Irritable Bowel Syndrome (IBS) is a common chronic gastrointestinal condition that affects approximately 10-20% of adults in Western countries. IBS is a disorder with chronic or recurrent colonic symptoms without a clear-cut etiology. This condition is characterized by chronic or recurrent ABDOMINAL PAIN, bloating, MUCUS in FECES, and an erratic disturbance of DEFECATION. Symptoms include cramping, abdominal pain, bloating, gas, and diarrhea or constipation, or both. Over 80% of individuals with IBS report food-related symptoms leading in the 70% of these patients to self-imposed food restrictions and/or modifications of their diet. These spontaneous unsupervised dietary modifications are associated with maladaptive eating patterns and unnecessary self-restricted diets, which could result in nutritional deficiencies.

BiOkuris product DDI-IBS-001 is a food multicomponents product based on BiOkuris proprietary chitin-glucan complex. The objectives of the VITABIOTIC study is to confirm the effectiveness of the DDI-IBS-001 product in improving global symptoms, abdominal pain, stool consistency, quality of life, anxiety and depression in IBS patients and to confirm the product's safety.

Inclusion Criteria:

1. Adult females and males, aged 18-75 years,

2. Diagnosis of IBS at least 6 months prior to study entry,

3. Confirmed IBS according to Rome-IV criteria (as determined by investigator),

4. Patient having either constipation (IBS-C), diarrhoea (IBS-D) or alternance of constipation/diarrhoea (IBS-M),

5. Possession of a digital device (i.e., smartphone or tablet),

6. Patient who read, understood, and signed the informed consent form (ICF),

7. Patient willing to adhere to the study visit schedule and capable to understand and comply with protocol requirements and product intake,

8. Male, or female patient of childbearing potential, who agrees to use acceptable birth control methods throughout the study period.

   As assessed at the end of the run-in period, week 2 :

9. Patient with a baseline score for abdominal pain ≥ 2 and < 6 assessed on a 7-point Lickert scale

10. Patient with correct and complete reporting of the study questionnaires and scores during the run-in period (≥75% completion)

Exclusion Criteria:

1. Severe gastrointestinal pathologies other than IBS, including: 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,

2. Metabolic disorders affecting intestinal transit function or nutrient absorption including uncontrolled diabetes and uncontrolled dysthyroidism,

3. Patients experiencing complications of abdominal radiotherapy,

4. Surgical operations to the mouth or gastrointestinal tract within 4 weeks prior to study entry, or planned during the study; appendectomy within 6 months prior to study entry,

5. Galactose intolerance ,

6. Use of opioids or narcotic analgesics within 6 weeks prior to week 0,

7. Systemic antibiotic treatment in progress or prescribed less than 4 weeks prior to study entry,

8. Use of products marketed as or rich in prebiotics, probiotics, or symbiotics (e.g., kefir, probiotic yogurt, baker's yeast, etc.) less than 2 weeks prior to week 0,

9. Use of laxatives, antibloating agents, antidiarrheal medication, antispasmodics, anxiolytics, antidepressants, analgesics, and non-steroidals anti-inflammatory drugs if started less than 2 months prior to week 0 . These medications are authorized if consumed for longer than 2 months before week 0 and maintained at a stable dosage for the entire study duration,,

10. Diets including 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 if started less than 2 months prior or stopped less than 1 month prior to week 0. These diets are authorized if followed for longer than 2 months before week 0 and maintained for the entire study duration,,

11. Excessive alcohol consumption (more than 10 units per week) and/or drug abuse,

12. Pregnancy and lactation, or plan to become pregnant during the study period,

13. Participation in other studies involving investigational or marketed products concomitantly or less than 3 months prior to study entry,

14. Known hypersensitivity to any of the ingredients or excipients of the investigational products,

15. Patient who has forfeited their freedom by administrative or legal award, or who is under guardianship or under limited judicial protection.

    As assessed at the end of the run-in period, week 2 :

16. Use of opioids or narcotic analgesics during the run-in period (between week 0 and week 1),

17. Systemic antibiotic treatment in progress or prescribed during the run-in period (between week 0 and week 1),

18. Deviation from lifestyle and dietary recommendations to be followed during the study (between week 0 and week 1).

The stage 2 of this study is a double-blinded study. Neither patients, nor investigators, nor trial staff, nor the sponsor study team will be aware of treatment assignments prior to the database lock at the conclusion of the study. The study products are DDI-IBS-001 and its matching placebo. DDI-IBS-001 and placebo will be provided as sachets containing 1980mg of powder to be dissolved in a glass of water (about 250 ml) and taken orally, with the same composition except for the active ingredient.