Drug-induced hypochlorhydria causes high duodenal bacterial counts in the elderly

Authors


Dowling Gastroenterology Unit, 18th Floor, Guy’s Tower, Guy’s Hospital, London Bridge SE1 9RT, UK.

Abstract

Background:

Small bowel bacterial overgrowth secondary to drug-induced hypochlorhydria may be of particular importance in the elderly, in whom anti-ulcer drugs are commonly prescribed and the consequences of malabsorption may be severe.

Methods:

Duodenal aspirates were obtained from elderly individuals before (n=24) and during a 2-month treatment course with either omeprazole (20 mg daily; n=8) or ranitidine (300 mg b.d.; n=6), and from six patients with small bowel bacterial overgrowth who had diarrhoea and malabsorption.

Results:

Before treatment, duodenal bacterial counts were normal (< 104 colony forming units/mL) in 23 elderly subjects (96%). However, six of 14 patients (43%) treated with omeprazole (5 of 8) or ranitidine (1 of 6) developed bacterial counts>  105 cfu/mL. All remained asymptomatic and had normal lactulose breath H2 profiles during treatment.

Conclusion:

Drug-induced hypochlorhydria causes high duodenal bacterial counts in the elderly but, in the short term, this bacterial overgrowth is not associated with malabsorption.

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