Lactulose in cirrhosis: Current understanding of efficacy, mechanism, and practical considerations

Role of Intestinal Barrier Disruption to Acute-on-Chronic Liver Failure

Acute-on-chronic liver failure (ACLF) is a severe condition in patients with decompensated liver cirrhosis, marked by high short-term mortality. Recent experimental and clinical evidence has linked intestinal dysfunction to both the initiation of ACLF as well as disease outcome. This review discusses the significant role of the gut-liver axis in ACLF pathogenesis, highlighting recent advances. Gut mucosal barrier disruption, gut dysbiosis, and bacterial translocation emerge as key factors contributing to systemic inflammation in ACLF. Different approaches of therapeutically targeting the gut-liver axis via farnesoid X receptor agonists, nonselective beta receptor blockers, antibiotics, and probiotics are discussed as potential strategies mitigating ACLF progression. The importance of understanding the distinct pathophysiology of ACLF compared with other stages of liver cirrhosis is highlighted. In conclusion, research findings suggest that disruption of intestinal integrity may be an integral component of ACLF pathogenesis, paving the way for novel diagnostic and therapeutic approaches to manage this syndrome more effectively.

LIVE-SMART: A sequential, multiple assignment randomized trial to reduce falls in cirrhosis

INTRODUCTION

Falls are a major threat to the well-being of patients with cirrhosis. We are performing a clinical trial to determine whether lactulose, TeleTai-Chi, or their combination will reduce falls in HE and improve health-related quality of life (HRQOL) among patients with cirrhosis.

METHODS AND ANALYSIS

Patients with cirrhosis and portal hypertension without HE will be enrolled in 3 US states and followed participants for 24 weeks. In stage 1 (12 wk), participants will be randomized to receive either lactulose therapy or enhanced usual care. In stage 2 (12 wk), participants will be randomized to either TeleTai-Chi or usual care. The primary outcome is a hierarchical composite: Injurious falls, noninjurious falls, incident HE, and death/transplantation. Secondary outcomes include cognitive function, days-alive and out-of-hospital, and HRQOL. After completion of the interventions, participants will be followed for 48 weeks for health and financial outcomes.

ETHICS AND DISSEMINATION

Our study has a central institutional review board with individual site IRB review. Dissemination includes the publication of study findings and patient-focused educational webinars.

Neurogastroenterology and motility disorders in patients with cirrhosis

Neurogastroenterology and motility disorders are complex gastrointestinal conditions that are prevalent worldwide, particularly affecting women and younger individuals. These conditions significantly impact the quality of life of people suffering from them. There is increasing evidence linking these disorders to cirrhosis, with a higher prevalence compared to the general population. However, the link between neurogastroenterology and motility disorders and cirrhosis remains unclear due to undefined mechanisms. In addition, managing these conditions in cirrhosis is often limited by the adverse effects of drugs commonly used for these disorders, presenting a significant clinical challenge in the routine management of patients with cirrhosis. This review delves into this connection, exploring potential pathophysiological links and clinical interventions between neurogastroenterology disorders and cirrhosis.

The future of clinical trials of gut microbiome therapeutics in cirrhosis

The last two decades have witnessed an explosion of microbiome research, including in hepatology, with studies demonstrating altered microbial composition in liver disease. More recently, efforts have been made to understand the association of microbiome features with clinical outcomes and to develop therapeutics targeting the microbiome. While microbiome therapeutics hold much promise, their unique features pose certain challenges for the design and conduct of clinical trials. Herein, we will briefly review indications for microbiome therapeutics in cirrhosis, currently available microbiome therapeutics, and the biological pathways targeted by these therapies. We will then focus on the best practices and important considerations for clinical trials of gut microbiome therapeutics in cirrhosis.

Dachengqi decoction ameliorated liver injury in liver fibrosis mice by maintaining gut vascular barrier integrity

BACKGROUND

Severe liver fibrosis may be accompanied by intestinal barrier damage, such as bacterial peritonitis, suggesting that the role of the gut-liver axis is nonnegligible. Dachengqi decoction (DCQD) was reported to improve bowel movements, but whether DCQD was effective for intestinal damage caused by liver fibrosis remained unclear.

PURPOSE

To investigate the role of DCQD in liver fibrosis-related gut vascular barrier (GVB) damage in mice.

STUDY DESIGN

DCQD was verified to reduce the imbalance of the intestinal vascular barrier and restore intestinal homeostasis to prove that DCQD acts through the gut-liver axis.

METHODS

Three graded doses of DCQD were gavaged into the CCL4-induced mice for 12 weeks to evaluate the resistance to liver and intestinal damage. Immunoblotting and primary flow cytometry were used to assess organ damage; PV-1 to indicate gut vascular barrier damage; serum endotoxin, fecal SCFAs, and liver microbiota translocation to examine the gut-liver axis's crosstalk. Network pharmacology and RNA sequencing were used to analyze and verify the signaling pathway of DCQD.

RESULTS

DCQD significantly ameliorated fibrosis and inflammatory response in the CCL4-induced mice, alleviated gut leakage, downregulated PV-1, relieved liver enterobacterial translocation, restored intestinal homeostasis, and reduced infiltration of myeloid cells in the lamina propria. Network pharmacology and RNA sequencing results indicated that DCQD exerted anti-fibrotic and anti-inflammatory effects in the liver through inhibition of the ESR1/NF-κB/TNFα pathway and maintained GVB homeostasis through the FUT2/Wnt/β-Catenin pathway.

