A Low-Fiber Diet May Not Be So Gut Friendly, Even If You Are Not Obese

4 years ago | Nutrition

By Joy Stephenson-Laws, J.D., Founder

I bet if I asked what is the most important role of fiber, many of you would say to help you go to the bathroom! And that is one of the reasons why dietary fiber is so important. But there’s also a lot more to fiber.

Let’s do a quick review of what exactly is fiber.

What exactly is fiber?

To put it simply, fiber is a type of carbohydrate that the body cannot digest.

(Carbs are one of the six basic nutrients you need to live. The others are protein, water, fats, vitamins and minerals).

There are two types of fiber: insoluble and soluble.

Insoluble fiber does not dissolve in water and is the type of fiber that makes you regular and prevents constipation. It helps food move through your digestive system like a broom.

Soluble fiber is a type of fiber which dissolves in water and swells like a sponge in the stomach, giving food a jellylike bulk. It combines with fat in the intestines and pulls it out of the body before it can enter the bloodstream. It is soluble fiber that may help lower blood cholesterol, slow the absorption of carbohydrates from foods and help stabilize blood sugar levels. Both types of fiber are readily available to us all in many types of foods, however, according to a recent report from the American Society for Nutrition, only seven percent of adults meet fiber recommendations.

Fiber and your gut.

We all have a gut microbiome. When I say “gut,” I am referring to the stomach and intestines, where trillions of microbes (more commonly called “gut bugs”) live. This community of bugs is sometimes referred to as the gut microbiome. It’s essentially an ecosystem within us that must be taken care of and balanced with a diverse amount of gut bugs.

According to a recent study published in the American Journal of Physiology-Endocrinology and Metabolism, following a low fiber diet may cause gut infection regardless if you are overweight or not.

(Being overweight or obese increases the risk and severity of baterial infection).

“Previous studies have found that obesity and related factors, such as a high-fat and high-sugar diet, may change the composition of the gut microbiome enough to increase the risk of inflammation and infection,” according to one Medical Xpress report that discusses the study.

“The typical Western diet containing highly processed foods also tends to be low in fiber. However, it's not clear if this type of diet is enough to predispose people to bacterial infection.”

The researchers explored whether a high-fat, low-fiber diet increased the risk of developing a strain of E. coli bacteria in the intestinal tract by using both obese and lean mice. The obese mice followed two high-fat, low-fiber diets (one being 60 percent fat and the other being 45 percent fat). When exposed to the bacteria, all of the mice developed E. coli expansion in the colon. Mice on the 60 percent high-fat diet were more overweight than the ones on the 45 percent, however, both groups had about the same amount of E. coli expansion.

The research team also fed lean mice a high-fat diet for a short period (before they became obese). After being exposed to the E.coli strain, the lean mice had more expansion of the bacteria than the control group of mice (which were a group of lean mice fed a normal diet).

“Finally, the research team found that mice on a low-fat, low-fiber diet had higher AIEC [the type of E.coli strain] burden than those eating a normal diet, suggesting that dietary fat was not the key ingredient, but ‘ingestion of lower dietary fiber is sufficient to promote expansion of AIEC throughout the gut,’” according to the Medical Xpress report.

Include plenty of fiber in your daily diet.

The good news is that if you eat healthily, it’s pretty easy to get plenty of fiber included in your daily diet.

A few sources of insoluble fiber include:

Brown rice
Legumes
Carrots
Cucumbers
Tomatoes
Pretty much any type of vegetable

A few sources of soluble fiber include:

Do not let the study discussed make you fearful of fat. Along with fiber, it is important to include healthy fats (and protein) in your diet which you can get from foods such as avocados and nuts.

As always, it is highly recommended to speak with a competent healthcare professional regarding your daily diet.

Enjoy your healthy life!

Disclaimer: This article is not intended to provide medical advice. Please consult with your doctor or another competent healthcare practitioner to get specific medical advice for your situation.

The pH professional health care team includes recognized experts from a variety of health care and related disciplines, including physicians, attorneys, nutritionists, nurses and certified fitness instructors. This team also includes the members of the pH Medical Advisory Board, which constantly monitors all pH programs, products and services. To learn more about the pH Medical Advisory Board, click here.