Nontraditional Treatment of Hepatic Encephalopathy.

The pathophysiology of hepatic encephalopathy (HE) is complex, with hyperammonemia playing a central role in its development. Traditional therapies for HE have targeted ammonia and include medications such as lactulose and rifaximin. Although these agents are considered standard of care, nontraditional treatments seek to affect other factors in the pathogenesis of HE. Finally, procedural therapies include albumin dialysis, shunt closure, and the ultimate cure for HE, which is liver transplant. The treatments discussed provide alternative options for patients who have failed standard of care. However, more high-quality studies are needed to routinely recommend many of these agents.

Preventing Readmissions for Hepatic Encephalopathy.

Hepatic encephalopathy is a strong predictor of hospital readmissions in patients with advanced liver disease. The frequent recurrence of hepatic encephalopathy and subsequent readmissions may lead to nonreversible organ dysfunction, resulting in a significant decrease of patient quality of life and increase of health care burden costs for patients and facilities. Many of these readmissions for hepatic encephalopathy are preventable. Multidisciplinary patient-centered care throughout the continuum is essential in the management of hepatic encephalopathy. Understanding the patient's daily functions and limitations in the outpatient setting is key to correctly identifying the cause of hospital admission.

Preventive and therapeutic effects of rifaximin on hepatic encephalopathy with differential application dosages and strategies: a network meta-analysis.

BACKGROUND: Hepatic encephalopathy (HE) is a neuropsychiatric syndrome that affects the prognosis of patients with liver disease and is considered an independent risk factor for hospitalization and death. Rifaximin has been approved for HE treatment. This review will analyze the effect of rifaximin on different stages of HE with differential application dosages and strategies by traditional and network meta-analyses. METHODS: We performed a systematic search of PubMed, EmBase, and Cochrane Library databases up to February 26, 2023, to identify randomized controlled trials (RCTs) about rifaximin for the prevention and treatment of HE. The outcomes included incidence of HE and HE progression, HE reversal, mortality, and adverse effects. RESULTS: A total of 21 studies were included. In the primary prevention of HE, rifaximin significantly reduced the incidence of HE (OR: 0.66; 95% CI: 0.45, 0.96; p = 0.032). In secondary prevention, rifaximin significantly reduced the risk of recurrence in patients who were in remission (OR: 0.38; 95% CI: 0.28, 0.52; p < 0.001). In the treatment of minimal HE, rifaximin significantly reduced the breakthrough of MHE to OHE (OR: 0.17; 95% CI: 0.04,0.63; p = 0.008). Rifaximin also significantly improved the clinical symptoms of MHE and OHE patients (OR: 3.76; 95% CI: 2.69, 5.25; p < 0.001). However, rifaximin did not reduce mortality at any stage in HE patients (OR: 0.79; 95% CI: 0.58, 1.08; p = 0.133). Additionally, rifaximin did not increase the risk of adverse effects (OR: 0.96; 95% CI: 0.74, 1.24; p = 0.749). In the network meta-analysis, the 400 mg T.I.D. intervention had a relative advantage for HE risks in primary and secondary prevention. In the treatment of MHE, 600 mg b.i.d. was superior in preventing the breakthrough from MHE to OHE. CONCLUSION: Rifaximin prevented HE risks and progression and improved clinical symptoms in patients with MHE but did not reduce mortality. For primary and secondary prevention, 400 mg t.i.d. could be considered. 600 mg b.i.d. could be considered in patients with MHE.

Rifaximin treatment shapes a unique metagenome-metabolism network in patients with decompensated cirrhosis.

