Prevalence and clinical significance of small intestinal bacterial overgrowth in patients with chronic liver disease

Aim: To study the prevalence of small intestinal bacterial overgrowth (SIBO) in chronic liver disease patients. To analyze its relationship with the etiology, severity and complications (Spontaneous bacterial peritonitis, hepatic encephalopathy) of chronic liver disease.
Materials & methods: Cases were 60 chronic liver disease patients (20 CHILD-A, 20 CHILD-B, 20 CHILD-C). 60 Controls were healthy persons who were not on any recent medications like antibiotics or probiotics. All patients underwent routine laboratory investigations, upper gastrointestinal endoscopy and glucose hydrogen breath test as per the protocol. Results: 60 cirrhotic cases were included in our study. 20 numbers included in each child status A, B and C. 44 males and 16 females were included in both cases and controls. The age ranged between 28 to 71 years (mean age - 51.42 years), 22 to 65 years (mean age - 50.47 years) among cases and controls respectively. 44 (73.30%) males and 16 (26.70%) females were present in both case and control group. Considering etiology of CLD was found to be 30 ethanol related, 9 HBV related, 5 HCV related and 16 cryptogenic. Child Turcot Pugh score varied from 6 to 12 with mean value 8.3. Model For End Stage Liver Disease score value ranged from 7 to 16 with mean 10.14. GHBT was positive in 20 out of 60 patients (33.3%). In controls only 2 out of 60 were positive for hydrogen breath test. Comparing the GHBT between two groups p value was found to be <0.001 which was statistically significant. GHBT glucose hydrogen breath testwas positive in 12 (20%) alcoholic liver disease, 1(1.7%) HBV related, 2 (3.3%) HCV related and 5 (8.3%) cryptogenic CLD. Presence of SIBO was not correlated with the etiology of liver disease (p value 0.435). Prevalence of SIBO among CTP class A was 20% (4/20), CTP class B was 35% (7 ⁄ 20), CTP class C was 45% (9 ⁄ 20). The prevalence of SIBO increased with the severity of liver disease (p = 0.013). Increased prevalence of small intestinal bacterial overgrowth in patients with decompensated (CTP score more than 7) cirrhosis than in patients with compensated cirrhosis was noted. Conclusion: Small intestinal bacterial overgrowth was prevalent in about 33% of cirrhotic patients. The frequency of small intestinal bacterial overgrowth increases with severity of liver disease. Severity of portal hypertension does not correlate with small intestinal bacterial overgrowth. Presence of ascites and high serum bilirubin can reliably predict presence of small intestinal bacterial overgrowth.