If you’ve got irritable bowel syndrome (IBS), you’re probably getting recommended a LOT of supplements. But do any of them actually work? Get a dietitian’s evidence-based take on the best supplements for IBS so you don’t waste your money.
If you’re new here, you may not know that digestive health is my jam. I’ve been working as a gut health dietitian for over a decade, and I literally wrote a book on it (coming March 2022 YAY!). But my interest in gut health isn’t just professional…my gut has been wonky since the birth of my first kid over a decade ago. So, I know that having IBS isn’t fun – and you want to do everything you can to make it go away. Case in point: as I was researching internet opinions for this article, I noticed that a suggested Google search was
how to cure IBS in one day
So yep, folks want this to go away fast but the truth is, you can’t make it go away in a day. I cringed my way through the first page of that search. Anyone who claims they can ‘fix’ your IBS like that is simply trying to get to page one of Google so they can sell you something (probably useless, probably expensive). Irritable bowel syndrome is a complex set of symptoms and root causes, from negative shifts in your microbiome to food intolerance to a dysregulated gut-brain connection. Going carnivore won’t make that better – nor will just popping a pill.
So how do you make IBS better, according to science?
First things first: start with your diet. As a registered dietitian, I take a food first approach because it WORKS. The way you eat can help you improve your bowel movements, nurture a healthy microbiome, and calm chronic inflammation. It doesn’t happen overnight, but it does happen. I can’t promise you that diet will fix everything – but it will move the needle for you. So before we even go recommending supplements for IBS, you want to give your diet some thought.
For some, simply transforming their diet into something that looks like more whole plant foods, such as my baseline anti-inflammatory healthy eating approach, may be all they need. For others, a temporary low FODMAP elimination may help get IBS symptoms under control. Doing this with the one-on-one support of a dietitian is always best but if you don’t have that available to you, this blog – along with my book Eat More Plants – has plenty of resources to get you started.
Next, you’ve got to consider stress. Because of the deep brain-gut connection in IBS, stress can really set your gut health off the rails. Like, even if you are eating well. Once you’ve set your care foundation, NOW we can talk supplements. Because they’re exactly that – a supplement to your care. No supplement is going to be all things to all people. Because IBS can have so many causes, you’ll have to find, through trial and error, which supplement is right for you.
The 5 Best Supplements for IBS
Psyllium is a seed, also known as ispaghula, that is very high in soluble fibre. This means, if you stir some psyllium husk into a glass of water, it’s going to form a gel real quick. This gel can help thicken up loose stools AND add hydration to dry stools making it useful in both diarrhea and constipation situations. As a bonus, psyllium isn’t very fermentable – meaning that your gut bacteria aren’t going to create a ton of gas from it. Which is good, because in IBS that gas production can cause pain if your gut nervous system is hypersensitized.
Sounds good, but what does the evidence say? Psyllium is the only fibre that has a sturdy evidence base for its use in IBS. The Canadian Association of Gastroenterology agrees that it may be helpful. Psyllium is a great way to boost fibre intake in a way that gentle on the IBS gut because some fibres can actually make IBS symptoms much worse.
How to Use Psyllium:
Want to add Grandma’s magic fairy dust into your life? If your gut is quite sensitive, or you typically have a low fibre diet, start with 1 teaspoon (5 mL) of psyllium stirred into some oats, coconut yogurt, or blended into a smoothie. Slowly work up to 1 tablespoon over a couple of weeks as tolerated. Be sure to drink plenty of water when using psyllium as fibre minus water could spell constipation.
Enteric-coated Peppermint Oil
Enteric-coated peppermint oil is one of the most evidence-supported supplements for IBS. It is used to help reduce the painful spasms of IBS. Peppermint oil is an anti-spasmodic, which means it helps soothe the smooth muscle lining the digestive tract so it may help relieve pain. Peppermint oil has been found effective in multiple reviews, including this 2018 review and this 2020 review. In one recent trial, peppermint oil helped improve pain, discomfort and IBS severity, although improvement did not reach the 30% pain decrease researchers were hoping for. It feels cooling to the gut, and is generally safe, but it can also make reflux symptoms worse so be warned.
