Exposure to environmental pollutants and human microbiome composition are important predisposition factors for tumour development^1,2. Similar to drug molecules, pollutants are typically metabolized in the body, which can change their carcinogenic potential and affect tissue distribution through altered toxicokinetics³. Although recent studies demonstrated that human-associated microorganisms can chemically convert a wide range of xenobiotics and influence the profile and tissue exposure of resulting metabolites^4,5, the effect of microbial biotransformation on chemical-induced tumour development remains unclear. Here we show that the depletion of the gut microbiota affects the toxicokinetics of nitrosamines, which markedly reduces the development and severity of nitrosamine-induced urinary bladder cancer in mice^6,7. We causally linked this carcinogen biotransformation to specific gut bacterial isolates in vitro and in vivo using individualized bacterial culture collections and gnotobiotic mouse models, respectively. We tested gut communities from different human donors to demonstrate that microbial carcinogen metabolism varies between individuals and we showed that this metabolic activity applies to structurally related nitrosamine carcinogens. Altogether, these results indicate that gut microbiota carcinogen metabolism may be a contributing factor for chemical-induced carcinogenesis, which could open avenues to target the microbiome for improved predisposition risk assessment and prevention of cancer.

Background: Bismuth quadruple therapies (BQTs) including bismuth, a proton pump inhibitor (PPI) and two antibiotics have been shown to be highly effective for treating Helicobacter pylori infection even in areas of high bacterial antibiotic resistance. Objective: To describe the time trends of use, effectiveness and safety of BQT in Europe using the European Registry on Helicobacter pylori Management (Hp-EuReg). Design: Patients registered in the Hp-EuReg from 2013 to 2021 who had received BQT were included. The regimens prescribed, the number of eradication attempts, effectiveness, adherence and safety were analysed. The effectiveness was assessed by modified intention to treat (mITT). Time-trend and multivariate analyses were performed to determine variables that predicted treatment success. Results: Of the 49 690 patients included in the Hp-EuReg, 15 582 (31%) had received BQT. BQT use increased from 8.6% of all treatments in 2013 to 39% in 2021. Single-capsule BQT—containing bismuth, metronidazole and tetracycline—plus a PPI (single-capsule BQT, ScBQT) was the most frequent treatment mode (43%). Schemes that obtained an effectiveness above 90% were the 10-day ScBQT and 14-day BQT using tetracycline plus metronidazole, or amoxicillin plus either clarithromycin or metronidazole. Only ScBQT achieved above 90% cure rates in all the geographical areas studied. Using the ScBQT scheme, adherence, the use of standard or high-dose PPIs, 14-day prescriptions and the use of BQT as first-line treatment were significantly associated with higher mITT effectiveness. Conclusion: The use of BQT increased notably in Europe over the study period. A 10-day ScBQT was the scheme that most consistently achieved optimal effectiveness. Trial registration number: NCT02328131 .

Inflammatory bowel diseases (IBD) remain challenging in terms of understanding their causes and in terms of diagnosing, treating, and monitoring patients. Modern diagnosis combines biomarkers, imaging, and endoscopic methods. Common biomarkers like CRP and fecal calprotectin, while invaluable tools, have limitations and are not entirely specific to IBD. The limitations of existing markers and the invasiveness of endoscopic procedures highlight the need to discover and implement new markers. With an ideal biomarker, we could predict the risk of disease development, as well as the possibility of response to a particular therapy, which would be significant in elucidating the pathogenesis of the disease. Recent research in the fields of machine learning, proteomics, epigenetics, and gut microbiota provides further insight into the pathogenesis of the disease and is also revealing new biomarkers. New markers, such as BAFF, PGE-MUM, oncostatin M, microRNA panels, αvβ6 antibody, and S100A12 from stool, are increasingly being identified, with αvβ6 antibody and oncostatin M being potentially close to being presented into clinical practice. However, the specificity of certain markers still remains problematic. Furthermore, the use of expensive and less accessible technology for detecting new markers, such as microRNAs, represents a limitation for widespread use in clinical practice. Nevertheless, the need for non-invasive, comprehensive markers is becoming increasingly important regarding the complexity of treatment and overall management of IBD.

