High occurrence of small intestinal bacterial overgrowth in primary biliary cholangitis

Background: Primary biliary cholangitis (PBC) is a chronic autoimmune liver disease affecting mainly middle-aged women. An alteration in intestinal motility has been well documented in cirrhosis predisposing to small intestinal bacterial overgrowth (SIBO). Patients with PBC frequently complain of various gastrointestinal symptoms compatible with SIBO. No study has specifically been published to this day to determine the occurrence of SIBO in PBC. Our objective was to determine the prevalence of SIBO in patients with PBC.

Methods: Retrospective study from 2010 to 2018. All patients diagnosed with PBC during this period had a systematic screening for SIBO in their diagnostic workup. The diagnosis of SIBO was made by a carbohydrate breath test (lactulose and/or glucose). Clinical and paraclinical factors of patients were compared with a control group of healthy subjects.

Key results: Ninety-eight subjects were included in the study (mean age 49, range 21-88 years) including 58 patients with PBC and 40 healthy subjects. The PBC group was older than the control group (mean age 56, range 31-88 vs 39, range 21-62 years; P < .001), but identical for gender and body mass index. The prevalence of SIBO was higher in PBC versus controls (32.8% vs 2.5%; P < .001). The PBC group with SIBO had significantly more diarrhea (78.9% vs 35.9%; P < .05) than the PBC group without SIBO, but the prevalence of abdominal pain and bloating was similar.

Conclusions & inferences: The high occurrence of SIBO in PBC may explain some of the frequently reported gastrointestinal symptoms. This study justifies the systematic screening for SIBO in PBC.