More than half of your body is not human.
Only about 43% of cells in the human body are human cells, the rest are composed of microorganisms such as bacteria, viruses, and fungi. These microbes are high in genetic diversity, and no two humans have the same microbiome. Therefore, we can say that microbes are not coexisting organisms, but a part of us as well.
What is the gut-brain axis?
The largest microbiome in your body is the gut microbiome, and the composition of our gut microbiota is so important, that it could largely determine your physical and mental health. The communication system between your gut and your brain is known as the gut-brain axis, and they “communicate” through signaling molecules such as the hormones cortisol, dopamine, and serotonin, which are key in determining one’s mental well-being.
Disturbance in the gut-brain axis may lead to diseases of the nervous system, such as Parkinson’s disease, Alzheimer’s disease, and irritable bowel syndrome. On the other hand, regulated communications via the gut-brain axis could modulate the immune system, the nervous system, and metabolism.
What is the gut-muscle axis?
In addition to the gut-brain axis, the gut microbiome also communicates with the muscular system via the gut-muscle axis. The trillions of microbes living in your gut make many different compounds that affect your muscle mass and muscle strength. Regular exercise has positive effects on the gut microbiome as well.