In 1998, Arlette Darfeuille-Michaud, Christel Neut and Jean-Frederic Colombel discovered a novel pathovar of Escherichia coli, adherent and invasive Escherichia coli (AIEC), in the ileum of patients with Crohn's disease (CD), that was genetically distinct from diarrheagenic E. coli, could adhere to and invade intestinal epithelial cells and survive in macrophages. The consistent association between AIEC and CD (approximately 30% across the world), their ability to exploit CD-associated genetic traits, and virulence in preclinical colitis models but not healthy hosts spurred global research to elucidate their pathogenicity. Research focused on integrating AIEC with the microbiome, metabolome, metagenome, host response and the impact of diet and antimicrobials has linked the luminal microenvironment and AIEC metabolism to health and disease. This deeper understanding has led to therapeutic trials and precision medicine targeting AIEC-colonised patients. In November 2023, prominent members of the AIEC research community met to present and discuss the many facets of basic, translational and clinical AIEC fields at 'AIEC: past, present and future' in NYC. This review is a summary of this international meeting highlighting the history of AIEC, knowledge accumulated over the past 25 years about its pathogenic properties and proposes a standardised approach for screening patients for AIEC.

Current treatments with tyrosine kinase inhibitors and immune checkpoint inhibitors have limited efficacy for hepatocellular carcinoma (HCC) due to drug resistance. Emerging therapies such as chimeric antigen receptor T (CAR-T) and macrophage-based cell therapies are promising but need to be improved.

Helicobacter pylori infection is the most prevalent bacterial infection worldwide. Attempts to develop a vaccine have not been successful, partly due to the absence of well-defined immune correlates of protection. The inflammatory response to H. pylori infection is characterised by the recruitment of T cells expressing markers of tissue-resident memory T (TRM) cells to the gastric mucosa. However, the function of TRM cells in gastric tissue during H. pylori reinfection remained poorly understood.

Endoscopic procedures are a notable source of medical waste, contributing significantly to environmental pollution. Prior studies report 0.5-3.0 kg of waste per procedure-compared with just 1.2 kg of household waste generated per person per day in Germany.

Pancreatic cancer exhibits limited clinical responses to immunotherapy, highlighting the need for new strategies to counteract its immunosuppressive microenvironment. Although metabolic reprogramming and epigenetic changes contribute to malignancy, the impact of lactate-driven histone lactylation on the tumour microenvironment (TME) has not been fully explored.

Patients with chronic hepatitis B (CHB) with indeterminate phase make up a diverse cohort with likely different outcomes.

Prophylactic clip closure after endoscopic mucosal resection reduces delayed bleeding in large and proximal colon lesions; however, evidence regarding its effectiveness in colorectal endoscopic submucosal dissection (ESD) is lacking.

The gut microbiota has been linked to non-communicable diseases, including chronic kidney disease (CKD). However, the relationships between gut microbiome composition changes, uraemic toxins (UTs) accumulation, and diet on CKD severity and progression remain underexplored.

Gastrointestinal acute graft-versus-host disease (GI-aGVHD) is one of the main complications of patients undergoing allogenic haematopoietic stem cell transplantation (allo-HSCT). A deeper understanding of the mechanisms of sustaining intestinal homeostasis is essential.

The intricate interplay between the gut microbiota and the GI tract has garnered significant attention, as growing evidence has identified the inflammasome as a crucial yet underexplored master regulator in microbiota-driven diseases. Triggered by a variety of dangers, inflammasomes are supramolecular complexes that regulate immune response. A large number of bacterial-derived inducers have been characterised so far. Although structurally divergent, threats are neutralised by the inflammasome, which is then classified into three families: (1) nucleotide-binding oligomerisation domain, leucine-rich repeat-containing proteins, (2) absent in melanoma 2-like receptors and (3) pyrin. An unbalanced microbiota composition, expressed by a dysbiotic phenotype, might therefore induce undesired inflammasome activation, altering the local host homeostasis. Recent studies on the 'microbiota-inflammasome axis' have uncovered unexpected roles for inflammasome signalling in various types of GI cancer and IBD. Additionally, beyond local gut functions, microbiota influences stress responses and neurological health through aberrant secretion of inflammasome-processed cytokines, linking gut-derived signals to systemic diseases via the vagus nerve and the hypothalamic-pituitary-adrenal axis. Besides the standard experimental approaches, this complex network of interactions is now being addressed by Artificial intelligence, which emphasises the profound impact of the gut microbiota on GI health, cancer progression and brain function, opening new avenues for therapeutic intervention in GI diseases, cancer and neurological disorders. Ultimately, microbiota-inflammasome interactions manage a regulatory framework that influences inflammation, cancer progression and systemic diseases, positioning it as both a mediator and a promising therapeutic target in GI malignancies and systemic diseases of the central nervous system.