It would appear from a review of studies conducted by researchers at the University of Oxford that the sky is the limit when it comes to probiotics’ influence on health. While it has been recognized for years that probiotics have a beneficial influence on physical health, more recently a gut-brain connection has been identified. Maintaining an optimal microbiome by including the right mix of probiotics in the diet enhances immune function, improves reactions to stress, and even has learning and memory advantages. Studies on mice show that probiotics often increase brain-derived neurotrophic factor or BDNF, which is closely linked to learning and memory. Prebiotics also are important players in the gut-brain scenario, as are activities, such as exercise and diet. The key players in this gut-brain connection are the nervous system of the intestines, the immune system, the vagus nerve, and possibly gut hormones and neurotransmitters, such as serotonin and dopamine. The researchers warn against probiotic and prebiotic supplements that are advertised to have psychobiotic effects. There are too many questions unanswered at this point about which strains of bacteria offer the best benefits, how they work, and whether they offset other benefits.
Elizabeth Somer, M.A.,R.D.
Sarkar A, Lehto S, Harty S, et al: Psychobiotics and the manipulation of bacteria-brain signals. Trends in Neurosciences 2016; October 25th.