Exercise is held up as one of the most important aspects of a healthy lifestyle. It burns calories, it is good for your heart and it can make you happier. Its benefits do not end there, though; new research has found that exercise also boosts the diversity of bacteria found in the gut, which can have positive long-term health implications.

The gastrointestinal (GI) tract – the stomach and intestines – is home to a complex community of bacteria referred to as the gut microbiota.

The gut microbiota contributes to the metabolism and the development of the immune system, and previous research has linked changes in its composition with conditions such as diabetes, GI diseases and obesity.

Reduced variation in microbiota has been associated with these health problems, while increased diversity has been linked to a favorable metabolic profile and immune system response.

Diet has already been found to be key in influencing the gut microbiota. Other areas of modern lifestyle have also been found to affect the microbiota population, but the degree to which these do is not clear.

The study, carried out by a team of researchers based in Ireland and published in Gut, is the first to specifically examine the link between exercise and its impact on gut microbiota.

As extremes of exercise are often associated with extremes of diet, the researchers focused their study on a group of athletes. They analyzed fecal and blood samples from 40 professional rugby players during their preseason training program in order to assess the range of their gut microbiota.

Two control groups were also assessed; one group matched with the athletes by size with a comparable body mass index (BMI), and one group matched by age but with lower BMI scores.

Each participant in the study completed a food frequency questionnaire and answered questions about their normal levels of physical activity. The questionnaire detailed how much and how often they had eaten different food items over the preceding 4 weeks.

The results found that the athletes had a significantly wider range of gut microbiota than the men in the comparison groups, and in particular the control group containing men with a high BMI.

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Athletes undergoing a rigorous training program were found to have a high diversity of gut bacteria.

The athletes also had better metabolic profiles than the men with a high BMI and much higher proportions of Akkermansiaceae, a type of bacteria that is known to be linked with lower rates of obesity and associated metabolic disorders.

The dietary analysis found that the athletes ate more of all of the food groups than the control participants. Protein accounted for more of their energy intake (22%) than the comparison groups (15-16%), and they also ate more fruits and vegetables and fewer snacks.

The authors say their findings indicate that exercise is another important factor in the relationship between microbiota, host immunity and host metabolism, with diet playing an important role.

They say that in future research, intervention-based studies to tease apart the relationship between lifestyle changes and the microbiota will be important and provide further insights into optimal therapies to influence the gut microbiota and its relationship with health and disease.

In a linked editorial, Dr. Georgina Hold, of the Institute of Medical Sciences, Aberdeen University, emphasizes the importance of investigating how different lifestyle changes can affect the bacteria in the GI tract:

By being able to identify the impact of such activities, we can aim to reproduce the positive impacts through manipulation of the gut microbiota.

As life expectancy continues to increase, it is important that we understand how best to maintain good health. Never has this been more relevant than in respect of our resident microbiota. Understanding the complex relationship among what we choose to eat, activity levels and gut microbiota richness is essential.”

“Developing new ways to manipulate the beneficial properties of our microbiota by finding ways to integrate health-promoting properties into modern living should be the goal,” she concludes.

Recently, Medical News Today reported on a study that found the more diverse the diet of a fish, the less diverse its gut microbiota was.