Colorectal cancer (CRC) is a multifactorial disease increasingly recognized for its complex interplay with the gut microbiota. The disruption of microbial homeostasis—dysbiosis—has profound implications for intestinal barrier integrity and host immune function. Pathogenic bacterial species such as Fusobacterium nucleatum, Escherichia coli harboring polyketide synthase (pks) island, and enterotoxigenic Bacteroides fragilis are implicated in CRC through mechanisms involving mucosal inflammation, epithelial barrier disruption, and immune evasion. These pathogens promote pro-tumorigenic inflammation, enhance DNA damage, and suppress effective anti-tumor immunity. Conversely, commensal and probiotic bacteria, notably Lactobacillus and Bifidobacterium species, exert protective effects by preserving epithelial barrier function and priming host immune responses. These beneficial microbes can promote the maturation of dendritic cells, stimulate CD8⁺ T cell cytotoxicity, and modulate regulatory T cell populations, thereby enhancing anti-tumor immunity. The dichotomous role of the microbiota underscores its potential as both a biomarker and a therapeutic target in CRC. Recent advances in studies have explored microbiota-modulating strategies—ranging from dietary interventions and prebiotics to fecal microbiota transplantation (FMT) and microbial consortia—as adjuncts to conventional therapies. Moreover, the composition of the gut microbiome has been shown to influence the responses to immunotherapy and chemotherapy, raising the possibility of microbiome-informed precision oncology therapy. This review synthesizes the current findings on the pathogenic and protective roles of bacteria in CRC and evaluates the translational potential of microbiome-based interventions in shaping future therapeutic paradigms.

Celiac disease (CeD) is an immune-mediated enteropathy triggered by gluten in genetically susceptible individuals, with a heterogeneous clinical spectrum spanning classical gastrointestinal symptoms, extraintestinal manifestations, and subclinical forms. We synthesize contemporary epidemiology, immunopathogenesis, and the updated 2025 European Society for the Study of Coeliac Disease diagnostic framework. Adaptive responses to deamidated gliadin peptides presented by human leukocyte antigen (HLA)-DQ2/DQ8, together with interleukin-15-driven activation of intraepithelial lymphocytes (IELs), culminate in villous atrophy, crypt hyperplasia, and increased IELs. Serology centered on tissue transglutaminase immunoglobulin A (tTG-IgA) with total immunoglobulin A assessment remains first-line, complemented by standardized duodenal sampling (≥4 distal + 2 bulb biopsies) and selective HLA typing. The guidelines conditionally endorse a no-biopsy pathway for adults <45 years with tTG-IgA ≥10× upper limit of normal confirmed on a second sample, emphasizing shared decision-making and exclusion of red flags. We delineate differential diagnoses (tropical sprue, Crohn’s disease, common variable immunodeficiency, small intestinal bacterial overgrowth) and contrast CeD with non-celiac gluten sensitivity, which lacks villous atrophy, disease-specific serology, and HLA association. Emerging tools (immunohistochemistry, CD3/CD8/γδ IELs, video capsule endoscopy, confocal laser endomicroscopy) and the limitations of salivary/fecal assays are reviewed. Early detection improves quality of life and reduces healthcare utilization. Future directions include artificial intelligence-assisted imaging, molecular immunophenotyping, and non-dietary therapeutics.

Colorectal cancer (CRC) remains one of the most important causes of cancer-related mortality worldwide, underscoring the need to better understand systemic inflammatory pathways across the colorectal neoplasia spectrum. In this exploratory case–control study, we characterized plasma levels of key inflammatory mediators in healthy individuals and patients with colorectal polyps or CRC. Healthy controls (n = 10), patients with colorectal polyps (CP, n = 16), early-onset CRC (EO-CRC, n = 11), and late-onset CRC (LO-CRC, n = 51) were prospectively enrolled. Plasma levels of sTNF-R, total TNF-α, PDGF-AA, IL-17A, and IL-1β were measured by ELISA. Group comparisons used Kruskal–Wallis tests with epsilon-squared effect sizes. PDGF-AA showed the strongest differences between controls and all neoplastic groups (ε² ≥ 0.15), and these comparisons remained significant after Benjamini–Hochberg false discovery rate correction. IL-17A levels were slightly higher in EO-CRC than in LO-CRC; however, this difference did not remain significant after adjustment for multiple testing. TNF-α and IL-1β showed no significant differences across groups. Overall, this study primarily provides descriptive and hypothesis-generating evidence of differential inflammatory patterns across colorectal neoplasia, with PDGF-AA emerging as the most robust signal in this exploratory dataset. These findings do not support immediate diagnostic application and require validation in larger, prospectively recruited cohorts.

