Although fermented foods have been consumed for thousands of years, a clear definition has been lacking. This Consensus Statement outlines a definition for the term ‘fermented foods’ as determined by an expert panel convened by the International Scientific Association for Probiotics and Prebiotics in September 2019.

The prevalence of nonalcoholic fatty liver disease (NAFLD)-related hepatocellular carcinoma (HCC) is projected to continue to increase worldwide. In this Review, Huang, El-Serag and Loomba discuss the global epidemiology and risk factors for NAFLD-related HCC, and propose strategies to tackle this problem.

Human microphysiology systems (MPS) have evolved as experimental model systems. This Review explores these so-called organ-on-a-chip systems and the role of biomimetic human liver MPS in drug development and precision medicine, providing insights into their design and use as models of liver physiology and disease.

The common end stage of liver disease is decompensated cirrhosis and the further development towards acute-on-chronic liver failure. In this Review, the authors discuss the possible pathogenic, diagnostic and therapeutic role of the gut microbiota in decompensation of cirrhosis and progression to acute-on-chronic liver failure.

A gluten-free diet is currently the only effective treatment for coeliac disease but an increased understanding of disease pathogenesis has led to the identification of several potential therapeutic targets. This Review provides a broad overview of current and emerging therapies for coeliac disease.

Dietary fibre has been shown to be beneficial for gastrointestinal health. This Review discusses the physicochemical and functional characteristics of dietary fibres and provides insight into their role in gastrointestinal health and the management of gastrointestinal disorders.

Data on the efficacy and safety of SARS-CoV-2 vaccines are now available, but evidence for these vaccines in those who are immunocompromised (including patients with inflammatory bowel diseases) are lacking. As vaccination begins, questions on advantages and disadvantages can be partially addressed using the experience from other vaccines or immune-mediated inflammatory disorders.

In 2020, there have been substantial advances in nonalcoholic fatty liver disease mechanisms, diagnostics and treatment. Key developments include the identification of a cellular and tissue signature to provide new insights into pathophysiology, advancements in non-invasive diagnostics and publication of interim results of the first phase III trial to demonstrate improvement in hepatic fibrosis.