind dementia. Brain inflammation, which is more common than you’d think, kills brain cells, thus gradually atrophying the brain and raising the risk of dementia. If you want to lower your risk of dementia, you need to learn how to prevent brain inflammation.

Best way to combat brain inflammation? Diet

The foods you eat influence the bacteria in your gut. Our intestines host about three to four pounds of vitally necessary bacteria. Gut bacteria number in the trillions, with hundreds of varieties discovered so far.

A more recent discovery is that these bacteria can travel to the brain via the vagus nerve, a large nerve that connects the brain with the gut. Communication travels back and forth between the brain and the vagus nerve in what is called the gut-brain axis. This means what you eat and the state of your digestive health profoundly affects your brain health.

The study found that a deficiency in gut bacteria can set the stage for inflammation in the brain, thus aging the brain more rapidly and increasing the risk of dementia.

Grow beneficial gut bacteria to protect your brain

This isn’t the first study to show the profound influence of gut bacteria on the brain. Researchers have found links between gut bacteria and depression, anxiety, mood disorders, memory, cognition, and more.

So it’s no surprise dementia is on the rise when you consider the modern diet, which seems designed to destroy good bacteria while populating the gut with harmful, inflammatory bacteria instead.

Modern diets and mass extinction of gut bacteria

In fact, researchers have found the modern gut is home to a mass extinction of many varieties of necessary gut bacteria that have been around as long as humans. Diets high in processed foods, meats, and sugars but pitifully low in plant fiber have killed off a rich diversity of gut bacteria on which our health depends. The result? Inflammation and chronic diseases such as dementia.

You can boost your beneficial gut bacteria by taking probiotics and eating fermented foods, such as sauerkraut. But it’s even more important to feed those bacteria with a diet that is primarily plant-based. Eat mostly vegetables, and switch up the vegetables you eat on a regular basis as your friendly bacteria depend on dietary diversity to thrive.

Also, avoid foods that have been shown to increase brain inflammation and raise the risk of dementia: Sugar, processed carbohydrates, excess salt, excess alcohol, and foods to which you have an immune reaction. Gluten and dairy are two common triggers of inflammation and can be particularly destructive to the brain in those who react to them.

The mass extinction of species happening in your gut

mass extinction gut bacteria copy

You probably already know the planet is experiencing an extinction crisis; scientists estimate we’ll lose up to 50 percent of current species during the next 20 years. But did you know there’s also an extinction crisis of gut bacteria happening among civilized humans?

The modern diet, which is high in processed foods, meats and sugars but pitifully low in plant fiber appears to have killed off a rich diversity of gut bacteria on which our health depends. The result? Inflammation and chronic disease.

Low fiber kills bacteria and increases inflammation

To prove the point, one study changed the diets of African Americans, who have a high risk of colon cancer, and native Africans in South Africa. They put the African Americans on a native diet high in plant fiber and the native Africans on a typical American diet high in processed foods and meats.

The researchers quickly saw a decrease in colon inflammation in the Americans eating increased fiber, and an increase in colon inflammation in the South Africans on a standard American diet.

In fact, studies of the few remaining indigenous cultures on the planet show humans once served as host to significantly more gut bacteria than is found in Westerners today. These cultures eat about 10 times more plant fiber than the average American. Those bacteria organize themselves in colonies to digest plant fiber, support immunity, and curb inflammation.

People around the world even have different strains of the same bacterium that is native to their area and genetics. Human migration over the years has wiped out some strains, increasing the risk of certain diseases as a result, such as gastric cancer.

How a diversity of gut bacteria protect your health

Just how do bacteria protect us from chronic disease?

For one thing, when they work at breaking down plant fibers, they create compounds called short-chain fatty acids (SCFAs) that stimulate the anti-inflammatory arm of the immune system.

Although it’s possible to supplement with SCFAs, unfortunately they won’t be as beneficial as when your own gut bacteria produce them. This is because the bacteria colonize themselves with similar bacteria in an internal ecosystem that protects the lining of the gut.

Starved bacteria eat the gut lining

One startling revelation researchers found is that gut bacteria starved of the plant fiber they need for fuel instead appear to feed on the protective mucus layer that lines the intestines. Studies of mice fed high-fiber diets showed this mucosal layer was as twice as thick as that of mice on a low-fiber diet.

A too-thin layer of protective mucus allows dangerous bacteria, undigested foods, and other pathogens into the bloodstream, where they trigger system-wide inflammation. This is known as leaky gut.

How to beef up your own gut bacteria

It’s quite possible that many of us today lack the diversity of gut bacteria our ancestors had, and our health suffers as a result. Researchers believe those who grow up on farms, with animals, and exposed to other sources of more diverse bacteria may fare better in terms of microbial diversity.

Nevertheless, a diet high in plant fiber can increase the diversity and population of your gut bacteria, thus helping you balance digestion and tame inflammation. If you find it difficult to tolerate a high-fiber diet, you may have a severe imbalance in your gut bacteria that needs attention. Ask my office for more information.