Prebiotics & Probiotics for IBS

Prebiotics are specific soluble fibers that ferment (slowly or rapidly, and the difference is critical) in the gut to create an environment of beneficial short chain fatty acids, such as butyrates. This environment then encourages the growth of healthy gut bacteria - the probiotics.

Probiotics are the actual live bacteria - microorganisms in your gut that are critical to digestive (and overall) health.

In other words, probiotics are the good bacteria, and prebiotics help those probiotics to flourish in your gut. It's worth noting that prebiotics do not encourage the growth of unhealthy gut bacteria, or interfere with antibiotics. Prebiotics can only cause the growth of healthy gut bacteria, and that good bacteria then keeps the bad bacteria in check.

Lactic acid bacteria and bifidobacteria are the most common types of microbes used as probiotic supplements.

Probiotics are also naturally present in fermented foods with active live cultures. Probiotics improve intestinal microbial balance, inhibiting pathogens and toxin producing bacteria. Probiotics are available as supplements or in yogurts with active cultures (avoid dairy yogurt, choose soy or rice or almond options - see IBS trigger foods to learn why).

Probiotics help normalize and maintain healthy gastrointestinal flora, which can minimize diarrhea, constipation, bloating, gas, and painful abdominal cramps. Probiotics are most effective when they're taken in conjunction with a slowly fermenting prebiotic, such as Tummy Fiber Acacia, which encourages the growth of probiotics in the gut.


Here's the kicker - it's critical with IBS that you stick to prebiotics that are slowly fermenting, because rapidly fermenting prebiotics (also known as FODMAPS) can actually cause extreme bloating, gas, spasms, and diarrhea. Inulin, FOS, GOS, MOS, XOS, oligosaccharides, artichoke extract, and chicory extract are the most notorious examples of rapidly fermenting prebiotics. Personally, I would avoid them entirely. The one (and only) time I tried an inulin fiber supplement the gas and bloating was so severe it caused chest pressure that felt like heart palpitations. Not fun.

Probiotics are particularly effective for IBS after your gut has been under assault from antibiotics, though they can also be very helpful when taken for daily maintenance. Quite a few research studies have shown that specific strains of probiotics can dramatically improve Irritable Bowel Syndrome symptoms. Probiotic supplements should normally be taken with food.

Prebiotics do not have to be used in conjunction with probiotics in order to be effective. They will encourage your healthy gut bacteria growth without taking any additional supplements. Prebiotics naturally occur in some soluble fiber foods (such as bananas), or can be added to the diet in the form of slowly fermenting prebiotic soluble fiber supplements such as Tummy Fiber Acacia. Prebiotics will work regardless of how you take them - with or without food, with or without probiotics, etc.

Interestingly, a 2018 study found that prebiotic supplementation could replace the low FODMAP diet as a treatment for functional gut disorders such as IBS. They compared the results of a prebiotic supplement plus Mediterranean-type diet, versus a placebo supplement plus the low FODMAP diet. Fecal microbiota composition, intestinal gas production, and digestive sensations were all measured outcomes. While both groups showed improved GI symptoms, only the prebiotic group showed significant improvements in microbial composition.

Alarmingly, the low FODMAP group actually showed an increase in pathogenic-associated bacteria. In addition, following the dietary intervention, improvements persisted only in the prebiotic group - not in the FODMAP group. (Wondering what on earth is a FODMAP?)

The upshot for IBS? Prebiotics and probiotics are likely some of the safest, most effective, and persistent treatments for IBS, with little to no risk and huge potential benefits.