3.4. Impact of the Probiotic Intervention on Stress and Autonomic Nervous System Parameters Linked to Acute Stress Response
The salivary cortisol concentration progressively increased up to 20 min following acute stress and then progressively decreased up to the last salivary sample at 40 min post-stressor. The cortisol stress response (AUCg and Cmax) was lower in the probiotic group compared to the placebo group at baseline, and the opposite pattern was observed post-intervention (Relative to baseline, stress responses on autonomic parameters were characterized by an increase in HR, the LF peak, and SCL during the stressor (see We observed a statistically significant difference between the two groups post-intervention for the positive PANAS change score from the pre-stressor stage (