Digestive Enzyme Formulation Intervention in IBS Patients Who Previously Clinically Responded to Mediterranean LFD

Irritable bowel syndrome (IBS) is a highly prevalent chronic functional gastrointestinal disorder. The cardinal symptoms include abdominal pain, flatulence, bloating, and changes in bowel habits related to stool frequency and consistency, in the absence of detectable structural and biochemical abnormalities1,2. The prevalence is estimated at 5-10% among different ethnicities3. A low FODMAP diet is the most common dietary intervention with clinically proven benefits in symptom management and quality of life improvement of patients with Irritable Bowel Syndrome (IBS)4. Recently, a dietary digestive enzyme formulation (FODZYME©) claims similar efficacy in symptom management based on an ex-vivo study5. The study aims to examine the clinical efficacy of this formulation in managing IBS symptoms in patients who have previously clinically responded to a low FODMAP diet.

IBS patients who participated in a two-arm clinical trial (ClinicalTrials.gov ID: NCT03997708) and responded to the Mediterranean Diet Adjusted Low FODMAP (MED-LFD) Diet will be considered eligible if their symptoms recurred one year after their initial response to the dietary intervention. Among them, patients without any or mild symptoms, defined as IBS severity scoring system (IBS-SSS) ≤ 175, will be excluded. Moreover, subjects who were randomized to the MED-LFD arm in the previous study, but could not adhere to the dietary intervention, will be included too.

A jar containing the digestive enzymes in the form of powder will be provided to each patient at the start of the study. Patients will be instructed to use the powder formulation according to manufacturer instructions for 1 month. To assess compliance, the weight of each jar will be measured both at the initiation and the end of the study. Patients will also be asked on three different days (one day from the weekend), to estimate the average number of meals per day. Due to the limited sample size (54 patients who received the MED-LFD diet in the previous phase will be screened for eligibility), a control group will be omitted. To reduce the placebo effect, patients will be misinformed that half will take a placebo formulation, randomly.

All patients will be thoroughly trained regarding the proper consumption of the powder (exact dose, timing, etc.), through personal training, videos, leaflets, and other type of training materials.

Eligibility Criteria:
Inclusion Criteria:

* Provision of written informed consent.
* Commitment to availability throughout the study period.
* Patients who fulfilled the Rome IV criteria for IBS (IBS-D, IBS-M, IBS-U) participated in the two-arm clinical trial (ClinicalTrials.gov ID: NCT03997708) as responders to the Mediterranean Diet Adjusted to Low FODMAP (MED-LFD) (if their symptoms recurred -with IBS-SSS \> 175- one year after their initial response to the dietary intervention).
* Subjects randomized to the MED-LFD arm of the previous study who could not adhere to the dietary intervention.

Exclusion Criteria:

* Patients who did not take part in the aforementioned study
* Patients who were randomized in the NICE group
* Patients with IBS-SSS\<175.