'Super soap' in the pipeline

The "super soap" gets rid of more bacteria

Scientists are developing innovative soaps and deodorants to make us even cleaner.

The "super soap", developed by a team at the Colgate-Palmolive Technology Centre in Piscataway, New Jersey, US, reduces the amount of bacteria that can attach themselves to the skin.

The deodorant, from Unilever Research and Development Laboratory, Port Sunlight, UK, works on the basis that bacteria in the armpit need the iron in sweat to produce body odour - so depriving them of iron reduces the smell.

Both developments were presented to a meeting of the American Society for Microbiology in Salt Lake City.

A UK expert said both pieces of research opened up interesting new areas for development.

Bacterial survival

Soaps work because of the combination of the mechanical action of washing and the ability of the detergent to "grab and hold" undesirable substances, including bacteria so that they are taken away with the soapy water.

Both of these pieces of research are very interesting

Dr Trish Coates, Skin Research Centre

Antibacterial soaps add ingredients that reduce the ability of bacteria to survive on the skin.

The Palmolive scientists are attempting to prevent the bacteria adhering to the skin in the first place.

Their Microbial Anti-attachment Technology (Mat) uses petrolatum (Vaseline), dimethicone and polyquaternium, all common ingredients of cleansing products which prevent bacteria sticking to the skin.

Mat was tested in three studies using Serratia marcesens, a bacteria which are not normally found on the skin, but which are easy to detect in tests.

One hand was washed with a commercially available soap or a dummy version, and the other with a soap containing Mat.

When the hands were dried, they were pressed against a plastic surface already coated with the bacteria.

The researchers then looked at how much bacteria were transferred from the plate to the hands.

It was found the amount of bacteria attachment to the hands washed with the Mat-containing soap was reduced by between 50 to 58% compared with those washed with placebo or commercial soaps.

The team, led by Dr Shamim Ansari, believe the Mat ingredients deposit a thin film on the surface of the skin, preventing the bacteria from taking hold, and perhaps also changing the surface properties of the skin.

He said: "The clinical data demonstrate that fewer bacteria bind to hand skin after washing with this soap technology."

Colgate's Protexâ Bar Soap, which uses this technology, is available in Latin America.

Unable to grow

The Unilever team, working on the development of new deodorants, found depriving bacteria of iron will prevent them producing body odour.

Bacteria need iron to function properly. It is the "waste products" they produce which smell.

A combination of two molecules was used, one which released all the iron in the sweat, and another which bound up the iron so the bacteria cannot get to it.

This, the researchers say, leaves the bacteria with very little iron and unable to grow.

The team tested the combination on 50 volunteers for two weeks and found a 90% reduction in the number of bacteria and much lower levels of underarm odour.

Dr Andrew Landa, who led the research, said: "Sweat itself does not smell.

"The bacteria on our skin are responsible for producing the malodour. They feed themselves on the secretions of glands in the underarm, producing odorous molecules as a by-product."

Bacteria warning

Dr Trish Coates, of the Skin Research Centre at Leeds University, told BBC News Online: "Both of these pieces of research are very interesting.

She said the development of the Mat technology could lead to "a new generation of soaps."

But she said it was not clear if it would work for all bacteria, and added: "I would be very worried about anything that could change the surface of the skin. Skin itself is very antibacterial."

"There are also good bacteria that live on the skin that, for a long time, we've thought that they actually stop more dangerous bacteria getting a hold, because they fill up a niche."

Of the deodorant research, Dr Coates said: "This is very interesting, but it's just another way of thinking about it, though it may well be that in the fullness of time, it would be more effective."