Early exposure to antibiotics could increase the risk of developing asthma, according to new research from Australia’s Monash University. The research team has isolated a molecule produced by gut bacteria that could in future be tested as a simple treatment in the form of a nutritional supplement for children at risk of developing asthma to prevent them from developing the disease.
The research, published on July 15 in the journal Immunity, was led by Monash University immunologist Professor Ben Marsland. The team discovered a molecule called APA that is crucial for long-term protection against asthma, which affects more than 260 million people worldwide and causes an estimated 455,000 deaths each year.
According to Professor Marsland, the discovery of the molecule, produced by healthy gut bacteria, provides an explanation for why frequent antibiotic users have an increased risk of asthma.
“We know that frequent antibiotic use early in life disrupts healthy gut microbes and increases the risk of allergies and asthma,” Marsland says, according to EurekAlert. “We discovered that one consequence of antibiotic treatment is a reduction in the bacteria that produce APA, thereby reducing a key molecule that can prevent asthma.”
The first years of life are important for developing a stable gut microbiome, Marsland said. “This is shaped primarily by diet, whether milk or solid foods, as well as genetics and environment,” he explained. “It has been shown that infants at high risk for allergies and asthma have delayed and disrupted maturation of their gut microbiome.”
“Antibiotic use in the first year of life can have the unintended effect of reducing health-promoting bacteria,” he added. “We now know from this research that antibiotics lead to a reduction in the amount of ABI, which we found is critical in early life as our lung cells mature, making it a candidate for early prevention of allergic airway infections.”
Asthma protection
The research team, which worked on mice prone to asthma, explained that when given antibiotics in early childhood, the mice were more susceptible to allergic inflammation in the airways caused by house dust mites, and this continued into adulthood.
This sensitivity was found to persist long-term even after gut microbes and ABI levels had returned to normal, suggesting that the function of this molecule was particularly important in early life.
When these mice were fed a diet enriched with APA in early life, the researchers found that the mice were virtually free from developing house dust mite-induced allergic airway inflammation or asthma in adulthood.