Probiotic May Help Reduce Response to Stress

Cortisol is the primary stress hormone in the body. Levels of salivary cortisol rise in response to stress. A new study suggests that the probiotic Lactococcus lactis subsp. Cremoris may help reduce an increase in cortisol in response to stress.

Twenty-seven men with an average age of 23.5 participated in the study. They were given 6 billion CFUs of the probiotic Lactococcus lactis subsp. Cremoris or a placebo daily for 8 weeks. Morning salivary cortisol levels, subjective sleep quality, and mood were evaluated at baseline and every 2 weeks during the study period. At the end of the study period, participants completed the Trier Social Stress Test to assess their stress response.

Participants in the probiotic group saw significantly lower levels of morning salivary cortisol levels compared to the placebo group. They also saw significant decreases in salivary cortisol levels in response to the stress test. In addition, they saw significant improvements in self-reported sleep quality and mood.

The study was conducted by researchers from Hokkaido University. It was published online ahead of print on August 4, 2021, in the European Journal of Clinical Nutrition.