Serum zonulin levels in patients with liver cirrhosis: Prognostic implications

Prediction models combining zonulin, LPS, and LBP predict acute kidney injury and hepatorenal syndrome-acute kidney injury in cirrhotic patients

The development of acute kidney injury (AKI) and hepatorenal syndrome-acute kidney injury (HRS-AKI) in cirrhosis has been associated with intestinal barrier dysfunction and gut-kidney crosstalk. We use the related markers such as zonulin, lipopolysaccharides (LPS), and lipopolysaccharide-binding protein (LBP) to predict AKI and HRS-AKI in cirrhotic patients and evaluate their in vitro effects on intestinal (Caco-2) cells and renal tubular (HK-2) cells. From 2013 to 2020, we enrolled 70 cirrhotic patients and developed prediction models for AKI and HRS-AKI over a six-month period. There were 13 (18.6%) and 8 (11.4%) cirrhotic patients developed AKI and HRS-AKI. The prediction models incorporated zonulin, LPS, LBP, C-reactive protein, age, and history of hepatitis B for AKI, and zonulin, LPS, LBP, total bilirubin, and Child-Pugh score for HRS-AKI. The area under curve (AUC) for the prediction of AKI and HRS-AKI was 0.94 and 0.95, respectively. Furthermore, the conditioned medium of LPS+hrLBP pre-treated Caco-2 cells induced apoptosis, necrosis, and zonulin release in HK-2 cells, demonstrating the communication between them. This study found that zonulin, LPS, and LBP are potential practical markers for predicting AKI and HRS-AKI in cirrhotic patients, which may serve as potential targets for renal outcomes in cirrhotic patients.

Short chain fatty acids and GIT hormones mitigate gut barrier disruption in high fat diet fed rats supplemented by synbiotics

High fat diet (HFD) predisposes to many metabolic changes; it may disrupt gut barrier integrity and gut microbiota composition. Synbiotic supplementation may promote host’s metabolic health by selective activation of the healthy microorganisms. This study aimed to probe the interaction between synbiotic supplementation, gut microbiota and gut hormones in HFD states. Twenty-seven adult male albino rats, 3 groups, group I: control, group II: HFD received HFD for 12 weeks and group III: synbiotic-supplemented HFD received synbiotic in the last 6 weeks. The anthropometric measurments were measured. Liver transaminases, lipid profile, parameters of insulin resistance, serum serotonin, glucagon like polypeptide-1 (GLP-1), oxidant/antioxidant markers (MDA/GPx), zonulin levels and quantitative cecal short chain fatty acids (SCFA) were assessed. Samples of liver and colon were employed for histopathological studies. Compared to HFD group, synbiotic led to a significant reduction in anthropometric measurements, liver enzymes, atherogenic index, HOMA-IR and MDA denoting improved dyslipidemia, insulin resistance and oxidative state. Moreover, synbiotic supplementation decreased serum zonulin and increased both serum serotonin, GLP-1 and cecal SCFAs. Synbiotic supplementation ameliorated the metabolic derangements and the disturbed integrity of the intestinal barrier induced by HFD. As synbiotics can increase gut hormones (serum GLP-1&serotonin) and SCFAs.

Zonulin as a Potential Therapeutic Target in Microbiota-Gut-Brain Axis Disorders: Encouraging Results and Emerging Questions

The relationship between dysbiosis and central nervous diseases has been proved in the last 10 years. Microbial alterations cause increased intestinal permeability, and the penetration of bacterial fragment and toxins induces local and systemic inflammatory processes, affecting distant organs, including the brain. Therefore, the integrity of the intestinal epithelial barrier plays a central role in the microbiota-gut-brain axis. In this review, we discuss recent findings on zonulin, an important tight junction regulator of intestinal epithelial cells, which is assumed to play a key role in maintaining of the blood-brain barrier function. In addition to focusing on the effect of microbiome on intestinal zonulin release, we also summarize potential pharmaceutical approaches to modulate zonulin-associated pathways with larazotide acetate and other zonulin receptor agonists or antagonists. The present review also addresses the emerging issues, including the use of misleading nomenclature or the unsolved questions about the exact protein sequence of zonulin.

Circulating mtDNA and Impaired Intestinal Barrier after Gastrointestinal Surgery Are Correlated with Postoperative SIRS

Background: This prospective study aimed to explore the correlation between circulating mitochondrial DNA (mtDNA), intestinal barrier function impairment, and postoperative SIRS in patients undergoing gastrointestinal surgery. Methods: Patients were recruited into this study after signing an informed consent form. Circulating mitochondrial DNA and serum DAO concentrations were measured preoperatively and on day 1 and day 7 postoperatively. Postoperative vitals, routine tests, and biochemical indicators were recorded in detail. Results: Forty patients undergoing gastrointestinal surgery were recruited for and completed this study. Patients were divided into non-fever, fever, and SIRS groups according to their postoperative temperature and other corresponding indexes. The mtDNA was expressed as the number of PCR cycles using three specific sequences. Circulating mtDNA tended to increase in patients after gastrointestinal surgery, but the difference was not significant. Nevertheless, mtDNA in the SIRS group was significantly higher than in patients in the fever and non-fever groups (p < 0.05). Serum DAO showed a trend of increase on the first day after surgery compared with that before surgery, but the difference was not significant (p > 0.05). However, patients in the SIRS group showed a significant increase (p < 0.05) compared with the others. Both circulating mtDNA and DAO showed a downward trend on the seventh day after surgery. Conclusions: Circulating mtDNA presented a trend of increase after gastrointestinal surgery, and the degree of the increased fold was related to the extent of the inflammation response. In general, the intestinal barrier damage indicator DAO was the same as mtDNA and tended to increase after gastrointestinal surgery and then gradually decrease, which may play a synergistic role in inducing postoperative fever and SIRS.