Group differences in State Trait Anxiety Inventory (STAI) Y1 (State) (A) and Y2 (Trait) (B) scores observed at D28 across the 4 interventions in 92 volunteers (n = 23 per group). ANCOVA was used to calculate intervention effect employing intervention as a fixed factor, D28 values as the dependent variable, and D0 values, sex, and PHQ-9 and GAD-7 scores as covariates. Results that are statistically significant between interventions are displayed by specified P values. Abbreviations: 2’FL, 2’fucosyllactose; OF, oligofructose; OF/2’FL, oligofructose/2’fucosyllactose.