Could a daily probiotic soothe teen anxiety?

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria (Adolescents): * Aged 15-17 years at the time of study screening * Able and willing to provide informed consent or assent, with parental consent where applicable. * Enrolled in school or college at the time of screening * Participants must be able to read and understand English. * Self-reporting mild-to-moderate feelings of anxiety (≥55 and ≤69 T-score - mild-to-moderate anxiety - on PROMIS Pediatric Anxiety CAT, as assessed during screening * Owner of a personal smartphone which: (i) only they have access to, and (ii) has Apple AppStore or Android store access to the free-to-use Trialflare app. * Willing to: * Consume the study product daily for the duration of the study * Setup a Garmin account by email * Wear a provided wearable device during the study period * Complete study assessments digitally Exclusion Criteria (Adolescents): * Pregnant, breastfeeding, or planning pregnancy during the study period * Known allergy or intolerance to any component of the study product * Presence of a significant medical or psychiatric condition that may: * Pose a safety risk, or * Confound interpretation of study outcomes, as judged by the Investigator * Current diagnosis of: * Bipolar disorder * Clinical anxiety disorder or depression * Current or recent (within the last 3 months) use of: * Antidepressants, anxiolytics, or antibiotics * Other probiotic products * Supplements intended to affect mood, sleep, stress, or anxiety * N.B. Use of such items may still be considered via an adaptive approach, reducing the time to last use to 1 month instead of 3 months * Participation in another clinical or nutritional study that could interfere with this study * Current use of cognitive behavioural therapy or counselling to manage anxiety- or low mood-like symptoms * Considered by the PI to be a poor candidate for compliance or data submission Inclusion Criteria (Parents) * Legal guardian of an enrolled A-Participant * Living in the same household as the A-Participant * Able to provide informed consent * Owner of a personal smartphone compatible with the study application Exclusion Criteria (Parents) * None