Factors Associated With Glucose Hydrogen Breath Test Positivity for Intestinal Bacterial Overgrowth in a Large Cohort of Diabetic Patients: Comparison With Non-diabetics

Abstract

Introduction: Small intestinal bacterial overgrowth (SIBO) is found in 16-44% of long term diabetics and is diagnosed by documenting increased breath H2 or CH4 excretion after a carbohydrate substrate. Breath test characteristics have not been contrasted in diabetics vs. non-diabetics. We accessed a large clinical database to test if diabetics: (i) more often exhibit positive breath tests for SIBO vs. non-diabetics, (ii) exhibit higher peak and shorter times to peak H2 and CH4 levels, and (iii) more often note gas and diarrhea with positive breath tests. Methods: 703 diabetics and 4389 non-diabetics underwent breath testing after 50 gm glucose, GBT, to exclude SIBO from 1989 to 2014. Results were compared to lactose (LBT), fructose (FBT), and sucrose (SBT) breath tests in the two groups. Positive GBT criteria was H2 >12 ppm and/or CH4 >12 ppm and positive LBT, FBT, and SBT were denoted by H2 > 15 ppm and/or CH4 > 15 ppm increasing within 120 min. Results: Breath H2 levels increased in 39% of diabetics vs. 26% of non-diabetics after glucose with an odds ratio of 1.97 (95% CI 1.168, 3.329)(P=0.01). Some but not all of this difference related to increased age of diabetics vs. non-diabetics (56+14 vs. 48+17 yrs) on regression modeling (P=0.02). Breath test positivity differences between groups were not influenced by sex, race, or BMI (P=NS). In contrast, no differences in CH4 after glucose (8 vs. 9%), or H2 or CH4 after lactose (43 vs. 36%, 10 vs. 8%), fructose (42 vs. 48%, 6 vs. 8%), or sucrose (18 vs. 23%, 0 vs. 8%) were noted in diabetics vs. non-diabetics (P=NS). Fasting and peak H2 levels after glucose were higher (P2 were shorter (P=0.03) in diabetics vs. nondiabetics (Table 1). Prevalences of gas (89 vs. 80%, P=0.001), bloating (89 vs. 83%, P=0.02), diarrhea (87 vs. 70%, P2 excretion, while constipation was reported more often in those with negative vs. positive breath tests (P=0.03)(Table 2).Table 1: Glucose Breath Test Characterstics in Diabetes vs. Non-DiabeticsTable 2: Initial Symptom Reports in Diabetics With Positive vs. Negative Hydrogen Production on Glucose Breath TestingConclusion: Glucose breath tests performed for SIBO diagnosis were more often positive and showed higher and earlier H2 peaks in diabetics vs. non-diabetics. Diabetics were older and reported greater GI symptoms than non-diabetics, though no symptom correlated with breath test positivity in diabetes. These findings from a large database improve our understanding of clinical factors associated with SIBO in diabetes.