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Background: The causal pathway between different dietary patterns (DPs) and gastric adenocarcinoma (GA) remains largely unexplored. The study aimed to identify DPs and evaluate how selected nutrients mediate the relationship between DPs and GA., Methods: This multicenter case-control study in Brazil involved 1751 participants (600 cases, 377 endoscopic controls, and 774 hospital controls). DPs were identified through exploratory factor analysis. A counterfactual-based mediation analysis was performed to decompose the total effect of DPs on GA into direct and indirect effects mediated by saturated fatty acids, added sugars, total fiber, and sodium intakes. Effects were expressed as ORs and 95% CIs., Results: Two DPs were identified-"unhealthy dietary pattern" (UDP) and "healthy dietary pattern" (HDP), which were associated with an increased and decreased risk of GA, respectively. Added sugars partly mediated the association between UDP and GA (percentage mediated between 7.3 and 21.7%), while sodium intake mediated most of the association between HDP and GA (percentage mediated between 52.4 and 100%). No significant mediating effects were detected for saturated fatty acids and total fiber., Conclusions: This study contributes innovative insights into the DPs-GA relationships, highlighting the significant mediating roles of sodium and added sugars, offering valuable information for preventive strategies and public health interventions targeting GA., Competing Interests: Declarations. Ethics approval and consent to participate: The study was conducted in accordance with the Declaration of Helsinki after obtaining the approval of the Committee on Ethics in Human Research of Antônio Prudente Foundation—A.C.Camargo Cancer Center under registration on the Brazil platform linked to the National Health Council of Brazil (grant no. 4708881–February 2016, registration CAAE: 53166915.9.1001.5432), as well as the local ethics committees of the study centers. All participants provided written informed consent for data collection and storage. Consent for publication: Not applicable. Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

Background: Helicobacter pylori (H. pylori) is a gram-negative bacterium associated with the etiology of several gastrointestinal tract pathologies, and cagA-positive (cagA+) strains are found in populations with gastric ulcers and precancerous lesions, inducing pro-inflammatory responses. The development of neoplasms is related to microRNA (miRNA) dysregulation, indicating highly expressed miRNA-629. The article aims to correlate the expression level of miRNA-629 with the presence of H. pylori and the pathogenicity marker cagA., Methods: 203 gastric biopsy samples were evaluated from individuals with normal gastric tissue (n=60), gastritis (n=96), and gastric cancer (n=47) of both genders and over 18 years old. The samples were subdivided according to the presence or absence of H. pylori, detected by polymerase chain reaction (PCR). RNA was extracted using a commercial kit and quantified. Complementary DNA (cDNA) was synthesized using commercial kits, and the relative expression was calculated using the 2-ΔΔCt method., Results: Individuals infected with H. pylori are nine times more likely to develop gastric cancer. Cancer patients appeared to have decreased expression of miRNA-629; however, the presence of the bacterium would not influence this reduction. Individuals in the cancer group showed lower miRNA-629 expression when cagA+; however, in the control group, the expression was higher when cagA+., Conclusion: H. pylori is a factor involved in the etiology and progression of gastric diseases. Reduction in miRNA-629 expression in cancer patients occurs independent of the presence of the bacterium, but when the cagA pathogenicity marker is present, it induces changes in the gene expression of the respective miRNA.

Background: Helicobacter pylori is an etiologic agent of gastroduodenal diseases. The microorganism, considered a type I carcinogen, affects about 50% of the global population. H. pylori virulence factors are determinant for the clinical outcome of the infection. The outer inflammatory protein A (oipA) gene encodes an outer membrane adhesin and is related to severe gastropathies, such as gastric cancer., Objective: The aim of this study was to evaluate the association of the oipA gene with the severity of gastroduodenal diseases in dyspeptic patients in region Central Brazil., Methods: The polymerase chain reaction (PCR) was used to determine the presence of H. pylori. Samples positives were used for molecular screening of the oipA gene. Gastropathies were categorized as non-severe and severe diseases., Results: Approximately 68% of patients had H. pylori and 36% were infected with H. pylori oipA+ strains. Infection was significantly associated in patients aged over 44 years (P=0.004). However, there was no association between oipA and patients' age (P=0.89). Approximately 46% of patients infected with oipA+ strains had some severe illness. Gastric adenocarcinoma was the most frequent severe gastropathy. The H. pylori oipA genotype was inversely associated with the severity of gastroduodenal diseases (OR=0.247, 95%CI: 0.0804-0.7149 and P=0.007)., Conclusion: The characterization of possible molecular markers will contribute to personalized medicine, impacting the prognosis of patients.

Background: Diet is one of the most important modifiable risk factors for the incidence of gastric cancer., Objective: To carry out an exploratory analysis on the dietary patterns of individuals with gastric adenocarcinoma (AdG) in the Central Brazil region., Methods: This is a case-control study carried out from April 2019 to July 2022, in three reference centers for cancer treatment in Goiânia-GO. The cases were patients diagnosed with AdG, the control 1 dyspeptic patients submitted to upper digestive endoscopy and the control 2 patients without gastric complaints. In the three groups, patients aged 18 to 75 years and of both sexes were recruited. To assess food consumption, a Food Frequency Questionnaire validated for the Brazilian population was used. Dietary patterns were identified by Exploratory Factor Analysis (EFA), using principal component analysis as the extraction method, followed by Varimax rotation., Results: The commonality values in the EFA for the foods/food groups consumed by the cases and controls were above 0.30 for all variables. The variance explained by the model was 66.7% for cases, 60.3% for control 1 and 59.7% for control 2. Three eating patterns were identified in cases, control 1 and control 2 that explained 34, 87%, 35.41% and 33.25% respectively of the total variance. The first pattern ("healthy") was characterized by the consumption of vegetables, fruits, meat and cheese; the second ("unhealthy") for sausages, pizzas, snacks, ketchup, sweet drinks and instant noodles and the third ("prudent") rice, beans, meat and fried fish and pasta., Conclusion: This study identified three dietary patterns among patients with AdG and controls in the Central Brazil region. According to the identified patterns, it will be possible to establish a relationship between diet and other epidemiological measures aimed at the prevention of gastric cancer.

