Nutrition to Relieve IBS Symptoms by Targeting the Microbiota

Inclusion criteria

• IBS patients that meet the Rome IV criteria. This will be evaluated by the medical supervisor;
• Male and female adults, aged 18-65 years;
• Having a Body Mass Index (BMI) between 18.5 and 30 kg/m2;
• Willing to keep a stable dietary pattern throughout the study;
• Having a smartphone to fill out the daily questionnaires.

Exclusion criteria

• Having a gastro-intestinal disease, such as celiac disease, Crohn's disease, or Ulcerative colitis;
• Having a history of intestinal surgery that might interfere with study outcomes. This does not include an appendectomy or cholecystectomy;
• Having a food allergy to milk protein or pulse protein;
• Presence of significant systemic diseases, such as diabetes mellitus, cancer, cardiovascular disease or respiratory disease;
• When applicable: currently pregnant or breastfeeding, or intending to become pregnant during the study, as this can affect stool patterns and wellbeing;
• Use of antibiotic treatment less than 3 months before start of the study and no use of antibiotics during the study;
• Use of prebiotics and/or probiotics (should be stopped 4 weeks before the start of the study) and infrequent use of other (fiber) supplements. Some supplements are allowed, but intake should be kept stable during the whole study period (Supplements will be judged by the medical supervisor MD Ben Witteman);
• Currently following a FODMAP-restricted diet;
• Use of medication that can interfere with the study outcomes, including anxiolytics, proton pump inhibitors, laxatives (Over-the-counter laxatives are allowed, but intake should be either stopped before the start of the study or kept stable during the complete study period), and codeine, as judged by the medical supervisor MD Ben Witteman;
• Participation in another clinical trial at the same time;
• Student or employee working at Food, Health and Consumer Research from Wageningen Food and Biobased Research;
• Alcohol intake ≥ 2 (women) or ≥ 4 (men) glasses of alcoholic beverages per day;
• Abuse of illicit drugs;
• Being incapacitated.