The primary objective of this study was to compare concomitant and hybrid therapy in the first line eradication treatment of Helicobacter pylori infection in Split-Dalmatia County, Croatia, in which clarithromycin resistance is above 20%. The secondary objective of the study was to determine and compare compliance and adverse events rate between these therapeutic protocols. In an open-label, randomised clinical trial 140 patients total with H. pylori infection were randomly assigned to either concomitant (esomeprazole 40 mg, amoxicillin 1 g, metronidazole 500 mg, clarithromycin 500 mg, twice daily for 14 days) or hybrid (esomeprazole 40 mg and amoxicillin 1 g twice daily during 14 days with adding metronidazole 500 mg and clarithromycin 500 mg twice daily, in the last 7 days,) treatment group. Eradication rates for concomitant group and hybrid therapy group were 84.1% (58/69) and 83.1% (59/71) respectively in the intention-to-treat analysis and 96.7% (58/60) and 95.2% (59/62) in per-protocol analysis. There was no significant difference between the groups (ITT analysis: P = 0.878; PP analysis: P = 0.675). Adverse events were more frequent in the concomitant group (33.3% vs 18.3%, P = 0.043). There was no difference among groups regarding compliance rate. Hybrid therapy has similar eradication rate as concomitant therapy, with lower adverse events rate. In the era of increasing antibiotic resistance, eradication regime with less antibiotic’s usage, as hybrid therapy, should be reasonable first line treatment choice for H. pylori infection. Clinical Trials, gov: NCT03572777.

INTRODUCTION: To evaluate the prescription patterns, effectiveness, and safety of adding probiotics to Helicobacter pylori eradication therapy, in Europe. METHODS: International, prospective, noninterventional registry of the clinical practice of the European gastroenterologists. Data were collected and quality reviewed until March 2021 at AEG-REDCap. The effectiveness was evaluated by modified intention-to-treat analysis, differentiating by geographic areas. Adverse events (AEs) were categorized as mild, moderate, and severe. RESULTS: Overall, 36,699 treatments were recorded, where 8,233 (22%) were prescribed with probiotics. Probiotics use was associated with higher effectiveness in the overall analysis (odds ratio [OR] 1.631, 95% confidence interval [CI] 1.456–1.828), as well as in triple (OR 1.702, 95% CI 1.403–2.065), quadruple (OR 1.383, 95% CI 0.996–1.920), bismuth quadruple (OR 1.248, 95% CI 1.003–1.554), and sequential therapies (OR 3.690, 95% CI 2.686–5.069). Lactobacillus genus was associated with a higher therapy effectiveness in Eastern Europe when triple (OR 2.625, 95% CI 1.911–3.606) and bismuth quadruple (OR 1.587, 95% CI 1.117–2.254) first-line therapies were prescribed. In Central Europe, the use of probiotics was associated with a decrease in both the overall incidence of AEs (OR 0.656, 95% CI 0.516–0.888) and severe AEs (OR 0.312, 95% CI 0.217–0.449). Bifidobacterium genus was associated with lower overall (OR 0.725, 95% CI 0.592–0.888) and severe (OR 0.254, 95% CI 0.185–0.347) AEs, and Saccharomyces was associated with reduced overall (OR 0.54, 95% CI 0.32–0.91) and severe (OR 0.257, 95% CI 0.123–0.536) AEs under quadruple-bismuth regimen. DISCUSSION: In Europe, the use of probiotics was associated with higher effectiveness and safety of H. pylori eradication therapy. Lactobacillus improved treatment effectiveness, whereas Bifidobacterium and Saccharomyces were associated with a better safety profile.

Background and Objectives: Helicobacter pylori (H. pylori) infection impairs quality of life. However, whether eradication therapy ameliorates gastrointestinal symptoms remains questionable. The main objective of this study was to evaluate the influence of H. pylori eradication therapy on gastrointestinal symptoms. Materials and Methods: A total of 140 patients, 59 women and 81 men, with a mean age of 61 and suffering from H. pylori infection in the University Hospital of Split, Croatia, were enrolled in the study. Patients were randomly assigned to either concomitant or hybrid therapies. The Gastrointestinal Symptom Rating Scale (GSRS) questionnaire was completed by patients prior to and after the eradication therapy. Results: In both groups, the total GSRS score improved significantly after therapy. In the concomitant group, the abdominal pain score, reflux symptoms score and indigestion score decreased significantly after therapy. In the group with hybrid therapy, all five groups of symptoms (abdominal pain, reflux symptoms, indigestion, diarrhea and constipation) significantly decreased after therapy. Patients with adverse events had significantly higher total GSRS scores after eradication therapy. Conclusions: H. pylori eradication therapy could alleviate gastrointestinal symptoms regardless of the treatment used, but the favorable effect seemed to be more pronounced after hybrid therapy.