Scientists have discovered what works better

A recent study examined the effectiveness of three different treatments for IBS, showing that dietary modifications, especially those low in FODMAPs and carbohydrates, are more effective at reducing symptoms compared to medication.

Dietary treatment is more effective than medications in irritable bowel syndrome (IBS). These are the findings of a study conducted at the University of Gothenburg. With dietary adjustments, more than seven in ten patients had significantly reduced symptoms.

Irritable bowel syndrome (IBS) is a common diagnosis that causes abdominal pain, abdominal bloating, diarrhea and constipation, in various combinations and with varying degrees of severity.

Treatment often consists of nutritional advice, such as eating small and frequent meals and avoiding excessive intake of food triggers such as coffee, alcohol and carbonated drinks. Patients may also be given medications to improve specific symptoms, such as gas or constipation, diarrhea, bloating, or abdominal pain. Antidepressants are sometimes used to improve symptoms of IBS.

The current research, published in The Lancet Gastroenterology & Hepatology, compared three treatments: two dietary treatments and one based on medication use. The participants were adult patients with severe or moderate IBS symptoms at Sahlgrenska University Hospital in Gothenburg.

Greater symptom relief after diet modification

The first group received traditional IBS nutritional advice, with an emphasis on eating behavior in combination with a low intake of fermentable carbohydrates, the so-called FODMAPs. This includes, for example, products containing lactose, legumes, onions and grains, which ferment in the large intestine and can cause pain in IBS.

The second group received a dietary treatment with few carbohydrates and relatively high levels of proteins and fats. In the third group, the best possible medication was given based on the patient’s most difficult IBS symptoms.

Each group consisted of approximately 100 participants and the treatment periods lasted four weeks. When the researchers then examined how well the participants responded to the treatments, using an established IBS symptom rating scale, the results were clear.

Sanna Nybacka, Stine Störsrud and Magnus Simrén, Sahlgrenska Academy at the University of Gothenburg. Credit: Photo by Margareta G. Kubista), Malin Arnesson and Johan Wingborg

Of those who received traditional IBS dietary advice and low FODMAP levels, 76% had significantly reduced symptoms. This proportion was 71% in the group that received few carbohydrates and a lot of proteins and fats, and 58% in the medication group.

All groups reported a significantly better quality of life, fewer physical complaints and fewer symptoms of anxiety and depression.

The importance of personalization

At six-month follow-up, when participants in the diet groups had partially returned to their previous eating habits, a large proportion still had clinically significant symptom relief; 68% in the traditional nutritional advice and low FODMAP group, and 60% in the low-carbohydrate diet group.

The study was led by Sanna Nybacka, researcher and dietician, Stine Störsrud, associate professor, and Magnus Simrén, professor and senior consultant, all at the Sahlgrenska Academy, University of Gothenburg.

“With this study we can show that nutrition plays a central role in the treatment of IBS, but that there are several alternative treatments that are effective,” says Sanna Nybacka.

“We need more knowledge about how to best personalize IBS treatment in the future and we will further investigate whether there are certain factors that can predict whether individuals will respond better to different treatment options,” she concludes.

Reference: “A low FODMAP diet plus traditional nutritional advice versus a low-carbohydrate diet versus pharmacological treatment in irritable bowel syndrome (CARBIS): a single-center, single-blind, randomized controlled trial” by Sanna Nybacka, Hans Törnblom, Axel Josefsson, Johann P Hreinsson, Lena Böhn, Åsa Frändemark, Cecilia Weznaver, Stine Störsrud and Magnus Simrén, April 18, 2024, The Lancet Gastroenterology and Hepatology.
DOI: 10.1016/S2468-1253(24)00045-1