Our genetic background has not changed over the past century, but chronic diseases are on the rise globally. In addition to the genetic component, among the critical factors for many diseases are inhabitants of our intestines (gut microbiota) as a crucial environmental factor. Dysbiosis has been described in liver diseases with different etiologies like non-alcoholic fatty liver disease (NAFLD), alcohol-related liver disease (ALD), viral hepatitis, autoimmune hepatitis (AIH), primary sclerosing cholangitis (PSC), primary biliary cholangitis (PBC), cirrhosis, hepatocellular carcinoma (HCC). On the other hand, new technologies have increased our understanding of liver disease genetics and treatment options. Genome-wide association studies (GWAS) identify unknown genetic risk factors, positional cloning of unknown genes associated with different diseases, gene tests for single nucleotide variations (SNVs), and next-generation sequencing (NGS) of selected genes or the complete genome. NGS also allowed studying the microbiome and its role in various liver diseases has begun. These genes have proven their effect on microbiome composition in host genome–microbiome association studies. We focus on altering the intestinal microbiota, and supplementing some bacterial metabolites could be considered a potential therapeutic strategy. The literature data promote probiotics/synbiotics role in reducing proinflammatory cytokines such as TNF-α and the interleukins (IL-1, IL-6, IL-8), therefore improving transaminase levels, hepatic steatosis, and NAFLD activity score. However, even though microbial therapy appears to be risk-free, evaluating side effects related to probiotics or synbiotics is imperative. In addition, safety profiles for long-term usage should be researched. Thus, this review focuses on the human microbiome and liver diseases, recent GWASs on liver disease, the gut-liver axis, and the associations with the microbiome and microbiome during/after liver disease therapy.

Introduction: Recent studies have shown that the intestinal microbiota can modulate certain systemic metabolic and immune responses, including liver graft function and the development of complications in patients after liver transplantation (LT). Akkermansia muciniphila (AKM) and Faecalibacterium prausnitzii (FAEP) are two of the most abundant gut commensal bacteria, with mucosa-protective and anti-inflammatory effects that are important for maintaining normal intestinal homeostasis and gut barrier function. Our objective was to quantify levels of Akkermansia muciniphila and Faecalibacterium prausnitzii in immunosuppressed patients with LT. Materials and methods: Fecal samples from 23 liver transplant patients (15 adults and 8 children) and 9 non-LT controls were examined. Bacterial DNA was isolated from the samples using the stool DNA isolation kit and the obtained DNA was analyzed with commercially available qPCR kit for AKM and FAEP. Results: We found a statistically significant decrease in the amount of AKM and FAEP compared to the control group. The median values were: for AKM 8.75 for patients and 10.25 for the control group (p = 0.030), and for FAEP 9.72 and 10.47, p = 0.003, respectively. In children after LT, this difference was also statistically significant: AKM (p = 0.051) and FAEP (p = 0.014). In contrast no statistically significant differences were found between adult patients and controls, AKM (p = 0.283) and FAEP (p = 0.056), although the amount of both bacteria showed tendency for reduction. Conclusions: In this pilot study, we found a reduction in the total amount of the two studied bacteria in transplanted patients compared to the control healthy group.

Background: Fecal calprotectin (FC) is a well-established, non-invasive biomarker of intestinal inflammation and is widely used to differentiate inflammatory bowel disease (IBD) from functional gastrointestinal disorders. Although enzyme-linked immunosorbent assays (ELISA) remain the reference method, rapid immunochromatographic tests (ICTs) offer important operational advantages for point-of-care (POC) diagnostics. However, variability in analytical performance among available ICTs remains a concern. Objective: This study aimed to evaluate the diagnostic accuracy of the CerTest Calprotectin one-step card (CerTest Biotec S.L., Zaragoza, Spain) in comparison with the Actim^® Calprotectin lateral flow assay and the reference Calprest^® ELISA (Eurospital Diagnostics, Italy). Methods: A total of 128 fresh stool samples from patients clinically suspected of IBD were analyzed in parallel using all three assays. For the reference ELISA (Calprest^®), a cutoff value of >40 µg/g was applied according to the manufacturer’s instructions. For discrepant results between assays, a cutoff of 200 ng/mL (equivalent to 200 µg hCp/g stool) was employed for ELISA Calprest^® to resolve inconsistencies. The results of the lateral flow assays (CerTest^® Calprotectin ICT and Actim^® Calprotectin) were interpreted using their respective manufacturer-recommended thresholds. Diagnostic sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated using ELISA as the reference standard. Agreement between methods was assessed using Cohen’s κ coefficient. Results: Using ELISA, 47 of 128 samples (36.7%) exceeded the 40 µg/g cutoff. Compared with the Actim^® assay, the CerTest card demonstrated a sensitivity of 88.0% (95% CI: 75.7–95.5), a specificity of 100.0% (95% CI: 95.4–100), and a strong agreement (κ = 0.90). When compared with ELISA, the CerTest assay showed a sensitivity of 87.2% (95% CI: 74.3–95.2), a specificity of 96.3% (95% CI: 89.6–99.2), a PPV of 93.2%, an NPV of 93.2%, and a strong agreement (κ = 0.85). Conclusions: The CerTest Calprotectin one-step card provides a rapid and reliable detection of fecal calprotectin, demonstrating a high sensitivity and specificity that are comparable to both other lateral flow assays and the ELISA reference method. These findings support the use of rapid immunochromatographic testing as a valuable tool for preliminary screening and clinical decision-making in patients suspected of IBD, while acknowledging that histology remains the gold standard for definitive diagnosis.