Source: Thailand Medical News Dec 17, 2019 5 years, 5 days, 7 hours, 57 minutes ago
Researchers from Washington University School of Medicine in St. Louis suggests there is a link between bacteria that live in the upper airway and the severity of
asthma symptoms among children with mild to moderate asthma.
The research raises the possibility that the airway's
microbiome could have a causal role in the severity of
asthma symptoms.
The research paves the way for future studies to discover whether altering the types of bacteria that live in the upper airway could help patients with
asthma.
The study findings were published in the journal Nature Communications.
Dr Avraham Beigelman, MD, an associate professor of pediatrics at Washington University and senior author told
Thailand Medical News, "There is an urgent need to develop better
asthma therapies for these patients. Though our study can't prove causation, it raises intriguing questions that we plan to pursue. If we somehow supplement such patients with what appear to be good bacteria, will they do better? We are interested in studying whether we can deliberately alter the airway
microbiome to reduce the risk of worsening
asthma symptoms."
Globally, about 300 million people are affected with
asthma and pediatric
asthma represents about 28 percent. It is the leading chronic pediatric disease and the No. 1 reason for missed school days, according to the
Asthma and Allergy Foundation of America.
The medical researchers found that children who experienced early warning signs that their
asthma was going to flare up were more likely to have bacteria associated with disease including Staphylococcus, Streptococcus and Moraxella bacterial groups living in their upper airways. In contrast, airway microbes dominated by Corynebacterium and Dolosigranulum bacteria were associated with periods of good health, when
asthma was well-controlled.
Dr Beigelman and his colleagues also found that children whose airway microbial communities switched from being dominated by Corynebacterium and Dolosigranulum bacteria to being dominated by Moraxella bacteria were at the highest risk of worsening asthma symptoms compared with children whose microbial communities made any other kind of shift.
Dr Yanjiao Zhou, MD, Ph.D., who conducted postdoctoral
microbiome and bioinformatics research at Washington University before joining the faculty at the University of Connecticut and first author of the study, commented, "Our data demonstrated a rapid change of the airway
microbiome in the children who transitioned from respiratory health to disease. It is also intriguing to find that the
microbiome changing pattern could play an important role in
asthma exacerbation. We are planning future studies to explore this possibility."
The study involving the upper airway
microbiome was conducted in conjunction with a clinical trial involving 214 children ages 5 to 11 with mild to moderate
asthma.
The trial called Step Up Yellow Zone Inhaled Corticosteroids to Prevent Exacerbations (STICS), was conducted as part of AsthmaNet, a national network of medical centers conducting
asthma research funded by the National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health (NIH). Washington University is an AsthmaNet site, and
asthma specialist and co-author of the current
microbiome study, Leonard B. Bacharier, MD, a professor of pediatrics at Washington University, led the pediatric portion of the STICS trial at Washington University.
The main clinical trial's purpose was to determine whether quintupling the dose of an inhaled corticosteroid at the first signs of worsening
asthma was better than keeping a low dose of the same medication. The trial found no benefit to the larger dose, and those results were published in The New England Journal of Medicine in 2018.
While during that trial, the researchers also collected nasal mucus samples from the children to study their upper airway
microbiomes. Samples were collected at the beginning of the trial, when all of the participants had controlled
asthma, as well as at the first early signs that
asthma control was slipping.
From these findings, Dr Beigelman and Dr Zhou said they plan to conduct studies in mice with carefully controlled airway microbiomes to see if the researchers can uncover a causal role for bacteria in asthma severity. In addition, such experiments could allow them to test different interventions that might deliberately alter the upper airway bacteria in a way that could be protective.
Reference : Zhou Y, Jackson D, Bacharier LB, Mauger D, Boushey H, Castro M, Durack J, Huang Y, Lemanske RF, Storch GA, Weinstock GM, Wylie K, Covar R, Fitzpatrick AM, Phipatanakul W, Robison RG, Beigelman A. The upper-airway microbiota and loss of asthma control among asthmatic children. Nature Communications. Dec. 16, 2019.
