Small bowel bacterial overgrowth in subjects living in residential care homes

Abstract

Objectives: in elderly people, bacterial overgrowth of the small bowel may be occult. The significance of positive breath tests are uncertain: many fit elderly subjects with positive tests show no evidence of malabsorption. We assessed the prevalence and significance of bacterial overgrowth in the small bowel in a relatively unselected elderly population. Methods: residents of seven elderly people's homes had a glucose hydrogen breath test. A medical history and anthropomorphic measurements were recorded. Volunteers with positive breath tests were given doxycycline. After 4 months all volunteers were reassessed. Results: of 140 residents, 62 were tested. Nine (14.5%) had a positive breath test. There was no difference in anthropomorphic and bowel habit data between those with positive and those with negative breath tests. After 4 months of antibiotic treatment, volunteers with a positive breath test had increased weight and body mass index, while those with a negative test had decreased weight and body mass index. Conclusions: the percentage of volunteers with a positive breath test was much lower than in previous studies. This may be due to the relatively unselected nature of the volunteers. Treatment of bacterial overgrowth resulted in a small but significant improvement in anthropometric indices. The lack of association of positive breath tests with baseline anthropomorphic measurements or bowel habit highlights the occult nature of the bacterial overgrowth and questions its clinical importance.

Enhanced allostimulatory activity of host antigen-presenting cells in old mice intensifies acute graft-versus-host disease

“…Bacterial LPS crosses damaged gut mucosa, amplifying systemic GVHD in animal models, and blockade of LPS or selective bowel decontamination can reduce clinical GVHD and improve survival (14,(42)(43)(44). Some clinical studies suggest that bacterial overgrowth in the small bowel increases with age, although these studies are small and may suffer from selection bias related to age (45,46). Even if such bacterial loading holds possible clinical relevance, the BM chimera experiments rule out this mechanism as an explanation for more severe GVHD in old mice in this experimental model.…”

Small Bowel Bacterial Overgrowth in Symptomatic Older People: Can It Be Diagnosed Earlier?

“…Gastric hypochlorhydria and bacterial colonization, with mainly Gram-positive fl ora (in the upper gut) may be present in up to 80% of healthy old people [10] . SBBO, as documented by glucose hydrogen breath test, has previously been reported as 14.5-15.5% of unselected, asymptomatic, care home residents [11,12] . However, the clinical relevance of bacterial overgrowth in asymptomatic older people has been questioned [13,14] .…”

Unclear Abdominal Discomfort: Pivotal Role of Carbohydrate Malabsorption

“…Furthermore, we confirmed a correlation of SIBO with age which has been extensively described before. 43,44 Malnutrition in the elderly has been discussed as a cause for malabsorption making the bowel more susceptible for bacterial overgrowth. 43,45 Furthermore, hypochlorhydria, impaired peristalsis, duodenal diverticula and previous gastrointestinal surgery have been mentioned as possible causes for intestinal malabsorption.…”