BACKGROUND: Patients with decompensated cirrhosis face poor prognosis and increased mortality risk. Rifaximin, a non-absorbable antibiotic, has been shown to have beneficial effects in preventing complications and improving survival in these patients. However, the underlying mechanisms of rifaximin's effects remain unclear. METHODS: We obtained fecal samples from decompensated cirrhotic patients undergoing rifaximin treatment and controls, both at baseline and after 6 months of treatment. Shotgun metagenome sequencing profiled the gut microbiome, and untargeted metabolomics analyzed fecal metabolites. Linear discriminant and partial least squares discrimination analyses were used to identify differing species and metabolites between rifaximin-treated patients and controls. RESULTS: Forty-two patients were enrolled and divided into two groups (26 patients in the rifaximin group and 16 patients in the control group). The gut microbiome's beta diversity changed in the rifaximin group but remained unaffected in the control group. We observed 44 species with reduced abundance in the rifaximin group, including Streptococcus_salivarius, Streptococcus_vestibularis, Haemophilus_parainfluenzae, etc. compared to only four in the control group. Additionally, six species were enriched in the rifaximin group, including Eubacterium_sp._CAG:248, Prevotella_sp._CAG:604, etc., and 14 in the control group. Furthermore, rifaximin modulated different microbial functions compared to the control. Seventeen microbiome-related metabolites were altered due to rifaximin, while six were altered in the control group. CONCLUSION: Our study revealed distinct microbiome-metabolite networks regulated by rifaximin intervention in patients with decompensated cirrhosis. These findings suggest that targeting these specific metabolites or related bacteria might be a potential therapeutic strategy for decompensated cirrhosis.

Improved cognition after rifaximin treatment is associated with changes in intra- and inter-brain network functional connectivity.

BACKGROUND: Rifaximin is a non-reabsorbable antibiotic which acts at gut level, and improves cognition and inflammatory parameters in minimal hepatic encephalopathy (MHE) patients, but not all patients show the same level of response. This study aims to assess brain activity, both within and between brain networks, following rifaximin treatment, considering the differences between response groups as well. METHODS: Twenty-two healthy controls and 53 patients with cirrhosis (22 without and 31 with MHE, diagnosed by Psychometric Hepatic Encephalopathy Score, PHES) performed psychometric, attention and coordination tests, and blood inflammatory parameters were measured. Resting-state functional magnetic resonance imaging (fMRI) acquisitions were performed on controls and MHE patients. Eighteen MHE patients underwent a rifaximin treatment for 6 months, after which all measures were repeated. fMRI images were analysed and changes after treatment were assessed. RESULTS: After rifaximin treatment, 13 patients improved their PHES score (Responder patients) while 5 did not (Non-responder patients). No significant decrease in blood ammonia was observed after rifaximin treatment, but there was a decrease in plasma inflammatory cytokines in responder patients. A global effect of rifaximin was detected on the sensorimotor and fronto-parietal networks. Responder patients showed a relative increase of thalamic network connectivity in comparison to non-responder patients. Before treatment, responder and non-responder patients showed connectivity differences in basal ganglia network. The connection of the sensorimotor and thalamic networks between them and with other networks suffered changes after treatment. These connections between networks mostly decreased after treatment. All changes and differences showed a significant level of correlation with the performance of psychometric tests and the blood levels of inflammatory biomarkers. CONCLUSIONS: There was an improvement of the communication between executive, motor and attention-related brain areas, and their functional independence following rifaximin treatment. Patients who respond also show a less deteriorated connection involved in these functions before treatment. Results suggest that the improved inflammatory state of MHE patients, following rifaximin treatment would favour the observed changes in brain function and enhanced cognitive performance.

Hepatic Encephalopathy in Children.

Hepatic encephalopathy, characterized by mental status changes and neuropsychiatric impairment, is associated with chronic liver disease as well as acute liver failure. In children, its clinical manifestations can be challenging to pinpoint. However, careful assessment for the development of hepatic encephalopathy is imperative when caring for these patients as progression of symptoms can indicate impending cerebral edema and systemic deterioration. Hepatic encephalopathy can present with hyperammonemia, but it is important to note that the degree of hyperammonemia is not indicative of severity of clinical manifestations. Newer forms of assessment are undergoing further research, and include imaging, EEG and neurobiomarkers. Mainstay of treatment currently includes management of underlying cause of liver disease, as well as reduction of hyperammonemia with either enteral medications such as lactulose and rifaximin, or even with extracorporeal liver support modalities.

Diagnostic Performance of the ICD-10 Code K76.82 for Hepatic Encephalopathy in Patients With Cirrhosis.

