A Review of Recent Advances in Fecal Microbiota Transplantation for the Treatment of Hepatic Encephalopathy.

Hepatic encephalopathy (HE) results from a debilitating complication of liver cirrhosis and acute liver failure, characterized by neuropsychiatric abnormalities ranging broadly from mild cognitive impairment to respiratory failure to coma. The pathogenesis of HE is multifactorial, with gut-derived toxins, particularly ammonia, playing a central role. Recent advances in understanding the gut-liver-brain axis have revealed the importance of gut microbiota and dysbiosis in the development and progression of HE. Fecal microbiota transplantation (FMT), a clinical procedure that is performed to transfer fecal microbiota from a healthy donor to a patient with HE (recipient), has emerged as a promising therapeutic strategy for modulating gut microbiota and ameliorating HE. FMT facilitates the restoration of gut microbiota composition with increased microbial alpha diversity, reestablishment of the balance between beneficial and pathogenic bacteria, reduction in the production of gut-derived toxins, and improvement of intestinal barrier function. It also modulates immune and inflammatory responses, alleviating hepatocyte and biliary injury. FMT has also demonstrated efficacy in improving cognitive function and reducing hospitalizations in HE patients and can maintain a stable donor-like microbiota profile for up to 12 months post-transplantation. FMT is generally well-tolerated, with most adverse events reported to be mild and transient, providing a desirable option for HE treatment. This review provides a comprehensive overview of the current understanding of the role of gut microbiota in the pathogenesis of HE, the mechanisms underlying the therapeutic effects of FMT, and the clinical evidence supporting its use in HE. We will also discuss the limitations, challenges, and future prospects for FMT in the treatment of HE.