High incidence of fermentation in the digestive tract in patients with reflux oesophagitis.

Objectives Because bacteria represent the sole source of gut hydrogen (H 2 ) and methane (CH 4 ), fasting breath H 2 and CH 4 gases have been used as markers of colonic fermentation. The presence of carbohydrates in the colonic lumen inhibits gastric and pancreatic secretions, and also influences lower oesophageal sphincter function in gastro-oesophageal reflux disease. Materials and methods Studies were performed in 793 consecutive patients undergoing oesophagogastroscopy (270 men and 523 women, aged 19-85 years). A fasting breath sample (20 ml) was collected before endoscopy. At endoscopy, we intubated the stomach without inflation by air, and 20 ml of intragastric gas was collected through the biopsy channel. Next, the tip of the endoscope was inserted into the second portion of the duodenum without inflation by air, and 20 ml of intraduodenal gas was collected. H 2 and CH 4 concentrations of each sample were measured by gas chromatography. Results Reflux oesophagitis was found in 147 of the 793 patients. The mean values of the H 2 and/or CH 4 levels of samples taken from the stomach, duodenum and exhaled air were higher in patients with reflux oesophagitis than those without reflux oesophagitis. High H 2 and/or CH 4 levels were more frequently found in patients with reflux oesophagitis. Conclusions We concluded that the presence of fermentation in the digestive tract was considered to be a risk factor for developing reflux oesophagitis.