The 7 Best Fiber Supplements of 2023, According to a Dietitian

Should I Take a Fiber Supplement?

While most of us are not getting enough fiber and likely could benefit from bumping up our fruit, vegetable, and whole grains, that may prove challenging for some populations. A fiber supplement could come in handy for certain conditions like:

• Irritable bowel syndrome (with constipation, diarrhea, or mixed)—For those with digestive discomfort, it might feel more reassuring to have a fiber supplement in your routine in addition to soluble or insoluble food forms of fiber. A supplement could be timed and dosed more specifically and provide more targeted relief for those with IBS.
• High cholesterol—There is good evidence that gel-forming fibers, like beta-glucan and psyllium husk, are beneficial for lowering serum cholesterol, and they may be useful for those at risk of cardiovascular disease.
• Diabetes—Soluble fiber has also been shown as a way to help keep blood glucose and insulin lower after eating which can be helpful for managing type 2 diabetes.
• Pregnancy—Increases in progesterone during pregnancy leads to a slow down of the gastrointestinal system, often increasing risk for constipation. Also, pregnant people might experience hemorrhoids or become less mobile as they progress into the third trimester, which could also set you up for constipation. A fiber supplement, along with plenty of fluid, could help provide some relief.
• Children that are very picky eaters—If you have a “selective” eater on your hands and there is a lack of fiber-filled fruits and veggies in your kiddo’s diet, a gentle kid-friendly fiber supplement could do wonders to encourage a daily bowel movement.
• Eating a limited diet—If your diet isn’t very colorful and you don’t eat many whole grains, you likely aren’t meeting your fiber needs. A fiber supplement could benefit your overall health. Jessica Gelman, MS, RD, IBCLC suggests eating a low fiber diet can negatively impact your gut microbiome, increase risk of certain chronic diseases and make it more challenging to lose weight. Limiting fiber-rich foods, you may be missing out on important nutrients like antioxidants, vitamins, and minerals that support optimal health.
• Inflammatory bowel diseases (such as Crohns’ disease or ulcerative colitis)- Eating a high fiber diet may be beneficial for lowering gut inflammation and protecting against flareups related to inflammatory bowel diseases. However, when there is a flareup with these diseases, a temporary lower fiber approach may be best until remission.

While the internet might make fiber supplements seem trendy and needed by everyone, Lavy says it’s important to discuss any supplements with a healthcare professional in order to ensure that the supplement is appropriate for your needs. Fiber supplements may not be appropriate for everyone, including:

• Pelvic floor dysfunction (PFD)- PFD could be common in postpartum persons, or anyone else who experiences frequent urination, urinary incontinence, fecal incontinence, painful vaginal sexual intercourse, or chronic prostatitis. Freuman says “PFD usually manifests as chronic constipation as the pelvic floor muscles are unable to relax, causing a back up of stool and more fiber could make it worse.”
• Difficulty swallowing- Fiber supplements may be quite bulky and difficult to swallow, so if you have narrowing of the esophagus or general difficulty swallowing you should speak with your doctor before taking fiber pills.
• Impacted stool (stool that has become hard and dried out in the lower GI tract)- In these cases, the best approach might be a laxative to promote movement, but always speak with a healthcare professional first.
• Gastroparesis (slow GI transit time)- If you aren’t clear which types of fiber help move things along or slow things down in the GI system, taking additional soluble fiber could wreak havoc on someone whose GI tract already moves food and fiber more slowly. 
  
• History of or current issue of bowel obstructions (blocked small or large intestine)- How much fiber you get is a delicate balance and might unintentionally lead to bowel obstructions, especially if you are already prone to them.

Our Supplement Research Process

Our team works hard to be transparent about why we recommend certain supplements; you can read more about our dietary supplement methodology here.

We support supplements that are evidence-based and rooted in science. We value certain product attributes that we find to be associated with the highest quality products. We prioritize products that are third-party tested and certified by one of three independent, third party certifiers: USP, NSF, or ConsumerLab.com.

