Review Articles, News & Views, Perspectives, Hypotheses, Analyses and Review in 2019

Colorectal cancer is one of the most common cancers worldwide. This Review provides a comprehensive summary of colorectal cancer epidemiology, with emphasis on modifiable lifestyle and nutritional factors, chemoprevention and screening.

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related death worldwide. This Review summarizes the epidemiology, risk factors (including viral hepatitis and NAFLD), molecular profiles and treatment of HCC, providing insights into how the global burden of HCC can be reduced.

During the metastatic process, cancer cells spread from the primary tumour to distant organs. Although metastases are the primary cause of cancer mortality, the dynamics of the metastatic process remain largely unknown. A new study suggests that during colorectal cancer progression, metastatic seeding might occur before clinical detectability.

The design of clinical trials for hepatocellular carcinoma is complicated by a number of obstacles. In this Review, the authors discuss the advances in systemic therapy for hepatocellular carcinoma and critically discuss trial designs in the context of past successes and failures.

Multi-omics technologies in gut microbiome research provide a global view of changes in genetic, metabolic and biochemical processes. This approach has now been applied to the gut microbiota in the context of IBD, providing first steps towards a functional understanding of host–microbe interactions during disease pathogenesis.

Macrophages are the gatekeepers of intestinal immune homeostasis. This Review discusses the molecular and cellular mechanisms involved in the differentiation and function of intestinal macrophages in homeostasis and inflammation, and their role in resolving the inflammatory process.

A new study has added valuable outcome data from adolescents 5 years after undergoing Roux-en-Y gastric bypass. By comparing outcomes from adolescents and adults, the study adds to the existing evidence base, highlighting metabolic and bariatric surgery as an increasingly valuable tool in the multidisciplinary management of adolescents with severe obesity.

A new study involving integrative genomic and transcriptomic analysis of dual hepatocellular–intrahepatic cholangiocarcinoma tumours has identified distinct subtypes that display different clinical and molecular features, and that could be used to guide therapeutic decisions.

The gut microbiota has been implicated in a range of diseases. This Review describes current understanding of probiotics and prebiotics as a means to manage the microbiota to improve host health, including mechanisms of actions and potential for clinical use.

Artificial intelligence (AI) has the potential to change many aspects of health-care practice. Two newly published trials explore the potential applications of AI to improve polyp detection and mucosal visualization in gastrointestinal endoscopy — both show the benefits of AI to improve detection in gastrointestinal endoscopy.

Nonalcoholic fatty liver disease (NAFLD) has become the most common form of chronic liver disease in children and adolescents. In this Review, the authors summarize current knowledge and new advances related to the epidemiology, pathogenesis and management of paediatric NAFLD.

Telomerase is a key enzyme for cell survival that prevents telomere shortening. In this Review, the roles of telomeres and telomerase in cirrhosis and liver carcinogenesis are discussed, in addition to their potential in clinical practice as biomarkers and therapeutic targets.

Telephone or web-based psychotherapy has been suggested to be as effective as face-to-face psychotherapy while lowering access restrictions and improving patient acceptability. A large new study in patients with IBS shows the superiority of such an approach in comparison with treatment as usual.

Small intestinal bacterial overgrowth (SIBO) has been linked to common gastrointestinal symptoms; yet its precise definition remains elusive. A new study shows that, when it comes to symptom prediction in functional gastrointestinal disorders, high-throughput sequencing analysis of the microbiome and not jejunal aspiration and culture is the clear winner.

New knowledge has been steadily acquired in genetic and congenital cholangiopathies. Here, the authors discuss Alagille syndrome, polycystic liver diseases, fibropolycystic liver diseases and cystic fibrosis-related liver disease and the insights that these conditions provide into the mechanisms of acquired cholangiopathies.

Single-cell RNA profiling of colonic epithelial crypts from healthy volunteers and patients with ulcerative colitis adds pH-regulating colonocytes and goblet cells expressing a major determinant of barrier maintenance to the current arsenal of uncovered colonic epithelial cell types.

A new study shows that a real-world care pathway for patients with NAFLD in primary care can increase the detection of patients with clinically significant liver disease and decrease referrals for patients who could be managed in the community.

The incidence of acute pancreatitis is increasing worldwide, and it is one of the most common gastrointestinal causes for hospital admission. In this Review, the authors provide a summary of advances in acute pancreatitis with an emphasis on pathophysiological mechanisms and clinical management.

Short-chain fatty acids (SCFAs) are speculated to have a key role in microbiota–gut–brain crosstalk, but the pathways influencing psychological functioning have not been fully elucidated. This Review summarizes existing knowledge of how SCFAs might indirectly or directly mediate psychological processes.

A new study provides evidence that platelets exert potent inflammatory effects and play a central part in the progression from simple steatosis to nonalcoholic steatohepatitis. The results from this and other studies raise important questions regarding the role of platelets in the development of hepatocellular carcinoma in individuals with fatty liver disease.