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

Live biotherapeutics have been used clinically both as defined probiotics and as undefined faecal microbiota transplants. Two new studies illustrate the risks of administering live microorganisms to highly compromised patients. These risks should be considered in the context of the potential therapeutic value of these treatments.

Primary biliary cholangitis (PBC) is a chronic, inflammatory and cholestatic liver disease with a variable rate of progression towards biliary cirrhosis. Here, the authors discuss the current understanding of PBC pathogenesis and highlight implications for new therapies.

An area of research suggests a role for microbiota in the pathogenesis of pancreatic diseases, such as pancreatitis, pancreatic cancer and type 1 diabetes mellitus. In this Perspectives, the authors examine the literature implicating microorganisms in diseases of the pancreas as well as the evidence of an inherent pancreatic microbiota.

This Review discusses the molecular heterogeneity of hepatocellular carcinoma, the intrinsic and extrinsic factors that stimulate tumour evolution and how this information can be leveraged to improve the clinical management of patients with this disease.

IBD treatment has an expanding repertoire of drugs targeting different aspects of the immune response. This Review focuses on unravelling the complexity of mucosal immune responses in IBD pathogenesis and how analytical assays might be harnessed to effectively stratify and individualise IBD therapy.

Functional constipation is common in children and adults worldwide. Here, the authors provide an overview of the differing management strategies for childhood and adult functional constipation, including insights into epidemiology, pathophysiology, diagnosis and therapy.

A new study demonstrates a novel role for an endocannabinoid in promoting hepatocyte steatosis. The study describes a mode of bidirectional communication between the alcohol-injured hepatocyte and the glutamate-activated hepatic stellate cell. This intercellular communication represents a novel targetable pathogenic mechanism that could lead to new strategies to prevent fatty liver disease progression to cirrhosis.

Primary liver cancers are frequently accompanied by rearrangements of metabolic pathways. This Review discusses the role of metabolic liver disruptions and the implications of these processes, emphasizing their clinical relevance and value in early diagnosis and prognosis and as putative therapeutic targets.

This Review discusses the genetics of nonalcoholic fatty liver disease (NAFLD), including evidence of shared genetic modifiers and possible pleiotropic effects between NAFLD and other liver diseases or metabolic disorders. The translational implications and future challenges are also discussed.

A new study reveals that a novel serotonin sensor in the spore-forming gut bacteria, Turicibacter sanguinis, might be important for host lipid and steroid metabolism. These findings support the emerging concept that bidirectional signalling pathways can influence bacterial community structure and exert effects on host physiology.

A new study is the first to investigate the relationship between liver-enriched antimicrobial peptide-2 (LEAP2) and different metabolic states, and highlights the reciprocal relationship between LEAP2 and ghrelin (known as the ‘hunger hormone’ for its role in stimulating appetite). These findings could have important implications given the worldwide increase in obesity since 1975.

Innate immune responses are currently seen as a key element driving hepatic inflammation in nonalcoholic steatohepatitis. However, this Review discusses the increasing evidence pointing to the role of adaptive immunity as an additional factor promoting liver inflammation and driving disease progression.

Screening and early diagnosis of pancreatic cancer are at the focal point of attention from researchers, physicians and patients. A new systematic review and recommendation statement by the USPSTF attempt to summarize the current state of affairs.

Colorectal cancer (CRC) is one of the most common cancers worldwide. This Review describes the role of microorganisms in colorectal carcinogenesis, and the potential clinical translation of the gut microbiota as a biomarker for CRC diagnosis and prognosis, and as an approach for disease prevention and to improve therapy.

Whether to administer purgative cleansing and oral antibiotics before colon surgery as a method to prevent postoperative infections, once standard of care, is now being considered unnecessary with today’s advancements of care. A new study questions the efficacy of this bowel preparation approach with a prospective randomized trial.

Multiple therapeutic approaches are being developed to achieve sustained, off-treatment suppression of HBV. In this Review, the authors examine T cell and B cell responses to HBV and the potential for immunotherapies to restore or release endogenous adaptive immunity by direct or indirect approaches.

Pancreatic cystic neoplasms are a heterogeneous group of pancreatic cysts with different biological behaviours and variable risk of progression to malignancy. This Review summarizes the latest developments in the diagnosis and management of pancreatic cysts, including the quality of available evidence.

There is an emerging understanding of the roles of intestinal gases, generated via chemical interactions or the microbial metabolism of dietary substrates, in gut homeostasis and pathophysiology. In this Review, the authors discuss these emerging data, highlighting links with dietary intake and new gas profiling methods.

Living donor liver transplantation is a proven option for end-stage liver disease. In a new study, a pioneering multi-organ transplantation programme in Canada critically reviews the motivations and facilitators of anonymous adult living liver donors over a 12-year period, providing insights into how we can push forward ethical living organ donation for transplantation.

Chronic HBV infection is a serious problem; few patients achieve the ultimate goal of hepatitis B surface antigen loss. This Review integrates findings from research in HBV infection kinetics and discusses how they can aid understanding and management of HBV infection.