It's important to note that the FDA does not review dietary supplements for safety and effectiveness before they go to market. Our team of experts has created a detailed, science-backed methodology to choose the supplements we recommend.

Experts we interviewed include: 

• Tamara Duker Freuman, MS, RD, CDN, digestive nutrition expert and author of The Bloated Belly Whisperer and Regular gave detailed insight into the various forms of fiber and how the work
• Alyssa Lavy, MS, RD, CDN, dietitian specializing in repairing gut health and food relationships reviewed who should use fiber supplements and gave some of her favorites to use with clients
• Jessica Gelman, MS, RD, IBCLC, food-focused gut health dietitian focused on natural ways to increase fiber intake and how to be sure you don’t take too much

Different Types of Fiber Supplements

Fiber supplements are available in powders, capsules, gummies, or food-based products. Ultimately the best form will depend on your personal preferences and goals. Powders can be added to beverages which may be easier than taking pills for some. For some types of fiber, you would need to take a high amount of capsules (sometimes upwards of fifteen) to achieve a therapeutic dose, so a powder would be a better choice.

Gummies may be useful for children who can’t swallow pills or are unwilling to try a beverage with a powdered mix; however, gummies do not always provide the best form of fiber for adults. Some gummies and powders may contain added sugars, so you’ll want to be mindful of those ingredients or seek out an alternative that uses an alternative sweetener. If a food-based supplement sounds more appealing, there is always ground flaxseed, or linaza, chia seeds, and even cookie-like wafers that are packed with fiber. 

It’s also worth noting that some fiber supplements are from natural sources, like oat bran, psyllium husk, or flax seed, while others are synthetic, such as methylcellulose, partially hydrolyzed guar gum (PHGG) and calcium polycarbophil. Both forms are effective, but some may increase gas and bloating more than others.

Ingredients: What to Pay Attention to

It is essential to carefully read the ingredient list and nutrition facts panel of a supplement to know which ingredients and how much of each ingredient is included, relative to the recommended daily value of that ingredient. Please bring the supplement label to a healthcare provider to review the different ingredients contained in the supplement and any potential interactions between these ingredients and other supplements and medications you are taking.

Supplement companies can try to pack in lots of “extras” to make their product seem like it has an advantage and buyers are getting a top quality supplement. However, Lavy says, “Some fiber supplements contain additional ingredients, which may or may not be appropriate for the individual.” In fiber supplements you may also find: 

Probiotics- For many, gut health can include sources of fiber and probiotics. Probiotics are the beneficial bacteria that keep the flora of our gut microbiome in a healthy balance. You can get probiotics from foods like yogurt, kimchi, or sauerkraut, and it’s becoming increasingly popular in supplement form. However, due to the varying strains and doses of probiotics, it is not clear as to their benefits for going to the bathroom.

Prebiotics- if probiotics are the bacteria themselves, think of prebiotics as the food for these good gut bugs. Prebiotics can be found in foods such as artichoke, asparagus, bananas, and chicory to name a few; there are also many artificially produced prebiotics like inulin (chicory root fiber), beta-glucan, lactulose, galactooligosaccharides, and fructooligosaccharides. Inulin is the most widely studied and may often be added to fiber supplements, but it can cause substantial gas and bloating.

Gluten- some fiber supplements contain gluten or are processed in a facility that also produces products with gluten, so if you have a gluten sensitivity, you will want to avoid these products.

How Much Fiber Supplements Should I Take?

