VANCOUVER, British Columbia, Oct. 2 (UPI) -- Infants may be prevented from developing asthma if they acquire four types of gut bacteria in their first three months of life, researchers in Canada found in a new study.
The four bacteria -- faecalibacterium, lachnospira, veillonella, rothia -- are generally acquired by infants from their environment, but sometimes they aren't.
Researchers in the study suggest rates of asthma, which affects about 20 percent of children in Western countries, have increased because of the hygiene hypothesis.
"This discovery gives us new potential ways to prevent this disease that is life-threatening for many children," said Dr. Stuart Turvey, director of clinical research in the Child and Family Research Institute at the University of British Columbia, in a press release. "It shows there's a short, maybe 100-day window for giving babies therapeutic interventions to protect against asthma."
Fecal samples from 319 children involved in the CHILD study were analyzed for the four gut bacteria in 3-month-old children, focusing on 22 children who had low levels of the bacteria and showed symptoms of asthma such as wheezing when they were 1 year old. Most of them had developed the condition by the time they turned 3.
"What's become clear recently is that microbes play a major role in shaping how the immune system develops," Dr. Brett Finlay, a microbiologist at UBC, told NPR. "And asthma is really an immune allergic-type reaction in the lungs. And so our best guess is the way these microbes are working is they are influencing how our immune system is shaped really early in life."
Finlay said the study supports the hygiene hypothesis that "we're making our environment too clean," preventing the exposure to and acquisition of bacteria essential to the development of the human immune system.
The study is published in Science Translational Medicine.