Effects of exposure to smoking on the microbial flora of children and their parents

This review presents our studies that investigated the effects of exposure to direct and indirect smoking on the colonization with pathogenic bacteria and organisms that interfere with their growth. The flora of smokers (S) contained less aerobic and anaerobic organisms with interfering capability and more potential pathogens as compared with non-smokers (N-S). The high number of pathogens and the low number of interfering organisms found in the nasopharynx of smokers revert to normal levels after complete cessation of smoking. A high recovery rate of potential pathogens and low number of interfering organisms were observed in otitis media prone (OMP) children. This was not related to their parents smoking habits. The flora of S parents contains more potential pathogens that are similar to the one recovered from their OMP children, and less interfering organisms as compared to N-S parents. Parents that smoked were more often colonized by potential pathogens than parents that did not smoke. The flora of healthy children of S parents contained high number of potential pathogens similar to the one found in their parents and OMP children. Concordance with pathogens in the parent was high among the OMP children of S parents but this was not observed in OMP children of N-S. A higher recovery rate of potential pathogenic organisms was observed in OMP children of both S and N-S parents, as compared to healthy children whose parents were N-S. Since S parents harbor more potential pathogens and less interfering organisms they may serve as a source of pathogens that can colonize and/or infect their children. These studies illustrate the adverse effects of direct and indirect exposure to smoking on colonization with potential pathogens.