The Importance of Healthy Gut Bacteria for Heart Health

What is gut bacteria?

Gut bacteria, also known as gut flora or gut microbiota, is the name given to the population of microorganisms that live in the intestines, most of which populate the large intestine and the colon. Our gut contains an estimated 100 trillion microorganisms including at least 1000 different species of known bacteria with more than 3 million genes (150 times more than human genes).

One third of our gut bacteria is common to most people, while two thirds are unique to each individual. [1]

Why is healthy gut bacteria important?

Our gut bacteria has a major influence on our health. The complex communities of microorganisms that make up our intestinal flora can affect metabolism, weight gain, blood sugar control and immunity.

To begin with, our gut bacteria affects our body’s metabolism by determining the calories and nutrients that we extract from food.[2] Recent studies have shown that obese people have less diversity in their gut bacteria than lean people.[3]

Unhealthy gut bacteria have been linked to Type-2 Diabetes and insulin sensitivity. Scientists have concluded that there are microbes that form toxins that enter the gut and then cause inflammation throughout the body, including liver and fat cells that can affect overall metabolism and insulin sensitivity.[4]

A healthy immune system is dependent upon healthy and varied gut bacteria. Your gut wall is comprised of 70% of cells that make up your immune system, and your gut flora help to strengthen the lining of the gut wall. New research is now discovering a high level of communication between your body’s immune system and the bacteria in the gut.

Researchers at Johns Hopkins University are studying how the composition of the gut changes in different diseases.

“A huge proportion of your immune system is actually in your GI (digesgtive) tract,” says Dan Peterson, assistant professor of pathology at the Johns Hopkins University School of Medicine. “The immune system is inside your body, and the bacteria are outside your body.” And yet they interact. For example, certain cells in the lining of the gut spend their lives excreting massive quantities of antibodies into the gut.

 “That’s what we’re trying to understand—what are the types of antibodies being made, and how is the body trying to control the interaction between ourselves and bacteria on the outside?” [5]

Further immune protection is provided by certain species of gut microbes that are able to produce antibacterial substances that fight bacteria like E.coli and Salmonella.[6]

As you can see our gut flora plays a vital role in maintaining a healthy immune system.

How do healthy gut bacteria improve cardiovascular health?

New research now highlights the direct link between gut bacteria and cardiovascular health. For example, two key cardiovascular risk factors are diabetes and metabolic syndrome. Both of these conditions are linked to the gut microbiome. Intestinal flora in people suffering from obesity and Type-2 diabetes has been shown to be less diverse than that of healthy individuals. [7] [8]  Insulin and leptin are key hormones that depend upon healthy gut bacteria for optimal function and dysfunction of these hormones can lead to metabolic syndrome. [9] In fact restoring gut flora is often the first step in healing these hormonal imbalances.

Intestinal permeability, or leaky gut, has been linked to an increase in abdominal fat — the fat that accumulates around the viscera or the abdominal organs. It has been well established that this type of fat is a strong cardiovascular risk factor. [10]

However, a varied and healthy gut bacteria can help to prevent and offer protection against leaky gut[11], diabetes and metabolic syndrome.

How high-fiber diets affect gut bacteria and improve heart health

Foods that are high in fiber feed the good bacteria in the intestines and function as prebiotics. It is the increase in good bacteria that can help to improve heart health.

A recent study by Marques and the Heart Failure Research Group in Melbourne, Australia highlights how a high-fiber diet can improve gut bacteria and positively affect cardiovascular health. In particular, a high-fiber diet was shown to dramatically increase short-chain fatty acid-producing bacteria in the gut. This is of paramount importance, as short-chain fatty acids have been proven to help lower blood pressure and improve overall heart function.[12] [13] These acids areproducedwhen dietary fiber is fermented by friendly gut bacteria in the colon.