Fiber 101: What You Need to Know for a Healthy Gut

Welcome to The Perfect Stool: Understanding and Healing the Gut Microbiome. This is your host, Lindsey Parsons, and today we're going to be talking all about fiber, the different types, where to find it in your diet, supplements for fiber, how much to get, and why fiber is critical for gut health, as well as contraindications for certain conditions. But before I do that, if you haven't yet followed or subscribed to the show, be sure to do so. And if you want to get transcripts of the podcast, pop over to my website, HighDesertHealthCoaching.com, and sign up for my newsletter. You'll also get my free ebooklet, Finding Your Root Cause Through Stool and Organic Acids Testing, when you sign up. And if you haven't yet done my quiz on which stool test would help you get to your root cause, you can find a link in the show notes and take that. Now on to the show. So as a gut health coach coming from a functional medicine perspective, I believe in finding and treating the root cause of chronic health conditions rather than just masking the symptoms. And when it comes to gut health, fiber is one of the most important factors to consider. First of all, fiber plays a critical role in maintaining regular bowel movements. With the standard American diet that's full of sugar and processed foods, you definitely don't get enough fiber. And without enough fiber in your diet, you may get constipated or at minimum have a less healthy microbiome, which may be one of the reasons that people who are constipated have an increased risk of gastrointestinal cancers as well as breast ovarian, and other cancers, in particular in the year following constipation. Although the direction of causality is not definitive in the studies, an undiagnosed cancer could be causing constipation as well. But the theory is that stool sitting around has toxins that get reabsorbed into the body. So fiber is good for you because it serves as the food for the trillions of bacteria that reside in our gut microbiome, which, as you all know, plays a critical role in our immune system, our metabolism, and our mood, as well as our gut health. Research has shown that a diet high in fiber can reduce inflammation, improve cholesterol levels, and even lower the risk of chronic diseases such as heart disease, diabetes, and certain types of cancer. So I recommend that most of my clients prioritize their fiber intake, except when it's contraindicated, which I will discuss later. Normally I suggest this in the context of diet, but for those who may struggle to get enough fiber from their diet alone, fiber supplements can also be a useful tool to consider. So you've probably heard that there are two main types of dietary fiber, soluble and insoluble, and a healthy diet will give you some of both types. Soluble fiber dissolves in water and forms a gel-like substance in the digestive tract, which can help slow down the digestive process, which is beneficial in particular for those with blood sugar concerns, or if you're eating anything sugary for normal people. And soluble fiber is also known for its prebiotic effects, which means that it feeds the beneficial bacteria in the gut. Also known as commensals. This will support a healthy gut microbiome and reduce inflammation in the body. And good sources of soluble fiber in the diet include oatmeal, beans, peas, lentils, and fruits like apples and citrus. On the other hand, insoluble fiber does not dissolve in water and passes through the digestive system mostly intact. And this type of fiber promotes regular bowel movements, prevents constipation, and supports healthy digestion and nutrient absorption by adding bulk to the stool and preventing it from becoming too loose. Good sources of insoluble fiber include whole grains, vegetables like broccoli and carrots, and fruits like berries and kiwi. Although most foods have a combination of both types of fiber. Resistant starch is another type of dietary fiber that resists digestion in the small intestine and reaches the large intestine intact. In the large intestine, it acts as a prebiotic and feeds beneficial gut bacteria, promoting a healthy gut microbiome, and in particular, higher butyrate production, which is important for feeding the cells lining the large intestine or colonocytes. Resistant starch has been linked to improved digestion, reduced inflammation, improved insulin sensitivity, and lower blood sugar levels. And it may also promote feelings of fullness, leading to reduced calorie intake and potential weight loss. Sources of resistant starch include foods such as green bananas, legumes, meaning beans, lentils, and chickpeas, oats, some whole grains, and cooked and cooled potatoes or rice. When cooked and cooled, potatoes and rice undergo a process called retrogradation, which changes the structure of the starch, making it more resistant to digestion. Therefore, it's left over for the gut bacteria to ferment. My favorite way of getting resistant starch is just making a large batch of jasmine rice and putting it in the fridge to eat with leftovers. If you eat it cold or don't reheat it too much, you retain much of the resistant starch. I often recommend that my clients incorporate fiber into their diets to support recovery of healthy gut microbiome, because for some reason, pathogenic bacteria tend to like sugar and white flour, and commensals are beneficial bacteria like fiber. I think about this particularly during treatment for H. pylori or Helicobacter pylori, which typically causes reflux and constipation, but not so much bloating, either through diet or through supplements. And also after SIBO treatment, especially for diarrhea or soft stool, to help restore butyrate producers in the colon. Here are some other type of fiber supplements you may want to consider, and I'll include links in the show notes for all of these. Psyllium husk is a type of soluble fiber that comes from the husks of plant