We examined causes and hematological consequences of low serum cobalamin (vitamin B12) concentration in two representative population samples of 70-year-old (N = 293) and 75-year-old subjects (N = 486). Subjects with values below 130 pmol/liter (4.8% and 5.6%, respectively) were investigated with Schilling test, upper gastrointestinal endoscopy, determination of serum gastrin and group I pepsinogens, and bone marrow examination. Gastrointestinal abnormalities of etiologic significance were found in 26 of the 32 examined subjects: atrophy of the gastric body mucosa (N = 16, with pernicious anemia in six), partial gastrectomy (N = 6), and intestinal malabsorption (N = 4). Megaloblastic hematopoiesis was found in 10 individuals, four of whom had macrocytic anemia. Our results indicate that low serum cobalamin concentration in the elderly is usually a consequence of disease rather than of high age per se and that gastric mucosal atrophy is a major etiologic factor.

Intragastric bacterial colonization is well known in pernicious anaemia (PA), but its consequences have rarely been investigated. We have studied the clinical history, blood samples, and endoscopic biopsies from the stomach and duodenum of 80 patients with PA. In a random subgroup of 22 patients gastric juice was collected for aerobic culture and for estimation of nitrate, nitrate-reducing bacteria, nitrite, and N-nitrosamines; duodenal juice was studied in parallel in eight of these subjects. Gastric and duodenal juice had high bacterial counts; faecal organisms were found in 14 patients. The mean count of nitrate-reducing bacteria was significantly higher than in a control group of patients with peptic ulcer disease (p less than 0.001), as was the nitrite concentration (p less than 0.001). Thirty-three of the 80 patients had gastric dysplasias; 1 early gastric carcinoma was also found. Duodenitis was present in 39 out of 80 cases, in 6 associated with partial villous atrophy. A history of malabsorption and/or chronic intermittent diarrhoea was obtained significantly more often from patients with duodenitis. Four patients developed acute gastroenteritis shortly before or during the time of the study, two having a salmonella infection. Bacterial overgrowth in PA may be facilitated by altered immunological conditions, since low serum levels of IgA and IgG were found in this patient group.

Malnutrition is common after total gastrectomy. Different pathophysiological reasons have been reported. We have investigated malabsorption in patients after total gastrectomy and Roux-Y esophagojejunostomy, analyzing the orocecal transit time, the bacterial flora of the upper intestine, and the small intestinal carbohydrate fermentation. Furthermore, we studied the benefit of pancreatic enzymes in this condition. The orocecal transit time was found to be short in 5/11 patients. In 4/11 patients upper intestinal bacterial overgrowth was probable. In the remaining 3/11 patients with steatorrhea, pancreatic dysfunction, due to understimulation, was suspected to be the reason for malassimilation. A subsequent double-blind, cross-over trial on supplementary treatment with pancreatic enzymes was performed in 15 patients. This treatment did not significantly reduce the degree of steatorrhea in these patients.

Three end-expiratory breath hydrogen (H2) sampling methods were compared in a patient group (n = 12) and a laboratory staff group (n = 12) on two separate occasions. H2 samples obtained with each method showed significantly different concentrations (p less than 0.001) but no significant differences in coefficient of variation when individual triplicate samples were evaluated. There was a high correlation between the breath H2 concentrations obtained by the three methods (r = 0.93-0.96). Fasting breath H2 values after an overnight fast and an unrestricted diet the day before the investigation were compared with values obtained after an overnight fast and a low-fibre diet the day before the test in two patient groups (n = 39 and 39) with a comparable distribution of diagnoses and in one group of healthy volunteers (n = 17). Fasting breath H2 concentrations were significantly lower after a low-fibre diet in the patient groups (p less than 0.005) and in healthy volunteers (p less than 0.02). We conclude that each of the three end-expiratory sampling methods can be chosen for use in H2 breath tests depending on suitability and convenience and that a low-fibre diet the day before the H2 breath test lowers fasting breath H2 concentration.