Psyllium husk is a unique type of soluble, viscous fiber that has conflicting opinions in regards to whether or not it should be considered a prebiotic. Prebiotics are defined as non-digestible, fermentable carbohydrates that promote the proliferation of beneficial microorganisms in the GM (14). There is conflict over psyllium’s prebiotic status because psyllium does not appear to be fermented in the human gut (27). However, psyllium husk supplementation was shown to positively impact the GMs of chronically constipated individuals by increasing the levels of probiotic microorganisms that are associated with increased production of SCFAs, and psyllium has been classified, and used with great efficacy, as a prebiotic in clinical trials testing the impact of synbiotic therapy on Crohn’s Disease and UC patients (28,29,30).
In a clinical trial testing the efficacy of synbiotic therapy, a fancy word for combined probiotics and prebiotics, ten patients with active Crohn’s Disease were given 75 billion CFUs in the form of Bifidobacterium and Lactobacillus as the probiotics and 9.9 grams of psyllium husk as the prebiotic each day (29). This study has several weaknesses, such as allowing the patients to adjust their intake of probiotics and the psyllium throughout the trial. But in any case, the end results after roughly one year showed that 6 patients were able to achieve remission, with 2 patients able to stop taking prednisolone, and 4 patients able to lower the dose of prednisolone (29). GM analysis was not performed on the patients unfortunately. However, based on prior knowledge about probiotics, prebiotics, the GM, and the role the GM plays in the pathogenesis of IBD, it stands to reason that the 6 patients who achieved remission most likely experienced some eubiotic effect on their GMs as a result of the synbiotic therapy that included psyllium as the prebiotic.
A randomized controlled trial (RCT) also tested the impact of synbiotic therapy, which again used psyllium husk as the prebiotic, on UC patients’ quality of life and inflammation levels (30). The results of the study found that compared to both the probiotic and prebiotic control groups, the group receiving synbiotic therapy had a statistically significant and overall greater improvement in quality of life scores (30). The synbiotic group was also the only group to have a significant decrease in C-reactive protein levels, a marker of intestinal inflammation (30). A GM analysis was not performed for this RCT either, however, I think it once again stands to reason that the synbiotic group most likely saw a positive eubiotic shift in the GM due to the fact their quality of life increased and inflammatory markers went down. While psyllium husk may not meet the technical standards to be defined as a prebiotic, there are strong indications that psyllium husk has eubiotic properties and successfully helps drive the GM towards eubiosis. And as a result, it is a tool that I think is worth adding to our GM optimizing regimen.
While the eubiotic properties of psyllium are obviously important, it is the viscous and expansive gel-forming component of psyllium that makes it such a great supplement for IBD in my opinion and experience. When mixed with liquid, psyllium husk absorbs a significant amount of water, causing it to solubilize, expand, and turn into a thick gelatinous gooey substance. This viscous, water-retaining gel is now a double-edged sword. If someone is struggling with constipation, psyllium husk supplementation will act as a natural laxative, stool softener, and it will improve BM frequency (27). On the other hand, if someone is struggling with diarrhea, psyllium husk supplementation will help to bulk up and form stools, slow down the stool transit rate, and decrease both BM urgency and frequency (27). Psyllium husk really is an incredible supplement that improves both constipation and diarrhea.
Specifically in regards to IBD, psyllium can be especially helpful because it is essentially the antithesis of roughage, which is mainly insoluble fiber. As discussed in module 3.2, insoluble fiber does not dissolve in water or form a gel when chewed or blended, and instead forms shard-like bits of individual fiber particles that can physically aggravate the gut lining (20). So in order to gain a visual explanation, imagine someone with IBD who has inflamed or ulcerated areas within the small intestine or colon. These inflamed and ulcerated areas are essentially just intestinal wounds. Imagine this person eats a large salad full of spinach, cabbage, kale, brown rice, and pomegranate seeds. All of that roughage is going to turn into shard-like bits of fiber particles after being chewed that cut, poke, and scrape across those intestinal wounds. This will cause increased inflammation and a worsening of symptoms. It is no different than an individual with a severe shoulder laceration who decides to rub the shoulder wound across a stone wall a few times per day. That shoulder wound is only going to remain aggravated, inflamed and won’t heal properly. That is why I think it’s a good idea to avoid foods that contain high amounts of insoluble fiber, aka roughage, and instead focus on soft prebiotic soluble fiber foods. Additionally, supplementing with psyllium will allow those soft prebiotic soluble fiber foods to be even softer and more soothing to those inflamed areas due to psyllium’s gelatinous soothing salve-like properties.
