The Effect of Mouthwash in Oral Microbiome: A Literature Review

Abstract

The oral microbiome contains over seven hundred bacterial species as well as fungi, viruses, archaea, and protozoa. The complex equilibrium between resident species in the oral cavity is responsible for the maintenance of a healthy state or a state associated with disease. Mouthwash has also been shown to reduce plaque and gingivitis. The purpose of this article is to update our current knowledge of the effect of mouthwash in oral microbiome and to discuss the impact of mouthwash on changes in the oral microbiome. The article was conducted of two databases and were limited to period January 2019 to May 2024 with combination of the following keywords: “oral microbiome” associated by the Boolean operator AND. The results obtained were 11 articles found at the beginning of the search in both databases, and the 6 full text articles were selected for further review and discussion. Commensal, gingivitis and halitosis associated species were significantly reduced by twice daily use of LCM (Listerine Cool Mint) or ACPM (alcohol-containing prototype mouthrinse). The AFPM (alcohol-free prototype mouthrinse) group showed no statistically significant reductions. Its microbiological action is not due to selective killing of pathogenic bacteria but rather via a reset mechanism, in which the plaque microbiome composition is shifted to a healthier state after repeated use. CHX (Chlorhexidine) led to an increase in the abundance of some genera such as Neisseria, Streptococcus and Granulicatella, and lowered the abundance of Actinomyces, but did not affect the abundance of Veillonella. The effect of mouthwash in oral microbiome are short-term and long-term impacts on supragingival plaque microbiome, return from dysbiosis to healthier levels, increasing abundance of common oral opportunistic bacteria, reduce the oral pathogenic microbial load in healthy subjects.