Double-blind, randomised, placebo-controlled study to evaluate the benefit of pasteurized Akkermansia muciniphila in reducing complaints related to irritable bowel syndrome.

Further objectives are to evaluate the beneficial potential of pAkk on any anxiety and depression complaints, as well as its safety and tolerability.

Irritable bowel syndrome (IBS) is one of the most common disorders of gut-brain interaction, globally affecting about 10% of the population. Typical predominant traits are abdominal pain and abnormal bowel habits. The use of probiotics in IBS has been continuously assessed; in recent systematic reviews and meta-analyses, single or combined probiotic strains were indicated to have beneficial effects and good tolerability in the affected population.

pAkk has recently been assessed as a safe novel food ingredient. Beneficial effects and very good tolerability of pAkk have been reported in individuals with metabolic disorders. The objective of the present clinical study - a double-blind, randomised, placebo-controlled, parallel group design, explorative pilot 12-week nutritional study, is to assess the potential of pAkk in IBS management.

The main study objective is then to evaluate the benefit of pAkk in reducing complaints related to irritable bowel syndrome. Further objectives are to evaluate the beneficial potential of pAkk on any anxiety and depression complaints, as well as its safety and tolerability. In total, 90 participants will be enrolled and will attend 4 study visits: one on site and 3 televisits.

Inclusion Criteria:

1. Men and women from 18 to 70 years old

2. Meeting Rome-IV criteria for IBS:

   Recurrent abdominal pain on average ≥1 day/ week in ≥3 months prior to study (with symptom onset ≥6 months prior to study), associated with ≥2 of the following criteria:

   • Related to defecation
   • Associated with a change in frequency of stool
   • Associated with a change in form (appearance) of stool

3. Consistent and stable body weight in the last 3 months prior to study (less than 5% self-reported change)

4. Having access to a smartphone or a computer with an internet access, either allowing a video call, and familiar with the use thereof (checked during the visit)

5. Subject's agreement to comply with study procedures, in particular:

   • to take IP as recommended
   • to avoid the use of other products which may influence the GI complaints during the study
   • to keep the habitual dietary habits, type and level of physical activity (including any specific exercise such as e.g. yoga) as well as the level of caffeine or nicotine (if any)
   • to complete the subject diary and study questionnaires

6. Women of childbearing potential:

   • commitment to use contraception methods
   • negative pregnancy testing (beta human chorionic gonadotropin test in urine)

7. Readiness not to participate in another clinical study during this study

Exclusion Criteria:

1. Self-reported known allergy or hypersensitivity to any of the components of the investigational product

2. Self-reported nocturnal GI complaints

3. Women of childbearing potential: self-reported GI complaints mainly related to menstruation

4. Self-reported lactose or fructose intolerance

5. Self-reported acute or chronic significant GI disease or digestion/absorption disorders (e.g. inflammatory bowel disease, coeliac disease, pancreatitis, disorders in digestive tract motility etc.)

6. Self-reported local anorectal problems (e.g. anal fissure, bleeding haemorrhoids)

7. Self-reported clinically significant findings in colonoscopy within the 2 years prior to study

8. Family history (immediate family) of colorectal cancer or inflammatory bowel disease; anxiety or depression requiring medication

9. Acute or chronic psychiatric disease (e.g. depression, anxiety, bipolar disorder) requiring medication

10. History and/or presence of other clinically significant condition/disorder, which per investigator's judgement could interfere with the results of the study or the safety of the subject, e.g.:

    • unstable thyroid gland disorder
    • unstable hypertension
    • unstable diabetes mellitus
    • eating disorder
    • immunodeficiency
    • relevant gynecological or urological disorder
    • any other relevant serious organ or systemic diseases (e.g. cardiovascular, liver, renal disease etc.)

11. Significant GI surgery within the last 6 months prior to or planned during the study

12. Regular medication and/or supplementation within the last month prior to and during the study:

    • antibiotics, probiotics, metformin
    • for management of IBS complaints, such as bile acid binders (e.g. cholestyramine), rifaximin, alosetron, lubiprostone, eluxadoline, linaclotide, peppermint oil
    • that could influence gastrointestinal functions (e.g. laxatives, opioids, systemic corticosteroids, anticho-linergics, anti-diarrheals etc.) as per investigator judgement

13. Regular use of psychotropic drugs (e.g. hypnotics / sedative drugs, anxiolytics, antidepressants, neuroleptics, anticonvulsants) within 3 months prior to study or adaptogens (e.g. ginseng, St. John's Wort) within 6 weeks prior to and during the study

14. Introductions of a specific diet (e.g. low carb, vegan, high-fibre, low FODMAP within last 3 months prior to and during the study

15. Women of child-bearing potential: pregnancy or nursing

16. History of or current abuse of drugs, alcohol or medication

17. Participation in another study during the last 30 days prior to and during the study

18. Any other reason for exclusion as per investigator's judgment, e.g. insufficient compliance with study procedures