The role of the gut microbiota in brain function is a hot topic. Evidence is accruing that there is a causal link between the gut microbiota and stress-related psychiatric disorders. The big question, however, is if it is possible to manipulate the gut microbiota to improve brain function. One means of manipulating the microbiota is through probiotic administration, and Health Canada recently determined that a specific probiotic product is able to help manage anxiety and mood.
Health Canada is the agency that approves the use of foods and Natural Health Products in Canada. They recently gave Lallemand Health Solutions Inc. the green light to make the following claims on one of their probiotic products:
- Helps to moderate general feelings of anxiety
- Promotes a healthy mood balance
- Helps to reduce stress-related gastrointestinal complications such as abdominal pain.
- Helps to reduce stress-related gastro-intestinal complications like nausea
The probiotic, which contains Bifidobacterium longum RO175 (320 million cfu) and Lactobacillus helveticus ROO52 (2.7 billion cfu), has been tested in mice (Messaoudi et al 2011; Ait-Belgnaoui et al. 2014) and humans (Messaoudi et al. 2011). The human studies considered both psychological endpoints (Messaoudi et al. 2011) and GI endpoints related to stress (Diop et al. 2008). A secondary analysis of the subjects in the Messaoudi et al. (2011) with low cortisol levels suggested that the probiotic may be more effective in subjects with low levels of stress (Messaoudi et al. 2011). Cortisol is a hormone that is released in response to stress, and is therefore a marker of stress levels being experienced by people.
The interrelationship between psychological stress and GI function is well established. The gut possesses the ability to directly communicate with the brain through nerves, hormones and gut microbiota signaling. Human studies on probiotics have shown that they can improve GI function and interact with colonizing host microbiota. Now we have evidence that probiotics can impact stress-related psychological symptoms.
How probiotics might impact psychological endpoints is an emerging area of research. See below for some additional information on the topic.
Other human studies on probiotics and psychological endpoints:
- helveticus aided sleep in elderly subjects
- Lactobacillus casei Shirota improved mood scores in healthy subjects
- casei Shirota decreased anxiety in patients with chronic fatigue syndrome
- Bifidobacterium bifidum W23, Bifidobacterium lactis W52, Lactobacillus acidophilus W37, Lactobacillus brevis W63, Lactobacillus casei W56, Lactobacillus salivarius W24, and Lactococcus lactis (W19 and W58) helped reduce negative thoughts associated with sad mood
- Fermented milk with probiotic modulated brain activity as measured with functional MRIs.
- Early probiotic intervention was associated with reduced risk of neuropsychiatric disorders later in childhood
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