The proximal small intestine is key for nutrition, metabolism and immune responses, and can be affected by a wide range of disorders. This Review describes the cellular and molecular bases of diseases of the proximal small intestine (including rare monogenic disorders), proposing a mechanism-based taxonomy.

Many aspects of the biology and pathogenesis of hepatitis E virus (HEV) infection remain underexplored. In this Review, Steinmann and colleagues summarize the role of the innate and adaptive immune systems in HEV infection.

This Perspective discusses the nomenclature change from nonalcoholic fatty liver disease to metabolic dysfunction-associated steatotic liver disease (MASLD) and proposes steps necessary to improve care and end the public health threat posed by MASLD and metabolic dysfunction-associated steatohepatitis.

Nature Reviews Gastroenterology & Hepatology is launching a new Series on justice, equity, diversity and inclusion in an effort to increase awareness and advance equitable health.

Therapeutic advances in inflammatory bowel disease (IBD) have been universally directed towards patients with established disease to control inflammation, ameliorate symptoms and hinder disease progression, but preventing IBD development or delaying its onset are highly attractive. This Comment discusses the emerging approaches and future promises of interventional disease prevention trials in IBD.

The current state of microbiome research in Africa can be leveraged to encourage the development and implementation of standardized processes for data collection and management. In this Comment, we provide some recommendations to enable the research community to fully harness the richness of the microbiome of African populations and potential opportunities therein.

Gastroenterology as a specialty can make a substantial contribution to reducing the carbon footprint of the health-care system. Concrete actions are needed to increase awareness, education and evidence-based knowledge on eco-sustainable diagnostic and therapeutic approaches to digestive diseases.