Can Probiotics Soothe IBS?

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Evidence supports the use of probiotics for IBS and enhanced quality of life

Constipation, bloating, flatulence, diarrhea and other digestive problems are not fun, especially for people who suffer from them frequently. The results of a recent international survey of over 73,000 adults are striking: 40% of participants said they suffered from one or more of these symptoms on a regular basis (at least once per week.)^[1]

Gastrointestinal symptoms can significantly affect one’s quality of life, even causing people to avoid social situations in order to prevent embarrassment.^[2]

Digestive problems can be the result of stress, medications, imbalances in the gut microbiota, or chronic medical conditions. If you have gastrointestinal distress, it is important to see a medical professional. A doctor or other healthcare provider will first look for a specific cause, such as a disease, blockage, infection, etc. If there is no obvious cause of the problem, you may be diagnosed with irritable bowel syndrome (IBS).^[3]

People suffering from irritable bowel often look to complementary and alternative medicine strategies, including probiotics, to support healthy digestive function.^[1] Probiotics are live microbial strains capable of persisting in (or transiently colonizing) the human intestinal tract. They are often used to support digestion and elimination and to soothe irritable bowel.

A growing body of evidence suggests that the regular consumption of Lactobacillus and Bifidobacterium species of “good” bacteria can improve gut function and enhance quality of life. Probiotics may even improve our ability to handle stressful events without getting our guts tied in knots. Today’s post will showcase results from well-designed clinical trials in humans.

Probiotic supplementation for constipation

Bifidobacterium lactis may provide significant relief from chronic constipation.

Constipation is a frequent symptom of IBS that can also occur as a standalone disorder.^[4] Clinical studies show that probiotics may alleviate constipation and other symptoms associated with this condition.^[5],[6],[7]

Bifidobacterium lactis may provide significant relief from chronic constipation. In one randomized controlled trial (RCT), 100 participants were given Bifidobacterium lactis (low or high dose) or a placebo once daily for 14 days.^[5] The researchers evaluated the frequency of symptoms such as abdominal pain, nausea, constipation, diarrhea, and flatulence. The low dose of Bifidobacterium lactis (1.8 billion colony-forming units [CFU] per day) improved seven out of nine symptoms. A higher dose (17.2 billion CFU/day) was slightly more effective, improving eight out of nine symptoms.

In a randomized, double-blind, placebo-controlled trial (RDBCT) of 1248 subjects, Bifidobacterium lactis supplementation increased the frequency of bowel movements in healthy adults with constipation.^[6] The subjects were men and women, 18 to 70 years old, with a low defecation frequency (2 to 4 days per week). Supplementation with Bifidobacterium lactis (1 or 10 billion CFU/day for four weeks) significantly improved defecation frequency.

These studies suggest that Bifidobacterium lactis can promote regular bowel function. Supplemental fiber can also be helpful, as constipation is often caused by inadequate fiber intake.^[8],[9],[10] Fibers with long carbohydrate chains, such as psyllium or guar gum, are preferred for individuals with IBS, as these fibers generally do not cause gas.^[11]

Probiotic supplementation for irritable bowel

Probiotics have been shown to relieve abdominal pain, bloating, gas, and diarrhea or constipation.

Probiotics have been shown to support digestive function and relieve abdominal pain, bloating, gas, and diarrhea or constipation associated with irritable bowel.^[12],[13] Let’s look at some of the most interesting clinical results.

In a RDBCT of 330 adults with IBS, subjects were given either Bifidobacterium lactis or Lactobacillus acidophilus (10 billion CFU/day) or a placebo daily for six weeks.^[14] There were improvements in abdominal distension, bowel habits (constipation or diarrhea), abdominal pain, and quality of life in the probiotic groups. More than half of the subjects experienced relief from abdominal pain with Lactobacillus acidophilus, and more than a quarter experienced relief with Bifidobacterium lactis.

