by: Michael Kabel 

    Babies given antibiotics during their first 12 months are 1.5 times more likely to develop asthma by age 7, according to a new study by The University of Manitoba.
    The findings, published in the June 2007 medical journal Chest, present new evidence in the ongoing debate about how much effect antibiotic course treatment has on children and asthma. Various other studies have yielded often-contradictory results, with experts remaining divided on a clear conclusion.

The Manitoba Study
    Researchers in the Manitoba study say children considered low risk, born to mothers with no history of asthma, were likely to develop asthma after completing even one course of antibiotics. The link held even when other risk factors, such as environment or allergies, were taken into account. 
    The study was performed by monitoring a prescription database for use of antibiotics in over thirteen thousand children between the ages of birth to seven years old. Researchers paid especially close attention to children given antibiotics in their first year and the later emergence of asthma. A separate, one page questionnaire was also given to parents that included questions regarding the infants' exposure to cigarette smoke and irritants such as pet dander. 
    Common reasons for prescribing antibiotics to children include symptoms common to asthma sufferers. The Manitoba study found antibiotics were given for respiratory infections such as bronchitis, ear and throat infections, and in some cases nonrespiratory-related problems such as skin rashes. 
    Study researcher Anita Kozyrskyj, PhD, told WebMd that one possible explanation involves antibiotics killing many of the natural, healthy bacteria in a child's digestive tract. These microflora are later used to boost the child's immune system and fend off asthma. She cautions that asthma is a complicated disease, however, partly genetic in nature, so finding an exact explanation for the link is complicated.

Other Studies Show Varying Results
    A separate report issued in 2006 analyzed the findings of five similar studies and found that children taking antibiotics their first year were more than twice as likely to develop asthma, compared to children who received no antibiotics at all during that same time frame. Still, some experts point to other factors, such as flawed parental recall or parental bias, as a possible explanation for the results.

The Asthma Epidemic
New diagnoses of children with asthma are reaching epidemic levels in the United States, with one in eight children now reported as having the disease. Some experts are coming forward with a "hygiene hypothesis," which blames increasingly sterile environments in homes and schools. These antiseptic conditions purportedly deprive the children's immune system a chance to grow robust and fight off infection.  

Options for Parents
Parents concerned about antibiotic use in treating their child's problems can request that only very narrow spectrum antibiotics be used to treat their child's infection. This class of antibiotics kills only very specific kinds of bacteria, and could possibly lower the asthma risk. In some cases, researchers admit, the need for the antibiotic may be very pressing, even necessary.