Lois Rogers

The Sunday Times 20 October 2013

Having spent the best part of the past century trying to eliminate germs from our daily lives, scientists are now making discoveries almost every week demonstrating just how good for us many types of bacteria really are.

The craze for probiotic drinks to colonise the digestive tract with health-giving bugs has sparked a growing interest in ways similarly to colonise the skin with the beneficial varieties of bacteria best at preventing flare-ups of spots, eczema and psoriasis — not to mention the weird red blotches nearly all of us suffer from when our faces suddenly engage in a private war against a harmful bacterial invader.

It has been known since Roman times that mineral-rich water from thermal spas soothes skin and reduces joint inflammation, and this interest in beneficial skin bacteria has led to a realisation that some of the health-giving properties of various types of spa water stem from the bacteria that thrive in the presence of the mineral elements in it, such as magnesium, copper or selenium.

Spa water, widely ignored in Britain since it stopped being prescribed on the NHS in the 1970s, has remained popular elsewhere in Europe — largely because there are many more hot springs on the Continent. Our mineral springs, with a few exceptions such as Bath and Buxton in Derbyshire, are all cold. Thanks to the discovery of these bacteria, however, spa water is coming back into fashion here.

“There’s very good evidence that sufferers from skin problems benefit from bathing in the mineral water here,” says Roger Rolls, a GP who practises close to Bath’s former Mineral Water Hospital and an authority on spa medicine. “Bacteria in the water may be the reason, though it has yet to be proved.”

Scientists at spas across France, Hungary, Poland and Germany are beavering away to do just that, but what may be the first evidence has already been produced by a team from La Roche-Posay, a small town south of Tours in western France, which has published details of the effect of a recently discovered bacterium called Vitreoscilla filiformis (VF), a form of which seems to thrive in the selenium-rich waters of the town’s natural springs.

The benefits to the skin of Roche-Posay water were discovered in the 17th century. Later, survivors from Napoleon’s North African campaign were dispatched there to be cured of the horrible skin diseases they had caught in the Egyptian desert. Today half of the 20,000 French people prescribed spa therapy by doctors to treat the worst types of skin diseases are treated in the town.

“There are about one million bacteria on every square centimetre of skin, and the healthier the skin, the greater the variety of different species of bacteria,” says Dr Luc Aguilar, advanced research director at La Roche-Posay’s parent company, L’Oréal. “We have been working on this since 2005, but, until recently, no one else was interested in understanding how the benefits of spa water worked because it was difficult to study what all the different bacteria were. Now we can rapidly detect the presence of different organisms by identifying their DNA.”

His colleague Dr Sophie Seité, scientific director at La Roche-Posay, is the specialist credited with working out exactly what VF does. Her team has found that it gets rid of disease-associated Staphylococcus aureus, the best known of the hospital superbugs, by creating conditions where the harmful bacteria can’t grow, and that it helps to promote beneficial bacterial diversity on the skin. “We know that if we increase the diversity of bacteria, we are reducing inflammation and increasing the efficiency of the immune system,” she says.

The Roche-Posay team are now working with dermatologists, including those from the University of Munster in Germany, to find out how to rebalance colonies of bacteria to reduce problems created by sensitive or acne-prone skin. The recipe for perfect skin, then, could be just around the corner: “There are all sorts of bacteria whose growth is boosted by different types of minerals in spa water, and we are working out which are the most effective,” Seité says.

The idea of harnessing the health-giving properties of spa-water bacteria is one that intrigues other scientists. “It is definitely a plausible hypothesis, but, as ever, we need more research,” said Paul Hunter, European editor of the Journal of Water and Health.

Evidence, it seems, is on the way. Studies using VF-derived proteins in people with skin problems have already produced good results. More research is in the pipeline and the first La Roche-Posay cream containing the ingredient, a moisturiser called Kerium DS, has already gone on the market. VF will be added to reformulated versions of other products within the next few months.

It will then be up to the other spas to show what their homegrown bacteria can do.