Helicobacter pylori is one of the most common cause of human infections. Infected patients develop chronic active gastritis in all cases, which can lead to peptic ulcer, atrophic gastritis, gastric cancer and gastric MALT-lymphoma. The prevalence of H. pylori infection in the population has regional characteristics and can reach 80%. Constantly increasing antibiotic resistance of H. pylori is a major cause of treatment failure and a major problem. According to the VI Maastricht Consensus, two main strategies for choosing eradication therapy are recommended: individualized based on evaluating sensitivity to antibacterial drugs (phenotypic or molecular genetic method) prior to their appointment, and empirical, which takes into account data on local H. pylori resistance to clarithromycin and monitoring effectiveness schemes in the region. Therefore, the determination of H. pylori resistance to antibiotics, especially clarithromycin, prior to choosing therapeutic strategy is extremely important for the implementation of these treatment regimens.

The gut microbiota’s pivotal role in human health is increasingly evident, particularly in chronic conditions like obesity, diabetes, and inflammatory diseases. This intricate symbiotic relationship influences metabolic balance and immune responses. Notably, gut microbial dysbiosis is linked to obesity’s metabolic disruption and chronic low-grade inflammation. Similarly, in diabetes, the microbiota’s impact on insulin resistance and glucose metabolism is becoming evident. Chronic inflammation, a common denominator in these conditions, is also a recognized precursor to carcinogenesis. This intersection prompts a compelling question: does the gut microbiota’s influence extend to gastrointestinal cancers like colorectal and pancreatic cancer? These malignancies are closely intertwined with inflammation and metabolic dysregulation. Exploring whether the microbial signatures associated with chronic conditions overlap with precancerous or cancerous states offers new perspectives. This article reviews emerging evidence on the interplay between the gut microbiota, chronic conditions, and gastrointestinal cancers. By elucidating these connections, we aim to uncover potential avenues for innovative diagnostic, preventative, and therapeutic strategies in colorectal and pancreatic cancer management.

The Maastricht VI/Florence consensus recommends, as one of the measures to enhance the efficacy of Helicobacter pylori infection eradication, a personalized treatment approach involving the selection of an antimicrobial agent based on the pre-determined resistance of H. pylori. To address the need to develop test systems for personalized drug selection, this study was designed to analyze the molecular resistance of H. pylori using a newly developed Sanger sequencing test platform. The characteristics of the test system were determined on 25 pure culture samples of H. pylori with known resistance. Sensitivity and specificity for detecting resistance to clarithromycin was 100% and those to levofloxacin were 93% and 92%, respectively. The test system has been tested in real clinical practice on 112 H. pylori-positive patients who had not previously received proton pump inhibitors (PPIs) or antibacterial drugs. Mutations indicating resistance to clarithromycin were found in 27 (24%) samples and those indicating resistance to levofloxacin were found in 26 (23%) samples. Double resistance was observed in 16 (14%) samples. The most common mutations leading to clarithromycin resistance were 2143G and 2142G and to levofloxacin resistance—261A and 271A in the gyrA gene, which account for 69% of all identified genetic determinants in levofloxacin-resistant bacteria. Thus, a personalized approach to the selection of H. pylori eradication therapy based on the detection of bacterial resistance before prescribing first-line therapy could help to avoid the prescription of ineffective H. pylori eradication therapies and, overall, contribute to the control of antibiotic resistance of H. pylori.

   Introduction: Peutz-Jeghers syndrome (PEUTZ-JEGHERS SYNDROME; PJS; OMIM#175200) is hereditary tumor syndrome and is characterized by the occurrence of hamartomatous polyps of gastrointestinal tract, melanocytic pigmentation of the skin and mucous membranes, as well as a high predisposition to malignant tumors of various locations. Despite the fact that the clinical features of PJS are currently well understood, the nature of the variability in the phenotypic manifestations of the disease has not been fully described.   Aims: to determine the phenotypic and clinical features in patients with PJS depending on the type of mutation in the STK11 gene.   Patients and methods: the clinical and genetic data of 3 patients aged 21, 28 and 39 years with clinical signs of PJS are presented. All patients underwent medical genetic counseling and molecular genetic diagnostics of the STK11 gene using NGS and MLPA methods.   Results: large deletions of ex2-8 and ex1 in the STK11 gene were revealed in two patients, and one patient showed a splice site variant c.921-1G > A. The identified variant ex2-8 has not previously been described in international databases. When evaluating the clinical and genetic features, the most severe picture of the disease was in a patient with an extended deletion of exons 2-8, large number of polyps and surgical procedures in history. However, in this case, melanocytic pigmentation became less with age, in contrast to patients with a splice site mutation and a single exon deletion. No cancers were detected in the patients.   Conclusion: the molecular genetic test made it possible to confirm the clinical diagnosis of PJS, based on various phenotypic features, and to work out the personalized plan for follow-up. Evaluation of the genotype-phenotype correlations will be possible with the development of a unified register of mutation carriers.

This study investigated the IgA antibodies targeting bovine serum albumin (BSA) in 27 adult celiac disease (CD) patients adhering to a gluten-free diet (GFD), compared to 123 controls (including individuals with autoimmune disorders, those with gastrointestinal cancers, and healthy donors). Serum samples were evaluated using a multiplex assay based on a microarray comprising 66 immobilized antigens, including autoantigens associated with autoimmune diseases, different albumins, cytokines, and inflammatory markers. Elevated IgA-BSA levels were detected in 22% of CD patients versus 3.25% of controls. IgA-BSA did not cross-react with milk proteins like casein, β-lactoglobulin, and γ-globulin, nor with autoantigens and human albumin, ruling out autoimmunity against self-proteins. The observed cross-reactivity with porcine albumin suggests that antibodies target epitopes shared by bovine and porcine albumin. Increased IgA-BSA levels may interfere with immunoassays performed using BSA as a stabilizer, necessitating protein-free buffers to avoid false results when testing CD patients. Elevated IgA-BSA levels may reflect ongoing gut barrier dysfunction in CD patients on a GFD, allowing dietary proteins like BSA to trigger immune responses. This study identifies a novel immune response in CD patients on a GFD, emphasizing the need for tailored diagnostic approaches (BSA-free assays) and further research into the clinical and dietary implications of IgA-BSA elevation.