Key Points:

New Zealand is leading world research into applications of useful bacteria to counter problems such as tooth decay, body odour and ear infections.

At a conference in Auckland yesterday, Professor John Tagg said products were already on the market as a result of University of Otago research to help protect against sore throats through lozenges that contain a streptococcus known to reduce the risk of infection.

Now Professor Tagg and his researchers in the microbiology department are turning their minds to other applications using similar principles. He is confident probiotics - live organisms that confer health when given to people - have a huge potential in a range of conditions.

Already an infant formula is being developed containing bacteria that will help fight middle-ear infections.

Professor Tagg said it was possible to come up with a body stick, with bacteria in the wax, to help deal with body odour, and lozenges with live bacteria to help fight either tooth decay or gum disease.

Professor Tagg told the Herald the area he was most excited about was developing some form of immunity against bacterial meningitis, through exploiting a bacterium that might be able to protect people from it.

The science involved in probiotics might also be useful in the future to help fight hospital superbugs, he said.

Professor Tagg is a consultant scientist to BLIS Technologies, which manufactures a range of probiotic products.

BLIS stands for Bacteriocin-Like Inhibitory Substance and its products have been on the market for about eight years and are starting to make a profit, he said.

Professor Tagg said he was also researching applications for bovine mastitis which "you would be very grateful for if you were a cow".