Table 2 Outcomes, definitions, and data sources used to assess trial feasibility

Recruitment

% of enrolled participants (children) from those that were eligible and invited to participate.

Recruitment records kept by researchers in excel files and REDCap, class rolls.

Retention

% of enrolled participants (children) completing follow-up data collection (questionnaires)

Data collection records kept by researchers in REDCap

Data collection and analysis

% of enrolled participants (children) completing questionnaires and cognitive assessment which were valid for analysis

Data collection records kept by researchers in REDCap.

Biological sample collection^a

% of participants (children) opting in for stool sample collection, and % completing baseline and follow-up sample collection.

Recruitment and data collection records kept by researchers in REDCap.

Intervention implementation

Dose delivered and fidelity of study processes and intervention as planned.

Process evaluation tools – Core components checklist.

Intervention acceptability

Acceptance and satisfaction of study processes and intervention.

Process evaluation tools – End of lesson (children) or intervention (parents, teachers) surveys.