title: Helicobacter pylori in patients can be killed by visible light.
abstract: BACKGROUND
  Helicobacter pylori colonizes the mucus layer of the human stomach and may cause peptic ulcer and adenocarcinoma. Novel antimicrobial approaches are sought due to the occurrence of antibiotic resistance and consequent treatment failure. We report here that H. pylori is susceptible to inactivation by blue light.
  
  
  METHODS
  A controlled, prospective, blinded, trial of endoscopically delivered blue light to eradicate H. pylori in regions of the gastric antrum, in 10 patients between the ages of 21 and 80 who tested positive for H. pylori. Light (405 nm) (40 J/cm2) was delivered to a 1-cm diameter spot in the gastric antrum via optical fiber passed through the endoscope and weighed biopsies were taken from treated and control spots and colonies quantitatively cultured.
  
  
  RESULTS
  Blue light killed 5 logs of bacteria in vitro. The mean reduction in H. pylori colonies per gram tissue between treated and control spots was 91% (7.4+/-4.8 x 10(6) vs. 8.1+/-1.9 x 10(7), two-tailed P < 0.0001). Some patients had reductions approaching 99%. No differences were observed on histological examination of light-treated and control gastric tissue.
  
  
  CONCLUSIONS
  Blue light phototherapy may represent a novel approach to eradication of H. pylori, particularly, in patients who have failed standard antibiotic treatment.
authors.affiliation: Sterilite LLC, Minnetonka, Minnesota, USA.
authors.forename: Robert A
authors.initials: RA
authors.lastname: Ganz
authors.forename: Jennifer
authors.initials: J
authors.lastname: Viveiros
authors.forename: Aamir
authors.initials: A
authors.lastname: Ahmad
authors.forename: Atosa
authors.initials: A
authors.lastname: Ahmadi
authors.forename: Ayesha
authors.initials: A
authors.lastname: Khalil
authors.forename: M Joshua
authors.initials: MJ
authors.lastname: Tolkoff
authors.forename: Norman S
authors.initials: NS
authors.lastname: Nishioka
authors.forename: Michael R
authors.initials: MR
authors.lastname: Hamblin
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004415:Dyspepsia / Q000382:microbiology; D005260:Female; D005753:Gastric Mucosa; D005773:Gastroscopy; D016481:Helicobacter Infections / Q000150:complications / Q000628:therapy*; D016480:Helicobacter pylori / Q000528:radiation effects*; D006801:Humans; D008027:Light; D008297:Male; D008875:Middle Aged; D010437:Peptic Ulcer / Q000382:microbiology; D010789:Phototherapy / Q000379:methods*; D010865:Pilot Projects; D011446:Prospective Studies; D011706:Pyloric Antrum; D016037:Single-Blind Method