Fiber needs are going to vary based on your age, dietary pattern, or medical conditions present, so it’s important to work with a dietitian or healthcare provider to determine how much of a fiber supplement you might need. According to the 2020-2025 Dietary Guidelines for Americans, it is recommended to consume the following:

• 2 to 3 years: 14 grams (g) (Males and Females)
• 4 to 8 Years: Females—17g, Males—20g
• 9 to 13 Years: Females—22g Males—25g
• 14 to 18 Years: Females—25g, Males—31g
• 19 to 30 Years: Females—28g, Males—34g
• 31 to 50 Years: Females—25g, Males—31g
• 51+ Years: Females—22g, Males—28g

If you’re thinking you’d be a super star for consuming well above the recommended grams of daily fiber, you might be mistaken. Gelman says, “Consuming too much fiber, especially when there is a dramatic increase in a short period of time, can result in GI symptoms such as diarrhea, constipation, bloating, gas, cramping and abdominal pain.” It’s better to ramp up your fiber intake slowly and to drink plenty of water. She goes on to say, “There are also less common risks, like bowel obstruction in those with certain gastroenterological conditions, and potential nutrient deficiencies with a very high fiber diet, as fiber can bind to certain minerals.”

So, while there is no established tolerable upper limit (UL), getting too much fiber or an increase of fiber without enough fluids could cause some stomach discomfort or unwanted side effects.

Your Questions, Answered

What is the difference between soluble and insoluble fiber?

Soluble fiber, which starts with “s” will help to slow and soften stools. Freuman says, “I describe it to my patients as poo glue, since it helps create soft, formed stools that consolidate straggling soft little pieces into a complete, log-like specimen.” Soluble fiber is great for diarrhea, but can also be helpful for softening up stool and help with constipation relief.

Think of insoluble fiber as the one to bulk up and get poop out. Ground flaxseeds and calcium polycarbophil are coarser fibers that can’t absorb water and pushes stool through your GI system by creating bulk. For a great visual, Freuman says, “It comes out pretty much how it looked going in.” 

Gelman explains, “Foods high in soluble fiber include oats, beans, barley, peas, and certain fruits and vegetables, like apples and carrots. Foods high in insoluble fiber include wheat bran, certain vegetables like cauliflower and celery, certain fruits (like those where skin and/or seeds are consumed), whole grains, nuts and legumes.”

What is the best form of fiber to take?

The best form to take is going to depend on why you need more fiber in the first place. Those suffering from IBS with constipation will benefit from one form of fiber, while someone who has IBS with diarrhea would be helped by a different type. Working with a healthcare professional like a dietitian can help to understand your symptoms and how they can be helped with a fiber supplement. 

What is the best fiber for cholesterol?

Some types of fiber act as a sponge in the blood vessels to help lower cholesterol. Fiber, especially the gel-forming fibers like beta-glucan, guar gum, and psyllium, help scoop up the LDL (the “bad”) cholesterol and remove it from the body. Other popular synthetic fibers, like inulin, fructooligosaccharides, and wheat dextrin do not have a significant cholesterol-lowering benefit, unless given at very high doses.

Does fiber help with weight loss?

If you have, for example, a big salad of leafy greens, crunchy vegetables on top, and chickpeas, by the end of this meal you may feel fairly full and not desiring much more food. The pull to “overeat” is less strong. The fiber in this meal has helped to promote satiety by expanding in your gut, and the fiber helps to quiet your hunger hormones, which in the long run could help manage your weight better.

The weight loss effect of fiber has also been shown in research. Studies have shown that increased fiber intake leads to increased weight loss and greater ability to stay with a balanced diet. Fiber promotes satiety and satiation, but different types of fiber have varying effects. For example, oatmeal might be more effective at promoting satiety than other fibers, such as those from vegetables or other whole grains, so it’s helpful to consume a diet with a wide variety of fibers.

Who We Are

Casey Seiden is a registered dietitian nutritionist and certified diabetes care and education specialist based in New York City. Casey works at Maternal Fetal Medicine Associates, the premier maternal-fetal medicine practice in Manhattan, where she provides nutrition therapy and counseling to women with high-risk pregnancies. She is also the founder of Casey Seiden Nutrition, a virtual private practice specializing in a non-diet approach to diabetes care and women’s health.