title: Microbial flora of the stomach after gastric bypass for morbid obesity.
abstract: BACKGROUND
  The normal stomach is virtually sterile but the effect of Roux-en-Y gastric bypass (RYGBP) on bacterial flora in the used (very small proximal pouch) and unused (large bypassed) gastric chambers is not known. In a prospective study, this variable was documented.
  
  
  METHODS
  Bariatric subjects (n=37) were submitted to endoscopic examination of both gastric reservoirs via FUJINON enteroscope model EN-450P5, 7.3 +/- 1.4 years after RYGBP. Age was 42.4 +/- 9.9 years (70.2% females), preoperative BMI was 53.5 +/- 10.6, and current BMI was 32.6 +/- 7.8 kg/m2. Methods included quantitative culture of gastric secretion along with gastric pH and lactulose/hydrogen breath test.
  
  
  RESULTS
  None of the subjects displayed diarrhea, malabsorption or other complaints suggestive of GI bacterial overgrowth. Elevated counts of bacteria and fungi were identified in both chambers, with predominance of aerobes and anaerobes, but not molds and yeasts, in the proximal stomach. Gram-positive cocci, bacilli and coccobacilli represented the majority of the isolates. Gastric pH was neutral (pH 7.0 +/- 0.2) in the proximal pouch, whereas the distal chamber mostly but not always conserved the expected acidity (pH 3.3 +/- 2.2, P<0.001). The breath test for bacterial overgrowth was positive in 40.5% of the population.
  
  
  CONCLUSIONS
  1) Frequent colonization of both gastric chambers was detected; 2) Aerobes, anaerobes and fungi were represented in both situations; 3) Gastric pH as well as bacterial count was higher in the functioning proximal stomach; 4) Breath test was positive in 40.5% of the subjects; 5) Clinical manifestation such as diarrhea, malabsorption or pneumonia were not demonstrated; 6) Further histologic and microbiologic studies of both the stomach and the small bowel are recommended.
authors: Endoscopy Service, Hospital das Clinicas, Sao Paulo, Brazil.
authors: Robson K
authors: RK
authors: Ishida
authors: Joel
authors: J
authors: Faintuch
authors: Ana M R
authors: AM
authors: Paula
authors: Christiane A
authors: CA
authors: Risttori
authors: Sabrina N
authors: SN
authors: Silva
authors: Elaine S
authors: ES
authors: Gomes
authors: Rejane
authors: R
authors: Mattar
authors: Rogerio
authors: R
authors: Kuga
authors: Adriana S
authors: AS
authors: Ribeiro
authors: Paulo
authors: P
authors: Sakai
authors: Hermes V
authors: HV
authors: Barbeiro
authors: Denise F
authors: DF
authors: Barbeiro
authors: Francisco G
authors: FG
authors: Soriano
authors: Ivan
authors: I
authors: Cecconello
mesh_terms: D000328:Adult; D000368:Aged; D001944:Breath Tests; D005260:Female; D005500:Follow-Up Studies; D015390:Gastric Bypass / Q000009:adverse effects; D005773:Gastroscopy; D006801:Humans; D008297:Male; D008875:Middle Aged; D009767:Obesity, Morbid / Q000382:microbiology* / Q000473:pathology / Q000601:surgery*; D011446:Prospective Studies; D013270:Stomach / Q000382:microbiology* / Q000473:pathology; D016896:Treatment Outcome