Cognitive and Biological Responses in Stress

The goal of this pilot part of the study (Step 1) is to identify the optimal population of high and low anxiety and stress individuals who will differentially respond to a laboratory stress task as measured by changes in subjective stress response (affect), cognition, attention, and biological measures (autonomic and metabolite responses). Based on experience with different study populations, the investigator's believe that a healthy, homogenous population (Caucasian, women, premenopausal) with higher levels of state anxiety and perceived stress, and with greater responsiveness to laboratory stress tasks (which can also be used in the probiotic intervention study in Step 2) will provide the highest likelihood of identifying the underlying central mechanisms of stress responsiveness in Step 1 and then for the probiotic intervention in Step 2. For this pilot study, the investigator's will look at baseline measures to determine differences in responses to four subjective (affect/cognition/attention) stress tasks (primary endpoints) and biological (secondary endpoints) measures in a high stress group and a low stress group. If for Step 1 of the study, the investigator's are able to verify the stratification of the participants into high and low stress groups based on questionnaire data and show differences between participants with high and low perceived stress in psychological characteristics, lab stress tasks and potentially in biological responses, this will help to determine the optimal cut off values, and the optimal stress tasks to be conducted in the planned probiotic intervention study of Step 2.