A month has already passed since the new year 2023 started. In the new year, most people make new resolutions and make plans. Among them, the goal that should never be missed is exercise. According to the Statistical Brain Research Institute (SBRI), an American market analysis agency, the probability of success in New Year’s resolutions is about 8%, and most of them are likely to fail. Why do New Year’s resolutions always fail? Studies have shown that this may be due to ‘gut microbes’.
The reason why exercise resolutions aren’t always kept well revealedㅣSource: Getty Image Bank
Gut microbes stimulate the brain-gut circuit to increase exercise motivation
Most of the microorganisms in our body are gut microbes. The number of microbes in the gut is more than twice the number of cells and the number of genes is 100 times greater. Gut microbes are closely linked to cells in the body, closely exchanging signals and stimuli, and play a role in optimizing cell function. It affects the human immune system, metabolism, and mental health, and helps humans adapt quickly to the external environment.
A research team led by Christoph Thaiss, a professor of microbiology at the University of Pennsylvania’s Perelman School of Medicine, found that gut microbes can increase a person’s desire to exercise. The research team set out to find a wide range of factors that determine exercise capacity, and carried out experiments in genetically diverse mice. The research team obtained data on various factors that can affect exercise activity, such as genes, the distribution of intestinal microbes, and metabolites. It was thought that genes were often the main cause of running, but contrary to the research team’s expectations, the factor that had the biggest impact on running activity was the distribution of intestinal microbes.
Afterwards, the research team found two types of bacteria (Eubacterium rectale and Coprococcus euatactus) that affect the movement of mice, and also identified the mechanism by which these bacteria affect motivation to move. These bacteria produce metabolites called fatty acid amides (FAs), which activate CB1 receptors that receive nerve substances called endocannabinoids in the intestinal sensory nervous system. When the receptor is activated, dopamine secretion becomes active in the striatum, a brain region involved in motivation and reward.
Mice with these bacteria released more dopamine than other mice when they exercised. Thanks to dopamine, the desire to exercise became stronger, and accordingly, the ability to exercise improved. Rats that exercised a lot also experienced more of a ‘Runner’s high’, which is the feeling of pleasure when exercising. When the research team eliminated intestinal microbes by giving antibiotics, the motor activity of the test mice was cut in half. On the other hand, when a fatty acid amide was injected, dopamine secretion was activated and exercise capacity improved again.
“If a similar gut-brain pathway exists in humans, it could be an effective way to increase people’s motivation and level of exercise to improve public health,” says Professor Christoph Thaiss, first author, it could also be used to treat dopamine-related addiction.” In this way, it can be used to treat addiction or depression by modifying reward-related activities in the brain, and even ordinary people can find a way to exercise regularly like an athlete by modifying their diet . The research results of the research team were published in the international journal Nature.
If you exercise regularly, your gut microbes will improve your athletic performance.
There have been previous studies on the correlation between gut microbes and exercise. Researchers at Harvard Medical School found that only people who exercised regularly had an abundance of gut microbes, and revealed that gut microbes affect athletic performance. The research team published the results of a study in the international journal Nature Medicine in 2019, which found that certain types of intestinal microbes supply energy to muscles and improve exercise performance for those who have been exercising regularly.
The research team collected stool samples from 15 runners who took part in the 2015 Boston Marathon, one week before the marathon and one week after the marathon. They then analyzed the genetic information of the microbes in the stool samples. As a result, it was found that the number of bacteria in ‘Bayonella’ increased rapidly after the marathon than before. The research team found that there was not much bayonella in the intestines of people who like to sit, but it is abundant in people who have been exercising regularly.
Bayonella breaks down lactic acid produced by muscles during exercise into short chain fatty acids such as propionic acid. These by-products move the muscles and are used as sources of energy. The research team also found a gene group that produces lactase in Bayonella’s genetic information, and also carried out an experiment where bayonella collected from human stool samples was given to the intestines of mice. Then the time the rats ran on the treadmill increased. Professor Aleksandar Kostic explained, “Bayonella breaks down lactic acid produced in muscles during exercise and supplies energy to muscles to improve exercise performance.”
