Irritable bowel syndrome (IBS) is common and challenging to treat. People who have IBS may feel incredibly frustrated because often doctors tell them there is no observable problem. All the same, they often suffer symptoms including abdominal pain, cramping, bloating, flatulence, diarrhea or constipation.
How Does Diet Affect IBS?
Gastroenterologists used to think that irritable bowel syndrome was mostly psychosomatic. (There’s more information below on talk therapy for this condition.) However, evidence now shows that some people do well when they eliminate easily fermented foods from their diets (Gut, Nov. 22, 2021). This approach, known as a low-FODMAP diet, helps some people but not everyone. To learn why, researchers conducted a month-long study in 41 people with IBS and their healthy household contacts. The investigators analyzed the subjects’ gut microbiota at the beginning of the study and after a month on the low-FODMAP diet.
People who responded well to the low-FODMAP diet started the study with a more pathogenic microbial signature in their intestines. Specifically, their bacteria were less diverse, and they had more Firmicutes family bacteria that can cause disease. In addition, they had fewer beneficial Bacteroidetes species. Following the diet resulted in a better balance of gut microbes as well as fewer symptoms of IBS.
In summary, the scientists suggest that one important outcome of the study is
“The potential development of a microbiota signature as a biomarker to manage IBS cases with a low FODMAP diet recommendation.”
Previous research also showed that a low-FODMAP diet may help ease symptoms of irritable bowel syndrome (American Journal of Clinical Nutrition, June 2021). FODMAP stands for Fermentable Oligosaccharides, Disaccharides, Monosaccharides, And Polyols. While humans may not digest them well, intestinal bacteria do. As a result of bacterial fermentation activity, however, certain individuals experience excess gas when they consume these foods. Despite the appeal of fewer symptoms, eliminating FODMAPs means missing out on some healthful foods, such as wheat, rye, legumes, garlic, onions, milk, yogurt, figs, mangoes or blackberries.
A study in China recruited more than 100 people with IBS and asked them to follow either a traditional or a low-FODMAP diet. Those who followed the low-FODMAP diet for three weeks had fewer symptoms and fewer carb-fermenting bacteria.
There is growing interest in the dietary management of IBS. Although this study suggests that diet can make a difference, telling everyone who may have this condition simply to avoid whole grains, fruits, vegetables and dairy products would impoverish their diet. Moreover, carbohydrate-fermenting bacteria are usually considered important elements of the microbial ecosystem. Consequently, we’ll be watching for more targeted dietary interventions that can improve symptoms.
Other Natural Approaches for Irritable Bowel Syndrome:
Q. Are there any natural treatments for IBS? I think they should call it cranky colon or irritable intestine or something alliterative. Sadly, I’ve had it for several years and there is little to be done for it. I have occasionally had painful rectal spasms so intense I pass out.
Doctors don’t have anything to offer, and I am tired of this socially unacceptable ailment. Do you know of anything I could try?
A. Research suggests that peppermint can ease spasms in smooth muscle, especially the digestive tract. Enteric-coated peppermint oil has been helpful for people with IBS in some trials (Journal of Clinical Gastroenterology, July 2014). As a result, it might be worth a try.
Probiotics May Help Irritable Bowel Syndrome:
People with IBS often benefit from taking beneficial bacteria called probiotics. You have probably seen these advertised as capsules or in foods.
We heard from a reader who reported that probiotics helped his IBS:
“While I’m not cured, the symptoms are now much easier to handle.”
A systematic review covered 11 randomized controlled trials and concluded
“that multi-strain probiotics supplemented over a period of time have the potential to improve IBS symptoms” (Nutrients, Sep. 2, 2019).
Multi-strain probiotics evaluated included species of Lactobacillus and Bifidobacterium as well as Streptococcus thermophilus. Yogurt or kefir with live cultures may offer these strains and might prove beneficial.
Soluble Fiber Is an Option:
Soluble fiber such as that found in oats, barley, beans and psyllium can help control symptoms (American Journal of Gastroenterology, Sep. 2014). Of course, people following a low-FODMAP diet will exclude some foods rich in soluble fiber. Using a psyllium supplement may make sense to start with. Over the long term, a dietitian with experience helping those with irritable bowel symptoms might provide guidance.
Don’t Dismiss Talk Therapy for IBS:
Cognitive behavioral therapy can help a range of conditions from depression to insomnia. A small study showed that this type of targeted talk therapy might also improve symptoms of irritable bowel syndrome. Patients who responded well within the first four weeks of treatment were especially likely to maintain their favorable response (Clinical Gastroenterology and Hepatology, May, 2010).
Many people with IBS have noticed that their symptoms may worsen when they are under stress. No one can avoid stress completely, but this may help explain why cognitive behavioral therapy seems to ease symptoms. On the other hand, doctors might be putting the cart before the horse. New research suggests that mast cell activation (a type of immune response related to allergies) may trigger both IBS symptoms and psychological distress (Journal of Inflammation Research, April 14, 2021).