Intestinal Permeability and Small Intestine Bacterial Overgrowth in Excess Weight Adolescents

Background: Increased intestinal permeability may be associated with certain disorders, such as obesity and small intestine bacterial overgrowth (SIBO).

Objective: This study aimed to investigate intestinal permeability and SIBO in excess weight adolescents.

Methods: This cross-sectional study included 67 adolescents with excess weight and 66 normal weight adolescents. Excess weight was defined as a body mass index for age (BMI/age) > +1 SD, which includes having excess body weight and obesity. SIBO was diagnosed by a breath test after the ingestion of lactulose according to the production of hydrogen and methane. Zonulin (haptoglobin) was considered an indicator of intestinal permeability.

Results: Adolescents with excess weight had a higher height/age Z-score (median [25th; 75th percentile]: +0.6 [-0.4; +1.0]) than those in the normal weight group (-0.1 [-0.6; +0.7]; P = .014). Zonulin (mg/mL) in the excess weight (2.3 [1.5; 3.8]) adolescents was higher than that in the normal weight (1.6 [1.0; 2.2]) adolescents (P < .001). SIBO was diagnosed in 23.3% (31/133) of the adolescents. The adolescents with SIBO had a lower (P < .05) BMI/age (+0.6 [-0.6; +1.9]) and height/age (-0.3 [-0.7; +0.3]) than the adolescents without SIBO (+1.3 [+0.1; +2.6] and +0.2 [-0.5; +1.0], respectively). No association was found between zonulin and SIBO.

Conclusion: Excess weight is associated with increased intestinal permeability. No relationship was found between SIBO and intestinal permeability; however, SIBO was related to lower BMI and height for age Z-scores.