Gastric acid secretion and Campylobacter pylori

Helicobacter (aka Campylobacter) pylori as the major causal factor in chronic hypochlorhydria

Helicobacter (formerly known as Campylobacter) pylori, a recently discovered gastrointestinal bacterial pathogen, has been shown to be etiologic for Type B or antral gastritis, and usually has chronic active pathological changes associated with its presence. Acute Helicobacter infection in most cases induces reduced stomach acid secretion which usually returns to normal levels of secretion after a few months. Yet Helicobacter gastritis has never been known to spontaneously remit after it has been established, and there is evidence suggesting that it often progresses to cause atrophic changes in the gastric mucosa. Since chronic gastritis has been shown in past studies to lead to chronic persistent hypochlorhydria from atrophic damage to secretory tissue, and Helicobacter has been shown to cause most chronic gastritis, the reasonable conclusion is that Helicobacter infection is etiologic for most chronic persistent hypochlorhydria. The apparent exception of the hyperchlorhydria in duodenal ulcer disease associated with Helicobacter infection is explained. The possible clinical relevance of hypochlorhydria will be the subject of a subsequent paper.

Helicobacter pylori infection and gastric function in patients with chronic idiopathic dyspepsia

Helicobacter pylori infection, histological features of the gastric mucosa, and gastric motor and secretory functions were evaluated in 45 consecutive patients with chronic idiopathic dyspepsia. H. pylori infection was found in 60% of dyspeptic patients, compared with 33% of 15 healthy controls (P = 0.1). No difference was detected in basal or stimulated gastric acid secretion between dyspeptic patients and healthy controls. Gastric emptying was significantly (P less than 0.01) delayed in dyspeptic patients compared with healthy controls when standardized for age and sex. Delayed gastric emptying was associated with a low frequency of H. pylori infection, female gender, and young age. Epigastric pain or burning and postprandial fullness were, respectively, more severe in patients with H. pylori infection (P less than 0.02) and in those with delayed gastric emptying (P less than 0.01). These findings support the existence of separate subsets of patients with chronic idiopathic dyspepsia. Despite the presence of overlaps, there appear to be partially different functional derangements and clinical features in different subgroups of dyspeptic patients.

Gastric injury and invasion of parietal cells by spiral bacteria in rhesus monkeys. Are gastritis and hyperchlorhydria infectious diseases?

The possibility of using the rhesus monkey as a model for studying gastric function in the presence of infection with spiral bacteria was studied. Endoscopic evaluation of the gastric mucosa was performed under general anesthesia in 29 colony-bred rhesus monkeys, and gastric pinch biopsy specimens were obtained from each animal. On a separate day, gastric emptying and acid output were determined using a 99mTc dilution technique. Biopsy samples were fixed for light microscopy (H&E, Gram, and Warthin-Starry stains) and for transmission electron microscopy. The presence of spiral bacteria and gastritis was assessed and rated on coded slides. In 8 of 29 monkeys, Helicobacter pylori-like organisms were observed in close proximity to the mucosal epithelial cells or in the lumen of the gastric pits. In 14 other monkeys, "Gastrospirillum hominis"-like organisms were observed in the mucus covering the surface of epithelial cells, in the lumina of the gastric glands, and overlying parietal cells. Gastritis was present in 8 of 8 animals positive for H. pylori-like organisms, in 2 of 14 animals positive for "G. hominis"-like organisms, and in none of the uninfected monkeys, and the mean gastritis index was significantly greater in animals positive for H. pylori-like organisms. Moreover, acid output was significantly higher in monkeys positive for "G. hominis"-like organisms than in controls or animals positive for H. pylori-like organisms. Gastric emptying was not significantly different in the three groups. In conclusion, (a) H. pylori-like, but not "G. hominis"-like, organisms cause gastritis while not modifying acid output; (b) "G. hominis"-like, but not H. pylori-like organisms, invade and on occasion damage parietal cells while apparently causing hyperchlorhydria; and (c) the rhesus monkey appears to be a good model for the study of gastric infection with spiral bacteria.