Antibiotic Use in 1st Year Might Boost Asthma Risk

The use of antibiotics in the initial year of life is associated with an elevated risk for asthma at age 7, a new study has found, and the reason may be that antibiotics destroy not merely disease-causing microbes, but also those which are beneficial towards the developing immune system.
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Antibiotic use had a higher impact on kids who would otherwise be regarded as at lower risk - children who lived in rural locations and those whose mothers didn't have asthma - than on those who were already at increased risk because of an urban environment or genetic predisposition.

Studies of antibiotic use and asthma have been complicated. Simply because antibiotics are used to treat respiratory illnesses, which are typically precursors of asthma, it has been tough to decide the effect of antibiotics alone. But this study, of 13,116 Canadian children, found that the risk of asthma increased even in kids treated with antibiotics for nonrespiratory illnesses within the 1st year of life. The study appears within the June issue of Chest.

Anita L. Kozyrskyj, the lead author and an associate professor of pharmacy at the University of Manitoba, stated the findings supported what scientists call the microflora hypothesis - that “you require very good bacteria within your digestive tract for regular development of the immune system to ensure that you don’t end up with asthma,” as she put it.

The researchers tracked medications by examining prescription records, and determined asthma status by therapy for asthma or any asthma drug use within the year following the seventh birthday. Six percent of the children developed asthma by age 7.

After statistically adjusting for respiratory and nonrespiratory illnesses, sex, maternal history of asthma, urban or rural location as well as other factors, researchers identified that 1 or two courses of antibiotics inside the very first year of life increased the risk of asthma by about 20 percent.

The far more frequent the antibiotic use, the greater the risk. Three to 4 courses of medicine conferred a 30 percent added risk, and more than four courses of antibiotics elevated the risk by virtually 50 percent.

The findings were stronger for the use of broad-spectrum antibiotics like the cephalosporins and amoxicillin than they had been for narrow-spectrum drugs like penicillin and erythromycin. “Lactobacilli, for example, are a lot more affected by the broad-spectrum drugs,” Dr. Kozyrskyj said, referring towards the useful bacteria contained in yogurt.

In a secondary locating making use of a little portion of the sample population, researchers discovered that among youngsters who had numerous courses of antibiotics in infancy, people who lived with no dog in the house had twice the risk of asthma compared with those who lived with one. The factors are not clear, but it may be that getting less contact using the germs that dogs carry results in lower microbial loads, producing a child far more sensitive to antibiotics. Dr. Kozyrskyj stated in an interview that she found no decreased risk with the presence of cats or other pets.

Jeroen Douwes, a professor of epidemiology at Massey University in New Zealand who has published widely on asthma in children but was not involved in this function, cited the study’s powerful methodology. “They had quite very good data on antibiotic use during the first year of life, and that’s actually very rare,” he said. “They measured exposure just before the disease occurred, while in most studies you need to rely on people’s recollections.”

The authors acknowledged that their findings don't conclusively confirm that antibiotic use is actually a trigger of asthma, and that further function could be required to sort out the associations among the composition of normal intestinal bacteria, antibiotic use, childhood allergies along with the development of the illness.

Dr. Kozyrskyj said this did not mean that antibiotics really should be avoided. “During the very first year of life, if there’s a severe infection, antibiotics are suitable,” she stated. “But broad-spectrum antibiotics possibly increase the risk for asthma. It is excellent clinical practice to start with the narrow-spectrum drugs first and then attempt the broad spectrum.”