title: Cleansing effect of acidic L-arginine on human oral biofilm.
abstract: BACKGROUND
  Dental plaque formed on tooth surfaces is a complex ecosystem composed of diverse oral bacteria and salivary components. Accumulation of dental plaque is a risk factor for dental caries and periodontal diseases. L-arginine has been reported to decrease the risk for dental caries by elevating plaque pH through the activity of arginine deiminase in oral bacteria. Here we evaluated the potential of L-arginine to remove established oral biofilms.
  
  
  METHODS
  Biofilms were formed using human saliva mixed with Brain Heart Infusion broth supplemented with 1 % sucrose in multi-well plates or on plastic discs. After washing the biofilms with saline, citrate (10 mM, pH3.5), or L-arginine (0.5 M, pH3.5), the retained biofilms were analyzed by crystal violet staining, scanning electron microscopy, and Illumina-based 16S rDNA sequencing.
  
  
  RESULTS
  Washing with acidic L-arginine detached oral biofilms more efficiently than saline and significantly reduced biofilm mass retained in multi-well plates or on plastic discs. Illumina-based microbiota analysis showed that citrate (pH3.5) preferentially washed out Streptococcus from mature oral biofilm, whereas acidic L-arginine prepared with 10 mM citrate buffer (pH3.5) non-specifically removed microbial components of the oral biofilm.
  
  
  CONCLUSIONS
  Acidic L-arginine prepared with citrate buffer (pH3.5) effectively destabilized and removed mature oral biofilms. The acidic L-arginine solution described here could be used as an additive that enhances the efficacy of mouth rinses used in oral hygiene.
authors.affiliation: Department of Microbiology, Faculty of Medicine, Kagawa University, 1750-1, Miki, Kagawa, 761-0793, Japan.|Department of Dental Oral Surgery, Faculty of Medicine, Kagawa University, 1750-1, Miki, Kagawa, 761-0793, Japan.
authors.forename: Ayano
authors.initials: A
authors.lastname: Tada
authors.affiliation: Department of Microbiology, Faculty of Medicine, Kagawa University, 1750-1, Miki, Kagawa, 761-0793, Japan.
authors.forename: Haruyuki
authors.initials: H
authors.lastname: Nakayama-Imaohji
authors.affiliation: Department of Cellular and Molecular Medicine, Wakayama Medical University Graduate School of Medicine, Wakayama, 641-8509, Japan.
authors.forename: Hisashi
authors.initials: H
authors.lastname: Yamasaki
authors.affiliation: Department of Dental Oral Surgery, Faculty of Medicine, Kagawa University, 1750-1, Miki, Kagawa, 761-0793, Japan.
authors.forename: Khaleque
authors.initials: K
authors.lastname: Hasibul
authors.affiliation: Department of Microbiology, Faculty of Medicine, Kagawa University, 1750-1, Miki, Kagawa, 761-0793, Japan.
authors.forename: Saori
authors.initials: S
authors.lastname: Yoneda
authors.affiliation: Department of Microbiology, Faculty of Medicine, Kagawa University, 1750-1, Miki, Kagawa, 761-0793, Japan.
authors.forename: Keiko
authors.initials: K
authors.lastname: Uchida
authors.affiliation: Department of Microbiology, Faculty of Medicine, Kagawa University, 1750-1, Miki, Kagawa, 761-0793, Japan.
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Nariya
authors.affiliation: Department of Microbiology, Faculty of Medicine, Kagawa University, 1750-1, Miki, Kagawa, 761-0793, Japan.
authors.forename: Motoo
authors.initials: M
authors.lastname: Suzuki
authors.affiliation: Department of Dental Oral Surgery, Faculty of Medicine, Kagawa University, 1750-1, Miki, Kagawa, 761-0793, Japan.
authors.forename: Minoru
authors.initials: M
authors.lastname: Miyake
authors.affiliation: Department of Microbiology, Faculty of Medicine, Kagawa University, 1750-1, Miki, Kagawa, 761-0793, Japan. tomomi@med.kagawa-u.ac.jp.
authors.forename: Tomomi
authors.initials: T
authors.lastname: Kuwahara
mesh_terms: D001120:Arginine / Q000494:pharmacology*; D018441:Biofilms / Q000187:drug effects*; D003731:Dental Caries / Q000517:prevention & control; D003773:Dental Plaque / Q000517:prevention & control*; D006801:Humans; D012463:Saliva
chemical_list: D001120:Arginine
keywords: Biofilm; L-arginine; Mouth rinse; Oral microbiome; Saliva