Background Hepatosteatosis is the earliest stage in the pathogenesis of nonalcoholic fatty (NAFLD) and alcoholic liver disease (ALD). As NAFLD is affecting 10–24% of the general population and approximately 70% of obese patients, it carries a large economic burden and is becoming a major reason for liver transplantation worldwide. ALD is a major cause of morbidity and mortality causing 50% of liver cirrhosis and 10% of liver cancer related death. Increasing evidence has accumulated that gut-derived factors play a crucial role in the development and progression of chronic liver diseases. Methods A selective literature search was conducted in Medline and PubMed, using the terms “nonalcoholic fatty liver disease,” “alcoholic liver disease,” “lipopolysaccharide,” “gut barrier,” and “microbiome.” Results Gut dysbiosis and gut barrier dysfunction both contribute to chronic liver disease by abnormal regulation of the gut-liver axis. Thereby, gut-derived lipopolysaccharides (LPS) are a key factor in inducing the inflammatory response of liver tissue. The review further underlines that endotoxemia is observed in both NAFLD and ALD patients. LPS plays an important role in conducting liver damage through the LPS-TLR4 signaling pathway. Treatments targeting the gut microbiome and the gut barrier such as fecal microbiota transplantation (FMT), probiotics, prebiotics, synbiotics, and intestinal alkaline phosphatase (IAP) represent potential treatment modalities for NAFLD and ALD. Conclusions The gut-liver axis plays an important role in the development of liver disease. Treatments targeting the gut microbiome and the gut barrier have shown beneficial effects in attenuating liver inflammation and need to be further investigated.

Gut barrier dysfunction and gut-derived chronic inflammation play crucial roles in human aging. The gut brush border enzyme intestinal alkaline phosphatase (IAP) functions to inhibit inflammatory mediators and also appears to be an important positive regulator of gut barrier function and microbial homeostasis. We hypothesized that this enzyme could play a critical role in regulating the aging process. We tested the role of several IAP functions for prevention of age-dependent alterations in intestinal homeostasis by employing different loss-of-function and supplementation approaches. In mice, there is an age-related increase in gut permeability that is accompanied by increases in gut-derived portal venous and systemic inflammation. All these phenotypes were significantly more pronounced in IAP-deficient animals. Oral IAP supplementation significantly decreased age-related gut permeability and gut-derived systemic inflammation, resulted in less frailty, and extended lifespan. Furthermore, IAP supplementation was associated with preserving the homeostasis of gut microbiota during aging. These effects of IAP were also evident in a second model system, Drosophilae melanogaster . IAP appears to preserve intestinal homeostasis in aging by targeting crucial intestinal alterations, including gut barrier dysfunction, dysbiosis, and endotoxemia. Oral IAP supplementation may represent a novel therapy to counteract the chronic inflammatory state leading to frailty and age-related diseases in humans.

Background Inflammation is known to be an essential driver of various types of cancer. An increasing number of studies have suggested that the occurrence and development of colorectal cancer (CRC) are linked to the inflammatory microenvironment of the intestine. This assumption is further supported by the fact that patients with inflammatory bowel disease (IBD) are more likely to develop CRC. Multiple studies in mice and humans have shown that preoperative systemic inflammatory response is predictive of cancer recurrence after potentially curative resection. Lipopolysaccharides (LPS) are membrane surface markers of gram-negative bacteria, which induce gut barrier dysfunction and inflammation and might be significantly involved in the occurrence and development of CRC. Methods A selective literature search was conducted in Medline and PubMed, using the terms “Colorectal Cancer”, “Gut Barrier”, “Lipopolysaccharides”, and “Inflammation”. Results Disruption of intestinal homeostasis, including gut barrier dysfunction, is linked to increased LPS levels and is a critical factor for chronic inflammation. LPS can activate the diverse nuclear factor-κB (NF-κB) pathway via Toll-like receptors 4 (TLR4) to promote the inflammatory response, which aggravates gut barrier dysfunction and encourages CRC development. An intact gut barrier prevents antigens and bacteria from crossing the intestinal endothelial layer and entering circulation. In contrast, a damaged gut barrier triggers inflammatory responses and increases susceptibility to CRC. Thus, targeting LPS and the gut barrier might be a promising novel therapeutic approach for additional treatment of CRC. Conclusion Gut barrier dysfuction and bacterial LPS seem to play an important role in the pathogenesis and disease progression of colorectal cancer and therefore require further investigation.

Objective: The aim of our study was to conduct a systematic review and meta-analysis comparing the survival outcomes of IBD-associated and non-IBD-associated CRC. Summary of Background Data: Investigations comparing the prognosis in CRC patients with and without IBD have yielded conflicting results. Methods: PubMed/MEDLINE, Embase, Web of Science, Cochrane Library were searched for studies evaluating the prognostic outcomes between CRC patients with IBD and those without IBD. Estimates of survival-related outcomes and clinicopathological features in IBD-CRC and non-IBD CRC were pooled through random-effects or fix-effects models. The study is registered with PROSPERO, CRD42021261513. Results: Of 12,768 records identified, twenty-five studies with 8034 IBD-CRC and 810,526 non-IBD CRC patients were included in the analysis. IBD-CRC patients have a significant worse overall survival (OS) with the hazard ratio (HR) of 1.33 [95% confidence interval (CI): 1.20–1.47] than those without IBD. Pooled estimates of cancer-specific survival demonstrated that IBD-CRC patients had a poorer cancer-specific survival than those without IBD with fixed-effect model (HR, 2.17; 95% CI: 1.68–2.78; P < 0.0001). Moreover, ulcerative colitis-associated CRC patients have favorable OS than Crohn’s disease-associated CRC (HR 0.79,95% CI: 0.72–0.87). Compared to non-IBD-CRC, patients with IBD-associated CRC are characterized by an increased rate of poor differentiation (OR 2.02, 95% CI: 1.57–2.61), mucinous or signet ring cell carcinoma (OR 2.43, 95% CI: 1.34–4.42), synchronous tumors (OR 3.18, 95% CI: 2.26–4.47), right-sided CRC (OR 1.62, 95%CI: 1.05–2.05), male patients (OR 1.10, 95% CI: 1.05–1.16), and a reduced rate of R0 resections (OR 0.60, 95% CI: 0.44–0.82). Conclusions: IBD-CRC patients have a significant worse OS than patients with non-IBD CRC, which may be attributed to more aggressive histological characteristics and a lower rate of R0 resections at the primary tumor site. Optimized therapeutic standards and tailored follow-up strategies might improve the prognosis of IBD-CRC patients.