Eligibility Details:
Inclusion Criteria:
1. Patients with a principal diagnosis of OCD (DSM 5) according to the MINI with a Y-BOCS
score of ≥20
2. The ability to comprehend and satisfactorily comply with protocol requirements
3. Written informed consent given prior to beginning of the study.
4. Current use of any psychotropic agent is permitted given that that individual has been
on a stable dose for at least 8 weeks.
Exclusion Criteria:
1. Participants with current Major Depressive Disorder.
2. A MADRS score ≥ 18. Patients with significant suicidal ideation (MADRS item 10 ≥ 3) or
who have enacted suicidal behaviors within 6 months prior to intake will be excluded
from study participation and referred for appropriate clinical intervention.
3. Individuals with current autoimmune disorders (rheumatoid arthiritis, systemic lupus
erythematosus, multiple sclerosis, etc.), inflammatory bowel disease, diabetes.
4. Current use of herbal psychoactive treatments i.e. St. John's Wort, Kava Kava,
Chamomile Extract, Valeria. Past use is permitted if treatment ended 3 months prior to
entering the study and stool sampling.
5. Participants receiving current psychotherapy, including cognitive behavioural therapy
for an anxiety or mood disorder. Past psychotherapy is permitted if treatment ended 3
months prior to entering the study and stool sampling.
6. Patients who currently fulfill criteria for a lifetime history of bipolar disorder,
history of drug abuse, a history of schizophrenia or other psychotic disorders,
delirium, dementia and amnesic and other cognitive disorders, or are in a current
agitated state.
7. Patients meeting criteria for current substance use disorder.
8. Antibiotic or probiotic use within 8 weeks of entering the study and stool sampling.
9. Reports frequent consumption of foods rich in/enriched with probiotics (yogurt etc).
10. Individuals with immune-compromised conditions (i.e. AIDS, lymphoma) or those
undergoing long-term corticosteroid treatment.
11. Individuals with a soy or lactose allergy.
12. Female participants must not be breastfeeding, pregnant or seeking to get pregnant
during the course of this study.
13. History of allergic response to probiotics or any other related drugs.
14. Currently physically unwell including experiencing nausea, fever, vomiting, abdominal
pain, bloody diarrhea.
15. Individuals with prosthetic heart valves, or a history of valvular heart disease.