INTRODUCTION: Hepatic encephalopathy (HE) is prevalent and is associated with increased morbidity and mortality among patients with cirrhosis. On October 1, 2022, a new, specific International Classification of Diseases-10 code for HE, K76.82, was introduced. We aimed to analyze the diagnostic accuracy of K76.82. METHODS: Diagnostic performance of K76.82 for HE (sensitivity, specificity, positive predictive ratio, and negative predictive ratio) was evaluated in 2 large health systems compared with lactulose, rifaximin, and K72.90. RESULTS: A total of 2,483 patients were analyzed. The combination term "lactulose or rifaximin" showed the highest sensitivity of >98% while K76.82 demonstrated a specificity of >87% in all cohorts. DISCUSSION: Although K76.82 is promising, the combination term "lactulose or rifaximin" identified patients with HE more accurately.

Hepatic encephalopathy: From novel pathogenesis mechanism to emerging treatments.

Hepatic encephalopathy (HE) is one of the major complications of liver disease and significantly affects the quality of life (QOL) of patients. HE is common and frequently relapses in cirrhotic patients. The management of HE is supportive, and precipitating conditions should be eliminated. Most drugs used to treat HE are conventional and include nonabsorbable disaccharides such as lactulose, and antibiotics such as rifaximin. However, their therapeutic efficacy is still suboptimal, and novel therapeutic agents are urgently needed. In addition, the optimal management and diagnosis of minimal HE/covert HE are under debate. In this review, we focus on novel pathogenetic mechanisms such as central nervous system clearance, and emerging therapeutic targets of HE, such as fecal material transplantation. We also discuss different classifications and etiologies of HE.

The potential for development of clinically relevant microbial resistance to rifaximin-α: a narrative review.

SUMMARYRifaximin-α is a gut-targeted antibiotic indicated for numerous gastrointestinal and liver diseases. Its multifaceted mechanism of action goes beyond direct antimicrobial effects, including alterations in bacterial virulence, cytoprotective effects on host epithelial cells, improvement of impaired intestinal permeability, and reduction of proinflammatory cytokine expression via activation of the pregnane X receptor. Rifaximin-α is virtually non-absorbed, with low systemic drug levels contributing to its excellent safety profile. While there are high concentrations of drug in the colon, low water solubility leads to low colonic drug bioavailability, protecting the gut microbiome. Rifaximin-α appears to be more active in the bile-rich small bowel. Its important biologic effects are largely at sub-inhibitory concentration. Although in vitro testing of clinical isolates from rifaximin recipients has revealed rifaximin-resistant strains in some studies, the risk of emergent rifaximin-α resistance appears to be lower than for many other antibiotics. Rifaximin-α has been used for many years for traveler's diarrhea with no apparent increase in resistance levels in causative pathogens. Further, rifaximin-α retains its efficacy after long-term and recurrent usage in chronic gastrointestinal disorders. There are numerous reasons why the risk of microbial resistance to rifaximin-α may be lower than that for other agents, including low intestinal bioavailability in the aqueous colon, the mechanisms of action of rifaximin-α not requiring inhibitory concentrations of drug, and the low risk of cross transmission of rifaximin-α resistance between bacterial species. Reported emergence of vancomycin-resistant Enterococcus in liver-disease patients maintained on rifaximin needs to be actively studied. Further studies are required to assess the possible correlation between in vitro resistance and rifaximin-α efficacy.

Neurofilament Light Chain Protein in Plasma and Extracellular Vesicles Is Associated with Minimal Hepatic Encephalopathy and Responses to Rifaximin Treatment in Cirrhotic Patients.

Neurofilament light chain protein (NfL) levels reflect neuronal damage in several neurological diseases and have been proposed as a possible biomarker. Plasma extracellular vesicles (EVs) could play an important role as mediators of the inflammatory changes associated with inducing minimal hepatic encephalopathy (MHE) in cirrhotic patients. This study investigated the association of NfL levels in plasma and EVs with the presence of MHE in cirrhotic patients, and with responses to rifaximin treatment. The NfL levels in plasma and EVs were assessed in 71 patients with liver cirrhosis (40 with MHE and 31 without MHE) and 26 controls. A total of 31 patients with MHE received rifaximin treatment. We examined changes in NfL levels in plasma and EVs before and after 6 months of rifaximin treatment. The NfL measures were correlated with cognitive alterations and plasma inflammatory cytokines. MHE patients showed increased plasma levels of NfL, which were reverted after rifaximin treatment in patients who responded to treatment. The NfL content in EVs also showed a reversal pattern in MHE patients treated with rifaximin. In multivariable analyses, NfL levels were independently associated with the presence of MHE. We also showed that patients with high levels of both ammonia and fractalkine had significantly higher NfL levels than patients with low levels of least one of these parameters. Rifaximin treatment in MHE patients showed promising results in improving axonal damage, suggesting that rifaximin may have therapeutic benefits against disease progression in MHE.

