Alterations in Oral Cecal Transit Time and Small Intestinal Microbiota in Minimal Hepatic Encephalopathy With Small Intestinal Bacterial Overgrowth

AIMS This study aimed to investigate the oral-cecal transit time (OCTT) and its correlation with small intestinal dysbiosis in cirrhotic patients with minimal hepatic encephalopathy (MHE) and co-existing small intestinal bacterial overgrowth (SIBO).

METHODS We enrolled 110 patients with a confirmed diagnosis of cirrhosis admitted to the Department of Gastroenterology at The Affiliated Hospital of Qingdao University between December 2021 and December 2023. The lactulose hydrogen breath test (LHBT) was utilized to diagnose SIBO and to measure OCTT. Patients were stratified into three cohorts: a SIBO(+) MHE group, a SIBO(-) MHE group, and a non-MHE group. Duodenal mucosal biopsies were collected from a subset of 26 cirrhotic patients and 5 healthy controls for microbial analysis.

RESULTS Among the 110 cirrhotic patients, the prevalence of MHE was 53.6% (59/110). Within the MHE cohort, the prevalence of SIBO was 71.19% (42/59). The SIBO(+) MHE group exhibited a significantly prolonged OCTT compared to both the non-MHE group (P<0.05) and the SIBO(-) MHE group (P<0.05). At the phylum level, Proteobacteria, Firmicutes, and Bacteroidetes were the most dominant taxa. At the genus level, Rothia, Streptococcus, Escherichia, Actinomyces, Prevotella, and Pseudomonas predominated. Significant differences in the small intestinal microbiota composition were found between the SIBO-MHE group and the other two cirrhotic groups (P<0.05). Patients with prolonged OCTT showed a greater relative abundance of Bacteroides, Streptococcus, Bacillus, Lactobacillus, Alphaproteobacteria, and Prevotella.

CONCLUSION Cirrhotic patients with SIBO(+) MHE demonstrate a prolonged OCTT compared to their counterparts without SIBO, indicating significant gastrointestinal dysmotility.