An assessment of bacterial overgrowth and translocation in the non-alcoholic fatty liver of patients with morbid obesity.

BACKGROUND: small intestinal bacterial overgrowth (SIBO) and bacterial translocation across the intestinal wall have been allegedly associated with non-alcoholic fatty liver (NAFL). Our goal was to study such alleged association in morbidly obese patients.

PATIENTS AND METHODS: patients with morbid obesity were consecutively included prior to bariatric surgery. Exclusion criteria included normal liver biopsy, other causes of liver disease, and duodenal mucosal atrophy. A gastroscopy was performed for duodenal aspirate culture and duodenal biopsy, and peripheral venous blood was drawn to assess lipopolysaccharide (LPS) and LPS-binding protein (LBP) levels. A liver biopsy was carried out during surgery.

RESULTS: seventy-one patients were included; 26 were excluded because of normal liver biopsy. Forty-five had NAFL. Eighteen were male, mean age was 45.8 years (22-69), and BMI was 47.8 kg/m2 (37-58). A total of 25% had SIBO in their duodenal aspirate culture. There was statistical significance for the association of LBP levels and SIBO with steatosis grade (p < 0.05 and p = 0.077, respectively). There was no statistical association with non-alcoholic steatohepatitis (NASH) index, but a trend towards association was found. LPS levels were not associated with steatosis grade or NASH index.

CONCLUSIONS: the higher the grade of liver steatosis, the higher were the circulating LBP levels and SIBO rates seen in patients with morbid obesity and NAFL.