Maria del Barrio

1 Introduction It is well known that the simultaneous presence of two liver diseases implies a greater challenge in patient management and is usually associated with a worse prognosis [1]. Primary biliary cholangitis (PBC) is a chronic cholestatic liver disease classified as a rare liver disease.

Elena Gómez Hospital Universitario 12 de Octubre, Madrid, Spain Contribution: Methodology, Writing - original draft, Formal analysis, Data curation, Conceptualization, ​Investigation, Validation, Visualization, Writing - review & editing, Project administration, Software, Supervision, Resources, Writing - review & editing, Data curation, Writing - review & editing, Data curation, Writing - review & editing, Data curation, Writing - review & editing, Data curation, Writing - review & editing,...

2.7. Microbiome The research carried out in recent years points to the fundamental role of the gut microbiome (GM) in the development of NAFLD as well as in multiple physiological processes such as energy metabolism and immune functions [96]. The human GM is dominated by four bacterial phyla: Bacteroidetes, Firmicutes, Proteobacteria and Actinobacteria [97]. Recent studies show that lean and obese individuals differ in gut bacterial composition [98].