seeds and is one of my favorite to recommend. Research has shown that psyllium can help to reduce constipation and firm up stool for those with softer stool. So it goes well in both directions. What's more, psyllium has been shown to reduce LDL cholesterol levels, making it a potential adjunct therapy for those with high cholesterol. My husband swears by his daily psyllium husk. You can build up slowly to a tablespoon of psyllium husk powder in 8 ounces of liquid, but drink it fast because it gums up quickly. Or put it in less liquid but follow it up with the rest of 8 ounces of liquid. It's best to do this away from any supplements you take because it may impede the absorption of the supplements. You can also take it in capsule format, but it takes 6 to get to a tablespoon, so it's a bit impractical. And by the way, Metamucil is primarily psyllium husk, but it's got other non-beneficial chemicals, so I'd avoid that and just get a pure psyllium husk product. Inulin is another type of soluble fiber that's found in many plants including chicory root, Jerusalem artichokes, asparagus, garlic, onions, and leeks, and can also be purchased as a supplement. Studies have shown that inulin can help to improve gut microbiota composition and reduce inflammation in the gut. Inulin may also have potential benefits for those with diabetes, as it's been shown to help regulate blood sugar levels. Guar gum is another type of soluble fiber that's derived from the seeds of the guar plant and is used as a thickening agent in many gluten-free foods. Research has shown that guar gum can help to improve stool frequency and consistency in individuals with chronic constipation. Additionally, guar gum has been shown to have potential benefits for those with high cholesterol and can also help to reduce LDL cholesterol levels. Partially hydrogenated guar gum, or SunFiber, which you can find in my FullScript dispensary, however, is used in IMO, or intestinal methanogen overgrowth, as a beneficial fiber to help with constipation. It's a type of guar gum that's been partially broken down enzymatically, making it easier to digest and less likely to ferment in the gut. Partially hydrogenated guar gum, or PHGG, has been shown to have similar benefits to regular guar gum, such as improving stool frequency and consistency, without the risk of worsening symptoms in individuals with SIBO or EMO. Acacia fiber, also known as gum arabic, is a type of fiber derived from the sap of the Acacia senegal tree. It's commonly used as a food additive to provide texture and stability, but it can also be taken as a dietary supplement. Acacia fiber is a highly soluble fiber that's fermented slowly by gut bacteria, producing short-chain fatty acids that can support gut health. Research has shown that acacia fiber can have a range of health benefits, including improving gut barrier function, reducing inflammation, and supporting healthy immune system function. And acacia fiber is a better choice in SIBO as it's less likely to cause bloating. Pectin is another type of soluble fiber that's found in fruits and vegetables, particularly apples and citrus fruits. It's also used as a food additive to thicken and stabilize products like jams and jellies. Pectin is fermented quickly by gut bacteria, producing high levels of short-chain fatty acids that can support gut health. And studies have shown that pectin also has a wide range of health benefits, including reducing inflammation, promoting healthy gut barrier function, and improving lipid metabolism. Modified citrus pectin is also used in particular to help with the chelation of heavy metals. Glucomannan is another type of soluble fiber derived from the root of the konjac plant, and it's commonly used as a dietary supplement to aid in weight loss, as it is shown to promote feelings of fullness and reduce appetite. It is also fermented slowly by the gut bacteria, which produces short-chain fatty acids to support gut health and can also help improve glycemic control and reduce constipation. If you're not dealing with bloating, you may want to try a combination fiber product like Thorn FiberMend or Pure Encapsulations PureLean Fiber, which you can find in my full script dispensary. But when starting any new fiber product or adding fiber to the diet through sources like beans and legumes, be sure to start slowly and build up so that your microbiome has time to adjust to avoid gas, bloating, or constipation. Aim to increase fiber intake from food or supplements by 5 grams per day until you reach the recommended daily intake of 25 to 30 grams per day. I like the tool Cronometer, which is an online nutrient calorie and macro checker to see how you're doing with your current levels of not just fiber but all nutrients. And you can even enter your supplements in there to see if you're getting the recommended daily allowances of all those. If you want to avoid fiber supplements, my best advice for a diet high in fiber is to eat beans and legumes. I know they've gotten a bad rep because of lectins, saponins, and phytic acid, but I don't find that most people are sensitive to these things. And you can do things like soak them and cook them slowly to get rid of most of those problematic substances. And I'll provide a link on how to do that. Unfortunately, most canned beans do not undergo pre-soaking, so it's best to make them yourself from dried beans. So while fiber is found in a variety of foods, of course, fruits and vegetables, whole grains, nuts and seeds, but beans and legumes really stand out for their high fiber. And in my opinion, it's very hard to hit the RDA for fiber without eating them. Which is 25 to 30 grams of fiber per day based on your calorie intake. Overall, beans contain more fiber per serving than any other type of food. So here's an example comparing a half cup of the highest fiber beans with many other fruits and vegetables. So black beans have 7.1 grams of fiber per half cup, kidney beans 7.3, pinto beans 6.9, lima beans 6.6, and chickpeas 5.3. Compare that to raspberries, which have 4.2 grams of fiber in a half cup. But realistically, who eats a half cup of raspberries at a sitting? 