Fiber-Rich Foods: Does it suit your digestive system?

We’re constantly being advised to eat fiber-rich foods, and government recommendations (including those from NICE) suggest 30 g daily for blood sugar regulation, heart and intestinal health, and other reasons.

However, not all fiber-rich foods function in the same manner.

According to a recent study (Goel et al., 2025), certain forms of fiber have a significantly stronger correlation with advantageous gut microbes than others. Some, such as resistant starches, have a more moderate function.

Which fibers should you concentrate on, then? The ranking of associations with gut health, from most potent to weakest, is as follows:

The fiber-rich foods listed first have the most significant effects on the gut microbiome, as indicated by the ranking based on statistical significance. (p-values).

• Glucuronic acid and glucosamine, which are found in seafood, mushrooms, and fermented foods such as miso, kombucha, and kimchi, may help fortify the intestinal barrier.

• Fructooligosaccharides (FOS) nourish bacteria that are good for the gut. They are found in garlic, onions, leeks, asparagus, bananas, chicory roots, wheat bran, Jerusalem artichokes, and lentils.

• Xylan: Increases the diversity of microorganisms. Found in: corn and whole grains (wheat, rye, oats, barley, and brown rice).

• Galactomannan: Linked to the health of the gut microbiome. Found in: carob (add to smoothies or sprinkle on Greek yogurt), alfalfa (add crunchy sprouts to salads), and fenugreek (a beautiful spice to use in curries).

• Xyloglucan promotes a healthy intestinal environment. It is found in flaxseeds, blueberries, persimmons, apples, cauliflower, and tamarind (add 12 tablespoons to soups, stews, curries, or marinades for tangy depth).

• Resistant starches are fibers that play a role in gut health but have a weaker association than other fibers. Found in: potatoes, quinoa, oats, legumes (lettuce, chickpeas, soybeans, peas), corn (especially popcorn), wheat, and non-glutinous rice (like basmati).

What you take away from this:

Fibers like glucosamine and FOS make the strongest connections with the microbes in your gastrointestinal tract. At the same time, resistant starches provide a more supportive function.

Easy methods to increase gut-friendly fiber intake:

✔ When cooking, start with onions and garlic.

✔ For breakfast, try rolled or steel-cut oats with nut butter or yogurt for protein.

✔ Use lentils or brown rice instead of white rice.

✔ Experiment with tamarind paste.

✔ Include mushrooms & fermented foods for gut support. Try new whole grains (pearl barley, farro, spelt) and pair them with legumes for a high-fiber, gut-nourishing meal.

✔ Snack on popcorn—it’s a surprisingly gut-friendly alternative!

Fuel your health with fiber-rich foods! Share your go-to sources of fiber and how you incorporate them into your daily diet. Let’s swap tips and inspire each other to stay healthy—comment below.

Not All Fiber Is the Same—Are You Consuming the Perfect Type?

Are you looking for weight loss strategies? Read this article and start your weight loss journey with the best fiber-rich foods.

Dr Usman Barkat, PT

Physical Therapist/Body Expert