Probiotics and the Brain: Exploring the Gut-Brain Axis
Probiotics are living microorganisms that provide health benefits when consumed in adequate amounts. They are commonly found in fermented foods and supplements, and have been shown to improve digestive health and boost the body’s immune system. But recent studies have also suggested a connection between probiotics and brain function, leading to the emergence of what is known as the gut-brain axis.
What is the Gut-Brain Axis?
The gut-brain axis is a bidirectional communication system that links the central nervous system (CNS) with the enteric nervous system (ENS), which controls the gastrointestinal function. The ENS is considered as the ‘second brain’ because it contains millions of neurons that regulate gut movements and secrete neurotransmitters such as serotonin, dopamine, and GABA, which are also present in the CNS. This means that the gut and the brain are in constant communication, and changes in one can impact the other.
How Probiotics Affect the Gut-Brain Axis
Studies have shown that probiotics can stimulate the production and release of neurotransmitters in the gut, which can then enter the bloodstream and influence brain function. For example, the probiotic strain Lactobacillus rhamnosus has been shown to increase GABA production in the brain, which can reduce anxiety and improve mood. Similarly, another strain called Bifidobacterium longum has been shown to reduce cortisol levels, which is a stress hormone that can impact cognitive function.
Probiotics and Mood Disorders
Several studies have suggested that probiotics may play a role in the treatment of mood disorders such as anxiety and depression. In a randomized, double-blind, placebo-controlled trial, participants who received a probiotic supplement containing Lactobacillus acidophilus and Bifidobacterium bifidum for eight weeks had a significant reduction in depression and anxiety scores compared to those who received a placebo. Another study found that a probiotic supplement containing the strain Lactobacillus helveticus and Bifidobacterium longum reduced symptoms of depression and anxiety in patients with chronic fatigue syndrome.
Probiotics and Cognitive Function
Probiotics may also have a beneficial effect on cognitive function. In a study of healthy young adults, participants who consumed a fermented milk product containing the probiotic strain Lactobacillus casei Shirota for four weeks had better memory recognition and reaction time compared to those who consumed a placebo. Another study found that a probiotic supplement containing Lactobacillus plantarum improved attention and processing speed in older adults with cognitive impairment.
Conclusion
The gut-brain axis is a complex system that involves the interplay between the central nervous system and the enteric nervous system. Probiotics have been shown to impact neurotransmitter production in the gut, which can then influence brain function and improve mood and cognitive function. While more research is needed to fully understand the mechanisms of the gut-brain axis, the evidence suggests that incorporating probiotics into a healthy diet may have benefits beyond just digestive health.
