“You are what you eat” is an old saying originally penned in 1826 by the gastronomic wizard Anthelme Brillat-Savarin for his essay on the physiology of gout.

He wrote, “Dis-moi ce que tu manges, je te dirai ce que tu es.”[Tell me what you eat, and I will tell you what you are.]

The same could be said for the trillions of bacteria in your gut: You are what they eat.

Researchers have known for a while that the gut biome needs to be fed water soluble fiber found in grains, veggies, and fruits for heart health.

But now they may know (more human studies are necessary) that your biome also needs insoluble fiber, which adds bulk to stool and helps food pass more quickly through the stomach and intestines, protecting your heart from high blood pressure.

The bacteria that gobble up insoluble fiber produce a fatty acid called propionate. According to a study in the journal Circulation, at least in mice that reduces cardiovascular problems associated with high blood pressure, including abnormal enlargement of the heart, irregular heartbeat, and atherosclerosis.

Insoluble fiber comes from eating foods such as beans, 100 percent whole wheat or bran products, green beans, potatoes, cauliflower, and nuts.

So if you have high blood pressure (75 million Americans do), feed your gut biome insoluble fiber — and you may get unbelievably big rewards. Not only may insoluble fiber protect your cardiovascular system, it's part of a brain-boosting diet as well.