The prevalence of FGID among general populations worldwide is approximately 20?30%.

Keywords: Adult, Bacterial overgrowth syndrome, Blind loop syndrome, Breath tests, Dyspepsiaįunctional gastrointestinal disorders (FGID) are among the most common disorders of the gastrointestinal tract reported in visits to health care providers and have a large impact on health care costs. Although the frequency of SIBO is low among patients with FGID, it may be important to be aware of SIBO as differential diagnosis when examining patients with refractory gastrointestinal symptoms, especially bloating, as a part of routine clinical care. Two patients initially diagnosed with FD and IBS were also diagnosed with SIBO as assessed by GHBT. Their symptoms were clearly improved and breath hydrogen levels decreased to normal following levofloxacin administration for 7 days. Of those, 2 (5.3%) were diagnosed with SIBO (one patient diagnosed with FD the other with overlapping FD and IBS). ResultsĪ total of 38 FGID patients, including 11 with functional dyspepsia (FD), 10 with irritable bowel syndrome (IBS), and 17 with overlapping with FD and IBS, were enrolled. A peak hydrogen value ≥ 10 ppm above the basal value between 60 and 120 minutes after administration of glucose was diagnosed as SIBO. A glucose hydrogen breath test (GHBT) was performed using a gas analyzer after an overnight fast, with breath hydrogen concentration measured at baseline and every 15 minutes after administration of glucose for a total of 3 hours. We prospectively enrolled patients with refractory FGID based on Rome III criteria. Here, we examined the frequency of SIBO in patients with refractory FGID. However, the prevalence and clinical conditions of SIBO in patients with FGID remain to be fully elucidated. All rights reserved.Small intestinal bacterial overgrowth (SIBO) is considered to be involved in the pathogenesis of functional gastrointestinal disorders (FGID). One hopes that the application of an ever-expanding armamentarium of modern molecular microbiology to the human small intestinal microbiome in both health and disease will ultimately resolve this impasse and provide an objective basis for the diagnosis of SIBO.ĭysbiosis Gut Microbiome Gut Microbiota Malabsorption Maldigestion Small Bowel Small Intestinal Bacterial Overgrowth.Ĭopyright © 2022 AGA Institute.

Furthermore, the pathophysiological plausibility that underpins SIBO as a cause of maldigestion/malabsorption is lacking in regard to its purported role in irritable bowel syndrome, for example. However, issues with the specificity of these same breath tests have clouded their interpretation and aroused some skepticism regarding the role of SIBO in this expanded clinical repertoire. The advent and ready availability of breath tests generated a dramatic expansion in both the rate of diagnosis of SIBO and the range of associated gastrointestinal and nongastrointestinal clinical scenarios.

Coincident with advances in medical science, diagnostic testing evolved from small bowel culture to breath tests and on to next-generation, culture-independent microbial analytics. Such colonization resulted in clinical signs, symptoms, and laboratory abnormalities that were explicable within a coherent pathophysiological framework. The concept of small intestinal bacterial overgrowth (SIBO) arose in the context of maldigestion and malabsorption among patients with obvious risk factors that permitted the small bowel to be colonized by potentially injurious colonic microbiota.