Prebiotics, probiotics, and postbiotics have all been identified as key players in our gut health, but important soluble fibers like inulin can also work wonders on our gut microbiome.
“Inulin is a type of fiber most found in plants like Jerusalem artichokes and chicory root, and it can act as a prebiotic since it [can be] easily fermented by the bacteria that live in our gut,” says Amanda Sauceda, MS, RD, a registered dietitian and gut health nutritionist. “As a result of that fermentation, short-chain fatty acids are produced, which can lead to positive changes to the gut microbiome.” Short-chain fatty acids have an array of positive effects on the gut, with the main ones being protection against inflammation, mucus production, and maintenance of the intestinal barrier integrity.
The positive changes to the gut microbiome can be attributed to the prebiotic nature of inulin, which can feed the bacteria in our gut that can produce butyrate—a form of postbiotics that helps maintain a healthy gut, adds Sauceda. A 2017 comprehensive review also points out that inulin is associated with improved gut microbiota, increased mineral absorption, stimulation of immune functions, reduced risks of irritable bowel diseases, and constipation. There’s been some research on how inulin consumption can help with other health concerns like type 2 diabetes and high blood sugar, but Sauceda says the research isn’t necessarily there yet to validate those claims.
What experts do know is that inulin can help maintain a healthy gut, which can support our overall well-being. It’s important to note that inulin is high in FODMAPs, which are short-chain carbohydrates that may cause intestinal distress, so this type of fiber may not be everyone’s cup of tea. “If you’re sensitive to FODMAPs or have irritable bowel syndrome (IBS), then you may experience bloating, gassiness, and overall discomfort when consuming inulin-rich foods or inulin supplements, so consult with a physician beforehand,” Sauceda says.
There is currently no Recommended Daily Allowance (RDA) for inulin, but the Academy of Nutrition and Dietetics does recommend eating around 14 grams of fiber per 1,000 calories consumed per day.
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Because soluble fiber can hold onto water and gel things up, inulin can help with constipation. "It has been shown to make stools softer, as well as possibly increase the number of stools per day," Kimberlain says. There's also evidence that inulin can be helpful in diabetes management, as it "may possibly improve blood sugar levels (in the short-term) as well as help [reduce] insulin resistance when inulin is taken along with a patients' diabetes medications," Kimberlain says. Note: It's a little confusing that the spelling of the fiber (inulin) is so close to that of the hormone (insulin).
Another possible benefit: as with other soluble fibers, inulin might help lower LDL cholesterol levels (the unhealthy kind) by binding to these triglycerides in your bloodstream.
And just a side note: Possible side effects (common when consuming a high-fiber diet) include abdominal pain, flatulence, bloating and possible belching, so someone with IBD would want to steer clear of products with this added in.
Even if you've never heard of inulin, chances are you've eaten it before. Here are a few natural food sources:
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Jerusalem artichokes
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Jicama
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Asparagus
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Onion
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Leeks
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Garlic
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Bananas (unripe)
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Chicory root
In addition to inulin fiber, these plant foods also contain important vitamins and minerals. Kimberlain recommends adding these foods to your diet (or eating them more often, if they're already staples) if you're hoping to reap the health benefits of inulin.
"There are many reasons why inulin is added to products," Kimberlain says. For starters, it has a naturally sweet taste, which means it can add some sweetness to products without adding any calories. Secondly, inulin can add creamy texture and some bulk to packaged foods like yogurt, protein drinks and powders, and sugar-free desserts like chocolate or ice cream, again without adding any calories. It's also cheap, which makes it attractive to food manufacturers.
While added inulin isn't unhealthy, Kimberlain warns of the "health halo" effect. "Many products sell based on how they're marketed," she says. Added inulin means more grams of fiber on the nutrition label, and maybe a high-fiber claim on the front of the packaging. "It creates the idea that if it has fiber, it must be healthier," she says. However, packaged foods with added inulin are usually lacking in the vitamins and minerals that whole-food fiber sources provide. "I always recommend food first (in its natural form) when possible," Kimberlain says. That is, eating a diet rich in high-fiber foods like fruits, vegetables, whole grains, beans, legumes, nuts and seeds.
Chicken, Avocado & Quinoa Bowls with Herb Dressing
Pictured Recipe: Chicken & Quinoa Buddha Bowls
If it's impossible to get enough fiber from whole foods, taking an inulin supplement could help with constipation, blood sugar control and possibly lowering LDL cholesterol. However, getting too much inulin (which is much easier to do when you take supplements or eat enriched products) can lead to gas and bloating, and can also worsen symptoms for people with irritable bowel disease, irritable bowel syndrome or other GI issues.
You can reap all of the potential benefits of inulin by eating a few servings each week of inulin-rich whole foods. If you want to try a supplement that's up to you, but be aware that too much inulin can lead to uncomfortable side effects.