Waterpipe Tobacco Chemical Content, Microbial Contamination, and Genotoxic Effects: A Systematic Review.

The spread of tobacco smoking has increased over time at the global and national levels. One of the widely spread tobacco products is waterpipe. Recent studies showed that waterpipe tobacco smoke contains toxic substances, including carbon monoxide and nicotine. Some of them are genotoxic carcinogen, such as formaldehyde. This study aims to provide comprehensive insight into the types and depth of the scientific literature on waterpipe tobacco smoke chemical content, its genotoxic effects, and waterpipe device microbial contamination. We conducted a systematic comprehensive review of articles published between 1986 and December 2018. Primary research articles focusing on the content of waterpipe smoke, including chemical, genotoxic, and microbial contaminants, were eligible for inclusion. Of the 1,286 studies generated, 22 studies were included. Twenty-three chemical families were extracted from waterpipe smoke. Aldehydes were the most identified chemical family in 6 studies, and next is polycyclic hydrocarbons, found in 5 studies. About 206 chemical compounds were identified. Flavobacterium, Pseudomonas, coagulase-negative Staphylococci, and Streptococcus were the most abundant pathogen contaminants. Waterpipe smoke had elevated levels of many DNA damage markers (8-hydroxy-2'-deoxyguanosine and cytochrome P450 1A1) and inhibited levels of many DNA repair genes (OGG1 and XRCC1) in waterpipe smokers. Waterpipe smoke is associated with the genotoxic effect, which elevates the levels of many DNA damage markers and inhibits the levels of many DNA repair genes. In addition, waterpipe smoking can expose smokers to a range of pathogenic bacteria.

Types of tobacco consumption and the oral microbiome in the United Arab Emirates Healthy Future (UAEHFS) Pilot Study.

Cigarette smoking alters the oral microbiome; however, the effect of alternative tobacco products remains unclear. Middle Eastern tobacco products like dokha and shisha, are becoming globally widespread. We tested for the first time in a Middle Eastern population the hypothesis that different tobacco products impact the oral microbiome. The oral microbiome of 330 subjects from the United Arab Emirates Healthy Future Study was assessed by amplifying the bacterial 16S rRNA gene from mouthwash samples. Tobacco consumption was assessed using a structured questionnaire and further validated by urine cotinine levels. Oral microbiome overall structure and specific taxon abundances were compared, using PERMANOVA and DESeq analyses respectively. Our results show that overall microbial composition differs between smokers and nonsmokers (p = 0.0001). Use of cigarettes (p = 0.001) and dokha (p = 0.042) were associated with overall microbiome structure, while shisha use was not (p = 0.62). The abundance of multiple genera were significantly altered (enriched/depleted) in cigarette smokers; however, only Actinobacillus, Porphyromonas, Lautropia and Bifidobacterium abundances were significantly changed in dokha users whereas no genera were significantly altered in shisha smokers. For the first time, we show that smoking dokha is associated to oral microbiome dysbiosis, suggesting that it could have similar effects as smoking cigarettes on oral health.