How to Use Peppermint Oil:
Take enteric coated peppermint oil capsules as directed, often 200mg before each meal – or as needed. Important note: Enteric-coated peppermint oil is NOT the same as essential oil. Do not take essential oils internally! Also, not all peppermint caps are vegan. They’re a bit harder to find. Look for Deva brand in the US and Boots brand in the UK.
Probiotics for IBS
Probiotics are tricky topic in IBS. On one hand, multiple literature reviews (like this one, this one and this one) suggest that probiotics are supportive in IBS. On the other hand, you have a marketplace filled with expensive junk that doesn’t actually work and guidance from the American Gastroenterological Society telling folks with IBS to stop taking their probiotics. So what gives?
The evidence supports that as a whole, probiotics appear to support IBS. But the evidence hasn’t decided which strains or products are best. So in this case, it’s important that you look for probiotics that have human clinical trials to show their efficacy. I have a whole blog post on how to choose the right probiotic, where I share my fave resource for fact-checking probiotics called the Probiotic Chart. You can find it at www.probioticchart.ca (Canada) or www.usprobioticguide.com (USA). It’s run by a third party medical advisory team and I look for products that have level 1 evidence for IBS specifically. There are a few!
How to take a probiotic:
If you’ve made the decision to try a probiotic, be consistent. Take it every single day for 12 weeks to see if it’s made a difference. What would that look like? Better poops, less gas, less pain….if it has done nothing, please don’t continue taking it. Try a different brand or ditch probiotics altogether in favour of spending your hard-earned money on a high plant food diet that will give you fibre to support better poops and plant fibres to boost the growth of your gut microbiota.
Iberogast is an evidence-supported herbal tincture that may help improve gut motility as well as decrease symptoms in IBS and functional dyspepsia. It’s a very European thing, but it is widely available in the US and Canada. Iberogast contains multiple herbs, including peppermint and licorice and it has been found in a few trials to help decrease IBS symptoms. It’s probably not my first line supplement, both for how often you have to take it and small evidence base but particularly if you have stomach symptoms like nausea or sensations of fullness.
How to take Iberogast:
You need to take 20 drops of Iberogast before each meal and because this is an herbal product, it is not appropriate for pregnant or breastfeeding women and you want to check that it doesn’t interfere with any pre-existing allergies.
Vitamin D for IBS
Now, this recommendation is not strictly about improving symptoms…it’s about the fact that we ALL need vitamin D for bone + immune health. Plus, evidence suggests that those with IBS may have lower vitamin D status than those without. AND there is the tiniest chance that taking it may support healing. This 2019 trial suggests that high dose weekly vitamin D improved quality of life and symptoms scores in IBS (never take high dose without your doc’s advice!). Vitamin D levels may be connected to gut barrier dysfunction AKA leaky gut in IBS. So, since we all need it anyways…this is just further motivation to get consistent on your daily dose.
How to take vitamin D:
Ideally, you’d have your D levels tested by your doc so they could optimize your dosage. In absence of that, taking 1000IU of vitamin D3 in the brightest 6 months of the year and 2000IU in the darkest six months of the year is a safe dose for life for all adults.
What about l-glutamine for IBS?
L-glutamine is a supplement that may support gut barrier dysfunction. In trauma, such as significant burns, it becomes conditionally essential and the gut actually uses up an enormous amount of the body’s l-glutamine supply. So it’s commonly recommended by health practitioners for digestive conditions where gut barrier dysfunction may be present, like irritable bowel syndrome. However, we don’t have a lot of evidence to show that it actually works.
When it comes to IBS, there is one trial to suggest that l-glutamine may be supportive in post-infectious IBS but the study design was critiqued by a well-respected IBS researcher. If people are really keen to try it, post-infectious IBS might be the only time to do so but again, not as my first line of defense. It’s quite pricey too.