Data published in Nutrients indicated that Bifidobacterium longum R0175, Lactobacillus helveticus R0052, and Lactiplantibacillus plantarum R1012 supplementation for four weeks led to subtle reductions in the stress response to mental exams.
“Since probiotics generally may maintain the health of healthy subjects as well as improve the symptoms of patients, this study could further lead to possible clinical implications for improving stress resilience and potential roles in the treatment of affective and gut-brain axis disorders,” wrote scientists from Örebro University in Sweden.
The study adds to the ever-growing body of science supporting the role of probiotics to beneficially impact the microbiota-gut-brain axis, that bidirectional interaction between the gastrointestinal tract and the nervous system.
The study used the commercial probiotic product called Puraflow from GSK Consumer Healthcare. The product is available in Italy and contains the three strains at a total dose of three billion CFUs (colony forming units) at the end of shelf life. The product is also formulated with inulin, zinc, magnesium, potassium, glutathione and lactoferrin.
The study was funded by Pfizer Consumer Healthcare (acquired by GSK in 2019) and the Swedish Knowledge Foundation.
The proof-of-concept study included 22 healthy young people with an average of 24 who were randomly assigned to either the probiotic product or placebo for four weeks. This was followed by a four week washout period before the volunteers crossed over to the other group.
The double-blinded, randomized, placebo-controlled, crossover study used functional magnetic resonance imaging while the subjects performed the Montreal Imaging Stress Task (MIST), reportedly the first time the MIST paradigm has been used in a probiotic intervention study. The Swedish researcher also assessed autonomic nervous system function during the Stroop task.
The data suggested that the probiotic acted differently on the phases of the stress responses, with reduced activation in regions of the lateral orbital and ventral cingulate gyri, regions linked to the stress response.
Probiotic consumption was also associated with greater functional connectivity was found between the upper limbic region and medioventral area, but no impact was observed on salivary cortisol secretion during the task
“This implies that the probiotic intervention primarily impacts initial stress responses in the absence of glucocorticoid signaling,” wrote the researchers.
“Overall, this is one of the first studies to demonstrate that probiotic supplementation affects brain activity during acute psychological situations, such as stress,” stated the researchers. “We found that the probiotic intervention altered activity in specific brain regions known to regulate emotion and stress response, including regions of the lateral orbital and ventral cingulate gyri, although these differences did not withstand correction for multiple comparisons.
“Furthermore, we found that the probiotic intervention significantly altered functional connectivity between the upper limbic and medioventral regions.”
2022, 14(7), 1329; doi: 10.3390/nu14071329
"Probiotic Mixture Containing Lactobacillus helveticus, Bifidobacterium longum and Lactiplantibacillus plantarum Affects Brain Responses to an Arithmetic Stress Task in Healthy Subjects: A Randomised Clinical Trial and Proof-of-Concept Study”
Authors: H.M.T. Edebol Carlman et al.