Probiotic Formula Alleviates Signs of Stress in Healthy Volunteers: New Randomized Study

The clinical study was supervised by the team of Drs Messaoudi and Bisson in Nancy (France). It assessed the effect of one-month Probio’Stick administration on anxiety, depression, stress and coping strategies in healthy human volunteers.

Nov 1 2010 --- According to a new study published ahead of print by the British Journal of Nutrition, Institut Rosell-Lallemand probiotic formula Probio’Stick (a combination of Lactobacillus Rosell-52 and Bifidobacterium Rosell-175), significantly alleviates psychological distress in volunteers, in a double-blind randomized study. These results are supported by a pre-clinical behavioural study also described in the same publication, demonstrating the anxiolytic-like effects of Probio’Stick in rats. In a previous randomized study, Probio’Stick was shown as the first probiotic preparation to efficiently reduce stress-induced gastrointestinal symptoms in chronic stress sufferers.

This probiotic study was also communicated for the first time on October 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).

The clinical study was supervised by the team of Drs Messaoudi and Bisson in Nancy (France). It assessed the effect of one-month Probio’Stick administration on anxiety, depression, stress and coping strategies in healthy human volunteers, thanks to a range of psychological self-assessment tests and a biomarker for stress and anxiety (24 hour urinary free cortisol monitoring). The study involved 55 healthy stressed subjects in total.

The randomized study showed that one month daily administration of Probio’Stick preparation (equivalent to 3X109 CFU/day) had a beneficial effect on general signs of anxiety and depression (in particular the somatisation, depression and anger-hostility components, as shown by Hopkins Symptom Checklist-90,  an instrument used to evaluate a broad range of psychological problems and symptoms of psychopathology).

The probiotic also improved the subject’s ability to cope with the stress of everyday’s life events (The Ways of Coping Checklist). Results of the self-assessment tests were correlated by a decrease of urinary free cortisol levels in the probiotic treated group, a biomarker for stress and anxiety. The investigators reported that it was the first time that free cortisol level was monitored during a probiotic clinical study.

The pre-clinical study that was described in the same publication was based on a rat model of anxiety which is commonly used to screen anxiolytic agents. After two weeks treatment, Probio’Stick showed a significant anxiolytic-like effect, comparable to that of Diazepam which was used as a positive control.

The authors concluded about the new Probio’Stick studies :

“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”.

A few months ago, another innovative pre-clinical study was presented by Professor Guy Rousseau at the New York Academy of Science. This behavioural study, performed in rats, showed the positive effects of the same probiotic preparation (Probio’Stick) on behavioural signs of depression following myocardial infarction.
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Three different mechanisms have been invoked to explain the beneficial effects of probiotics on anxiety and depression:

1) Competitive exclusion of gut pathogens by the probiotics (certain gut pathogens produce substances shown to induce anxiety and aggression in animals, e.g. propionic acid).
2) Decrease in pro-inflammatory cytokines (a link has been drawn between depression and high levels of certain inflammatory markers).
3) Direct communication with the central nervous system via vagal sensory fibers, leading to changes in neurotransmitter levels or function.

The authors explain that it has been shown in the past that both Lactobacillus Rosell-52 and Bifidobacterium Rosell-175 exert anti-inflammatory properties on human intestinal epithelial cells.

Moreover, Lactobacillus Rosell-52 was also recently demonstrated to protect the gut microflora against the invasion of pathogenic bacteria and both strains are well known to reduce intestinal permeability thanks to their “barrier effect”.

The combination of these actions could lead to reduce the inflammation and neuro-inflammation caused by stress at the level of the gut mucosa and may explain the clinical effect of Probio’Stick on both physical and psychological symptoms of stress.

1 Messaoudi M., Lalonde R., Violle N., Javelot H., Desor D, Nejdi A., Bisson J.-F., Rougeot C., Pichelin M., Cazaubiel M. And Cazaubiel J.-M.: Assessment of psychotropic-like properties of a probiotic formulation (Lactobacillus helveticus R0052 and Bifidobacterium longum R0175) in rats and humans. Br J Nutr. 2010 Oct 26:1-9.