The hygiene hypothesis contends that fewer opportunities for infection have led to increases in the prevalences of asthma and other allergic diseases.
This study evaluated the association between asthma, wheeze, and hay fever and antibodies to 2 oral bacteria associated with periodontal disease.
Data were obtained from the Third National Health and Nutrition Examination Survey. Serum levels of IgG antibodies to Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis were quantified by enzyme-linked immunoassays in 9385 subjects age 12 years and older. The outcomes were current asthma, wheeze, and hay fever. Odds ratios (ORs) representing a 1–log-unit increase in IgG concentrations were estimated with logistic regression. ORs were adjusted for 8 confounders and weighted to represent the US population.
For each disease outcome, geometric mean antibody concentrations were higher in persons without the disease outcome than with the disease outcome. For a 1–log-unit increase in P gingivalis antibody concentration, adjusted ORs were 0.41 (95% CI, 0.20-0.87) for asthma, 0.43 (0.23-0.78) for wheeze, and 0.45 (0.23-0.93) for hay fever. For A actinomycetemcomitans, those ORs were 0.56 (0.19-1.72), 0.39 (0.17-0.86), and 0.48 (0.23-1.03), respectively.
Consistent with the hygiene hypothesis, higher concentrations of IgG antibodies to P gingivalis were significantly associated with lower prevalences of asthma, wheeze, and hay fever, and higher concentrations of IgG antibodies to A actinomycetemcomitans were significantly associated with a lower prevalence of wheeze.
Colonization of the oral cavity by bacteria and other microbes might play a protective role in the etiology of allergic disease.