Probiotics for IBS: do they work?

Irritable bowel syndrome

If irritable bowel syndrome (IBS) is affecting your quality of life then you're not alone. Symptoms linked to this long-term condition of the gut are thought to affect around one in five people in the UK at some stage in their lives¹.

Certain foods, stress, infections, and oversensitivity to pain are all known triggers of IBS symptoms. If you have IBS, you may experience tummy cramps (abdominal pain), bloating, diarrhoea, or constipation on a regular basis.

If left unmanaged, these uncomfortable and inconvenient symptoms can interfere with everyday life, including your work life and your personal relationships.

While experts are not sure of the exact cause of IBS, they do know that it's a problem with the way your gut (also called your bowel) works. Dr Nirusa Kumaran, GP and lifestyle and functional medicine specialist, explains:

"Research has identified three potential reasons for the onset and ongoing symptoms of IBS:"

1. An imbalance in the gut microbiome - sometimes called gut flora, this refers to the microorganisms living in your digestive system.

2. Changes in the gut-brain connection - the two-way connection between the gut and the brain via nerve endings, hormones and chemical signals.

3. Increased intestinal permeability - your intestinal walls allowing harmful substances to enter.

Are probiotics good for IBS?

This is why methods that improve your gut health are being explored for IBS management. While there is no cure for IBS, probiotics for IBS may help ease and reduce symptom flare-ups.

Probiotics for IBS can be explored in addition to any medicines, dietary changes, and lifestyle changes recommended by your doctor.

"While they may not work for everyone, several studies have demonstrated the positive influence of probiotics on reducing the symptoms of IBS," says Kumaran. "So it is definitely worth considering probiotics for IBS."

A 2020 review of 28 studies involving 3,606 people found that probiotics for IBS could be beneficial for overall symptoms². In a 2015 review involving 1,793 people, results showed that probiotics could reduce instances of tummy cramps, bloating, and wind³.

Not all available probiotic supplements undergo rigorous testing through clinical trials, but there are ways to spot the high-quality products on the market. This is covered in the next section.

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Irritable bowel syndrome

IBS stands for irritable bowel syndrome, and it is a long-term chronic condition of the gut (bowel) that causes episodes of tummy (abdominal) cramps, bloating and either constipation or diarrhoea. IBS is a problem with how the bowel works. There is otherwise nothing wrong with the bowel.

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What is the best probiotic to take for IBS?

There is evidence that different strains of probiotics for IBS may be best suited to treat certain types of IBS. The research in this area tends to be quite mixed, and it can be a case of trial and error to find the probiotic that works best for you.

How long should probiotics be taken for IBS?

If you start a course of probiotics for IBS, don't expect to see results straightaway. One 2019 review found it took an average of eight weeks or more for people with IBS to notice the health benefits⁷.

The National Institute for Health and Care Excellence (NICE) recommends that people choosing to use probiotics for IBS should take the same brand for at least four weeks at the dose recommended by the manufacturer⁸.

Taking probiotics for IBS over an extended period of time is thought to be safe. There is no evidence that probiotics for IBS can cause any harm in the long term, although more research is needed on the effects of long-term use.

IBS and your diet

IBS can be different for each person, both in terms of severity and in what can trigger symptoms. If particular foods cause your symptoms to worsen, it's important to look at your diet alongside any probiotic supplements you choose to take.

For some, following a healthy diet which includes lots of fruit, vegetables, and plenty of water is enough to make a big difference. Others may need to be more strict with what they eat. If you're unsure if certain foods you eat are aggravating your condition, keep a food symptom diary and note down when symptoms occur after you eat certain foods.

Probiotic-rich foods

As well as various supplement forms, you can also boost your probiotic intake through your diet. Certain fermented foods are naturally rich in probiotics because they are created through the growth of live microbial cultures.

There are also a range of unfermented foods that have probiotics added to them. NIH cautions that whether these foods can truly count as probiotics depends on⁶:

• The number of microorganisms they contain;

• Whether the strains they contain have health benefits; and

• Whether they survive digestion.

Low FODMAP

For up to 70% of people with IBS, eating certain foods can make their symptoms worse⁹. If this is you, being careful about what you eat and getting to know your food triggers could be key to making life with IBS much easier.

Of course, avoiding all your food triggers all of the time is easier said than done. You can also take probiotics to help your gut digest these foods. "It is thought that greater numbers of beneficial probiotic bacteria will help break down the high-FODMAP foods that often trigger IBS," explains Kumaran.

FODMAP stands for Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols. Put simply, these are foods that cause your gut bacteria to produce a lot of gas when they're digested. It's this gas that often causes the typical and uncomfortable IBS symptoms of pain, wind, and bloating.

One 2016 study concluded that up to 86% of people with IBS found that following a low- FODMAP diet significantly improved their IBS symptoms¹⁰. However, a strict low-FODMAP diet can be very restrictive, so you should have guidance from a dietitian.

Further reading

1. Ford and Talley: Irritable bowel syndrome.

2. Sun et al: Efficacy and safety of probiotics in irritable bowel syndrome: a systematic review and meta-analysis.

3. Didari et al: Effectiveness of probiotics in irritable bowel syndrome: Updated systematic review with meta-analysis.

4. Guglielmetti et al: Randomised clinical trial: Bifidobacterium bifidum MIMBb75 significantly alleviates irritable bowel syndrome and improves quality of life--a double-blind, placebo-controlled study.

5. Lyra et al: Irritable bowel syndrome symptom severity improves equally with probiotic and placebo.

6. National Institutes of Health: Probiotics.

7. Dale et al: Probiotics in irritable bowel syndrome: an up-to-date systematic review.

8. National Institute for Health and Care Excellence: Irritable bowel syndrome in adults: diagnosis and management.

9. Altobelli et al: Low-FODMAP diet improves irritable bowel syndrome symptoms: a meta-analysis.

10. Nanayakkara et al: Efficacy of the low FODMAP diet for treating irritable bowel syndrome: the evidence to date.