EU Customers Please Visit:

Lactobacillus acidophilus and Irritable Bowel

Lactobacillus acidophilus and Irritable Bowel

Lactobacillus acidophilus and Irritable Bowel


Lactobacillus acidophilus is one of the best-known probiotics and has been available as a supplement for many decades. This probiotic is widely used to support healthy immune function; help maintain healthy cholesterol levels; combat Candida overgrowth (thrush); and reduce the recurrence of urinary tract infections (UTIs).

Perhaps the most popular use of L. acidophilus is to offer support for digestive health. Here, we take a look at Lactobacillus acidophilus and irritable bowel syndrome (IBS).

What is Lactobacillus acidophilus?

L. acidophilus is a lactic acid-producing bacteria that loves to hang out in the small intestine, oral cavity (i.e., mouth), vaginal tract, and the urinary system. It forms colonies in these places and helps to digest food, produce anti-inflammatory substances, inhibit the growth of disease-causing pathogens, and perform myriad other helpful actions.

L. acidophilus has been extensively studied for its role in supporting the health of the small intestine. As a resident bacterium, it is well placed to prevent pathogenic bacteria, yeasts, and other microorganisms from causing health problems.

How does L. acidophilus support the gut?

L.  acidophilus has direct benefits for digestion, including helping us to digest lactose, the main sugar in milk. If you’re lactose intolerant but still want to eat dairy, you’ll want to have L. acidophilus in your corner! Otherwise, that undigested lactose can cause diarrhoea, cramps, flatulence (gas), and abdominal pain and discomfort, as well as bad breath and other symptoms

Many of these symptoms are connected to increased inflammation in the gut. L. acidophilus produces short-chain fatty acids including butyric acid which have an anti-inflammatory effect, helping to ease discomfort.

L. acidophilus breaks down food and produces a variety of chemicals that help to make the small intestine more acidic. This is beneficial for supporting better digestion and is also great for creating gut conditions that bad bacteria don’t like.

By supporting the small intestine, this probiotic can keep your bowel movements regular. As such, L. acidophilus isn’t just helpful for diarrhoea, it can also help if you’re constipated. And by keeping food moving properly through your system, L. acidophilus supports better absorption of nutrients and more timely elimination of waste products.

L. acidophilus and irritable bowel problems

Irritable bowel syndrome (IBS) is a common health concern characterised by abdominal pain or discomfort and diarrhoea or constipation (known as altered bowel regularity). Many sufferers also experience gas, bloating, and other symptoms. 

For many people, certain foods seem to trigger symptoms of IBS. Over time, this can lead people to cut out a wide range of foods. While this may help prevent serious IBS flares, the streamlined diet may lack adequate nutrition for good health, which can itself affect the function of the digestive system. It’s clear to see that this creates a vicious circle from which it’s hard to break free. Dietary restriction is also quite stressful, and stress is itself a trigger for IBS!

Probiotics such as L. acidophilus offer an alternative to restricting a wide variety of foodstuffs. What’s more, researchers demonstrated in 2007 that L. acidophilus could help reduce abdominal pain in IBS by interacting directly with opioid and cannabinoid receptors in the gut (Rousseau et al., 2007).

What the research says about L. acidophilus and IBS

In one recent multicentre, double-blind, parallel groups, placebo-controlled, randomized clinical trial, 80 adults with IBS received either a placebo or L. acidophilus (LacidophilusNCFM and LAFTI L10) for 8 weeks (Maixent et al., 2020). The probiotic dose was two capsules daily, with each capsule providing 5 billion colony forming units (cfu). 

After 4 and 8 weeks, the probiotic group had a significant decrease in gas and flatulence compared to the placebo group.Interestingly, this study did not find any significant differences in abdominal pain with the probiotic, although other studies (and laboratory research) suggest this as a benefit of L. acidophilus.

For example, a larger trial looked at a wide range of effects of the probiotic on 340 adults with IBS (Lyra et al., 2016). Participants took either a placebo, 1 billion or 10 billion cfu of Lactobacillus acidophilus NCFM daily for 12 weeks. The researchers measured outcomes based on a standard assessment for IBS Symptom Severity Score (IBS-SSS), as well as individual IBS symptoms, IBS-related Quality of Life, anxiety and depression, defecation frequency, and stool consistency.

At the end of the 12 weeks, the volunteers receiving L. acidophilus had improvements in IBS-SSS, with the greatest improvement seen in the 10 billion cfu group, compared to placebo. In those adults with moderate to severe abdominal pain at the start of the study, the probiotics significantly reduced abdominal pain, with scores decreasing by 29.4 and 31.2 in the low-dose and high-dose groups compared to just 20.8 with placebo.

All in all, it makes sense that L. acidophilus can help relieve IBS symptoms, including pain, gas, and bowel irregularity. After all, this powerful probiotic has a wide range of beneficial activities in the gut. Given that L. acidophilus is considered safe, with no known side effects, it’s certainly worth a shot if you’re suffering with an irritable bowel.



Lyra, A., Hillilä, M., Huttunen, T., et al. (2016). Irritable bowel syndrome symptom severity improves equally with probiotic and placebo. World journal of gastroenterology22(48), 10631–10642. 

Maixent, J. M., Pons, O., Sennoune, S. R., & Sadrin, S. (2020). Clinical effects of Lactobacillus strains as probiotics in the treatment of irritable bowel syndrome. Results from the LAPIBSS trial: Future objectives. Cellular and molecular biology (Noisy-le-Grand, France)66(3), 211–214.

Rousseaux, C., Thuru, X., Gelot, A., et al. (2007). Lactobacillus acidophilus modulates intestinal pain and induces opioid and cannabinoid receptors. Nature medicine13(1), 35–37.