Correlation of Gastrointestinal Motility with 14C D-Xylose Breath Test in Small Intestinal Bacterial Overgrowth: 2011 ACG Presidential Poster

Abstract

Purpose: Small intestinal bacteria overgrowth (SIBO) is diagnosed by measuring the early appearance of 14C following administration of 14C D-Xylose, which transits through the small intestine and is broken down by colonic bacteria. Gastrointestinal motility affects the delivery of intestinal contents and could impact the 14C D-Xylose breath test (BT) results. In this study, we aim to evaluate whether delayed gastric emptying, fast bowel transit (represented as diarrhea), and slow bowel transit (represented as constipation) affect the pattern of D-Xylose BT results. Methods: A retrospective chart review was conducted on 401 patients with a positive 14C D-Xylose BT between 2005 and 2009, Male:Female 35:366 (ratio 1:9.6), median age 60 years (age range 21-88). The clinical presentation, past medical history, and gastric emptying scintigraphy results were reviewed. The D-Xylose BT results were obtained by measuring 14C at baseline, 30, 60 and 180 minutes. Positive D-Xylose BT defined as an increase value of 14C at any one or more time frame. A delayed gastric emptying by scintigraphy was defined by T1/2 greater than 90 minutes after ingestion of a standard 254 calorie meal based on 2 hour continuous scanning. Results: Of 401 patients with positive D-Xylose BT, 186 patients had gastric emptying studies, and 77/186 patients were found to have delayed gastric emptying by scintigraphy. The proportion of patients with a positive BT at 30 and 60 minutes were similar in both the normal and abnormal gastric emptying group. However, a significantly increased number of patients with delayed gastric emptying had a positive D-Xylose BT at 180 minutes (84.4% vs. 68.8%, p<0.05). A total of 237 patients had reported diarrhea and 42 patients had reported constipation. Nevertheless, positivity time on the D-Xylose BT did not correlate with symptoms of diarrhea or constipation.Table: Table. Correlation of gastric emptying, diarrhea, and constipation with 14C D-xylose breath testConclusion: This study demonstrates that delayed gastric emptying correlates significantly with D-Xylose BT positivity at 180 minutes. Therefore, findings on the D-Xylose BT over the 180-minute period could warrant further investigations for an underlying motility disorder such as gastroparesis or even small bowel dysmotility. Therefore, performing the D-Xylose BT over a full 180-minute period of time is paramount. Interestingly, neither diarrhea nor constipation affects the pattern of D-Xylose breath test results. (NIH Grant UF CTSI 1UL1RR029890).