'Cause that costs like $5. And artichokes, 4 grams of fiber, broccoli, 2.3, blueberries, 2, carrots, 2, green beans, 2, cauliflower, 1.5, cooked cabbage, 1, raw spinach, 0.8, and romaine lettuce, 0.5. So think about that. Like, A big salad is gonna get you about 2 grams of fiber, whereas you only have to eat a half cup of beans to get 7. So it's a lot more bang for your buck. One way I recommend getting more beans and legumes into your diet is adding them to your breakfast. Just make a batch and use them as your breakfast carb. Start with a tablespoon and work your way up, or do a combo of rice and beans. That was a common breakfast that went great with an egg with a soft yolk dripping over it when I lived in Costa Rica. They call that gallo pinto there. But there are many varieties of this from different Latin American countries, and I'll include, I'll include a recipe in the show notes for gallo pinto. I suggest breakfast because most people don't vary their breakfasts a lot, so it makes it easier to make it a habit. Nuts are also another good source of fiber, but again, for a quarter cup serving, it's still only 2 to 4 grams of fiber. And, you know, of course they're very filling and fattening too. I mean, not in a bad way, but they're, you know, they've got a lot of fat in them, so you can't eat tons the way you could perhaps with beans. And of course, it's important to note that fruits and vegetables also provide a wide range of other important nutrients such as vitamins, minerals, and antioxidants, and they're important for overall health. So of course, it's best to get some of your fiber from other fruits and veggies, and a balanced diet will include a variety of fiber-rich foods including the fruits, vegetables, nuts, and legumes. Now, you may be wondering, if I have a gut health condition like IBS or IBD, should I take fiber? So as I mentioned earlier, there are some contraindications for taking fiber or getting much fiber in your diet in certain gut health conditions. If you are in an active flare of inflammatory bowel disease, meaning Crohn's disease or colitis, studies show that a high-fiber diet will cause increased inflammation and disease activity. Therefore, a low-fiber diet like the Specific Carbohydrate Diet, low FODMAPs, or IBD-AID are recommended during times of active cramping or diarrhea. However, slowly introducing fiber once your symptoms have settled and could be described as mild or not present One Food at a Time is recommended to help keep your condition in remission. In human studies, psyllium husk, inulin, and germinated barley foodstuff all showed positive results for decreasing remission rates, while wheat bran showed no benefit. If you're suffering with IBS-like symptoms, in particular bloating and gas after eating, or have diagnosed SIBO, small intestine bacterial overgrowth, it's also recommended that you decrease your fiber and avoid prebiotics like inulin, fructans, and GOS, which is galactooligosaccharides, for because they're high in FODMAPs, also known as fermentable oligosaccharides, disaccharides, monosaccharides, and polyols, which feed the bacteria and archaea that are typically overgrown in SIBO. So for people with active SIBO, I usually recommend either a low FODMAP diet, Nirala Jacobi's biphasic diet, or Mark Pimentel's low fermentation diet. If you do wanna continue fiber supplementation to help with bowel movements by either bulk up the stool and decreasing diarrhea, or to help promote more frequent bowel movements during a low fiber diet, Acacia fiber is a SIBO-safe fiber, and partially hydrogenated guar gum, also known as SunFiber, is helpful in EMO or methane SIBO. Because fiber can be irritating in certain conditions, one way I help people get the microbiome benefit of fiber without the irritation of it while healing from gut health conditions is to recommend supplemental butyrate or tributyrin, the preferred form of butyrate, while healing. This is something I tend to recommend only to people with soft stool or diarrhea, as it can be constipating. It's one of the short-chain fatty acids that people tend to most lack when they have conditions like SIBO-D and IBD, which tend to go along with overgrowth of proteobacteria, which do not produce butyrate. And I'm sure you've heard that I have my own tributyrin supplement called Tributyrin Max, which you can get for 15% off of your first order with the code INTRO15 at tributyrinmax.com. Or super exciting, I finally now have it for sale on Amazon, same discount code INTRO15. And links for that will be in the show notes. And you may be asking yourself about prebiotic fibers too, beyond traditional fiber supplements. And I have done another podcast on prebiotics, which may have some overlapping material, but that's episode 28, Prebiotics and Fiber. And of course, if you're struggling with some type of chronic disease, chronic inflammation, bloating, constipation, diarrhea, soft stool, acid reflux, et cetera, and want to get to the bottom of it, that's what I help my clients with. You're welcome to set up a free 30-minute breakthrough session if you think you might like to sign up for a 3 or 5 session package, or I offer individual consultations as well. You can find links for those in the show notes. And if you'd like to support the show, you can make a regular donation on Patreon or buy vetted high-quality supplements from my Fullscript dispensary, or give me a 5-star review on Apple Podcasts. To reach out to me in other ways, I have a Gut Healing Facebook group for asking questions, or I'm on Instagram, Pinterest, Twitter, and now TikTok. Links for all those are in the show notes or on my website, High lindseyparsons@healthcoaching.com. Thanks for listening, and here's wishing you all the perfect stool.