In the present study the main goal has been to clarify the effect of the probiotic bacteria Lactobacillus plantarum 299v on the salivary cortisol level in young adults under examination stress. Salivary IgA from minor glands and in whole human saliva was measured as alternative marker of stress. The hypothesis was that the levels of cortisol would be reduced or stabilized in the test group in comparison to the placebo group where the cortisol levels were expected to increase due to the examination-induced stress. By contrast, the salivary IgA levels were expected to increase in the test group in comparison to the placebo group.

Inclusion Criteria:

• adults
• studying at the University in Lund
• participation in ongoing examination period

Exclusion Criteria:

• pregnancy
• intake of antibiotics
• medication with cortisone during the study period