Inclusion Criteria:  Diagnosed with IBS within 36 months prior to study entry Confirmed IBS according to Rome-IV criteria (determined by Investigator) An IBS Symptom Severity Scale score of ≥125 points at baseline Male or female between 18 and 64 years of age (age ranges included) Possession of a smartphone Willing and eligible to provide consent and comply with protocol and product intake.  Exclusion Criteria:  Unclassifiable IBS (IBS-U) as determined by Investigator  Use of products marketed as prebiotics, probiotics or synbiotics within 4 weeks prior to study entry  o Regular cheese or yogurt containing lactic acid bacteria are not an exclusion criterion.  Systemic antibiotic or antimycotic treatment within 4 weeks prior to study entry Use of laxatives or antidiarrheal medication within 4 weeks prior to study entry Use of high-dose antidepressants/antipsychotics (>50mg) within 6 months prior to study entry. Low-dose antidepressants/antipsychotics should be stable for 3 months prior to study entry. Confirmed lactose intolerance, defined as patients who report response to dietary elimination of lactose/dairy products. Confirmation is patient-reported and not done within the scope of this study. Confirmed food allergy, with reported confirmation based on OFC, IgE, or skin prick test. Confirmation is patient-reported and not done within the scope of this study. Galactosemia (galactose metabolism disorder)  Following diets likely to affect study outcomes, including:  o low FODMAP, KETO/high-fat, gluten free/coeliac, paleo, weight loss, caloric restriction, low-carb, 5:2/whole day energy restriction, Atkins/high-protein, sugar-free, single-food, juicing/any day of juicing, any other restriction diet (e.g. very low calory), or vegan diets (GOS is derived from cow's milk).  Severe illness(es) or medical condition(s), including gastrointestinal pathologies:  o ulcers, coeliac disease, inflammatory bowel disease, bowel cancer, bowel resection, auto-immune diseases (e.g. Rheumatoid Arthritis, Systemic lupus erythematosus, Multiple Sclerosis, Graves' Disease), bariatric surgery, acute or chronic diarrhoea secondary to confirmed infectious gastroenteritis, or enteral or parenteral nutrition  Surgical operations to the mouth or gastrointestinal tract within 4 weeks prior to study entry, or planned during the study  o Appendectomy within 6 months prior to study entry  Recent unintended weight loss:  o >5% of total body weight within 6 months prior to study entry  Excessive alcohol consumption (>10 units per week) and/or drug abuse Pregnancy and lactation, or plan to become pregnant during the study period Participation in other studies involving investigational or marketed products concomitantly or within 3 months prior to study entry Changes in diet, supplement use or medication likely to affect study outcomes within 3 months prior to study entry or planned during the study (at the discretion of the Investigator).