Many people still associate fiber mainly with constipation. But current research suggests that its role is much broader. It affects the composition of the gut microbiome, supports the health of the intestinal lining, helps regulate cholesterol and blood sugar levels, and can also help us feel full for longer.
That does not mean buying a tub of psyllium will solve everything.
Not All Fiber Is the Same
You may have heard of soluble and insoluble fiber. Soluble fiber absorbs water and forms a gel in the gut, while insoluble fiber adds bulk to stool and helps it move through the digestive tract.
But that is only part of the story.
Current research suggests that knowing exactly which type of fiber you are eating may be less important than getting enough of it from a variety of sources.
In other words, your body will not benefit as much from a single spoonful of fiber every day as it will from variety.
Why Our Gut Loves Fiber
Unlike proteins or digestible carbohydrates, fiber cannot be fully broken down by the human body. And that is precisely what makes it so interesting.
It travels through the digestive tract to the large intestine, home to the billions of microorganisms that make up our gut microbiome. Some of these microbes use fiber as a source of energy, producing compounds known as short-chain fatty acids (SCFAs) in the process.
The name may sound complicated, but their role is relatively straightforward. They provide energy for cells in the colon, help maintain a healthy intestinal lining, and are involved in regulating inflammatory processes in the body.
The microbiome is not just another wellness buzzword. In recent years, a growing body of research has suggested that it may influence far more aspects of our health than we thought only a few years ago.
It Is Not Just About Digestion
Most people start paying attention to fiber only when they experience digestive problems. But its potential benefits extend much further.
Adequate fiber intake has long been associated with:
- better bowel function and more regular bowel movements,
- healthier cholesterol levels,
- better regulation of blood sugar after meals,
- feeling full for longer,
- a lower risk of some cardiovascular diseases,
- a lower risk of colorectal cancer.
Researchers are also paying increasing attention to the relationship between the gut microbiome and the brain. The findings are promising, but it is important to be clear that this is an area in which science still does not have all the answers.
How Much Fiber Do We Actually Need?
Recommended daily fiber intake for adults is generally around 25 grams for women and 30–38 grams for men.
The reality, however, looks very different.
Most people do not come close to these amounts. They may not even notice because they are eating enough calories and protein, but not enough fruit, vegetables, legumes, or whole grains.
How to Add More Fiber Without Giving Yourself a Stomachache
This is one of the most common mistakes I see.
Someone realizes they are not eating enough fiber and, the very next day, buys psyllium, adds two servings of legumes to their diet, and starts eating enormous amounts of vegetables.
The result is often bloating, abdominal discomfort, or diarrhea.
That does not mean fiber is harmful. It simply means that neither the digestive system nor the microbiome is used to that amount yet.
A much better approach is to increase fiber gradually while also making sure you drink enough fluids.
Where Can You Find Fiber?
The good news is that you do not need any expensive supplements.
Some of the best natural sources of fiber include:
- oats,
- legumes,
- fruit, ideally with the skin where appropriate,
- vegetables,
- chia seeds and flaxseeds,
- nuts,
- whole-grain bread, pasta, and rice.
Each of these foods contains a slightly different type and combination of fibers. That variety is one of the things that can benefit the gut microbiome most.
Psyllium Alone Is Not Enough
Psyllium can be very useful, and I use it occasionally myself.
But it should not replace a varied diet.
Different microbes in the gut use different types of fiber. If you rely on just one type over the long term, your microbiome misses out on the variety that appears to be important for it.
Whole foods also provide much more than fiber. They contain vitamins, minerals, and other bioactive compounds that no dietary supplement can fully replace.
What This Looks Like in My Own Diet
I am not suggesting that my diet is the only right way to eat. But I have found that relying on several sources of fiber and spreading them naturally throughout the day works well for me.
In the morning, whole-grain bread is usually my main source of fiber.
At lunch, I try to include a generous serving of vegetables and, whenever possible, choose whole-grain pasta or other whole-grain alternatives instead of their refined versions.
My snacks vary depending on what I feel like eating, but they often include fruit, vegetables, or an additional source of fiber such as psyllium or chicory-root syrup. I mainly use psyllium on days when I know I have not eaten as many vegetables as I would have liked.
Dinner follows a similar pattern: whole-grain tortillas or bread, a larger serving of vegetables, or some seeds added to the meal.
I do not count every gram of fiber. I simply try to include it naturally in every meal.
At the same time, I am careful not to eat too much at once or consistently go far beyond the recommended intake. A very large amount in a single meal can place more strain on digestion than it helps, and the same may be true of a consistently very high overall intake.
This change made the biggest difference for me. I used to look for a single food or supplement that would solve everything. Eventually, I found that combining a variety of fiber sources worked much better.
Over time, my digestion improved, and some of the issues I experienced after consuming sulfites became less pronounced.
Of course, this does not mean that fiber can cure an allergy or intolerance. Everyone responds differently, and my experience may not apply to everyone. The underlying cause remains the same. In my case, however, improving my diet helped create conditions in which my digestion works significantly better than it did before.
Final Thoughts
Fiber may not be as appealing a topic as protein desserts or the latest supplements. Even so, it is one of the parts of our diet whose health benefits are supported by some of the strongest evidence.
You do not have to change your entire diet overnight. You can start with something simple: add fruit to breakfast, replace white bread with a whole-grain option, include legumes once a week, or swap a sweet snack for a handful of nuts occasionally.
You do not have to be perfect or transform your diet from one day to the next. Small changes you can maintain over time often bring far more benefit than short-lived extremes.
Sources
- EatingWell. (2026). Fiber’s Big Glow-Up: Why This Nutrient Is Trending Now. www.eatingwell.com
- European Food Safety Authority (EFSA). (2024). Nutrition. www.efsa.europa.eu
- Harvard Health Publishing. (2024). How — and why — to fit more fiber and fermented food into your meals. www.health.harvard.edu
- Harvard Health Publishing. (2025). How to feed your gut. www.health.harvard.edu
- Harvard Health Publishing. (2026). How to get more fiber in your diet. www.health.harvard.edu
- National Institutes of Health (NIH). (2022). Health benefits of dietary fibers vary. www.nih.gov
- Verywell Health. (2026). Eating More Fiber Could Benefit Your Brain—Not Just Your Gut. www.verywellhealth.com
- World Health Organization (WHO). (2026). Healthy diet. www.who.int
- Author’s own materials. How to Improve Your Health — Gut Health and Beyond — with Fiber.
About the author
Blanka Sopoušková helps people and companies use technology and AI to work smarter and make everyday life and work easier. She is a business analyst, consultant, nutrition specialist, and business management PhD candidate, with experience across fintech, e-commerce, and services. More on the About page and on LinkedIn.