New research shows that babies who lack certain "good" bacteria in their intestines in the first months of life may be at higher risk of asthma.
The study, published Wednesday in the journal Science Translational Medicine, identified four specific bacteria that experts think may protect children from developing asthma.
In the study, researchers at the University of British Columbia tracked health records of 319 children from birth to age 3, and analyzed stool samples taken during infancy to check their gut bacteria.
The first clue: There were 22 youngsters deemed very high risk because of early asthma warning signs — and at 3 months of age, all of them harbored much lower levels of the four specific gut bacteria than the other babies.
That doesn't prove the missing bugs are protective. But the researchers infected germ-free mice with an at-risk tot's stool sample alone, or with a supplement of the four "good'' bacteria. Restoring the missing bugs markedly reduced airway inflammation in the mice's offspring, they reported.
Doctors are still unsure how these bacteria develop naturally in the immune system. But stool samples from one-year-olds didn't show much difference between the at-risk group and the rest, suggesting the first three months of life may be a critical time period, the researchers concluded.
They speculated that cesarean section deliveries, antibiotics and use of formula instead of breast milk could have some effect on which good bacteria develop.
Wednesday's study raises the provocative possibility of one day altering tots' buildup of protective bugs, maybe through probiotics.
"I want to emphasize that we're not ready for that yet,'' cautioned study co-author Dr. Stuart Turvey, a pediatric immunologist at the University of British Columbia and BC Children's Hospital. But a "vision for the future would be to prevent this disease.''
The British Columbia team has already begun testing samples from 500 more babies who are enrolled in a larger Canadian study exploring factors in the development of allergy and asthma.
Medical experts say asthma is on the rise in recent decades, particularity in Western nations. The disease causes wheezing, breathing problems and coughing, and in some cases can be fatal.
Some information for this report came from AP.