Diabetes and the Gut-Brain Axis

“Diabetes is caused by melancholy.” —Thomas Willis

When we think about diabetes, the first organ to come to mind is not the gut but the pancreas. But a new review finds that the gut plays a major role in diabetes, a deadly disease that affects one-tenth of the population and rising.

To add insult to injury, diabetics are three times more likely to be depressed than the rest of the population, which is already pretty depressed. Perhaps the more interesting statistic is the converse: Depressed people are 60 percent more likely to develop diabetes.

Type 1 diabetes comes from a lack of insulin-producing cells and is typically treated with injections of insulin. But it accounts for less than 10 percent of diabetes. The vast majority of diabetes is type 2, and that’s where the gut comes in.

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The Role of Diet and the Gut Microbiome in Diabetes

Because diabetics have trouble controlling blood sugar, what they eat makes a big difference. So, on one level, it’s obvious that the gut contributes to diabetes. But there is another important factor: the microbes that live there. The gut microbiome, in fact, may really be how diabetes starts—and how it ends.

The typical American eats a lot of carbs, which our intestine breaks down into sugars that are quickly absorbed, fueling our tissues. In response to sugar, the pancreas produces insulin, a molecule that acts like a doorman to escort sugar into the hungry cells of our body.

Our microbes, however, need fiber. Sadly, food manufacturers have spent the last several decades removing fiber from our diets in order to give us delicious white breads, cakes, and cookies. That effort parallels the rise in obesity and diabetes, which is unlikely to be a coincidence.

The lack of fiber is killing our gut microbes and can lead to a disrupted state called dysbiosis. Over time, dysbiosis can lead to a leaky gut that allows toxins to seep into the surrounding tissues and blood vessels.

This prompts the immune system to create millions of new immune cells, each one craving sugar. The body obliges by making muscle cells resistant to insulin, freeing up extra sugar for the inflammatory fight. For an acute infection, this is a wonderful system, and as soon as the immune system triumphs, muscle cells become sensitive to insulin again.

But if the gut dysbiosis continues, the inflammation becomes chronic, and so does the insulin resistance. Diabetes starts to set in.

To show how important a healthy gut microbiome is to insulin sensitivity, a 2013 Dutch study transferred feces from healthy lean people into people with metabolic syndrome. Six weeks later, the recipients had doubled their insulin sensitivity.

There are other factors involved. Genetics, mitochondrial stress, sleep disruption, stress, exercise, and body fat all play a role. But a dysbiotic microbiome can fan the inflammation and tip the scales from metabolic syndrome into full-blown type 2 diabetes.

Diet and Lifestyle Changes for Diabetes Prevention and Recovery

You can’t control your genes, and stress seems ubiquitous, but you have control of your diet and exercise regimen. The proper diet is something like Mediterranean with plenty of fiber and ferments to please your microbes. It’s a delicious way to recover.

It’s likely that at least two-thirds of diabetics could recover with diet and exercise, although only about one-third currently do. Success is tied to how much weight is lost. A stunning 86 percent of those who lost 15 percent of their weight were able to achieve full remission. After the fat drains out of the liver and pancreas, these organs tend to reboot, and functionality returns.

Fiber steadies blood sugar levels as well as feeds beneficial bacteria. That gives fiber a double punch in the fight against diabetes. If you can squeeze 25 grams of fiber into your diet each day, you’ll see a remarkable improvement in your general health.

Stock up on grains and vegetables, which are full of fiber. Fruits, especially berries, are also fiber-rich, but if you’re especially sensitive to sugar, you might want to monitor your consumption. Beans, lentils, and peas are fantastic sources of fiber as well. As a bonus, via the gut-brain axis, this diet can also improve your mood.

If you aren’t used to fiber, start slowly, and talk to your doctor first if you have gut flare-ups. Fair notice: When you eat fiber, you grow beneficial bacteria that may produce gas. That can lead to flatulence, but bear with it; it gets better as you go. Farts are humorous; diabetes is not.