Clinical implications of nicotine as an antimicrobial agent and immune modulator.

Nicotine is perhaps the most important and potent, pharmacologically active substance in tobacco products. This commentary examines the possible effects that nicotine has on microbial viability and also on the host's immune system as it responds to the indigenous microflora (the microbiome) due to nicotine-induced changes to the indigenous microbial environment and any associated antigenic stimulation / immunization that may occur. To our knowledge, the analysis of such profound microbiologic changes attributable to a tobacco-related product, such as nicotine, has not been fully explored in the context of its consequences on the viability of the microbiome/microbiota and on some of the host's basic physiologic processes, such as the immune response, and its possible association on the induction and persistence of certain immunologically related diseases. Future studies should be aimed at uncovering the molecular mechanisms involved in such interactions, especially in the context of manipulating them for therapeutic purposes.