NANCY, France—Daily administration of a special probiotic formulation may alleviate stress in healthy adults, according to a new study (Br J Nutr. ePub 26 Oct 2010. DOI: 10.1017/S0007114510004319). The findings build on previous work investigating the anxiolytic effects of Probio’Stick®, a probiotic formulation from Institut Rosell-Lallemand consisting of Lactobacillus helveticus Rosell-52 and Bifidobacterium longum Rosell-175.
In the new study, researchers from ETAP-Ethologie Appliquée conducted a pre-clinical behavioral trial in rats as well as a clinical intervention in healthy adults. In the pre-clinical study, rats were administered the probiotic formula daily for two weeks and subsequently tested in the conditioned defensive burying test, a screening model for anti-anxiety agents. After two weeks, Probio’Stick showed a significant anxiolytic-like effect, comparable to that of the anxiety drug diazepam, which served as a positive control.
For the clinical trial, a total of 55 healthy volunteers were recruited for the double blind, placebo-controlled, randomized parallel group study. Subjects received a placebo or Probio’Stick preparation (equivalent to 3x10(9) CFU/day) for one month. Researchers used several psychological self-assessment tests and 24-hour urinary free cortisol monitoring to determine stress and anxiety. Daily subchronic administration of the probiotic mixture had a beneficial effect on general signs of anxiety and depression, particularly somatisation, depression and anger-hostility; the active intervention also improved subjects’ ability to cope with everyday stressors. Further, the results of the self-assessment tests were correlated with a decrease of urinary free cortisol levels, a biomarker for stress and anxiety.
A statement from Institut Rosell regarding the study included a quote from the authors, who stated: “Consumption of Probio’Stick mitigated psychological distress in three tests without displaying any adverse event. These results provide further evidence that gut microflora plays a role in stress, anxiety and depression, perhaps via the enteric nervous system as well as centrally. Subject to the confirmation of these results, probiotics might offer a useful novel therapeutic approach to neuropathologic disorders and/or as adjunct therapies in psychiatric disorders."
The results of this study were first presented Oct. 28, 2010, at the 2nd World Congress on Immunity Ingredients in Malta, which was organized by the International Society of Antioxidant in Nutrition and Health (ISANH).