CONCLUSIONS

DCQD broke the closed-loop damage of the gut-liver axis to improve GVB injury in mice with liver fibrosis.

Systems of care that improve outcomes for people with hepatic encephalopathy

Hepatic encephalopathy (HE) is a critical neuropsychiatric complication of liver cirrhosis with a significant impact on patient quality of life and survival. The global prevalence of cirrhosis and associated HE necessitates a comprehensive understanding of the condition and effective systems of care to optimize outcomes. This review addresses the epidemiology, classification, diagnosis, and management of HE, with an emphasis on systems of care that improve outcomes for people with HE. Current diagnostic challenges include differentiating cognitive deficits attributable to HE from those caused by other etiologies, highlighting the need for accurate diagnostic methods. Traditional psychometric tests, while valuable for diagnosing covert HE (CHE), are limited in their ability to predict overt HE (OHE) due to various confounding factors. As a result, non-psychometric tools have been developed to provide outcome-based predictions aligned with the clinical course of HE. The management of HE includes addressing precipitating factors, pharmacologic interventions to reduce ammonia levels, and supportive care, with lactulose and rifaximin playing a central role. Preventive strategies with the use of remote monitoring in the outpatient management of HE, integrating technology for real-time tracking of therapy compliance and symptom evolution, could contribute to reducing hospital readmissions and improving patient care.

The crucial role of risk factors when dealing with hepatic Encephalopathy

Hepatic encephalopathy (HE) is a common condition in patients with cirrhosis, representing the second most frequent cause of decompensation. Approximately 30-40% of patients with cirrhosis will experience overt HE during the clinical course of their illness. In most cases, it is possible to identify a precipitating or risk factor for HE. These are distinct concepts that play different roles in the development of this condition. While precipitating factors act acutely, risk factors are generally present over an extended period and contribute to the overall likelihood of developing HE. The two types of factors require different approaches, with risk factors being more susceptible to prevention. The aim of this review is to describe the most important risk factors (such as severity of liver disease, previous episode of HE, minimal/covert HE, spontaneous and iatrogenic shunt, malnutrition, chronic therapies, metabolic diseases) for the development of HE and how to prevent it.

Therapeutic manipulation of the microbiome in liver disease

Myriad associations between the microbiome and various facets of liver physiology and pathology have been described in the literature. Building on descriptive and correlative sequencing studies, metagenomic studies are expanding our collective understanding of the functional and mechanistic role of the microbiome as mediators of the gut-liver axis. Based on these mechanisms, the functional activity of the microbiome represents an attractive, tractable, and precision medicine therapeutic target in several liver diseases. Indeed, several therapeutics have been used in liver disease even before their description as a microbiome-dependent approach. To bring successful microbiome-targeted and microbiome-inspired therapies to the clinic, a comprehensive appreciation of the different approaches to influence, collaborate with, or engineer the gut microbiome to coopt a disease-relevant function of interest in the right patient is key. Herein, we describe the various levels at which the microbiome can be targeted-from prebiotics, probiotics, synbiotics, and antibiotics to microbiome reconstitution and precision microbiome engineering. Assimilating data from preclinical animal models, human studies as well as clinical trials, we describe the potential for and rationale behind studying such therapies across several liver diseases, including metabolic dysfunction-associated steatotic liver disease, alcohol-associated liver disease, cirrhosis, HE as well as liver cancer. Lastly, we discuss lessons learned from previous attempts at developing such therapies, the regulatory framework that needs to be navigated, and the challenges that remain.

Engineering Bacillus subtilis for highly efficient production of functional disaccharide lactulose from lactose

Bioconversion of lactose to functional lactose derivatives attracts increasing attention. Lactulose is an important high-value lactose derivative, which has been widely used in pharmaceutical, nutraceutical, and food industries. Lactulose can be enzymatically produced from lactose by cellobiose 2-epimerase (CEase). Several studies have already focused on the food-grade expression of CEase, but they are all aimed at the biosynthesis of epilactose. Herein, we reported for the first time the biosynthesis of lactulose using the recombinant food-grade Bacillus subtilis. Lactulose biosynthesis was optimized by varying lactulose-producing CEases and expression vectors. Caldicellulosiruptor saccharolyticus CEase and pP43NMK were determined to be the optimal CEase and expression vector. Fine-tuning of CEase expression was investigated by screening a beneficial N-terminal coding sequence. After fed-batch cultivation, the highest fermentation isomerization activity reached 11.6 U/mL. Lactulose was successfully produced by the broth of the engineered B. subtilis with a yield of 52.1 %.

Food for the Brain: Is Vegan/Vegetarian Diet the Way to Go for Hepatic Encephalopathy?

High-protein diet is the cornerstone of supportive care for patients living with hepatic encephalopathy. Although any protein source is better than protein restriction, there is uncertainty regarding the benefits of specific protein types. Using a randomized trial, Badal et al. evaluate the effect on ammonia levels and metabolomics from 3 protein sources in burgers made from beef, vegan products, and vegetarian products. The vegan and vegetarian burgers did not raise ammonia and may result in favorable metabolomic profiles.