Table 2 Eligibility criteria of participants enrolled in the Moving Moods Pilot Study

Inclusion criteria:

 1. Adults (age 18–65 years)

 2. MDD according to Structured Clinical Interview for DSM-5 (SCID-5) MDD module

 3. Moderate-to-severe score on MADRS (i.e. score of greater than or equal to 20)

 4. Stable treatment (i.e. pharmacological and psychological) for 1 month prior to commencing trial

Exclusion criteria:

 1. Active suicidality (a MADRS suicide item score of 5 or 6)

 2. Use of probiotics, antibiotics, or any experimental drug in the 1 month prior to study entry

 3. Serious gastrointestinal conditions (including active inflammatory bowel disease, bowel cancer, or a history of major bowel surgery, but not including IBS, chronic diarrhoea, or constipation)

 4. Pregnancy or breastfeeding (pregnancy will be excluded using a urine pregnancy test at baseline)

 5. Major comorbid psychiatric disturbances including bipolar disorder, a primary psychotic illness, obsessive-compulsive disorder, anorexia nervosa, or bulimia nervosa

 6. Active substance-use disorder, defined as a score of 6 or greater on the brief Drug Abuse Screening Test (DAST-10), and/or a score of 16 or greater in the Alcohol Use Disorders Identification Test (AUDIT)

 7. Inability to read and understand the participant information and informed consent form

 8. Patients with a history of severe anaphylactic or anaphylactoid food allergy

 9. A condition that could jeopardize the safety or rights of the subject, make it unlikely for the subject to complete the study, or confound the results of the study