Relief from gastrointestinal distress was also observed in a RCT of 123 IBS patients supplemented with Lactobacillus rhamnosus (12 billion CFU daily for six weeks).^[15] Benefits were also reported in a RDBCT of 25 IBS patients who were given a combination of Lactobacillus rhamnosus and Bifidobacterium longum (1 billion and 4 billion CFU/day, respectively).^[16]

In the latter study, participants were also supplemented with vitamin B6, due to a previously-established link between B6 deficiency and IBS.^[17] Individuals consuming Lactobacillus rhamnosus, Bifidobacterium longum, and B6 experienced significant reductions in abdominal pain (-49%), bloating (-36%), and overall symptom severity (-30%) after 30 days.^[16]

In yet another RDBCT of 52 participants with IBS, a supplement comprising strains of Lactobacillus acidophilus, Bifidobacterium lactis, and Bifidobacterium bifidum (25 billion CFU/capsule) was reported to relieve IBS symptoms.^[18] The participants reported fewer days of pain, greater satisfaction with bowel habits, and an improved quality of life over the eight-week intervention period.

A blend of Lactobacillus and Bifidobacterium species (total dose 10 billion CFU/day) was shown to relieve overall symptoms in a RDBCT of 50 adults with diarrhea-dominant IBS.^[19] A full 48% of participants experienced adequate relief after eight weeks, compared with only 12% of the placebo group.

A slightly different blend of Lactobacillus and Bifidobacterium species was shown to relieve IBS symptoms in a RDBCT of 109 individuals with celiac disease, who had gastrointestinal distress despite following a strict gluten-free diet.^[20] The authors report, “A 6-week probiotic treatment is effective in improving the severity of IBS-type symptoms in celiac disease patients on strict gluten-free diets, and is associated with a modification of gut microbiota, characterized by an increase of bifidobacteria.”

Probiotics also alleviate lactose intolerance

Lactobacillus acidophilus and Bifidobacterium longum churn out an enzyme (lactase) that aids in the digestion of lactose.

One in three individuals with IBS has lactose intolerance, a condition caused by inadequate digestion of the sugar known as lactose that is present in dairy products.^[21] Lactose intolerance can exacerbate or even trigger IBS.^[21]

In people with this condition, undigested lactose passes into the large intestine, where it is fermented by the indigenous microflora into gases that cause a variety of unpleasant symptoms.^[21],[22] Obviously, lactose intolerance can make it difficult to enjoy your favorite latte or smoothie!

Fortunately, some probiotics, including Lactobacillus acidophilus and Bifidobacterium longum, churn out an enzyme (lactase) that aids in the digestion of lactose.^[23] That may be why adults with lactose intolerance, who regularly consumed Lactobacillus acidophilus, experienced reductions in diarrhea and abdominal cramping.^{[24],[25],[26]} A combination of Bifidobacterium longum and Lactobacillus rhamnosus (4 billion and 1 billion CFU/day, respectively) was also shown to alleviate symptoms of lactose intolerance within 30 days.^[27]

Probiotics can also relieve stress and enhance quality of life

Probiotics may improve our ability to handle stressful events without getting our guts tied in knots.

Stress is incredibly common in our modern world and it may play a role in IBS. Scientists have discovered that chronic stress promotes the development of IBS by altering intestinal sensitivity, motility, secretion and permeability, all of which affect gut function.^[28],[29]

To manage chronic stress, consider incorporating one or more stress reduction techniques in your daily life. A program known as mindfulness-based stress reduction (MBSR), for example, has been shown to significantly improve irritable bowel symptoms.^[30]

In humans, the impact of stress depends on the individual’s subjective interpretation of stressful events. Clinical studies involving over 1,000 subjects to date suggest that probiotics can reduce subjective stress levels.^[31] In other words, probiotics may improve our ability to handle stressful events without getting our guts tied in knots.^{[32],[33],[34],[35]}

Here’s how it works: typically, the brain “lights up” in response to fearful or stressful stimuli, signaling the fight-or-flight response which prepares us to deal with danger. In a RDBCT of 44 adults with IBS, supplementation with a Bifidobacterium longum strain altered brain responses to fearful images, suggesting the probiotic moderated the fight-or-flight response.^[36] Similar effects have been seen in animal studies, consistent with a gut-brain connection.^[37],[38]

In sum, irritable bowel is a truly irritating condition that can significantly impact one’s human experience. Probiotic supplementation may help improve gut function and enhance quality of life – a truly worthy goal. Benefits are most often seen with combinations of Lactobacillus and Bifidobacterium species at doses of 2 billion CFU/day or more.^[13]

Note: It can be illuminating to evaluate your own quality of life with the assistance of questionnaires like the ones used in clinical studies.^[36] Check out this online 36-item quality-of-life questionnaire.

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