Nicole A. Noble

Altered profile of human gut microbiome is associated with cirrhosis and its complications

BACKGROUND & AIMS The gut microbiome is altered in cirrhosis; however its evolution with disease progression is only partly understood. We aimed to study changes in the microbiome over cirrhosis severity, its stability over time and its longitudinal alterations with decompensation. METHODS Controls and age-matched cirrhotics (compensated/decompensated/hospitalized) were included. Their stool microbiota was quantified using multi-tagged pyrosequencing. The ratio of autochthonous to non-autochthonous taxa was calculated as the cirrhosis dysbiosis ratio (CDR); a low number indicating dysbiosis. Firstly, the microbiome was compared between controls and cirrhotic sub-groups. Secondly, for stability assessment, stool collected twice within 6months in compensated outpatients was analyzed. Thirdly, changes after decompensation were assessed using (a) longitudinal comparison in patients before/after hepatic encephalopathy development (HE), (b) longitudinal cohort of hospitalized infected cirrhotics MELD-matched to uninfected cirrhotics followed for 30days. RESULTS 244 subjects [219 cirrhotics (121 compensated outpatients, 54 decompensated outpatients, 44 inpatients) and 25 age-matched controls] were included. CDR was highest in controls (2.05) followed by compensated (0.89), decompensated (0.66), and inpatients (0.32, p<0.0001) and negatively correlated with endotoxin. Microbiota and CDR remained unchanged in stable outpatient cirrhotics (0.91 vs. 0.86, p=0.45). In patients studied before/after HE development, dysbiosis occurred post-HE (CDR: 1.2 to 0.42, p=0.03). In the longitudinal matched-cohort, microbiota were significantly different between infected/uninfected cirrhotics at baseline and a low CDR was associated with death and organ failures within 30days. CONCLUSIONS Progressive changes in the gut microbiome accompany cirrhosis and become more severe in the setting of decompensation. The cirrhosis dysbiosis ratio may be a useful quantitative index to describe microbiome alterations accompanying cirrhosis progression.

Modulation of the fecal bile acid profile by gut microbiota in cirrhosis.

BACKGROUND & AIMS The 7α-dehydroxylation of primary bile acids (BAs), chenodeoxycholic (CDCA) and cholic acid (CA) into the secondary BAs, lithocholic (LCA) and deoxycholic acid (DCA), is a key function of the gut microbiota. We aimed at studying the linkage between fecal BAs and gut microbiota in cirrhosis since this could help understand cirrhosis progression. METHODS Fecal microbiota were analyzed by culture-independent multitagged-pyrosequencing, fecal BAs using HPLC and serum BAs using LC-MS in controls, early (Child A) and advanced cirrhotics (Child B/C). A subgroup of early cirrhotics underwent BA and microbiota analysis before/after eight weeks of rifaximin. RESULTS Cross-sectional: 47 cirrhotics (24 advanced) and 14 controls were included. In feces, advanced cirrhotics had the lowest total, secondary, secondary/primary BA ratios, and the highest primary BAs compared to early cirrhotics and controls. Secondary fecal BAs were detectable in all controls but in a significantly lower proportion of cirrhotics (p<0.002). Serum primary BAs were higher in advanced cirrhotics compared to the rest. Cirrhotics, compared to controls, had a higher Enterobacteriaceae (potentially pathogenic) but lower Lachonospiraceae, Ruminococcaceae and Blautia (7α-dehydroxylating bacteria) abundance. CDCA was positively correlated with Enterobacteriaceae (r=0.57, p<0.008) while Ruminococcaceae were positively correlated with DCA (r=0.4, p<0.05). A positive correlation between Ruminococcaceae and DCA/CA (r=0.82, p<0.012) and Blautia with LCA/CDCA (r=0.61, p<0.03) was also seen. Prospective study: post-rifaximin, six early cirrhotics had reduction in Veillonellaceae and in secondary/primary BA ratios. CONCLUSIONS Cirrhosis, especially advanced disease, is associated with a decreased conversion of primary to secondary fecal BAs, which is linked to abundance of key gut microbiome taxa.

