Asthma risk in infants may be reduced by gut bacteria

The finding is part of a larger research project for the Canadian Healthy Infant Longitudinal Development (CHILD) Study, which began in 2007 by recruiting 4,000 pregnant women across Canada. Analyzing fecal samples from babies from Vancouver, Edmonton, Manitoba and Toronto, the researchers found that children treated with antibiotics before the age of 1 were more likely to have increased asthma risk. These bacteria are nicknamed FLVR (Faecalibacterium, Lachnospira, Veillonella, Rothia).

The study found few differences in levels of the four microbes in samples from 12-month-old children, showing that the first three months of a person’s life are a critical period in the development of the immune system, the researchers said. The kids who had lower levels of FLVR when they were three months old somehow gained normal levels of them by the time they turned one, making their gut microbiota virtually indistinguishable from their non-wheezy peers.

To test their findings, the Canadian researchers injected the FLVR bacteria into one set of lab mice.

They could also lead to new ways to diagnose and perhaps prevent asthma, which has been sharply on the rise in developed countries for reasons that are still unclear, but are thought to include a reduction in exposure to microbes. By this they mean scientists may be able to design a “friendly bacteria” cocktail to be given to children at high risk of asthma, which could reduce their chances of getting allergies and asthma. “But this study and others like it emphasize that we’ve evolved with bacteria and they’re really important for our health”.

Asthma rates have increased dramatically since the 1950s and now affect up to 20 per cent of children in western countries. “It shows there’s a short, maybe 100-day window for giving babies therapeutic interventions to protect against asthma”, lead researcher Stuart Turvey, of British Columbia Children’s Hospital, said. Furthermore, the study has no clear evidence that the absence of those four bacteria species actually prevented asthma.

Turvey cautioned that treatment with bacteria is a long way off. “We are not ready for that yet”, he said.

“That’s important because that sets the scene for the next steps, when we think about using these bacteria as a way to prevent asthma in the future”.

Doctors are still unsure how these bacteria develop naturally in the immune system.

According to the Centers for Disease Control and Prevention, asthma is a disease that affects the lungs and causes repeated episodes of wheezing, breathlessness, chest tightness, and nighttime or early morning coughing.

Then, the scientists need to determine which microbes would be best for a probiotic therapy, and whether such a treatment would be safe and effective, the researchers said.

Mice inoculated with bacteria from a baby in the high risk group had offspring with severe lung inflammation.

Another 297 children from the study group had significantly higher numbers of the microbes in their guts, and were not considered to be at risk according to a range of test results.