The role of microbes in childhood infections and asthma

Lay summary by Leo Gnatovskiy

You have probably heard about the importance of washing your hands and brushing your teeth to kill harmful microbes and avoid getting sick. What you may not realize is that your body is home to an astounding number of beneficial microbes. Trillions of these microscopic residents populate our skin, nest in our mouth, and inhabit our stomach and intestines. This is our “microbiome”. It helps us digest our food and protect us against harmful invading viruses and bacteria. Because of its significant impact on health and disease, scientists now recognize it as a separate organ. Scientists today are discovering startling insights about our well-being and disease by studying human microbial makeup, and how it changes in people with diseases such as diabetes and infections.

In this study, Australian, British and American scientists investigated the microbiome of the nasal passages during a child’s critical first year of life. They were particularly interested in nasal microbiome’s contribution to infections and asthma. The nose provides a kind of passageway for invading viruses and harmful bacteria that cause infections in the airways. Infections such as pneumonia, which reaches down into the lungs, can be especially deadly in children, and can predispose them to asthma that frequently progresses to chronic asthma in adults.

To address these questions, the authors profiled the microbial and viral makeup of 234 children using a technique that allows them to document different kinds of microbes by obtaining gene sequences unique to different microbes and viruses. Nurses collected samples from the children at 2, 6, and 12 months of age, by washing out the snot from their nasal passages. Additionally, they collected microbiome samples within 2 days anytime the child showed signs of respiratory infection. Afterwards, by examining associations between the microbes found in the noses of healthy children and during infections, the authors determined which microbes contributed to more serious infections and the development of asthma. Researchers also looked at factors such as delivery mode, breastfeeding, presence of brothers or sisters, day care attendance, and antibiotic use, to examine possible impacts of the environment on the nasal microbiome.

This research will help scientists and doctors to figure out alternative treatments for serious infections and ways to prevent the development of chronic asthma. In future studies, scientists want to figure out in more detail the consequences of antibiotic use. Researchers believe that by killing off certain microbes, antibiotics can create space for other microbes to thrive. In this fashion, antibiotics can change the microbiome makeup that potentially leads to serious infections and asthma later in life.

For further information

Read the Cell Host and Microbe original research article which this summary is based on The Infant Nasopharyngeal Microbiome Impacts Severity of Lower Respiratory Infection and Risk of Asthma Development (May 2015).

Visit the profile of the research ambassador, Leo Gnatovskiy, who wrote this summary.

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