Exploring the Microbial Diversity and Composition of Three Cigar Product Categories

Abstract

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.

Keywords: 16S rRNA gene amplicon sequencing; Cigar; Cigarillo; Filtered cigar; Microbiome.

Fig. 1

Alpha diversity (a) Observed richness (b) Shannon diversity by product category (Lines connecting box plots indicate significant difference using the Dunn test. (** P < 0.01; *P < 0.05). Filtered cigars showed lower observed richness and Shannon diversity compared to large cigars and cigarillos, with large cigars having the highest measure of alpha diversity

Fig. 2

Principal component analysis (PCoA) of Bray–Curtis distances between cigar samples of different product categories. The ellipse is drawn at a 90% confidence level. PCoA analysis indicated significant differences in beta diversity measures between the three cigar categories

Fig. 3

Core and shared microbiome in different categories in (a) Phylum level showing in each category in percentage (b) Genus level similarity and specific to each category in Venn diagram

Fig. 4

Stacked bar chart showing the percentage of the dominant top 20 genera within the microbial population of each filtered cigar sample

Fig. 5

Stacked bar chart showing the dominant top 20 genera of each cigarillos

Fig. 6

Stacked bar chart showing the dominant top 20 genera of each large cigar