Impact of rifaximin use following an initial overt hepatic encephalopathy hospitalization on rehospitalization and costs.

AIM: To assess the impact of rifaximin (± lactulose) use following discharge of an initial overt hepatic encephalopathy (OHE) hospitalization on OHE rehospitalizations and healthcare costs in a real-world setting. METHODS: Adults (18-64 years) with an OHE hospitalization were identified from MarketScan® Commercial claims (Q4'15-Q2'20), classified into two mutually exclusive treatment cohorts (i.e. rifaximin and no rifaximin treatment), and further stratified into four subgroups based on decreasing quality of care (QoC; i.e. Type 1 - rifaximin without delay post-discharge; Type 2 - rifaximin with delay post-discharge; Type 3 - lactulose only post-discharge; Type 4 - no rifaximin/lactulose treatment post-discharge). The impact of rifaximin use on 30-day and annualized OHE hospitalizations and healthcare costs were assessed between cohorts and by the QoC subgroup. RESULTS: Characteristics were similar between the rifaximin (N = 1,452; Type 1: 1,138, Type 2: 314) and no rifaximin (N = 560; Type 3:337, Type 4: 223) treatment cohorts. The 30-day risk of OHE rehospitalization was lower for the rifaximin vs. no rifaximin treatment cohort (odds ratio 0.56, p < .01) and increased with decreasing QoC. The annual rate of OHE hospitalizations was 59% lower for the rifaximin treatment cohort (incidence rate ratio 0.41, p < .01) and increased with decreasing QoC. Compared to the no rifaximin treatment cohort, the rifaximin treatment cohort had higher pharmacy costs, lower medical costs, and no difference in total healthcare costs. LIMITATIONS: This was a claims-based study subject to common data limitations such as billing inaccuracies or omissions in coded claims. Total healthcare costs were reported from a payer's perspective, which do not capture indirect costs associated with patient burden. CONCLUSIONS: Initiation of rifaximin after an OHE hospitalization was associated with reduced OHE hospitalizations both in the 30-days following and annually. Further, reduced medical costs offset increased pharmacy costs, and no annual cost differences were observed between cohorts.

High rifaximin out-of-pocket costs are associated with decreased treatment retention among patients with hepatic encephalopathy.

BACKGROUND AND AIMS: Hepatic encephalopathy (HE) is associated with significant morbidity and mortality for those with cirrhosis. Despite the known benefits of rifaximin use for HE, treatment retention remains low. This study aimed to evaluate the impact of out-of-pocket (OOP) rifaximin cost on treatment retention among commercially insured patients in the United States. METHODS: Adult patients with cirrhosis and HE were identified from the IBM MarketScan claims database. Those who began rifaximin treatment between January 1, 2011, and December 1, 2021 were included. Regression models were used to analyze the relationship between patients' 30-day OOP rifaximin cost and rifaximin retention (≥80% eligible days with rifaximin supply) at 180, 360, and 540 days. Models were controlled for patient demographic and clinical characteristics including age, sex, comorbid conditions, Charlson comorbidity index (CCI), and lactulose use. RESULTS: A total of 6839 adult patients were included. Most patients were between 55 and 64 years (57.1%), male (60.4%), and living in urban settings (84.6%). Treatment retention was low for all time periods; retention rates for rifaximin were 42%, 25%, and 16% at 180, 360, and 540 days, respectively. In multivariable analysis, 30-day OOP costs of ≥ $150 were associated with a decreased likelihood of rifaximin retention at 180, 360, and 540 days [relative risk (RR) = 0.67, RR = 0.62, and R = 0.60, respectively]. Younger age was associated with reduced treatment retention for all time periods. Metastatic cancer and depression were associated with reduced treatment retention at 180 days (RR = 0.70 and RR = 0.87, respectively). CONCLUSIONS: Rates of rifaximin treatment retention are low despite the known benefits of rifaximin use for breakthrough HE. High 30-day OOP cost is associated with reduced rifaximin treatment retention.