Background: Helicobacter pylori colonizes approximately half of the world's human population. Its presence in the gastric mucosa is associated with an increased risk of gastric adenocarcinoma, gastric lymphoma, and peptic ulcer disease. In Brazil, the high prevalence of H. pylori infection is a serious health problem. H. pylori virulence factors are associated with an increased risk of serious gastrointestinal disorders. The cagA gene encodes a cytotoxin-A-associated antigen (CagA) that is involved in bacterial pathogenicity. H. pylori strains carrying the cag pathogenicity island (cag-PAI) are significantly associated with severe clinical outcomes and histopathological changes., Objective: The present study aims to investigate the prevalence of the cagA gene among H. pylori isolates from patients with different gastric pathologies. Further, the study hopes to verify its association with clinical outcomes. In addition, phylogenetic analysis was performed on cagA-positive H. pylori strains from patients with severe and non-severe diseases., Methods: Gastric specimens were collected through a biopsy from 117 patients with different esogastroduodenal diseases. DNA was extracted from these gastric specimens and the polymerase chain reaction was performed to amplify the gene fragments corresponding to the 16S ribosomal RNA and cagA genes using specific primers. The polymerase chain reaction products of selected samples positive for cagA were sequenced. The sequences were aligned with reference sequences from the National Center for Biotechnology Information (NCBI) (Bethesda/USA), and a phylogenetic tree was constructed., Results: H. pylori was detected in 65.9% (77/117) of Brazilian patients with different gastroduodenal disorders. Overall, 80.5% (62/77) of the strains were cagA-positive. The ages of patients with cagA-positive strains (15 males and 47 females) ranged from 18 to 74 years. The lesions were categorized as non-severe and severe according to the endoscopic and histopathological reports the most prevalent non-severe esogastroduodenal lesion was gastritis 54/77 (70.12%), followed by esophagitis 12/77 (15.58%) and duodenitis 12/77 (15.58%). In contrast, the most prevalent severe lesions were atrophy 7/77 (9.09%), followed by metaplasia 3/77 (3.86%) and gastric adenocarcinoma 2/77 (2.59%). Phylogenetic analyses performed with the partial sequences of the cagA gene obtained from local strains were grouped in the same clade. No differences in phylogenetic distribution was detected between severe and non-severe diseases., Conclusion: The cagA gene is highly prevalent among H. pylori isolates from gastric lesions in Brazilian patients. The presence of the cagA gene was not considered a marker of the severity of esogastroduodenal lesions in the present study. This is the first study to investigate the phylogenetic population structure of H. pylori strains in a Brazilian capital, which may improve our understanding of the clinical outcome of H. pylori infection.

Purpose: The aim of this study was to evaluate the expression of miR-125a-5p in patients with dyspeptic symptoms and gastric cancer, correlating them with the development of this cancer and H. pylori., Methods: Patients were divided in groups according to histopathological analysis (control, gastritis, and cancer groups). Polymerase chain reaction was performed to detect H. pylori and real-time quantitative PCR to determine miR-125a-5p expression., Results: H. pylori was detected in 44% of the patients, with prevalence in the gastritis and cancer groups. A statistically significant decrease of miR-125a-5p expression was found in the control positive (p = 0.0183*), gastritis positive (p = 0.0380*), and cancer positive (p = 0.0288*) groups when compared with the control negative group., Conclusion: We suggest that decreased expression of the miRNA-125a-5p associated with the presence of the H. pylori is an important mechanism in gastric diseases and could be a possible marker for early diagnosis of gastric cancer.

Helicobacter pylori (H. pylori) induces an intense inflammatory response, mediated by proinflammatory cytokines, including interleukin (IL)-6 and its membrane receptor (IL-6R), which activates important signaling pathways in the development of gastric disease and cancer. We investigated the gene and protein expression of IL-6 and IL-6R and the influence of polymorphisms rs1800795, rs1800796, and rs1800797 on its gene expression together with H. pylori infection. Furthermore, an in-silico analysis was performed to support our results. Gastric biopsies were obtained from patients with gastric symptoms and patients with gastric cancer (GC) and were divided into groups (Control, Gastritis, and Cancer). H. pylori was detected by PCR. Real-time-qPCR was employed to determine gene expression, and western blot assay was used to analyze protein expression levels. PCR-RFLP was used to characterize IL-6 polymorphisms. Bioinformatics analyses were performed using the Gene Expression Omnibus (GEO) database and GEO2R to screen out differentially expressed genes (DEGs). H. pylori was detected in 43.3% of the samples. Statistically significant differences were found for IL-6 (P=0.0001) and IL-6R (P=0.0005) genes among the three groups, regardless of the presence of H. pylori. Among patients with H. pylori infection, the IL-6 and IL-6R gene and protein expressions were significantly increased, highlighting IL-6 gene overexpression in patients with GC. No statistically significant differences were found for the rs1800795, rs1800796, and rs1800797 polymorphisms compared to IL-6 gene expression. The results indicated that the IL-6 polymorphisms do not influence its expression, but IL-6 and IL-6R expression seems to be altered by the presence of H. pylori.