Advances in Natural Medicines, Nutraceuticals & Neurocognition

The neuromediators epinephrine (adrenaline), dopamine and serotonin stimulate at a concentration of 1M the growth of some

strains of Lactococcus lactis subsp. lactis, a popular probiotic species that is widely used in functional food items. The growth of the strain L. lactis subsp. lactis 194c is threefold accelerated by all the three neuromediators. Epinephrine and serotonin produced no statistically significant effect on the growth of the other strains tested (K-205, 729 and F-116). Dopamine increased the growth of K-205 and 729 but not of the fusion strain F-116. It is known that neuromediators accumulate in the bloodstream and in the intestinal lumen of stressed individuals, especially if the stress is accompanied by local intestinal inflammation. Therefore, it is in a stressed organism that the tested probiotic strains are expected to grow particularly fast. This fact is of indesputable medical interest because probiotics including L. lactis subsp. lactis help the organism cope with stress. Using HPLC with an amperometric detector, it was established that strains K-205 and F-116 produce submicromolar amounts of their own dopamine and of its precursor, 2,3-Dihydroxyphenylalanine (DOPA). DOPA passes the gut–blood and the blood–brain barriers. Therefore, such DOPA-producing probiotic cultures could be applied, in the form of drugs or fermented dairy products for the purpose of improving the physical and mental health state of patients with neurological disorders including Parkinson’s disease.