Small Intestinal Bacterial Overgrowth Is Associated with Non-Alcoholic Fatty Liver Disease.
BACKGROUND
Changes in gut bacteria play a role in type 2 diabetes mellitus (DM) and hepatic steatosis. There is a lack of studies evaluating the frequency and risk factors for non-alcoholic fatty liver disease (NAFLD) in patients tested for small intestinal bacterial overgrowth (SIBO).


OBJECTIVE
To evaluate the frequency of NAFLD and associated risk factors in patients tested for SIBO.


METHODS
In this case-control study, 372 eligible patients submitted to glucose hydrogen/methane breath test for SIBO who also had an abdominal imaging study were included. Patients were divided into SIBO-positive and SIBO-negative groups. Clinical, demographic and laboratory variables were evaluated in addition to the presence of NAFLD on abdominal imaging.


RESULTS
Of the 372 eligible patients, 141 (37.9%) were tested positive for SIBO (study group) and 231 (62.1%) were negative for it (control group). NAFLD occurred in 45.4% (64/141) of the study group compared to 17.3% (40/231) of the control group (p<0.001). Patients in the study group were found to have higher rates of elevated aspartate aminotransferase (AST) (20.6% vs. 11.3%; p=0.034) and alanine aminotransferase (ALT) levels (56.0% vs. 40.7%; p= 0.039), type 2 diabetes (23.4% vs. 13.9%; p=0.041), hypertension (54.6% vs. 40.3%; p=0.046) and metabolic syndrome (78.0% vs. 60.2%; p=0.020). In the multivariate analysis, SIBO (odds ratio [OR]: 1.95; 95% confidence interval [CI]: 1.14-3.31; p=0.014), type 2 DM (OR: 3.04; 95%CI: 1.57-5.90; p=0.001) and obesity (OR: 3.58; 95%CI: 1.70-7.54; p=0.001) remained associated with NAFLD.


CONCLUSIONS
Patients with SIBO have an increased risk for hepatic steatosis and may benefit from aggressive control of the risk factors for NAFLD including metabolic syndrome.
Department of Internal Medicine, The Cleveland Clinic Foundation, Cleveland, OH, USA.
Andrea
A
Fialho
Department of Internal Medicine, The Cleveland Clinic Foundation, Cleveland, OH, USA.
Andre
A
Fialho
Department of Gastroenterology and Hepatology, The Cleveland Clinic Foundation, Cleveland, OH, USA.
Prashanthi
P
Thota
Department of Gastroenterology and Hepatology, The Cleveland Clinic Foundation, Cleveland, OH, USA.
Arthur J
AJ
McCullough
Department of Gastroenterology and Hepatology, The Cleveland Clinic Foundation, Cleveland, OH, USA. shenb@ccf.org.
Bo
B
Shen
D001419:Bacteria / Q000254:growth & development*; D001944:Breath Tests; D016009:Chi-Square Distribution; D057286:Electronic Health Records; D005260:Female; D000069196:Gastrointestinal Microbiome; D006801:Humans; D007421:Intestine, Small / Q000382:microbiology*; D016015:Logistic Models; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D065626:Non-alcoholic Fatty Liver Disease / Q000000981:diagnostic imaging / Q000382:microbiology*; D016017:Odds Ratio; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012307:Risk Factors; D014057:Tomography, X-Ray Computed; D014463:Ultrasonography