Relationship between acetaldehyde concentration in mouth air and characteristics of microbiota of tongue dorsum in Japanese healthy adults: a cross-sectional study

Abstract

Acetaldehyde, associated with consumption of alcoholic beverages, is known to be a carcinogen and to be related to the tongue dorsum. Objective The aim of this study was to investigate the relationship between acetaldehyde concentration in mouth air and bacterial characteristics on the tongue dorsum. Methodology Thirty-nine healthy volunteers participated in the study. Acetaldehyde concentrations in mouth air were evaluated by a high-sensitivity semiconductor gas sensor. A 16S rRNA gene sequencing technique was used to compare microbiomes between two groups, focusing on the six samples with the highest acetaldehyde concentrations (HG) and the six samples with lowest acetaldehyde concentrations (LG). Results Acetaldehyde concentration increased in correlation with the increase in bacterial count (p=0.048). The number of species observed in the oral microbiome of the HG was higher than that in the oral microbiome of the LG (p=0.011). The relative abundances of Gemella sanguinis , Veillonella parvula and Neisseria flavescens in the oral microbiome of the HG were higher than those in the oral microbiome of the LG (p<0.05). Conclusion Acetaldehyde concentration in mouth air was associated with bacterial count, diversity of microbiome, and relative abundance of G. sanguinis , V. parvula , and N. flavescens .

A review of constituents identified in e-cigarette liquids and aerosols

“…Acetaldehyde, a known toxicant identified in several e-liquids and aerosols, increases the reinforcing effects of nicotine and has been shown to have reinforcing effects itself. It also can alter the oral microbiome, which may result in poor oral hygiene and downstream negative health impacts 43 . Nicotine increases the risks of cardiovascular, respiratory, and gastrointestinal disorders, lowers the human immune response, can harm reproductive health, and can lead to cancer.…”

Acetaldehyde as a Food Flavoring Substance: Aspects of Risk Assessment

“…Studies investigating the role of the oral cavity microbiome in acetaldehyde production revealed an association between acetaldehyde levels in the oral cavity air and bacterial counts, bacterial diversity, and relative abundance of Gemella sanguinis , Veillonella parvula , and Neisseria flavescens . [ 56 ] In esophageal cancer patients, dental hygiene was reported to reduce bacterial counts and acetaldehyde levels in the oral cavity air. [ 57 ] Alcohol consumption has also been demonstrated to influence the oral cavity microbiome, [ 58 ] and there appears to be an association between alcohol consumption, poor oral cavity health status, and increased acetaldehyde levels.…”

The microbiome in the pathogenesis of lung cancer

“…However, some microbial metabolites are classified as carcinogens. For example, acetaldehyde produced by bacteria is an important carcinogen [78]. Circulating metabolites from the gut microbiome are known to facilitate the development of tumors by altering the availability of metabolites and promoting DNA damage.…”