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Tiny bug could be key to beat asthma
Nobel laureate Barry Marshall holding an endoscope. Picture: Michael O'Brien/The West Australian

Nobel prize-winning researcher Barry Marshall is on a mission, hoping to use the tiny squid-like bug that helped earn him the top gong in medicine to revolutionise how a vast range of infections and diseases such as the flu and asthma are prevented.

In the next stage of his extraordinary research that has spanned more than three decades, the 61-year-old WA professor has singled out a relatively harmless strain of the bacteria helicobacter pylori, HPS2, for a groundbreaking role.

If his gut instinct is right, HPS2 could not only piggyback a range of edible vaccines but also prevent allergies and asthma in children.

The bacterium helped Professor Marshall and colleague Dr Robin Warren win the 2005 Nobel Prize for Medicine after they found it was the most common cause of stomach ulcers, rather than the stress and spicy food long-blamed for painful upsets.

Professor Marshall helped prove the link by swallowing a drink with live bacteria to infect himself and then wiped them out using antibiotics.

In one of the most radical changes in how patients were treated, people who would otherwise have spent years in agony with stomach ulcers suddenly found themselves cured by a simple two-week course of medication.

But while the germ is known to cause ulcers and in rare cases stomach cancer, it has a Jekyll and Hyde nature, often relatively harmless and sometimes even beneficial.

Now Professor Marshall and his private biotech company Ondek are moving closer to being able to tap into its potential upside, hopeful that HPS2 could be used in a yoghurt-type mixture containing multiple vaccines against diseases and infections.

The list of targets is endless - the flu, hepatitis B, whooping cough, malaria and cholera to name a few.

The plan would be to use a probiotic drink or yoghurt with helicobacter infused with viruses to stimulate the immune system and produce antibodies to any number of diseases, while causing no harm.

A trial of 30 patients at Sir Charles Gairdner Hospital, which tested five strains of helicobacter, showed they had no major ill-effects on the stomach while producing a strong immune response.

HPS2 was considered the pick of the bunch and researchers now want another 24 volunteers to use it to give them the final tick-off into its safety and effectiveness.

First cab off the rank for the vaccine trial is likely to be the flu virus, which could not only help deliver quick and cheap vaccinations but has a potential global market of about $4 billion a year.

But Professor Marshall also has a radical theory the bacteria could play an important role in helping people with immune problems, possibly preventing allergies and asthma in children.

It is based on the so-called hygiene hypothesis that argues children in developed countries are not exposed to enough germs to help their immune systems develop properly.

"When kids spend time outside and around dirt it seems to give them some protection, and that's why kids in developing countries might have higher rates of infections but interestingly have little or no allergies and asthma," Professor Marshall said.

"What we're seeing in the 21st century is more people having immune systems that are hyperactive, so we're seeing more of things like peanut allergies, particularly in children.

"The allergy clinic at Princess Margaret Hospital is seeing large numbers of children who are developing allergies from an early age, and one theory is that helicobacter pylori could actually help to prevent things like allergies, infant eczema and asthma."

Professor Marshall said helicobacter was once "common as dirt" and almost everyone carried low levels of it a century ago before that dropped back to about 30-40 per cent. Now he estimated it was as low as 15 per cent of the population.

He believed it was possible to harness the upside of his favoured strain to "dampen down" hyperactive immune systems linked to allergies and asthma.

He says animal studies in conjunction with the Telethon Institute for Child Health Research had added some weight to the theory after finding mice infected with helicobacter were less likely to develop asthma.

"The mechanism and association seem to there, so we just have to do the hard stuff now and take it to the next level," he said.