Exercises are beneficial for intestinal environment!
As one of the preparations for the 2020 Summer Olympic and Paralympic Games in Tokyo, the topics about the maintenance and improvement of health through sports have often come up in Japan. At the same time, research results about the intestinal microbiota of professional athletes have been announced. Now, many people pay attention on the relationship between intestinal health and sports and exercise.
Many studies have reported that exercise provides positive effects on various metabolic activities and immunity in our bodies. On the other hand, there are still many unknown mechanisms related to how exercise affects the balance of intestinal bacteria. Sone studies have shown that the diversity of the intestinal microbiota decreases by the lack of a varied diet and the attenuation of the ability to exercise, such as experiencing difficulty in moving the body during the senior years, less opportunities to exercise, etc. Many people have started recognizing the importance of exercise for the intestinal environment.
However, heavy exercise may cause adverse effects to the intestinal environment. It is important to understand what kind of exercise can be effective for one’s intestinal environment.
Professional athletes have an amazing intestinal environment!
Exercise varies with its types and intensity. We would like to introduce here some data from the research study with professional athletes. Scientists have studied the dietary intake and physical activities of the international rugby team of Ireland during their training period just one year before the World Cup. It is noteworthy that the professional rugby players are classified as overweight or obese by judging with BMI levels because of their muscle size. In this study, the low BMI group (healthy subjects) and the high BMI group (healthy subjects) were set as the control group.
In this test, the professional rugby players constantly ingested meals throughout the day, while the control group ingested meals at regular times. Compared to the low BMI group, professional athletes ingested meals which contains diets significantly higher level of proteins, lipids, carbohydrates, sugars, cholesterol and polyunsaturated fatty acids. As a result of this test, despite the fact that creatine kinase, which is normally used as an indicator of muscle damage during heavy exercises, was present at a considerably high level in the blood of the rugby players. This means they are under a hard exercise condition. However, a small level of inflammatory cytokine was found in their blood.
In addition, this study suggested that the professional rugby players exhibit a great diversity of their intestinal microbiota. There were 22 phylum (phylum is a level of classification for intestinal bacteria) of microorganisms in their intestines, whereas 11 phylum in the intestines of the low BMI group and 9 phylum with the high BMI group. Other existing researches have already shown that obese individuals have less diversity in their intestinal microbiota, but the professional rugby players have exhibited a large diversity. The low BMI group and the professional rugby players have many Akkermansia muciniphila and Faecalibacterium prausnitzii which are known as microorganisms largely present in the intestines of thin people. Based on these findings, regular exercise with a certain level of intensity like the one performed by professional athletes does provide an anti-inflammatory effect towards the intestinal environment and the diversity of intestinal microbiota.
Pay attention to exercise requiring stamina because it can aggravate the intestinal environment
Unlike the sports mixed of aerobic exercise and non-aerobic exercise such as rugby and soccer, the endurance competitions mainly with aerobic exercises rise the stress levels in the intestines. The endurance competitions include running, cross country skiing, cycling, swimming, etc. The energy requirement lasts for a long time for these sports that require stamina, so many physiological adaptabilities are necessary in order to maintain body homeostasis. Lately, marathons and cycling are becoming popular in Japan because people want to maintain their health with those exercises. However, people practicing those kind of exercises need to particularly care for their intestinal environment.
Blood circulates constantly in our bodies. Blood conveys nutrition and oxygen to all the body cells and recovers carbon dioxide and waste products. Other than these functions, it takes many important roles such as transferring hormones, adjusting body temperature, controlling moisture metabolism, etc. After the exercise, muscles and the heart require more blood than usual; therefore, the amount of blood supply for the intestines decreases. As a result, intestinal cells become disordered which will cause dehydration and abdominal cramping. In some cases, diarrhea with bleeding may occur as well. Damages to the intestinal cells cause the reduction of the barrier functions in the intestines that allow toxins called endotoxins, which are produced by bad bacteria, enter the intestines. This bad process provides adverse effects to the body. The amount of antibacterial substances secreted from intestinal cells and immune cell transportation decrease, so the risk of developing infections will increase. Thus, chronic heavy exercises, especially endurance competitions, may provide harmful effects to intestinal functions.
Keeping the intestinal environment well by exercising moderately!
Heavy exercises provides adverse effects to intestines. However, moderate exercises keep the condition of intestines well. Regular moderate exercise alleviates the barrier function of intestines damaged by stresses. It also reduces the degree of intestinal permeability, prevents the invasion of bad bacteria and increases the secretion of antimicrobial proteins. Some studies have reported that when the study subjects do moderate exercise, intestinal inflammation is alleviated even if they eat a high fat diet, and their intestines can be kept healthy.
Furthermore, researches about the effect of lactic acid bacteria among athletes have been conducted. The researchers in Australia have studied the functions of intestinal barrier in order to verify the effect of lactic acid bacteria administration to the athletes. 23 male athletes with an average age of 38 years old took supplements that blended several kinds of lactic acid bacteria for 14 weeks. As a result, the functions of intestinal barrier was obviously improved in the subject group who tool lactic acid bacteria compared to the placebo group. The group with lactic acid bacteria showed the lower level of an indicator for inflammation which meant the inflammation was suppressed. Considering these results, when people do aerobic exercise, proper ingestion of lactic acid bacteria and meal that is good for the intestinal care, they can keep the condition of their intestines normal.
Lack of exercise decreases muscle mass which cools the body down and disturbs the hormonal balances. As a result, intestinal condition is deteriorated causing constipation and other symptoms. On the other hand, frequent exercise with higher intensity causes inflammation in the intestines due to the disturbance of the blood flow. In order to make the intestines healthier, it is important to carry out regular mild intensity exercises and be aware of feeding intestinal bacteria from our own diet.
Credit to: Muneaki Takahata Ph.,D.