Rifaximin for prevention and treatment of hepatic encephalopathy in people with cirrhosis.

BACKGROUND: Hepatic encephalopathy describes the spectrum of neuropsychiatric changes that may complicate the course of cirrhosis and detrimentally affect outcomes. Ammonia plays a key role in its development. Rifaximin is a non-absorbable antibiotic that inhibits urease-producing bacteria and reduces absorption of dietary and bacterial ammonia. OBJECTIVES: To evaluate the beneficial and harmful effects of rifaximin versus placebo, no intervention, or non-absorbable disaccharides for: (i) the prevention of hepatic encephalopathy, and (ii) the treatment of minimal and overt hepatic encephalopathy, in people with cirrhosis, both when used alone and when combined with a non-absorbable disaccharide. SEARCH METHODS: We searched the Cochrane Hepato-Biliary Group Clinical Trials Register, CENTRAL, MEDLINE, Embase, three other databases, the reference lists of identified papers, and relevant conference proceedings. We wrote to authors and pharmaceutical companies for information on other published, unpublished, or ongoing trials. Searches were performed to January 2023. SELECTION CRITERIA: We included randomised clinical trials assessing prevention or treatment of hepatic encephalopathy with rifaximin alone, or with a non-absorbable disaccharide, versus placebo/no intervention, or a non-absorbable disaccharide alone. DATA COLLECTION AND ANALYSIS: Six authors independently searched for studies, extracted data, and validated findings. We assessed the design, bias risk, and participant/intervention characteristics of the included studies. We assessed mortality, serious adverse events, health-related quality of life, hepatic encephalopathy, non-serious adverse events, blood ammonia, Number Connection Test-A, and length of hospital stay. MAIN RESULTS: We included 41 trials involving 4545 people with, or at risk for, developing hepatic encephalopathy. We excluded 89 trials and identified 13 ongoing studies. Some trials involved participants with more than one type of hepatic encephalopathy or more than one treatment comparison. Hepatic encephalopathy was classed as acute (13 trials), chronic (7 trials), or minimal (8 trials), or else participants were considered at risk for its development (13 trials). The control groups received placebo (12 trials), no/standard treatment (1 trial), or a non-absorbable disaccharide (14 trials). Eighteen trials assessed rifaximin plus a non-absorbable disaccharide versus a non-absorbable disaccharide alone. We classified 11 trials as at high risk of overall bias for mortality and 28 for non-mortality outcomes, mainly due to lack of blinding, incomplete outcome data, and selective reporting. Compared to placebo/no intervention, rifaximin likely has no overall effect on mortality (risk ratio (RR) 0.83, 95% confidence interval (CI) 0.50 to 1.38; P = 48, I2 = 0%; 13 trials, 1007 participants; moderate-certainty evidence), and there may be no overall effect when compared to non-absorbable disaccharides (RR 0.99, 95% CI 0.49 to 1.97; P = 0.97, I2 = 0%; 10 trials, 786 participants; low-certainty evidence). However, there is likely a reduction in the overall risk of mortality when comparing rifaximin plus a non-absorbable disaccharide to a non-absorbable disaccharide alone (RR 0.69, 95% CI 0.55 to 0.86; number needed to treat for an additional beneficial outcome (NNTB) = 22; P = 0.001, I2 = 0%; 14 trials, 1946 participants; moderate-certainty evidence). There is likely no effect on the overall risk of serious adverse events when comparing rifaximin to placebo/no intervention (RR 1.05, 95% CI 0.83 to 1.32; P = 68, I2 = 0%; 9 trials, 801 participants; moderate-certainty evidence) and there may be no overall effect when compared to non-absorbable disaccharides (RR 0.97, 95% CI 0.66 to 1.40; P = 85, I2 = 0%; 8 trials, 681 participants; low-certainty evidence). However, there was very low-certainty evidence that use of rifaximin plus a non-absorbable disaccharide may be associated with a lower risk of serious adverse events than use of a non-absorbable disaccharide alone (RR 0.66, 95% CI 0.45 to 0.98; P = 0.04, I2 = 60%; 7 trials, 1076 participants). Rifaximin likely results in an overall effect on health-related quality of life when compared to placebo/no intervention (mean difference (MD) -1.43, 95% CI -2.87 to 0.02; P = 0.05, I2 = 81%; 4 trials, 214 participants; moderate-certainty evidence), and may benefit health-related quality of life in people with minimal hepatic encephalopathy (MD -2.07, 95% CI -2.79 to -1.35; P < 0.001, I2 = 0%; 3 trials, 176 participants). The overall effect on health-related quality of life when comparing rifaximin to non-absorbable disaccharides is very uncertain (MD -0.33, 95% CI -1.65 to 0.98; P = 0.62, I2 = 0%; 2 trials, 249 participants; very low-certainty evidence). None of the combined rifaximin/non-absorbable disaccharide trials reported on this outcome. There is likely an overall beneficial effect on hepatic encephalopathy when comparing rifaximin to placebo/no intervention (RR 0.56, 95% CI 0.42 to 0.77; NNTB = 5; P < 0.001, I2 = 68%; 13 trials, 1009 participants; moderate-certainty evidence). This effect may be more marked in people with minimal hepatic encephalopathy (RR 0.40, 95% CI 0.31 to 0.52; NNTB = 3; P < 0.001, I2 = 10%; 6 trials, 364 participants) and in prevention trials (RR 0.71, 95% CI 0.56 to 0.91; NNTB = 10; P = 0.007, I2 = 36%; 4 trials, 474 participants). There may be little overall effect on hepatic encephalopathy when comparing rifaximin to non-absorbable disaccharides (RR 0.85, 95% CI 0.69 to 1.05; P = 0.13, I2 = 0%; 13 trials, 921 participants; low-certainty evidence). However, there may be an overall beneficial effect on hepatic encephalopathy when comparing rifaximin plus a non-absorbable disaccharide to a non-absorbable disaccharide alone (RR 0.58, 95% CI 0.48 to 0.71; NNTB = 5; P < 0.001, I2 = 62%; 17 trials, 2332 participants; low-certainty evidence). AUTHORS' CONCLUSIONS: Compared to placebo/no intervention, rifaximin likely improves health-related quality of life in people with minimal hepatic encephalopathy, and may improve hepatic encephalopathy, particularly in populations with minimal hepatic encephalopathy and when it is used for prevention. Rifaximin likely has no overall effect on mortality, serious adverse events, health-related quality of life, or hepatic encephalopathy compared to non-absorbable disaccharides. However, when used in combination with a non-absorbable disaccharide, it likely reduces overall mortality risk, the risk of serious adverse events, improves hepatic encephalopathy, reduces the length of hospital stay, and prevents the occurrence/recurrence of hepatic encephalopathy. The certainty of evidence for these outcomes is very low to moderate; further high-quality trials are needed.

