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

Rev Esp Enferm Dig. 2019 Apr;111(4):294-300. doi: 10.17235/reed.2019.5942/2018.


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.

Publication types

  • Observational Study

MeSH terms

  • Acute-Phase Proteins
  • Adult
  • Aged
  • Bacterial Translocation*
  • Biomarkers / blood
  • Biopsy
  • Carrier Proteins / blood*
  • Cross-Sectional Studies
  • Duodenum / pathology
  • Fatty Liver / blood
  • Fatty Liver / pathology
  • Female
  • Humans
  • Intestine, Small / microbiology*
  • Lipopolysaccharides / blood
  • Liver / pathology
  • Male
  • Membrane Glycoproteins / blood*
  • Middle Aged
  • Non-alcoholic Fatty Liver Disease / blood
  • Non-alcoholic Fatty Liver Disease / complications
  • Non-alcoholic Fatty Liver Disease / microbiology*
  • Non-alcoholic Fatty Liver Disease / pathology
  • Obesity, Morbid / blood
  • Obesity, Morbid / complications
  • Obesity, Morbid / microbiology*
  • Prospective Studies
  • Young Adult


  • Acute-Phase Proteins
  • Biomarkers
  • Carrier Proteins
  • Lipopolysaccharides
  • Membrane Glycoproteins
  • lipopolysaccharide-binding protein