Background: Colorectal cancer (CRC) represents one of the leading causes of cancer-related morbidity and mortality globally. Although national screening programs in Europe and the United States have demonstrated success in reducing incidence and death rates among populations aged 50 and above, a concerning increase in early-onset colorectal cancer (EOCRC), defined as diagnosis before age 50, has emerged. Methods: This paper is a narrative literature review comparing American and European CRC screening guidelines. A comprehensive search was conducted using the PubMed database with emphasis on publications from the past ten years. Results: The United States has adapted more swiftly to EOCRC trends by lowering the recommended screening age to 45, supported by modeling studies showing life-years gained and improved cost-effectiveness. In contrast, European programs remain largely organized and cost-efficient but predominantly initiate screening at age 50, potentially missing high-risk younger adults. EOCRC appears to demonstrate unique molecular and pathological features compared to late-onset CRC. Participation and adherence to screening also vary significantly between regions and modalities, with colonoscopy remaining the gold standard but less scalable than fecal immunochemical tests. Conclusions: The rising incidence of EOCRC calls for a reassessment of CRC screening policies. While the European model emphasizes equity and structure, its slower responsiveness to epidemiological changes may lead to late detection in younger cohorts. The American model’s earlier screening age addresses emerging trends but faces challenges in implementation equity. A hybrid approach may provide the optimal management, balancing public health benefit with system sustainability.

Background/Objectives: Antimicrobial resistance (AMR) remains a major global health threat, strengthening the case for antimicrobial stewardship that limits unnecessary broad-spectrum empiric therapy while preserving timely coverage in severe infection. Large language models (LLMs) are being explored for decision support, but require rigorous offline evaluation before any clinical implementation. Methods: Single-center retrospective paired evaluation at Clinical Emergency Hospital of Bucharest (Internal Medicine, 2020–2024). The unit of analysis was the admission (N = 493), with paired 24 h empiric regimens (clinician-prescribed vs post hoc LLM-recommended via OpenAI API; not visible to clinicians; no influence on care). Local laboratory-derived epidemiology was precomputed from microbiology exports and provided as structured prompt context to approximate information parity with clinicians’ implicit local ecology knowledge. Primary (prespecified) endpoint: any contextual guardrail violation (unjustified carbapenem/antipseudomonal/anti-MRSA under prespecified structured severity/MDR-risk rules), exact McNemar. Key secondary (prespecified): Δ contextual guardrail penalty (LLM − Clin), sign test and Wilcoxon signed-rank (ties reported). Ethics committee approval was obtained. Results: Guardrail violations occurred in 17.0% of clinician regimens vs 4.9% of LLM regimens (paired RD −12.2%; matched OR 0.216, 95% CI 0.127–0.367; McNemar exact p = 1.60 × 10⁻¹⁰). Δ penalty had median 0 with 398/493 ties; among non-ties, improvements (Δ < 0) exceeded adverse shifts (79 vs 16; sign-test p = 3.47 × 10⁻¹¹). Conclusions: In this offline, non-interventional paired evaluation, LLM regimens were associated with fewer prespecified contextual guardrail violations compared to clinician empiric regimens under a rule-based stewardship benchmarking framework. These endpoints strictly quantify concordance with stewardship constraints rather than patient outcomes, necessitating cautious interpretation of secondary and subset analyses. Ultimately, reproducible guardrail-based benchmarking may support subsequent prospective, safety-governed evaluations.