News & Views

Studies of liver regeneration after injury have provided knowledge of the role of external signals and internal metabolic and regenerative pathways. However, less is understood about homeostatic maintenance of normal liver size in the absence of external injury. Three important new studies explore liver regeneration and homeostasis using novel lineage tagging of hepatic cells and single-cell RNA transcriptomics.

Intense research is ongoing to dissect the reciprocal interactions between microbiota and drugs. New work finds that a drug to dampen host inflammation can also have off-target effects on the microbiota at transcriptional, metabolic and compositional levels, with resultant expanded benefits to the host.

The prevalence of nonalcoholic fatty liver disease (NAFLD) has increased rapidly and is associated with obesity in epidemiology and pathogenesis. A new study reports that hepatic and extrahepatic complications can develop in lean individuals with NAFLD, highlighting the importance of metabolic phenotypes in NAFLD assessment instead of BMI-based approaches.

Necrotizing enterocolitis (NEC) is an acute intestinal emergency in preterm infants, which is often later complicated by cognitive delay and neurodevelopmental disability. A new study performed in mice suggests that CD4⁺ T cells can travel from the NEC-inflamed gut to the brain and cause IFNγ-mediated brain injury.

Inflammatory bowel disease (IBD) has emerged as a global disease, yet identifying those at higher risk of developing IBD remains challenging. A new study highlights the use of a multi-ethnic polygenic risk score to determine risk of inflammatory bowel disease in a large primary care population.

A new study elevates our understanding of how the immune system regulates the pathogenesis of biliary atresia through a powerful single-cell approach. Cell-specific transcriptome analyses indicate key roles for macrophages, T cells and B cells in hepatobiliary injury of affected infants.

The enteric nervous system (ENS) is an important component of gastrointestinal function and a pivotal hub connecting the gut to other organs. A new study now explores the human and mouse ENS at the single-cell level, providing key insights into the transcriptomic landscape of the ENS and its constituent cells.

A new study sheds further light on the interplay between environmental stimuli, the gut microbiota and intestinal inflammation. Identification of modifiable environmental triggers and the mechanisms by which they act has implications for the prevention and treatment of inflammatory bowel disease.

Liver biopsy sample evaluation is an essential part of clinical studies in nonalcoholic steatohepatitis (NASH) and is key in excluding confounding morbidities. Current scoring systems, which are decisive for study inclusion, rely on imprecisely defined histological features, leading to a high observer variability of disease categorization. In this News & Views, measures to overcome these limitations are discussed.

Vagus nerve stimulation has shown promise in treating inflammatory bowel disease. A new study identifies a hepatic vagal branch pathway necessary to maintain colonic immune cell homeostasis in experimental colitis, challenging the dogma that an anti-inflammatory reflex requires an intact spleen and that α7-nicotinic receptor agonists are a panacea for inflammatory conditions.

Pancreatic cancer is notorious for its affinity for invading nerves. A new study using a systematic unbiased RNA-interference screen of neuronal chemokines in cocultures of mouse sensory neurons and pancreatic cancer cells has now identified CCL21 and CXCL10 as key mediators of neural invasion, neural remodelling and pain in pancreatic cancer.

Most patients who undergo curative intent surgery for pancreatic cancer will still die of recurrent disease. A new study shows that pancreatic tumours that pass through the genetic bottlenecks of surgery and additional chemoradiotherapy have altered mutational signatures, driver genes and subclonal architecture.

A mountable ‘smart’ toilet system has been developed to personalize health monitoring. The system uses excretion data, including urinalysis, urodynamics, stool form and defecation timing, stored in a cloud server. This smart toilet system has the potential to provide useful information to characterize symptoms of patients with bowel dysfunction or defecatory disorders.

Obesity is a known risk factor for pancreatic cancer. Now, a new study reports that obesity accelerates early pancreatic cancer development and growth in mice through local perturbations in the pancreatic microenvironment and implicates pancreatic islet-derived cholecystokinin as a driving factor.

Two new position papers convincingly propose that nonalcoholic fatty liver disease needs a new name — metabolic associated fatty liver disease (MAFLD). A new name for this disease affecting nearly one billion people globally is overdue, as knowledge gained from the past decades has assuringly demonstrated that MAFLD is a purely metabolic disorder.

Details about IgE-producing B cells in the gut in the context of food allergy are scarce, despite the frequent exposure of the gut and its associated lymphoid tissues to dietary antigens. A new study finds that IgE-producing B cells are enriched in gut tissues and are probably generated from local antibody isotype switching.

New national hepatitis C virus (HCV) screening guidance from the United States Preventive Services Task Force includes a recommendation for one-time testing for all adults aged 18 to 79 years. Implicit in the new guidance is that all people diagnosed with chronic HCV infection should be offered HCV treatment.

The microbial communities that occupy the intestinal tract are shaped by a variety of different factors, including the immune system. A new study has observed and quantified, at unprecedented depth, regionally distinct microbial and immune niches along the human colon using simultaneous analyses of the gut microbiota and neighbouring immune cells.

Colibactin-producing bacteria are abundant in the gut microbiota of colorectal cancer tumours and promote colon tumorigenesis in mouse models. Now, a new study demonstrates a direct link between exposure of human intestinal epithelial cells to colibactin and two unique mutational fingerprints found in human colorectal tumours.

Genomic alterations are well-described in Barrett oesophagus and its sequela, oesophageal adenocarcinoma, but epigenomic events have not been so widely investigated. In a new study, Jammula et al. analysed the DNA methylation profiles of Barrett oesophagus, oesophageal adenocarcinoma and control tissues. Four molecular subtypes were identified, revealing four distinct epigenomic classes and potential therapeutic targets.