Volume 14 Issue 2, February 2017

In 2016, key studies have increased our understanding of the part played by the brain–gut–microbiota axis in disorders as diverse as depression, obesity and autism spectrum disorder. The data indicate that alterations in gut-microbial composition can substantially affect central physiology, and that transplantation of the gut microbiota can transfer a behavioural or physiological phenotype.

The burden of HBV infection remains high and new strategies to improve HBV vaccination and therapy are needed. Key research in 2016 highlights the efficacy of current approaches and proposes new concepts for some of the immunological defects that need to be overcome for HBV functional cure.

The challenge to obtain needle biopsy samples from patients with cancer has steered the development of new blood-based diagnostics called 'liquid biopsy'. In 2016, major advances have been made in the use of circulating tumour cells and cell-free DNA for monitoring tumour evolution in patients with cancer of the gastrointestinal tract, with a focus on colorectal cancer.

In 2016, personalized medicine for IBD has been evolving. Increasing comfort with biosimilar infliximab was achieved with 'real-life' data. Drugs with alternative modes of action confirmed substantial benefit, even in patients failing anti-TNF agents. Adipose-derived mesenchymal stem cells yielded a new treatment option for perianal fistulas.

In 2016, obeticholic acid became the first new licensed therapy for primary biliary cholangitis in >20 years. This therapeutic came at a time of improved disease understanding from biliary and immunological mechanistic insights.

Fascination about the gut microbiota shows no signs of slowing down. The launch of the US National Microbiome Initiative in 2016, and similar efforts across the globe, underscore the continued enthusiasm for microbiome studies in the USA and beyond. Indeed, 2016 has been yet another notable year for gut microbiota research.

Here, the authors comprehensively explore evidence that maternal obesity and/or obesogenic diet, mediated by factors such as altered maternal metabolism, microbiota colonization, macrophage programming and epigenetic changes, can programme NAFLD risk and disease progression in offspring. Current and potential clinical interventions are also discussed.

Effective diagnostic imaging can improve prognosis for patients with pancreatic diseases such as pancreatitis, pancreatic cancer and diabetes mellitus, which benefit from early treatment. Here, Kelly and colleagues review current and future technologies for imaging pancreatic disease, and discuss the development of new contrast agents and molecular imaging targets.

Obesity affects 15–40% of patients with IBD. Here, Singh and colleagues discuss the evidence linking obesity to IBD pathogenesis, the effect of obesity on disease outcomes and treatment response, and obesity-related issues in abdominal imaging and IBD surgery.

Chronic HCV infection is a global health problem. In this Review, the authors describe the global burden of hepatitis C and HCV-related disease, including hepatocellular carcinoma, cirrhosis and extrahepatic manifestations. How the new direct-acting antiviral agents might influence disease burden is also discussed.