Clinical implications of nicotine as an antimicrobial agent and immune modulator

Abstract

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.

Keywords: Anti-microbial activity; Immune response; Microbiome; Nicotine.

Graphical abstract

Fig. 1

(Panel A) Dose-dependent growth inhibition of the following bacteria: Escherichia coli, Klebsiella pneumoniae, Listeria monocytogenes, and viridans Streptococci by nicotine. Organisms were mixed with nicotine in vitro and cultured onto blood agar. After re-incubation, colony-forming units (CFU) of the number of surviving bacteria were counted. Each data point represents the mean value of 3 replicate experiments. (Panel B) Dose-dependent growth inhibition of the following bacteria and fungi: Staphylococcus aureus, Mycobacterium phlei and Candida albicans. Organisms were mixed with nicotine in vitro and cultured onto blood agar. After re-incubation, CFU of the number of surviving organisms were counted. Each data point represents the mean value of 3 replicate experiments.