title: Assessing the adhesion of putative indigenous probiotic lactobacilli to human colonic epithelial cells.
abstract: OBJECTIVE
  Adherence of bacteria to epithelial cells and mucosal surfaces is a key criterion for selection of probiotic. We assessed the adhesion property of selected indigenous probiotic Lactobacillus strains based on their hydrophobicity and ability to adhere to human epithelial cells.
  
  
  METHODS
  Five human faecal Lactobacillus isolates, one from buffalo milk and one from cheese were assessed for hydrophobicity following the microbial adhesion to hydrocarbons (MATH) method and colonization potentials based on their adherence to Caco2 and HT-29 colonic adenocarcinomal human intestinal epithelial cell lines. Lactobacillus strains that adhered to Caco2 and HT-29 cell lines were quantified by plating after trypsinization and simultaneously the adhered bacteria were also examined microscopically after staining with Geimsa stain and counted in different fields.
  
  
  RESULTS
  Among the tested faecal isolates, L. plantarum Lp91 showed maximum percentage hydrophobicity (35.73±0.40 for n-hexadecane and 34.26±0.63 for toluene) closely followed by L. plantarum Lp9 (35.53±0.29 for n-hexadecane and 33.00±0.57 for toluene). Based on direct adhesion to epithelial cells, L. plantarum Lp91 was the most adhesive strain to HT-29 and Caco2 cell lines with per cent adhesion values of 12.8 ± 1.56 and 10.2 ± 1.09, respectively. L. delbrukeii CH4, was the least adhesive with corresponding figures of 2.5 ± 0.37 and 2.6 ± 0.20 per cent on HT-29 and Caco2 cell lines. Adhesion of the six isolated Lactobacillus strain to HT-29 cell and Caco2 lines as recorded under microscope varied between 131.0 ± 13.9 (Lp75) to 342.7 ± 50.52 (Lp91) and 44.7 ± 9.29 (CH4) to 315.7± 35.4 (Lp91), respectively.
  
  
  CONCLUSIONS
  Two Indigenous probiotic Lactobacillus strains (Lp9, Lp91) demonstrated their ability to adhere to epithelial cell and exhibited strong hydrophobicity under in vitro conditions, and thus could have better prospects to colonize the gut with extended transit.
authors.affiliation: Department of Dairy Microbiology, National Dairy Research Institute (ICAR), Karnal, India.
authors.forename: Raj Kumar
authors.initials: RK
authors.lastname: Duary
authors.forename: Yudhishthir Singh
authors.initials: YS
authors.lastname: Rajput
authors.forename: Virender Kumar
authors.initials: VK
authors.lastname: Batish
authors.forename: Sunita
authors.initials: S
authors.lastname: Grover
mesh_terms: D001422:Bacterial Adhesion; D018938:Caco-2 Cells; D003106:Colon / Q000166:cytology; D004847:Epithelial Cells / Q000166:cytology / Q000382:microbiology; D005243:Feces / Q000382:microbiology*; D041981:Gastrointestinal Tract / Q000382:microbiology*; D019073:HT29 Cells; D006801:Humans; D006838:Hydrocarbons / Q000737:chemistry; D057927:Hydrophobic and Hydrophilic Interactions; D007422:Intestines / Q000166:cytology; D048191:Lactiplantibacillus plantarum / Q000737:chemistry* / Q000302:isolation & purification; D019936:Probiotics / Q000737:chemistry*
chemical_list: D006838:Hydrocarbons