title: [Probiotic properties of Lactobacillus spp isolated from gastric biopsies of Helicobacter pylori infected and non-infected individuals].
abstract: BACKGROUND
  Gastric microbiota is a complex ecosystem, composed by diverse microorganisms, where H pylori and Lactobacillus are relevant species.
  
  
  OBJECTIVE
  To study the probiotic properties of Lactobacillus spp isolated from gastric biopsies of subjects bearing or not H pylori.
  
  
  METHODS
  Gastric biopsies from 197 individuals that consulted for gastrointestinal disorders were cultivated in media specific for H pylori and Lactobacillus spp. Probiotic properties of lactobacilli isolates and histological diagnosis of H pylori colonized patients were performed.
  
  
  RESULTS
  Among 197 individuals evaluated, Hpylori was detected in 43%, Lactobacillus spp in 24%, while 8% presented both bacteria simultaneously. Forty one percent of the Lactobacillus spp strains produced hydrogen peroxide, S'3% presented a highly hydrophobic surface and 32% had an inhibitory effect upon Hpylori ATCC 43504, even greater than Lactobacillus LGG or LAL reference strains. The main pathological diagnosis of patients ivas chronic non-atrophic gastritis (73%) followed by intestinal metaplasia (19%). A similar proportion of both conditions were observed in patients colonized by Lactobacillus spp, while not colonized individuals developed preferentially chronic non-atrophic gastritis (p =0.002).
  
  
  CONCLUSIONS
  Lactobacillus spp and H pylori were mutually excluded, suggesting a competitive colonization model between probiotic bacteria and pathogens .
authors.affiliation: Laboratorio de Patogenicidad Bacteriana, Departamento de Microbiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile. apgarcia@udec.cl
authors.forename: Apolinaria
authors.initials: A
authors.lastname: García C
authors.forename: Patricio
authors.initials: P
authors.lastname: Henríquez A
authors.forename: Carolina
authors.initials: C
authors.lastname: Retamal R
authors.forename: Susana
authors.initials: S
authors.lastname: Pineda C
authors.forename: Carolina
authors.initials: C
authors.lastname: Delgado Sen
authors.forename: Carlos
authors.initials: C
authors.lastname: González C
mesh_terms: D000293:Adolescent; D018407:Bacterial Physiological Phenomena; D001706:Biopsy; D015169:Colony Count, Microbial; D005753:Gastric Mucosa / Q000382:microbiology*; D016481:Helicobacter Infections / Q000382:microbiology* / Q000473:pathology; D016480:Helicobacter pylori / Q000254:growth & development* / Q000302:isolation & purification; D006801:Humans; D007778:Lactobacillus / Q000302:isolation & purification / Q000378:metabolism / Q000502:physiology*; D019936:Probiotics / Q000378:metabolism*