Mucosal cytokines may be involved in the process of gastric bacterial contamination that may occur after Roux-en-Y bypass for morbid obesity in both gastric chambers, with inflammation and gastritis mostly in the excluded stomach.
A prospective observational study in a homogeneous population with nonspecific complaints.
Outpatient clinic of a large, public, academic hospital.
Subjects (n = 37; 26 [70.3%] female; mean ± SD age, 42.4 ± 9.9 years) seen a mean ± SD of 7.3 ± 1.4 years after Roux-en-Y gastric bypass and nonoperated on morbidly obese control subjects (n = 10; 7 [70%] female; mean ± SD age, 44.0 ± 8.9 years).
Enteroscopy was performed to collect samples for cytokine assays and bacteriologic studies.
Main Outcome Measures
Concentrations of tumor necrosis factor α and transforming growth factor β in the gastric mucosa of both chambers in patients undergoing Roux-en-Y gastric bypass and correlation with bacterial overgrowth and Helicobacter pylori infection.
High microbial counts (>105 colony-forming units per milliliter) were detected in 22 (59.5%) and 7 (18.9%) of the 37 samples from the functional pouch and excluded reservoir, respectively; and H pylori investigation was positive in 6 of 37 samples (16.2%). The tumor necrosis factor α concentration (mean ± SD, 2.1 ± 1.9 pg/g of protein) and the transforming growth factor β concentration (mean ± SD, 24.2 ± 12.8 pg/g of protein) in the excluded stomach, but not in the proximal pouch, were elevated with regard to the corpus or antrum of controls, and correlation with bacterial overgrowth and with H pylori infection was demonstrated.
Overexpression of tumor necrosis factor α and transforming growth factor β occurred in the distal stomach, positive cytokine correlation with microbial invasion by H pylori and nonspecific germs was seen, and further studies addressing phenotypic and genotypic changes of gastric mucosa are recommended.