Medically reviewed by Onikepe Adegbola, MD, PhD
The improvement of core symptoms in patients with Irritable Bowel Syndrome (IBS) doesn’t depend solely on the dietary intake. Psychological and microbial factors play a key role, too, according to a study.
The study, “Predictors of Symptom-Specific Treatment Response to Dietary Interventions in Irritable Bowel Syndrome,” published in the journal, Nutrients, provides important insights into the effect of dietary intervention on managing IBS symptoms in patients and how several miscellaneous factors intervene in the treatment response.
This study didn’t divide the participants of the study into two standard groups of respondents and non-respondents. Instead, the results focused on the core IBS symptoms: cramping, bloating, diarrhea, and constipation.
IBS is a disorder of the large intestine that’s characterized by symptoms like gas, bloating, abdominal pain, cramping, constipation, diarrhea, or both in some cases. Being chronic, IBS must be managed in the long term.
Some factors that may be potential causes of IBS include stronger muscle contractions in the digestive tract that last longer than they should, abnormalities in the nervous system that may make you feel more discomfort and pain when the abdomen stretches, severe life stress or trauma, bacterial infections, and changes in the composition of gut microbes.
The first approach to managing IBS symptoms is making dietary interventions. Patients are put on a traditional IBS diet or a low FODMAP (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols) diet, but this does not guarantee to mitigate symptoms completely, which is what prompted researchers to study if there were any other factors at play, and if yes, how did they affect the treatment response.
Sixty-seven patients, divided into groups of 33 and 34, were included in the study. One group was put on a traditional IBS diet, and the other was given a low FODMAP diet for four weeks, and the responses were recorded. Predictors of improvement in IBS symptoms were investigated during the study period.
The baseline measures in the study included fecal dysbiosis, daily energy, non-gastrointestinal somatic symptoms, and psychological distress. The results were analyzed on how severe the symptoms were in each group of patients.
Both the traditional IBS diet and low FODMAP diet showed a similar level of effectiveness in both study groups (when the only independent variable was time). Both diets reduced the severity of diarrhea, bloating, and pain. The results for constipation were quite different.
With pain as the focus point, patients who took a higher energy diet had a better response to symptom management following traditional IBS and low FODMAP diet. Their pain improved more than the patients whose energy intake was relatively lower.
Patients who scored lower on the Dysbiosis Index showed better responses to dietary interventions in the management of constipation.
Patients who were under greater psychological response responded poorly to the dietary intervention. Stress and anxiety were found to hinder the effectiveness of both traditional and low FODMAP diets in managing core IBS symptoms in patients.
The study indicated that patients who had less severe IBS symptoms responded better than those who presented advanced clinical characteristics. Moreover, symptoms in patients with a Dysbiosis Index result closer to healthy individuals, and greater energy intake improved more than those with greater Dysbiosis Index scores and lower energy consumption.
To conclude, the first approach to relieving IBS symptoms should be to begin a traditional IBS diet and move to a diet that is low in FODMAP only when the traditional IBS diet doesn’t help in symptom relief. Also, the baseline characteristics significant for the response to any one type of diet may not be of equal importance to the other types of diet.
Colomier, E., Van Oudenhove, L., Tack, J., Böhn, L., Bennet, S., Nybacka, S., Störsrud, S., Öhman, L., Törnblom, H., & Simrén, M. (2022). Predictors of Symptom-Specific Treatment Response to Dietary Interventions in Irritable Bowel Syndrome. Nutrients, 14(2), 397. https://doi.org/10.3390/nu14020397