Probiotics are bacteria that live in the human intestine which in specific amounts provide health benefits to the host body. In general, probiotics play an essential role in helping the organ to digest food, produce vitamin K and various types of hormones, and maintain the balance of intestinal microbiota. Probiotics are now known to play an essential role in communication between the intestine and brain through nerves, the immune system, and hormones. The probiotic bacteria Lactobacillus Plantarum has been studied to influence neurotransmitters and neurotrophin expression in the brain and intestines.
Intestinal microbiota communities can influence the expression of brain-derived neurotrophic factor (BDNF), neurotrophin (NT) growth factors, serotonin (5-HT), and serotonin transporters (5-HTT) in the hippocampus and amygdala. These substances play a role in the development and plasticity of the brain. Clinical studies have reported that changes in intestinal microbiota cause observable changes in mood and behaviour; conversely, consumption of probiotics can positively affect brain function in healthy people.
90% of the serotonin in the body produced in the digestive tract and released from enterochromaffin cells from the gastric mucosa in response to various stimuli, including signals from intestinal microbiota. Serotonin is involved in the detection of food availability in the intestine and regulation of bowel movements. Serotonin is also related to bone metabolism and organ development. In platelets, serotonin contributes to the process of blood clotting and the central nervous system (CNS), serotonin regulates mood, cognition, appetite, and sleep.
Neurotrophin is a growth factor in the CNS that promotes resistance, development, and function of nerve cells. Neurotrophin works by inducing the release of BDNF from nerve cells in the hippocampus. BDNF is the most widely found and widespread growth factor in the CNS and is essential for survival, nerve migration and differentiation, axonal growth and nerve cell dendrites, synapse formation, regulation of synapse plasticity and sensitivity, and neurogenesis in the hippocampus. A study has shown that mice without intestinal microbiota have low BDNF expression in the brain, where the provision of probiotic supplementation increases BDNF expression and has an effect on reducing anxiety in mice.
Serotonin transporters contribute to maintaining the balance of BDNF levels, increasing serotonin sensitivity, and brain function. Intestinal microbes regulate the expression of serotonin transporters. Previous studies have shown that the administration of live bacteria Lactobacillus rhamnosus GG (LGG) increases the expression of serotonin transporters in rat intestines, where other types of probiotics, namely Lactobacillus acidophilus and Bifidobacterium longum also have the same effect.
Research has been conducted to observe the effects of probiotic supplementation on activation of the intestinal-brain axis in mice. A total of 20 mice were divided into two groups, namely the group that received Lactobacillus Plantarum supplementation for seven days and the control group that did not receive supplementation. Activation of the intestinal-brain axis is evaluated by immunohistochemical examination of rat intestine to observe cells that express serotonin and mouse brain fragments keep cells that express BDNF, neurotrophin, and serotonin transporters.
From the observations, mice that received probiotic supplementation showed an increase in the number of cells that secrete serotonin in the small intestine relative to the control group (p
We found in this study that BDNF expression in the brain in the hippocampus was enhanced by the administration of Lactobacillus Plantarum relative to mice that were not given supplementation. BDNF is supported by an increase in neurotrophin in the brain. Thus, L. Plantarum supplementation can increase endurance, differentiation, and growth of nerve cells, and improve brain development, especially memory and brain plasticity. The number of neurons in the hippocampus also expresses higher serotonin transporters in mice that receive Lactobacillus Plantarum supplementation. The increase in serotonin transporters supports the improvement of serotonergic function in the brain.
The conclusion of this study is the supplementation of probiotic Lactobacillus Plantarum can increase intestinal serotonin and serotonin transporters, BDNF, and brain neurotrophin in adult rats. These findings indicate that probiotics can improve brain development and function and provide an illustration of the effects of exogenous factors on the intestinal-brain axis. (*)
Author: Dr. Reza, G.
Detail information from this research can be seen in our writing:
Ranuh R, Athiyyah A, Darma A, V berisiko, Riawan W, S. Surono I, Sudarmo S. Pengaruh probiotik Lactobacillus plantarum IS-10506 pada stimulasi BDNF dan 5HT: peran mikrobiota usus pada poros usus otak . Iran J Microbiol. 11 (2): 145-150.