What does bacteria have to do with it? Am I at risk?

Carolyn Williams, PhD, RD
October 26, 2017

If you're invested in learning more about your intestinal health, “leaky gut” is a term you see thrown around a lot lately, often in reference to gut bacteria and inflammation. Many want to understand it better and learn more – without sliding down a dark hole of complex microbe-gut permeability-science talk.

So we've cut through the research and science to try and pare down the concept of leaky gut to just the basics and how it could affect you.

What is leaky gut?

Leaky gut syndrome occurs when the walls of the small intestine essentially leak toxins, waste, and/or bacteria through the intestinal wall into the bloodstream. Technically, leaky gut or leaky gut syndrome isn’t an official diagnosis per medical standards, but everyday research seems to tie more symptoms and diseases back to gut health giving leaky gut real credibility.

A healthy gut versus a leaky gut

The easiest way to understand leaky gut is by first looking at how intestines are supposed to operate during digestion.

Take a glance at how a healthy gut operates:

After a meal is consumed, foods are gradually broken down as they make their way through the GI tract. The goal of the GI tract is to digest food into single nutrients and components that become small enough to be absorbed. The small intestine plays a central role since it’s where digestion of carbs, fats, and proteins is completed, and then where those nutrients are absorbed through the intestinal wall into the bloodstream for use by the body. Anything that can’t be digested fully—like fiber and waste product, as well as some toxins and bacteria—goes on to the large intestine to either be fermented and/or continue on to be excreted as waste product.

Now, let’s compare that to an unhealthy gut:

After consuming a meal, foods are broken down in similar fashion so that their nutrients can be absorbed, but it’s the absorption process where trouble occurs. In an unhealthy or damaged gut, there are holes or gaps in the intestinal lining which means digested nutrients are absorbed into the bloodstream, but things like toxins, antigens, microbes, and waste components can also leak through the intestinal wall and into the body. It’s this entrance into the body that is thought to play a role in the initiation or development of many chronic diseases.

Getty Images

What makes a gut leaky?

The bacterial composition of the gut seems to largely define how permeable or leaky it is, and this explains why discussions about leaky gut bring up things like gut health and probiotics. Intestine with a variety of plentiful good bacteria tend to be healthier, allowing digested nutrients, but not much else, to pass through. It’s when the microbe balance becomes disrupted that a state of dysbiosis, or microbial imbalance, occurs and appears lead to a weakened, leaky gut.

So what causes imbalances in gut microbes?  

Recent research suggests that a diet that’s low in fiber and high in added sugars, saturated fats, and processed foods is the cause for many Americans. Other contributors include stress, antibiotics and certain medications, artificial sweeteners, chemicals, and excessive alcohol—essentially any food or environmental component that can inflame the gut lining.

Photo: PeopleImages.com

What health risks are caused by a leaky gut?

Several research studies suggest autoimmune diseases are associated with a leaky gut: Specifically Alzheimer’s disease, as well as other chronic conditions and symptoms like obesity, insulin resistance, depression, asthma, arthritis, and cancer. Researchers have yet to pinpoint an exact cause-and-effect, but the research definitely points toward health issues when the gut is unbalanced.

What does this mean for you?

Building and maintaining a healthy balance of gut bacteria appears to be the best mode of prevention and to increase overall health within the body. While there are still lots of unknowns, research findings point towards consumption of a less processed, whole foods diet with plenty of fiber fruits and vegetables, microbe-rich foods like fermented foods and yogurt, and limited added sugars, saturated fats, and trans fats. Additionally, it appears unnecessary chemicals and additives likely improves gut health, and some individuals may even benefit from taking a probiotic supplement to restore some of the good cultures. The bottom line is that a healthy diet supports a healthy gut and appears to lead to better overall health. The gut and its microbiota are a hot area of research right now, so be on the lookout for more information and guidance as researchers learn more.