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

Abstract

Background/Objectives: In older people, small bowel bacterial overgrowth syndrome may be a common, but under-diagnosed, cause of diarrhoea and nutrient malabsorption. We aim to determine which clinical features and baseline laboratory investigations indicate a high likelihood of small bowel bacterial overgrowth as defined by a positive glucose breath test. Methods: A retrospective analysis of records for all patients referred for glucose breath test over a 6-year period to a teaching hospital. Results: Out of 197 referrals, 168 patient records were located and analysed (62 male, 106 female; median age 65). Patient characteristics predictive of a positive glucose breath test were: increasing age (p < 0.01), low serum vitamin B₁₂(p = 0.02), low serum albumin (p = 0.03), previous partial gastrectomy (p < 0.01), previous right hemi-colectomy (p < 0.01), presence of small bowel diverticulae (p = 0.01) and concurrent use of a proton pump inhibitor (p < 0.01). 52.5% (n = 21/40) of patients studied who were over 75 years old versus 21.8% (n = 28/128) of those under 75 years old had a positive glucose breath test (p < 0.01). The median time to diagnosis, from first hospital visit to positive glucose breath test, was 39 weeks. Conclusions: There is often a significant delay in diagnosis of small bowel bacterial overgrowth. We suggest that this diagnosis should be considered earlier in the investigative algorithm in older patients with indicative symptoms and a predisposing factor (including previous partial gastrectomy, previous right hemi-colectomy, small bowel diverticulae or use of a proton pump inhibitor) or concurring laboratory indices (low vitamin B₁₂ or albumin).

Myelo-optico-neuropathy in copper deficiency occurring after partial gastrectomy

“…A predisposing anatomical abnormality, as the blind loop of Billroth II gastrojejunostomy, altered intestinal peristalsis, or hypochlorhydria induced surgically or pharmacologically by the use of PPI, can give rise to small intestinal overgrowth of bacteria [29,30]. SBBO has been recognized as an important cause of occult malabsorption in the elderly [31].…”

Right extended hemicolectomy, falls and low B₁₂

“…He had however had no further falls. Although bacterial overgrowth can also cause low B 12 post hemicolectomy, the patient denied any diarrhoea and there was no biochemical evidence of malabsorption [5]. The delay in manifestation of B₁₂ deficiency is due to the large amounts of B₁₂ stored in the liver and therefore any reduction in vitamin B₁₂ for whatever mechanism may take five to ten years to manifest clinically.…”

Proton pump inhibitors overuse: only inappropriate prescriptions or further iatrogenic damage?

“…30 Moreover, although it is thought that PPIs have a minor effect on altering the intestinal bacterial microbiota and observational studies have suggested that PPIs may or may not increase risk of enteric infections, these drugs can cause bacterial overgrowth in the small bowel and consequently the diarrheal disease defined as small intestinal bacterial overgrowth syndrome, sometimes mistakenly diagnosed as irritable bowel syndrome. 31,32 PPIs not only increase intestinal bacterial colonization but also accelerate intestinal transit.…”