From my understanding, psyllium husk helps to prevent irritation of the inflamed areas within the intestines, or at least mitigate irritation of those areas, when consumed with food. The gel and absorptive properties of psyllium help to bind the food it's consumed with, and help hold it together as it passes through the intestinal tract. It also bulks up the BM and improves the formation of stool, and allows that stool to glide, rather than scrape, over those inflamed and ulcerated areas. Like a soothing salve.
So, in summary, psyllium husk clearly has eubiotic potential, especially when taken in combination with probiotics. This is the first reason that I recommend consuming probiotic foods and psyllium together with each meal. The second reason is because consuming psyllium with a meal helps to mechanically bulk up BMs, helps to prevent further mucosal irritation, and improves both diarrhea and constipation.
There are a few side effects and precautions that anyone taking psyllium husk needs to understand. First of all, do NOT take medication and psyllium husk at the same time because psyllium husk can prevent the proper absorption of medication (31). If you are currently taking medication, speak to your doctor about the best time to take psyllium husk each day so that it does not interfere with the absorption of the medication. If the medication you are taking needs to be taken with meals, then one potential option to speak to your doctor about would be to simply take psyllium husk separate from meals and medication just before bed with the nightly probiotic supplements. There are ways to successfully and safely incorporate psyllium husk while also taking medication on a daily basis, but the timing needs to be worked out with your doctor to be as safe as possible and ensure proper absorption.
Psyllium husk powder is also a potential choking hazard if not consumed with an appropriate amount of water. It also has the potential to cause constipation or even bowel blockages if not enough water is consumed with the psyllium, or if too much psyllium is consumed at one time (32). A standard ratio of 25 mL of water is recommended to be consumed with every 1 gram of psyllium husk powder, though I once again recommend double-checking this ratio with your doctor (33). A study done in 1987 concluded that 20-30 grams of psyllium husk significantly improved constipation, abdominal pain, and diarrhea in patients with Irritable Bowel Syndrome (34). I think 30 grams of psyllium husk powder per day is an excellent dosage that is worth building up to, however, I would not exceed this dosage. One tablespoon (TBSP) is roughly equivalent to about 15 grams, so 2 TBSPs should be the maximum amount taken in a day. I would recommend starting with about ½ TBSP (about 7.5 grams) of psyllium husk powder per meal for the first week of the program outlined in Module 5. So, to calculate how much water you need to mix with psyllium, simply multiply the number of grams by 25 mL of water. So if you want to consume ½ TBSP (7.5 grams), simply multiply 7.5 x 25 = 187.5 mL of water that needs to be mixed with the psyllium at minimum. 1 TBSP is about 15 grams, so 15 x 25 = 375 mL of water. So if you build up to 1 full TBSP of psyllium husk powder per meal, you will need to mix or blend at least 375 mL of liquid with the psyllium as well. Mix thoroughly!
Per the Icahn School of Medicine at Mount Sinai, you should NOT take psyllium husk if you have bowel obstructions, spasms, difficulty swallowing, esophageal strictures, or any other narrowing or obstruction of the GI tract without a doctor’s consent and supervision (35). Psyllium husk is also known to possibly cause increased gas and bloating among other side effects (35). Before implementing psyllium husk into your GM optimizing protocol, discuss its usage, precautions, and dosages with your doctor, and do not proceed without your doctor’s consent.
© Copyright Good Health Hunting 2026 - All Rights Reserved
Biome Optima™ Sources