Using live hookworms to combat diabetes may sound like a case of the treatment being worse than the disease, but researchers are hopeful their small trial will eventually lead to drugs to help people living with the condition.

Hookworms remain a problem for millions of people around the world but studies have also suggested that places with a lot of people living with the parasites also have fewer metabolic diseases such as type 2 diabetes.

So scientists at James Cook University used microscopic hookworm larvae to infect participants, and found a small dose was not only safe but improved people's glucose metabolism, reducing their level of insulin resistance.

Insulin helps regulate blood sugar levels, and insulin resistance occurs when cells have trouble responding to the hormone and struggle to take glucose from the blood.

Consistently high blood sugar levels can lead to pre-diabetes and type 2 diabetes, which is linked to rising obesity rates.

The university recruited 40 people who had risk factors for developing metabolic diseases such as heart disease and type 2 diabetes, and exposed them to the human hookworm species Necator americanus or a placebo.

Necator hookworms are well adapted to humans and affect people across Africa, Asia and the Americas, causing problems such as anaemia and malnutrition.

Humans usually contract them when larvae burrow through the skin after contact with contaminated dirt.

From there they make their way into the bloodstream, the lungs and then the gut.

To mimic this, the Queensland researchers dripped water containing 20 or 40 larvae on participants' forearms.

"Metabolic diseases are characterised by inflammatory immune responses and previous studies have suggested that hookworms release proteins into their host to control the immune system and safeguard their survival," said Doris Pierce from the university's Australian Institute of Tropical Health and Medicine.

Dr Pierce said participants exposed to 20 hookworm larvae found their level of insulin resistance almost halving to a normal, healthy range in a year, with their median Homeostatic Model Assessment of Insulin Resistance level falling from 3.0 units to just 1.8 units.

JCU senior research fellow and immunologist Paul Giacomin said the trial showed infection with live hookworms was safe and appeared to lead to some improvements in people's metabolic health.

Dr Giacomin said trial results warranted follow-up studies and hoped they would be confirmed by larger international clinical trials in future.

And mindful that few people would find absorbing live hookworms appealing, the scientists hope to learn more about what the parasites release into the body so scientists can design protein-based treatments that copy their effects.