The link between our mental health and digestion has become more understood over recent years. IBS sufferers are now aware of how stress can trigger symptoms and research has shown that up to 95% of serotonin is made in the gut – proving the link between our stomachs and our mental make-up. But new research has shown that your physical wellbeing could also have an impact on your microbiome.
The paper, published in Research in Sports Medicine, has shown that injuries to the joints and muscle tissue are associated with less gut biodiversity. That might sound like a loose connection – how does damage to places far away from our stomach impact what happens in our gut? – but it’s all part of the ‘global consequences’ of an injury, according to researchers.
Scientists were inspired to look into the link after reading previous studies which showed that muscle and joint injuries can lead to stunted signalling from the brain to the lower extremities and change the structure of the cerebellum (the part of the brain involved in motor control).
Given that gut microbiota – the microorganisms that live in our digestive tract – are known to change in response to brain injury or pathologies of the nervous system, they wondered how the brain changes caused by physical injury could impact the gut. They took stool samples from previously injured athletes and non-injured athletes to find that those with a history of lateral ankle sprains (LAS) lacked microbiome diversity.
While the exact reasons why these ankle injuries were associated with worse gut health aren’t clear, the researchers concluded that it could be because of the neural effects of injury, increased psychological stress, or a possible ‘communication’ pathway between gut microbiota and the joints, which could cause changes in the bacteria that cause inflammation.
How gut health causes injury
To explain more about the ‘gut-joint’ axis, we spoke to Evelyn Toner, sports specialist dietician from The Gut Health Clinic. “Inflammatory joint disorders may be linked to gut health because inflammation is related to the immune system,” she says. Inflammation is actually part of the healing process – the body’s immune response uses inflammation as it begins acting on damaged cells.
“We know that around 70% of the body’s immune cells are located in the gut, so when it’s busy working to heal injuries, it can’t support its bacteria in the same way,” says Toner.
Then there’s the fact that being injured – especially as an athlete, when you can’t continue with your training and career – is a huge amount of psychological stress. “Traumatic experiences and stress may affect the gut microbiota and decrease or deplete the types of bacteria found there,” says Toner. “This may be due to the release of stress hormones that dampen the microbiome.”
Stress is also related to a dysregulation of eating habits. And eating habits among those who exercise regularly may change with the reduced load associated with injury. “If an athlete is taking time off training for recovery, they may see it as an opportunity to pay less attention to the nutritional value of their food or to eat fewer sources of carbohydrates. If they reduce the variety of plant-based foods in their diet, this may have a knock-on effect on their gut bacteria and result in reduced bacterial diversity,” says Toner.
How to support gut health through injury
For those who are taking time out of their training, Toner advises supporting gut health through both diet and mental health practices. “By this I mean increasing the number of different plant-based foods you consume over the course of a week – aim for as many different types and colours of fruit and vegetables as possible, different types of wholegrain starchy carbohydrates, nuts, seeds and legumes.
“As we know that mental health can also have a knock-on effect on gut health, try to take some small, achievable steps to manage and reduce feelings of stress. Some nice ideas to help with this include doing 10 minutes of gentle exercise that your body can manage during injury, like a gut-directed yoga flow daily, and some short breathing/meditations daily.”
While there’s a lot of research still to be done between physical health and a well-functioning gut, it’s clear that we need to start seeing our body as a totally connected network, rather than treating individual aches and pains.
For more exclusive health and fitness content, sign up to the Strong Women Training Club.
Chloe Gray is the senior writer for stylist.co.uk's fitness brand Strong Women. When she's not writing or lifting weights, she's most likely found practicing handstands, sipping a gin and tonic or eating peanut butter straight out of the jar (not all at the same time).