Exploring the Microbial Diversity and Composition of Three Cigar Product Categories.

Cigars and cigarillos are emerging as popular tobacco alternatives to cigarettes. However, these products may be equally harmful to human health than cigarettes and are associated with similar adverse health effects. We used 16S rRNA gene amplicon sequencing to extensively characterize the microbial diversity and investigate differences in microbial composition across 23 different products representing three different cigar product categories: filtered cigar, cigarillo, and large cigar. High throughput sequencing of the V4 hypervariable region of the 16 s rRNA gene revealed 2124 Operational Taxonomic Units (OTUs). Our findings showed that the three categories of cigars differed significantly in observed richness and Shannon diversity, with filtered cigars exhibiting lower diversity compared to large cigars and cigarillos. We also found a shared and unique microbiota among different product types. Firmicutes was the most abundant phylum in all product categories, followed by Actinobacteria. Among the 16 genera shared across all product types were Bacillus, Staphylococcus, Pseudomonas, and Pantoea. Nine genera were exclusively shared by large cigars and cigarillos and an additional thirteen genera were exclusive to filtered cigars. Analysis of individual cigar products showed consistent microbial composition across replicates for most large cigars and cigarillos while filtered cigars showed more inter-product variability. These findings provide important insights into the microbial diversity of the different cigar product types.