Antibiotics linked to huge rise in allergies
Report on the research of Gary Huffnagle at the University of Michigan in Ann Arbor and his report presented at the American Society for Microbiology general meeting in New Orleans, May, 2004 

Could it be that a life-saving medicine is also causing problems for our long-term health? So says Gary Huffnagle whose research group at the University of Michigan in Ann Arbor has uncovered experimental evidence that antibiotics upset the regular function of bacteria in the stomachs of laboratory mice. This, in turn, leads to a malfunction of the immune system which depends upon these bacteria to perform an important function.

"The microbial gut flora is an arm of the immune system," says Huffnagle. He links the use of antibiotics with the increasing prevalence of asthma and allergies. Somehow, the immune system uses the bacteria in our guts to distinguish between harmless chemicals and harmful diseases. This may result, for example, in an immune response to harmless pollen grains or the yeast in bread.

There is no doubt that asthma and allergies are on the rise. The last two decades have seen a 1.6 times increase in the rates of asthma. This problem is now greater in the young than in the old. Statistical studies of population groups reveal that the use of antibiotics coincides with allergies and asthma, though this was not a necessarily causative link. One study in Detroit, Michigan, showed that children given antibiotics in the first six months of life were 2.6 times more likely to develop allergic asthma. Another study in Berlin, Germany, revealed the effects of antibiotics by comparing East Germany with West Germany since the East used antibiotics far less frequently. Since the reunification, asthma rates have risen in the East to match the west. This is extremely useful data since the populations are very similar genetically and live in a nearly identical environment.

Huffnagle has now added experimental support for this hypothesis. His laboratory used mice to show how a course of antibiotics resulted in increased sensitivity to harmless yeast found in the environment as compared with a control group. Since the bacteria in the stomach of the mice was killed by the antibiotics, somehow, the mice's immune system was subsequently unable to ignore the foreign chemicals that the yeast presented. Presumably, allergies can develop while one is taking antibiotics. These allergies can last a lifetime as long as exposure to the allergen continues. And for most of us, eliminating exposure to pollen, and other allergens, is impossible unless we happen to live above the arctic circle.

Huffnagle concluded that, after taking antibiotics, "Suddenly, your ability to ignore a mold spore has gone." His lab repeated the experiment with a different breed of mice and a different allergen to ensure the results were not peculiar to any single defect in a single mouse breed's genome.

Though we are not yet sure how the bacteria in our stomachs may influence our immune system's ability to ignore harmless molecules, at least we are sure that the statistical epidemiological link is causative. So, what should we do with this information? We should make sure to avoid antibiotic use unless absolutely necessary to preserve life. Otherwise, we alleviate temporary suffering at the expense of a lifetime of agonizing allergies... and possibly fatal autoimmune diseases. In addition, if antibiotics are deemed necessary, they should be followed, after antibiotics have stopped, with probiotic tablets to reestablish good bacteria in the stomach.