Public Release: 

Four gut bacteria decrease asthma risk in infants

University of British Columbia

New research by scientists at UBC and BC Children's Hospital finds that infants can be protected from getting asthma if they acquire four types of gut bacteria by three months of age. More than 300 families from across Canada participated in this research through the Canadian Healthy Infant Longitudinal Development (CHILD) Study.

"This research supports the hygiene hypothesis that we're making our environment too clean. It shows that gut bacteria play a role in asthma, but it is early in life when the baby's immune system is being established," said the study's co-lead researcher B. Brett Finlay, Peter Wall Distinguished Professor in the Michael Smith Laboratories and the departments of microbiology & immunology and biochemistry and molecular biology at UBC.

Asthma rates have increased dramatically since the 1950s and now affect up to 20 per cent of children in western countries. The discovery opens the door to developing probiotic treatments for infants that prevent asthma. The finding could also be used to develop a test for predicting which children are at risk of developing asthma.

The researchers analyzed fecal samples from 319 children involved in the CHILD Study. Analysis of the gut bacteria from the samples revealed lower levels of four specific gut bacteria in three-month-old infants who were at an increased risk for asthma.

Most babies naturally acquire these four bacteria, nicknamed FLVR (Faecalibacterium, Lachnospira, Veillonella, Rothia), from their environments, but some do not, either because of the circumstances of their birth or other factors.

The researchers also found fewer differences in FLVR levels among one-year-old children, meaning the first three months are a critical time period for a baby's developing immune system.

The researchers confirmed these findings in mice and also discovered that newborn mice inoculated with the FLVR bacteria developed less severe asthma.

"This discovery gives us new potential ways to prevent this disease that is life-threatening for many children. It shows there's a short, maybe 100-day window for giving babies therapeutic interventions to protect against asthma," said co-lead researcher Dr. Stuart Turvey, pediatric immunologist, BC Children's Hospital, director of clinical research and senior clinician scientist at the Child & Family Research Institute, Aubrey J. Tingle Professor of Pediatric Immunology at UBC.

The researchers say that further study with a larger number of children is required to confirm these findings and reveal how these bacteria influence the development of asthma.


The study was published today in in Science Translational Medicine.

Watch a video with the researchers: Video files are available for download, please contact Heather Amos at 604.828.3867.


-There are trillions of bacteria in the human body, and they play an important role in human health. In fact, there are 10 times as many bacterial cells in the human body as there are human cells.

-The CHILD Study involves over 3,500 children across Canada whom researchers are tracking from before birth to age five in order to identify the factors associated with developing allergy and asthma. The CHILD Study has recruiting centres at BC Children's Hospital in Vancouver, Women & Children's Health Research Institute in Edmonton, the University of Manitoba, and SickKids in Toronto with its national coordinating centre headquartered at McMaster University in Hamilton.


This research was supported by the Canadian Institutes of Health Research (CIHR). The CHILD Study is supported by the Allergy, Genes and Environment Network (AllerGen NCE Inc.), CIHR, Health Canada, Environment Canada, Canada Mortgage and Housing Corporation, and the Childhood Asthma Foundation. The researchers are supported by BC Children's Hospital Foundation, the University of British Columbia, Michael Smith Foundation for Health Research and Tula Foundation.

The Child & Family Research Institute conducts discovery, translational and clinical research to benefit the health of children and their families. CFRI is supported by BC Children's Hospital Foundation and works in close partnership with BC Children's Hospital, the Provincial Health Services Authority and its agencies, and the University of British Columbia. For more information, visit

BC Children's Hospital, an agency of the Provincial Health Services Authority, provides expert care for the province's most seriously ill or injured children, including newborns and adolescents. It is an academic health centre affiliated with the University of British Columbia, Simon Fraser University, and the Child & Family Research Institute. Sunny Hill Health Centre for Children is the provincial facility that offers specialized child development and rehabilitation services to children and youth. For more information, visit

AllerGen NCE Inc., the Allergy, Genes and Environment Network (est. 2004), is a national research network dedicated to improving the quality of life of people suffering from allergic and related immune diseases. Funded by Industry Canada through the federal Networks of Centres of Excellence (NCE) Program, the network is hosted at McMaster University in Hamilton. Visit for more information.

The University of British Columbia (UBC) is one of North America's largest public research and teaching institutions, and is consistently ranked among the world's 40 best universities. Surrounded by the beauty of the Canadian West, it is a place that inspires bold, new ways of thinking that have helped make it a national leader in areas as diverse as community service learning, sustainability and research commercialization. UBC offers more than 58,000 students a range of innovative programs and attracts $519 million per year in research funding from government, non-profit organizations and industry through over 8,000 projects and grants.

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