Current vision on diagnosis and comprehensive care in hepatic encephalopathy.

The first clinical guidelines on hepatic encephalopathy were published in 2009. Almost 14 years since that first publication, numerous advances in the field of diagnosis, treatment, and special condition care have been made. Therefore, as an initiative of the Asociación Mexicana de Gastroenterología A.C., we present a current view of those aspects. The manuscript described herein was formulated by 24 experts that participated in six working groups, analyzing, discussing, and summarizing the following topics: Definition of hepatic encephalopathy; recommended classifications; epidemiologic panorama, worldwide and in Mexico; diagnostic tools; conditions that merit a differential diagnosis; treatment; and primary and secondary prophylaxis. Likewise, these guidelines emphasize the management of certain special conditions, such as hepatic encephalopathy in acute liver failure and acute-on-chronic liver failure, as well as specific care in patients with hepatic encephalopathy, such as the use of medications and types of sedation, describing those that are permitted or recommended, and those that are not.

Antibiotics and Probiotics for Irritable Bowel Syndrome.

Irritable bowel syndrome (IBS) is a disorder of a gut-brain interaction characterised by abdominal pain and a change in stool form or frequency. Current symptom-based definitions and the classification of IBS promote heterogeneity amongst patients, meaning that there may be several different pathophysiological abnormalities leading to similar symptoms. Although our understanding of IBS is incomplete, there are several indicators that the microbiome may be involved in a subset of patients. Techniques including a faecal sample analysis, colonic biopsies, duodenal aspirates or surrogate markers, such as breath testing, have been used to examine the gut microbiota in individuals with IBS. Because of a lack of a clear definition of what constitutes a healthy gut microbiota, and the fact that alterations in gut microbiota have only been shown to be associated with IBS, a causal relationship is yet to be established. We discuss several hypotheses as to how dysbiosis may be responsible for IBS symptoms, as well as potential treatment strategies. We review the current evidence for the use of antibiotics and probiotics to alter the microbiome in an attempt to improve IBS symptoms. Rifaximin, a non-absorbable antibiotic, is the most studied antibiotic and has now been licensed for use in IBS with diarrhoea in the USA, but the drug remains unavailable in many countries for this indication. Current evidence also suggests that certain probiotics, including Lactobacillus plantarum DSM 9843 and Bifidobacterium bifidum MIMBb75, may be efficacious in some patients with IBS. Finally, we describe the future challenges facing us in our attempt to modulate the microbiome to treat IBS.

Comparative Efficacy of Treatment Options for the Prevention of Post-TIPS Hepatic Encephalopathy: A Systematic Review and Network Meta-analysis.

BACKGROUND AND AIMS: Transjugular intrahepatic portosystemic shunt (TIPS) is often used in patients with cirrhosis to manage portal hypertension-related complications. Unfortunately, 35-50% of patients develop overt hepatic encephalopathy (HE) after TIPS. However, data on lactulose and rifaximin to prevent post-TIPS HE is limited. Therefore, we aimed to perform a network meta-analysis to investigate the efficacy of multiple pharmacological regimens in the prevention of post-TIPS HE. METHODS: A comprehensive search strategy to identify reports of studies of rifaximin use on post-TIPS hepatic encephalopathy was constructed using truncated keywords, phrases, and subject headings developed in Embase. This strategy was translated to MEDLINE, Cochrane Central Register of Controlled Trials, and the Web of Science Core Collection, with all searches performed on 10 February 2022. No publication date or language limits were used. RESULTS: The initial search identified 72 studies, and 56 studies were screened after removing duplicates. Five studies, two randomized controlled trials (RCTs) and three retrospective studies, met our inclusion criteria and were included in the final analysis. A total of 840 patients were included, with 65% male. Our meta- analysis did not find a statistically significant difference between lactulose vs placebo/no prophylaxis, nor rifaximin vs placebo/no prophylaxis, nor rifaximin plus lactulose vs placebo/no prophylaxis in the reduction of post-TIPS HE. CONCLUSIONS: Rifaximin alone, lactulose alone, and rifaximin plus lactulose did not significantly reduce the development of post-TIPS HE. Based on the P-scores of the three treatment groups, the combination of rifaximin plus lactulose showed the most promising trend towards preventing post-TIPS HE. More studies, especially large RCTs, are warranted.

Update on the Role of Rifaximin in Digestive Diseases.

Various environmental factors affecting the human microbiota may lead to gut microbial imbalance and to the development of pathologies. Alterations of gut microbiota have been firmly implicated in digestive diseases such as hepatic encephalopathy, irritable bowel syndrome and diverticular disease. However, while these three conditions may all be related to dysfunction of the gut-liver-brain axis, the precise pathophysiology appears to differ somewhat for each. Herein, current knowledge on the pathophysiology of hepatic encephalopathy, irritable bowel syndrome, and diverticular disease are reviewed, with a special focus on the gut microbiota modulation associated with these disorders during therapy with rifaximin. In general, the evidence for the efficacy of rifaximin in hepatic encephalopathy appears to be well consolidated, although it is less supported for irritable bowel syndrome and diverticular disease. We reviewed current clinical practice for the management of these clinical conditions and underlined the desirability of more real-world studies to fully understand the potential of rifaximin in these clinical situations and obtain even more precise indications for the use of the drug.