Australian scientists unveiled a "radical" approach that could revolutionise asthma treatment at a research conference in Canberra on Monday.
The research, described as a "world first", used subtle changes in diet to help keep the respiratory disease under control.
It was presented for the first time at the annual meeting of the Thoracic Society for Australia and New Zealand.
"This is the first time anyone has looked at the impact of altering the gut microbiome on asthma control in humans," the society's president Professor Peter Gibson said.
"We're at the tip of a new paradigm for how diet can be used to treat asthma."
Asthma is a chronic lung condition that affects more than two million people throughout Australia and at least 300 million across the globe.
It is projected that between 2016 and 2019 the treatment of asthma will cost the Australian taxpayer at least $4 billion.
The study, led by the University of Newcastle's Priority Research Centre for Healthy Lungs, used fibre supplements to change the composition of bacteria in the gut.
These changes were associated with reduced airway inflammation and had a beneficial effect on asthma control.
They were particularly effective in groups of asthmatics who struggled to control the disease, such as those who were overweight or obese.
"For many obese asthmatics, using puffers to control their asthma simply isn't working and it has doctors baffled," Professor Gibson said.
"With almost two out of three adult Australians obese or overweight, this is becoming an increasingly pressing issue.
"These studies - which shed light on how diet can impact asthma by its effect on the gut microbiome and airway inflammation - hold particular significance for this group."
Professor Lisa Wood, the study's lead researcher, said the breakthrough could have a massive impact on the way asthma was treated.
"This ground-breaking research offers hope of a viable, complementary treatment for tens of millions of asthmatics around the world struggling to control their asthma with existing medications," she said.
Another study presented at the conference probed the effect of fatty foods on asthma, showing that meals high in saturated fats could worsen inflammation and bring on symptoms such as coughing and chest tightness.
"These studies show both how diets high in fat can worsen asthma and how, conversely, a diet high in soluble fibre can help manage it," Professor Wood said.
"It illustrates just how vitally important it is that Australians eat healthily and how fundamentally important gut bacteria are to our well being."
