Small Intestinal Bacterial Overgrowth: What It Is and What It Is Not

Curr Opin Gastroenterol. 2014 Mar; 30(2):141-6. doi: 10.1097/MOG.0000000000000040.
Quigley E. M.


Purpose of review: To critically review recent literature on small intestinal bacterial overgrowth (SIBO).

Recent findings: When originally described, SIBO was added to the list of causes of the malabsorption syndrome and the pathophysiology of its consequences for the digestion and absorption of various nutrients was gradually revealed. More recently, SIBO was incriminated as a cause of diarrhea, especially in the elderly. However, the suggestion that SIBO may be a causative factor in irritable bowel syndrome and of its constituent symptoms has sparked debate and controversy on the very definition of SIBO. This debate revolves around the tests employed and the diagnostic cut-off values (for bacterial numbers) used to diagnose SIBO in clinical practice.

Summary: A fundamental problem with SIBO, and one that allows controversy to simmer, is the lack of a universally accepted and applied gold standard for the diagnosis of SIBO. Hopefully, the application of molecular microbiological methods to the characterization of the small intestinal microbiome will tell us, once and for all, what is normal and when 'abnormality' is truly responsible for symptoms and disease. Meanwhile, therapy remains, for the most part, empirical and is based on the correction, wherever possible, of any underlying cause, attention to nutritional deficiencies, and the use of antibiotics.

Information NutriBib

Reference work for leading, current and selected literature in the field of clinical nutrition

Publications on clinical nutrition have grown steadily in recent years and the scientific evidence has been improved by numerous observational as well as intervention studies. Various umbrella organisations, such as the Swiss Society for Clinical Nutrition (GESKES), the German Society for Nutritional Medicine (DGEM) or the European Society for Clinical Nutrition and Metabolism (ESPEN) publish guidelines on nutrition in various clinical situations at regular intervals. Thus, a large amount of literature is available for evidence-based nutritional medicine.

The NutriBib aims to filter out authoritative publications in the various fields of nutritional medicine and thus to provide an overview of the abundance of literature. A large number of experienced nutrition experts contributed to the selection of relevant sources and allow a broadly based selection. Nevertheless, the literature selection cannot be considered exhaustive. Specific literature can be found by entering search words (using the magnifying glass at the top right) or by searching the table of contents.

Is important literature still missing? We would be very pleased to hear from you:

List of abbreviations

DGEM German Society for Nutritional Medicine (German Deutsche Gesellschaft für Ernährungsmedizin)
GESKES  Swiss Society for Clinical Nutrition (German Gesellschaft für klinische Ernährung der Schweiz) 
ESPEN European Society of Clinicl Nutrition and Metabolism