Tu1481 Slow Gastric Emptying Delays 14c D-Xylose Breath Test PEAK Time in Small Intestinal Bacterial Overgrowth (SIBO)

Abstract

Background: Delayed gastric emptying is commonly seen in small intestinal bacterial overgrowth (SIBO), and is often proposed as a major risk factor for this condition. The 14C DXylose breath test (XBT) has been used to diagnose SIBO and based on our data has demonstrated excellent reliability as a diagnostic measure (King & Toskes Gastro 1986). Delayed gastric emptying affects the delivery of nutrients to the small intestine and therefore could impact the results of XBT. Objectives: We aim to evaluate (1) whether delayed gastric emptying affects the pattern of D-Xylose BT results, and (2) whether delayed gastric emptying increases the risk of SIBO. Methods: A retrospective chart review was conducted on 846 patients with XBT between 2005 and 2009, male: female 168:678 (ratio 1:4), median age 57 years (age range 20-88). All of the patients were referred by GI clinics for various GI symptoms to rule out SIBO. The XBT was obtained by measuring 14C at baseline, 30, 60 and 180 minutes as per our protocol. Positive XBT was defined as an increased value of 14C at any one or more time points. A delayed gastric emptying by gastric emptying scintigraphy (GES) 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 846 patients with XBT, 498 patients tested positive for SIBO. Of these patients positive for SIBO, 229 had GES completed and 41% (94/229) were found to have delayed gastric emptying. Of 348 patients with a negative XBT, 167 had GES with 45% (75/167) having delayed gastric emptying. The risk of delayed gastric emptying was similar in both XBT positive and the negative group, with a likelihood ratio of 0.7, p>0.2. Of 229 patients with a positive XBT, the proportion of patients with a positive D-Xylose BT at 30 and 60 minutes were similar in both the normal and abnormal GES groups. However, a significantly increased number of patients with delayed gastric emptying had a positive XBT at 180 minutes (72.7% vs 54.4%, likelihood ratio = 6, p<0.02). Conclusion: Delayed gastric emptying significantly delays XBT positivity to 180 minutes. Prolonged duration of XBT up to the 180-minute period would increase the sensitivity of the breath test in patients with underlying motility disorders such as gastroparesis or even small bowel dysmotility. Surprisingly, based on our retrospective analysis, delayed gastric emptying was not found to be an independent risk factor of SIBO. A well-designed prospective study in the future with standard GES would be indicated to assess the association of SIBO and gastroparesis. (Acknowledgment: This study was funded by University of Florida CTSI NIH Grant UL1RR029890, and UF KL2RR029888 Award to Baha Moshiree MD, MS)