Imagine this: you’re an elite athlete, and you’ve spent years working towards your shot at Olympic glory. You’ve trained hard, been totally dedicated to your sport and now, here you are in Rio, getting ready for the pinnacle of your sporting career. It’s your time to shine. But suddenly, without warning, you are hit with stomach cramps. It’s not nerves – it’s more intense than that. Vomiting and diarrhoea kick in. Slowly and devastatingly, your chances of success go down the toilet.
Competing internationally is not without its challenges: extreme temperatures, different food and water, and exposure to new disease-causing microbes all take their toll on the human body. Combined with the strain that training, travelling and competition can put on the immune system, world-class athletes can suffer an increased risk of picking up infections.
That’s why, time and time again, we hear about elite athletes competing abroad being struck down by travellers’ diarrhoea (TD) – an acute gastrointestinal condition characterised by diarrhoea, vomiting, fever and abdominal pain.
Imagine trying to compete when you are feeling so ill – or even in the days after the infection has gone, when you are still dehydrated and tired. At international competitions such as the Olympics – when the difference between winning and losing can be the tiniest of margins – TD can be a game changer.
Just look at what happened in the 2010 Commonwealth Games in Delhi, for example, when a fifth of the England team were reported to be suffering from gastroenteritis. And who can blame Usain Bolt for sticking to a diet of chicken nuggets at the Beijing Olympics?
On top of the known risks, Rio may have its own specific hygiene problems. Water sports athletes competing in Guanabara Bay, Copacabana Beach and the marina may be at an increased risk of contracting a number of infections, including ones that target the gut, respiratory system and skin.
Bacteria fighting back
So, how can people protect themselves against TD when travelling abroad? The answer may lie with the billions of microorganisms living within our guts. These organisms work with us; for example, they can aid digestion, modify immune functions and outcompete invading microorganisms. As such, they could be key players in reducing our TD risk.
It all comes down to the types and amounts of microorganisms that dominate in the gut. We host thousands of different species of microorganisms; some are beneficial for us, some are less so. The composition of this microbial consortium is greatly influenced by diet, and other factors such as stress, training intensity and antibiotic use have an impact, too.
Research shows that maintaining an appropriate balance of these microorganisms has the potential to have a positive impact on our health. One way to improve our gut microbial community is to consume prebiotics. Prebiotics are foods (fibre), which reach our large intestines and enhance the growth or activities of the health-promoting microbes within.
The idea is that by fortifying our own gut bacteria with prebiotics, we are better equipped to fight off the bacteria that can cause TD. Our own bacteria may outcompete the disease-causing bacteria, and even aid immune function and produce anti-microbial substances to limit the growth of other organisms.
For instance, a prebiotic called galactooligosaccharide (B-GOS) has been shown to reduce the ability of Salmonella to stick to the gut wall, which is how infection takes hold. Another study showed that there was a lower TD incidence among travellers who used B-GOS, compared with those who took a placebo. So, there’s a growing body of evidence to suggest that fortifying our gut community can help us to fight against TD.
For all those travelling to Rio this year, there are a few things you can do to reduce the risk of getting travellers’ diarrhoea. Taking a prebiotic supplement a week before your trip will help your gut bacteria to adjust. And continue taking them after you arrive, to keep your gut in optimal condition – ready to fight back against any disease-causing bacteria you encounter.
There are also, of course, all the familiar travellers' laws: only drink bottled water, and use it when cleaning your teeth, too. Steer clear of ice cubes, which are likely to be made from local water. Only eat hot food, and avoid street vendors. Always carry sanitising gel, and use it before you handle food, and after going to the toilet. By following these tips, you’ll help your gut to put on a gold-medal performance during the games.\