Fiber and the Microbiome: What’s the Connection?

Microbiome. Fiber. What’s the connection between these two terms? Find out in our post!

It’s no secret that gut health has been one of the biggest health topics this year. From the buzz surrounding turmeric supplements for a healthy internal response, to probiotics to balance intestinal flora, the nutritional spotlight this year has been all about your gut.

However, savvy health readers will know that supporting your gut isn’t actually a new idea.

In fact, there is a wealth of information about the connection of your gut’s health to other processes in your body (we’ve even written a few posts about it!). What you may not know is that your gut health may be tied directly to the functioning of your microbiome, which is in turn influenced by a specific nutrient: fiber.

Fast Fiber Facts

Every time you pour a bowl of cereal or eat a slice of your favorite whole-wheat avocado toast, you’re consuming fiber. Dietary fiber is an indigestible complex carbohydrate found in the cell wall of plants. It’s sometimes called roughage, and is primarily found in grains, fruits, and vegetables. There are two main types of fiber: soluble and insoluble.

Soluble fiber is named because of its ability to absorb water during digestion. This absorption creates a gel-like substance that works to slow down your digestion and help you feel full. Soluble fiber may also support healthy cholesterol levels already in the normal range. Food sources of soluble fiber include oatmeal, oat bran, lentils, apples, oranges, pears, strawberries, flax seeds, beans, blueberries, psyllium, and more.

By contrast, insoluble fiber doesn’t absorb water and passes through the digestive system more-or-less intact. This type of fiber supports regular bowel movements, and works to prevent constipation. It also supports overall intestinal health. Sources of insoluble fiber include whole wheat, whole grains, seeds, nuts, barley, cous cous, brown rice, bulgar, zucchini, celery, dark leafy vegetables, raisins, grapes, and other sources.

Typically, adults need on average 25 to 30 grams of fiber per day; however, most only get about 15 grams per day, about half the recommended amount. Your fiber intake isn’t just important to maintaining metabolic processes, it may also have a direct link to the health of the human microbiome.

The Human Microbiome: an Overview

The microbiome refers to the genetic material of the trillions of bacterial cells that reside in your body. These living microorganisms (also referred to as microbiota) perform important functions that support your health, including protecting our bodies from infectious invaders, synthesizing nutrients and combating inflammation. Having a healthy balance of microbiota throughout your body is considered essential to your health, and since most of these microbiota live in your intestines, they are linked with the overall health of your gut.

Your gut harbors the most diverse species of microbiota in the body, although the specific kinds of microogranisms can differ from person to person. Despite the differences, microbiota in the gut contribute to metabolic processes and support healthy digestion. This is where fiber plays a role.

Fiber and the Microbiome

According to Dr. Justin Sonnenberg, a biologist at Stanford University and head of the Sonnenberg Lab, “Dietary fiber and diversity of the microbiota complement each other for better health outcomes.” Sonnenberg’s lab studies the relationship between the microbiota and fiber, (referred to as dietary microbiota-accessible carbohydrates or MACs), and how these microbiota extract nutrients from the fiber we consume. Sonnenberg believes that consuming the proper amount of fiber will not only support the overall microbiome, but will also support a healthy internal response, promote immune system health and function, and may also support a healthy weight (which we examined in a previous blog). A 2016 study confirmed this idea, suggesting that not getting enough fiber in your diet may cut down on the diversity of microbial species and the subsequent production of short chain fatty acids.

The necessity of a fiber-rich diet is further examined in a recent study about the interplay between fiber and the microbiome. Researchers studied the effects of soluble (or fermentable) fiber on the microbiomes of both human and animal subjects, and concluded that:

the fermentability of fiber and the consequent changes in the intestinal microbiome and/or their metabolites likely lead to the body weight–unrelated anti-inflammatory activity locally in the intestine and systemically.

Essentially, these researchers discovered that fiber promoted the healthy growth and development of intestinal bacteria, which displayed increased anti-inflammatory responses throughout the microbiome.

Although there is still a significant amount of work to be done in order to understand the full extent of fiber’s relationship to the microbiome, it’s clear that the amount of fiber you consume does affect your gut’s health. If you’re like many adults and need extra fiber in your diet, we offer a number of high-quality fiber supplements to support your health. Browse through our selection to find options from trusted brands like Pure Encapsulations, Renew Life, NOW Foods and more!