The Prevention of Viral Infections: The Role of Intestinal Microbiota and Nutritional Factors.

Viral infections pose significant global challenges due to their rapid transmissibility. Therefore, preventing and treating these infections promptly is crucial to curbing their spread. This review focuses on the vital link between nutrition and viral infections, underscoring how dietary factors influence immune system modulation. Malnutrition, characterized by deficiencies in essential nutrients such as vitamins A, C, D, E, and zinc, can impair the immune system, thereby increasing vulnerability to viral infections and potentially leading to more severe health outcomes that complicate recovery. Additionally, emerging evidence highlights the role of commensal microbiota in immune regulation, which can affect hosts' susceptibility to infections. Specific dietary components, including bioactive compounds, vitamins, and probiotics, can beneficially modify gut microbiota, thus enhancing immune response and offering protection against viral infections. This review aims to elucidate the mechanisms by which dietary adjustments and gut microbiota impact the pathogenesis of viral infections, with a particular focus on strengthening the immune system.

Pseudopyloric Metaplasia Is Not Associated With the Development of Gastric Cancer.

INTRODUCTION: Corpus atrophic gastritis (CAG) is associated with intestinal metaplasia (IM) and pseudopyloric metaplasia (PPM). Prospective data on corpus mucosa PPM and its link to the development of gastric cancer (GC) are lacking. This study aimed to investigate the relationship between the presence of corpus mucosa PPM at baseline and the development of GC at follow-up in patients with CAG. METHODS: A longitudinal cohort study was conducted on patients with consecutive CAG adhering to endoscopic-histological surveillance. Patients were stratified for the presence/absence of corpus PPM without concomitant corpus IM at baseline, and the occurrence of gastric neoplastic lesions at the longest available follow-up was assessed. RESULTS: A total of 292 patients with CAG with a follow-up of 4.2 (3-17) years were included. At baseline, corpus PPM without corpus IM was diagnosed in 62 patients (21.2%). At the follow-up, GC was detected in 5 patients (1.7%) and gastric dysplasia (GD) in 4 patients (1.4%). In all these 9 patients with GC/GD at the follow-up, corpus IM was present at baseline and follow-up. Age <50 years (odds ratio [OR] 2.5), absence of pernicious anemia (OR 4.3), and absence of severe corpus atrophy (OR 2.3) were associated with corpus PPM without corpus IM. DISCUSSION: At the 4.2-year follow-up, in patients with CAG characterized at baseline with corpus PPM without corpus IM, GC or GD was not observed because these lesions were consistently associated with corpus IM. Corpus PPM without corpus IM was associated with younger age, absence of pernicious anemia, and severe corpus atrophy, suggesting a lower stage of disease progression. Corpus PPM alone seems not to be associated with GC, whose development seems to require the presence of corpus IM as a necessary step.

Intrinsic factor autoantibodies by luminescent immuno-precipitation system in patients with corpus atrophic gastritis.

BACKGROUND: Corpus atrophic gastritis (CAG) may lead to intrinsic factor (IF) deficiency and vitamin B12 malabsorption. Intrinsic factor autoantibodies (IFA) are considered markers of pernicious anemia, but their clinical utility in CAG has not been evaluated. This study aimed to assess IFA in CAG patients and controls using a luciferase immunoprecipitation system (LIPS). METHODS: Recombinant nanoluciferase-tagged IF secreted from transfected Expi293F cells was used as antigen in an IFA-LIPS assay. IFA IgG were measured in sera from subjects undergoing gastroscopy and biopsy (updated Sydney system) mainly for anemia (57%) or dyspepsia (34%). This cohort comprised 105 patients with histologically-proven-CAG (cases: median age 64 years, 68% females) and 110 subjects with suspected CAG that were histologically negative (controls: median age 67 years, 54% females). Cut-off values were selected by Q-Q-plot analysis (negative: <2.5 arbitrary units). RESULTS: IFA levels were higher in cases than in controls (Mann-Whitney:p < 10-5). The ROC-AUC was 0.67 (95%CI 0.60-0.73, p < 0.0001). The IFA LIPS sensitivity and specificity for CAG were 32% (95% CI 24-42) and 95% (95% CI 90-99). This diagnostic performance remained similar after stratification for the presence/absence of anemia, dyspepsia or vitamin B12 deficiency. IFA levels were higher in females compared with males (p = 0.0127). In females aged <65 years, IFA-positives were more prevalent than in males (43.5% vs 6.6%, p = 0.011). CONCLUSIONS: The IFA-LIPS assay discriminated between CAG patients and controls showing a good specificity (95%) at the cost of sensitivity (32%). IFA-positivity occurred independently from anemia and vitamin B12 deficiency, but was more frequent in younger females. IFA testing should be considered in patients at high clinical suspicion of CAG.