Small Intestinal Bacterial Overgrowth in Patients With Cirrhosis

Abstract

Small intestinal bacterial overgrowth (SIBO) is defined by increased density and/or abnormal composition of microbiota in the small bowel. SIBO is often encountered in patients with cirrhosis as a result of impaired intestinal motility and delayed transit time, both of which are exacerbated by more severe liver disease. Additional risk factors for SIBO commonly encountered in cirrhotic patients include coexisting diabetes, autonomic neuropathy, and/or alcoholic use. Diagnosis of SIBO is performed by breath testing or jejunal aspiration, the gold standard. In cirrhotic patients, the presence of SIBO can lead to profound clinical consequences. Increased intestinal permeability in these patients predisposes to bacterial translocation into the systemic circulation. As a result, SIBO is implicated as a significant risk factor in the pathogenesis of both spontaneous bacterial peritonitis and hepatic encephalopathy in cirrhotics. Antibiotics, especially rifaximin, are the best studied and most effective treatment options for SIBO. However, prokinetics, probiotics, nonselective beta-blockers, and treatment of underlying liver-related pathophysiology with transjugular intrahepatic portosystemic shunt placement or liver transplantation are also being investigated. This review will discuss the risk factors, diagnosis, manifestations in cirrhosis, and treatment options of SIBO.

Changes in the Body Composition and Nutritional Status after Long-term Rifaximin Therapy for Hyperammonemia in Japanese Patients with Hepatic Encephalopathy

“…The curative effect of rifaximin on improving the dietary intake may be due in part to the improvement of hepatic encephalopathy and small intestinal bacterial overgrowth (SIBO). Patients with hepatic encephalopathy have a high prevalence of SIBO and are often encountered with cirrhosis as a result of an impaired intestinal motility and delayed transit time, including malabsorption ( 23 ). Rifaximin is the best studied antibiotic for SIBO treatment, as it is a poorly absorbed oral antibiotic, which allows for local enteric antibacterial activity with a minimal risk of systemic toxicity.…”

Cognitive-Behavioural Correlates of Dysbiosis: A Review

“…Moreover, in patients with cirrhosis, a reduced intestinal motility has been described. As a matter of fact, the consequent delayed small intestinal transit could represent a risk factor for dysbiosis [ 77 ].…”

Current Status and Prospects of Spontaneous Peritonitis in Patients with Cirrhosis

“…For patients with liver cirrhosis, bacterial translocation (BT) as a result of intestinal gram-negative Enterobacteriaceae infections is the main cause of SBP occurrence and development [ 6 , 52 , 53 ]. Previous studies have shown that gastrointestinal stasis due to portal hypertension in patients with liver cirrhosis, intestinal bacterial overgrowth due to low levels of bile acid and gastric acid, delayed intestinal transport, altered intestinal permeability, and immune dysfunction promote BT and ultimately SBP [ 5 , 7 , 8 ] ( Figure 1 ).…”

“…In recent studies, gastrointestinal stasis due to portal hypertension, relative lack of bile and gastric acid secretion, intestinal dyskinesia, and long-term use of broad-spectrum antibiotics in patients with liver cirrhosis are implicated in increased intestinal aerobic bacteria and colonic bacterial migration to the jejunum and duodenum. These changes further cause SIBO and promote BT, which is implicated in SBP prognosis in patients with liver cirrhosis [ 7 ]. Notably, the most common pathogenic microorganisms were isolated from the intestinal flora of cirrhotic ascites in SBP patients [ 69 ].…”

“…Studies show that bacterial translocation plays a key role in the occurrence and development of SBP [ 5 , 6 ]. Bacterial translocation is caused by disorder of gut microflora, increased intestinal permeability, and host immunodeficiency [ 7 , 8 ]. Although gram-negative bacilli are the main cause of SBP, infections due to gram-positive bacteria drug-resistant bacteria have been reported [ 9 – 11 ].…”