We all know that fruits and vegetables are the foundation of any good diet. They provide a host of vitamins, minerals, micronutrients, antioxidants, and other beneficial things like fiber. 

Fiber isn’t the sexiest substance to talk about, but it’s definitely one of the most important. Of course, we all know that fiber is what keeps us “regular,” but it has other critical functions too. Most notably, fiber reduces risk of some of our deadliest diseases, including colorectal cancer, heart disease, obesity, and diabetes. 

Research is also starting to uncover ways that fiber indirectly benefits health. But before getting into that, it helps to understand what fiber is and what it does in your body.

Fiber 101

Fiber is a carbohydrate—but not a sugar or starch like you usually assume when you hear that term. It’s actually a structural carbohydrate—the supportive scaffolding that helps kale, Swiss chard, and other edible plants stand up in a garden. 

There are two types of fiber: soluble and insoluble. 

Soluble fiber works by absorbing water in the intestines. This forms a gel-like substance that gets fermented in the large intestine. In the process, the gut sends messages telling the brain, “I’m full.” 

Insoluble fiber works a little differently. It travels through the digestive tract like a scrubbing sponge, collecting residue for elimination. While soluble fiber sends the message of fullness to the brain, insoluble fiber creates actual, physical fullness so you don’t overeat. 

How Gut Bacteria Aid in Digestion

While fiber is edible, it is mostly indigestible. So, when it arrives in the large intestine, billions of gut bacteria take over the digestive process. 

These bacteria carry enzymes that break down the fiber. They then ferment the resulting sugars into a variety of prebiotics (food for the bacteria themselves) and short-chain fatty acids (SCFAs). 

SCFAs have several important functions. They help the bacteria nourish and heal the intestinal lining. They also help reduce inflammation in the gut and other parts of the body. They may even play a role in insulin sensitivity and controlling body weight.

This whole communication loop between gut and bacteria all depends on adequate fiber supply. When there’s plenty of fiber, bacteria thrive and send proper signals to the intestinal cells. The intestine responds by fortifying its mucus layer in which bacteria live. 

But when fiber intake is too low, bacteria starve. The protective mucus lining starts to wane, causing bacteria to dig deeper into the intestinal wall. This leads to inflammation—which can progress to more serious diseases down the road.

A lot of research has shown just how much fiber and gut bacteria depend on each other.

In one study, researchers put mice on a low-fiber diet. They found that the lack of fiber caused a major tenfold decline in beneficial microbes. Not only that, the protective mucus layer of the intestine became thinner, which triggered inflammation. Those mice also ended up gaining weight and experiencing blood sugar problems.1

Fortunately, a recent study has shown that just two weeks of eating more fiber can significantly alter your microbiome for the better. 

In this study, 26 people upped their fiber intake over a two-week span to include up to 50 grams daily. Stool samples were analyzed by researchers. They found that the increase in fiber changed the composition of gut microbes by 8%.2

Step #1 to a Healthier Gut: More Fiber

The FDA recommends 35 grams of fiber per day for men and 25 grams for women. At least 6 grams of that should be soluble. 

However, fewer than 5% of Americans eat enough fiber. On average, teens and adults are getting only about 50% of their daily fiber needs.

It’s hard to blame anyone for this dietary transgression. After all, when most people think of fiber, beans and oatmeal automatically come to mind. Not exactly the most popular foods!

It’s true—beans and oats do pack a serious fiber punch. But you certainly don’t have to rely only on them. Plenty of fruits, veggies, and nuts contain fiber. Your goal should be to eat a robust variety of fiber-rich whole foods every day to meet your fiber requirements.

Fiber supplements are also an option, but these tend to cause abrupt changes in gut bacteria, which can lead to bloating and gas. If you can, stick to whole foods.

Step #2 to a Healthier Gut: Add Probiotics

Along with more fiber, the second way to promote a healthier microbiome and overall gut health is to take probiotic supplements, which replenish and nourish the friendly bacteria in the gut. Newport Natural Health’s Microencapsulated Probiotic is an excellent choice, as it is designed to survive the journey through the harsh digestive tract so that the bacteria can be delivered safely to the intestines. 

Both of these habits are relatively easy ways to make a huge impact on your health and longevity. Remember, the changes noticed in the bacterial diversity of study participants happened after only two weeks. Imagine all the good that could happen if you ate a high-fiber diet and supplemented with probiotics every day for the rest of your life!

References

1. Zou J, et al. Fiber-Mediated Nourishment of Gut Microbiota Protects against Diet-Induced Obesity by Restoring IL-22-Mediated Colonic Health. Cell Host Microbe. 2018 Jan 10;23(1):41-53.e4. 

2. Oliver A, et al. High-Fiber, Whole-Food Dietary Intervention Alters the Human Gut Microbiome but Not Fecal Short-Chain Fatty Acids. mSystems. 2021 Mar 16;6(2):e00115-21.