Your gut microbiome and IBS:
Microbes in your gut could help soothe IBS

If you suffer from IBS, chances are that like many others, you’ve tried ‘everything’ to heal and soothe these gut-wrenching symptoms: abdominal pain, chronic diarrhoea, constipation, and bloating, leading to significantly reduced quality of life.

Growing research suggests that our gut microbes might be here to help! These three avenues of research could pave the way for treatments to soothe your IBS symptoms.

IBS is common, affecting >320 million people worldwide. Dysfunctional gut-brain interactions play a role and often the gut microbes differ compared with healthy people. This so-called ‘dysbiosis’, or imbalance in gut bacteria, has been identified as a major contributor to chronic inflammatory conditions, such as IBS.

So, to help treat IBS, it makes sense to look at how we can restore balance and regulate our gut microbiome – the 100 trillion microbes inside your gut.

The following three areas of research are worth noting, as we look for ways of easing IBS symptoms.

3 ways the gut microbiome could heal IBS

Prebiotics, probiotics and fecal microbiota transplant (FMT) are being studied to better understand their effects on the painful symptoms of IBS.


Can probiotics help heal IBS?

Probiotics have been widely studied in IBS and adding probiotic supplements may be benefit by enhancing, or balancing, our gut microbiota.

Scientists say there is insufficient evidence for widespread use, however they have found multi-strain probiotics do tend to have a more favourable outcome than single-strain probiotics; that is, probiotic supplements with several types of bacteria vs. just a single type.

Multi-strain probiotics tend to have a more favourable outcome than single-strain probiotics

Probiotics Learning Lab advises us that “when choosing a probiotic supplement for IBS, it is important to select one which is supported by good quality research. Different probiotic strains can be beneficial for different symptoms of IBS, as each strain can have unique properties. Clinical studies show the best probiotic supplements for IBS contain strains that have been scientifically tested in clinical trials for typical symptoms of IBS, such as constipation, bloating, or diarrhoea”.

When choosing a probiotic supplement for IBS, it is important to select one which is supported by good quality research

Probiotics Learning Lab

Clinical trials of Bifidobacterium bifidum (published in The Lancet and Alimentary Pharmacology & Therapeutics) found that it may relieve the symptoms of IBS, even when inactivated. This is important because inactive probiotics have several potential advantages over ‘active’ probiotics (Harvard Health). For example, active probiotics may be a worry if you are susceptible to infection, and inactive probiotics should ease these concerns.

What about prebiotics for IBS?

First of all, what are prebiotics? They are fibers that us humans cannot digest and so they travel through to the latter part of our digestive tract – the large intestine. Here our gut microbes await, and they feast on these fibers and use them as fuel, which boosts the growth of beneficial bacteria.

Prebiotics have been found to increase the abundance of the beneficial Bifidobacteria and one recent trial found that human milk oligosaccharides (HMO) had some effect on IBS symptoms.

Overall, however, a beneficial effect of prebiotics in easing IBS symptoms has yet to be confirmed.


Could FMT help heal IBS?

FMT is a highly effective treatment for recurring Clostridioides difficile infection and has been found to be effective in some IBS patients.

FMT is administered through various routes, including oral capsules, nasojejunal (feeding) tube, and upper and lower endoscopy. However, a recent review found that FMT via oral capsules was ineffective while administration through a feeding tube tended to show benefit.

The effects of FMT for IBS patients vary in clinical trials. FMT does change the gut microbiome and subgroups of IBS patients may benefit.

However, the effects of FMT have been found to be transient, with no difference in symptoms after one year compared to baseline. Side effects of FMT can include diverticulitis and transmission of pathogens.

In summary: our microbiome and IBS

Probiotics are beneficial bacteria found in certain foods, an in supplement form. Prebiotics are types of fiber that feed the friendly bacteria in your gut.

You can add both pre- and probiotics to your diet as foods or supplements.

Probiotics may benefit some patients by enhancing or balancing the gut microbiota. Multi-strain probiotics, with several types of probiotic bacteria, tended to have a more favourable outcome than single-strain probiotics.

Prebiotics generally have not been proven to reduce gastrointestinal symptoms, although HMO have shown some effect on IBS symptoms in clinical trials.

FMT may benefit a subgroup of IBS patients. It’s important to note the potential side effects of FMT which may include diverticulitis (a disease of the digestive tract) and transmission of pathogens.

This does not constitute or substitute for medical advice! Seek professional healthcare advice as needed, including which therapy or probiotic might be suitable specifically for you!

Other features you might enjoy:

Sources and further reading

Probiotics versus Prebiotics, explained – Inner Health

Probiotics and Prebiotics: What’s the Difference? (

Treatments targeting the luminal gut microbiota in patients with irritable bowel syndrome – ScienceDirect

The Best Probiotics for IBS Symptoms, According to a Nutritionist (

Probiotics — even inactive ones — may relieve IBS symptoms – Harvard Health

Heat-inactivated Bifidobacterium bifidum MIMBb75 (SYN-HI-001) in the treatment of irritable bowel syndrome: a multicentre, randomised, double-blind, placebo-controlled clinical trial – PubMed (