Modulation of the Metabiome by Rifaximin in Patients with Cirrhosis and Minimal Hepatic Encephalopathy

Hepatic encephalopathy (HE) represents a dysfunctional gut-liver-brain axis in cirrhosis which can negatively impact outcomes. This altered gut-brain relationship has been treated using gut-selective antibiotics such as rifaximin, that improve cognitive function in HE, especially its subclinical form, minimal HE (MHE). However, the precise mechanism of the action of rifaximin in MHE is unclear. We hypothesized that modulation of gut microbiota and their end-products by rifaximin would affect the gut-brain axis and improve cognitive performance in cirrhosis. Aim To perform a systems biology analysis of the microbiome, metabolome and cognitive change after rifaximin in MHE. Methods Twenty cirrhotics with MHE underwent cognitive testing, endotoxin analysis, urine/serum metabolomics (GC and LC-MS) and fecal microbiome assessment (multi-tagged pyrosequencing) at baseline and 8 weeks post-rifaximin 550 mg BID. Changes in cognition, endotoxin, serum/urine metabolites (and microbiome were analyzed using recommended systems biology techniques. Specifically, correlation networks between microbiota and metabolome were analyzed before and after rifaximin. Results There was a significant improvement in cognition(six of seven tests improved,p<0.01) and endotoxemia (0.55 to 0.48 Eu/ml, p = 0.02) after rifaximin. There was a significant increase in serum saturated (myristic, caprylic, palmitic, palmitoleic, oleic and eicosanoic) and unsaturated (linoleic, linolenic, gamma-linolenic and arachnidonic) fatty acids post-rifaximin. No significant microbial change apart from a modest decrease in Veillonellaceae and increase in Eubacteriaceae was observed. Rifaximin resulted in a significant reduction in network connectivity and clustering on the correlation networks. The networks centered on Enterobacteriaceae, Porphyromonadaceae and Bacteroidaceae indicated a shift from pathogenic to beneficial metabolite linkages and better cognition while those centered on autochthonous taxa remained similar. Conclusions Rifaximin is associated with improved cognitive function and endotoxemia in MHE, which is accompanied by alteration of gut bacterial linkages with metabolites without significant change in microbial abundance. Trial Registration ClinicalTrials.gov NCT01069133

Second infections independently increase mortality in hospitalized patients With cirrhosis: the north american consortium for the study of end‐stage liver disease (NACSELD) experience

Bacterial infections are an important cause of mortality in cirrhosis, but there is a paucity of multicenter studies. The aim was to define factors predisposing to infection‐related mortality in hospitalized patients with cirrhosis. A prospective, cohort study of patients with cirrhosis with infections was performed at eight North American tertiary‐care hepatology centers. Data were collected on admission vitals, disease severity (model for endstage liver disease [MELD] and sequential organ failure [SOFA] scores), first infection site, type (community‐acquired, healthcare‐associated [HCA] or nosocomial), and second infection occurrence during hospitalization. The outcome was mortality within 30 days. A multivariate logistic regression model predicting mortality was created. 207 patients (55 years, 60% men, MELD 20) were included. Most first infections were HCA (71%), then nosocomial (15%) and community‐acquired (14%). Urinary tract infections (52%), spontaneous bacterial peritonitis (SBP, 23%) and spontaneous bacteremia (21%) formed the majority of the first infections. Second infections were seen in 50 (24%) patients and were largely preventable: respiratory, including aspiration (28%), urinary, including catheter‐related (26%), fungal (14%), and Clostridium difficile (12%) infections. Forty‐nine patients (23.6%) who died within 30 days had higher admission MELD (25 versus 18, P < 0.0001), lower serum albumin (2.4 g/dL versus 2.8 g/dL, P = 0.002), and second infections (49% versus 16%, P < 0.0001) but equivalent SOFA scores (9.2 versus 9.9, P = 0.86). The case fatality rate was highest for C. difficile (40%), respiratory (37.5%), and spontaneous bacteremia (37%), and lowest for SBP (17%) and urinary infections (15%). The model for mortality included admission MELD (odds ratio [OR]: 1.12), heart rate (OR: 1.03) albumin (OR: 0.5), and second infection (OR: 4.42) as significant variables. Conclusion: Potentially preventable second infections are predictors of mortality independent of liver disease severity in this multicenter cirrhosis cohort. (HEPATOLOGY 2012;56:2328–2335)

The Multi-Dimensional Burden of Cirrhosis and Hepatic Encephalopathy on Patients and Caregivers

OBJECTIVES:Cirrhosis and hepatic encephalopathy (HE) can adversely affect survival, but their effect on socioeconomic and emotional burden on the family is not clear. The aim was to study the emotional and socioeconomic burden of cirrhosis and HE on patients and informal caregivers.METHODS:A cross-sectional study in two transplant centers (Veterans and University) of cirrhotic patients and their informal caregivers was performed. Demographics for patient/caregivers, model-for-end-stage liver disease (MELD) score, and cirrhosis complications were recorded. Patients underwent a cognitive battery, sociodemographic, and financial questionnaires. Caregivers were given the perceived caregiver burden (PCB; maximum=155) and Zarit Burden Interview (ZBI)-Short Form (maximum=48) and questionnaires for depression, anxiety, and social support.RESULTS:A total of 104 cirrhotics (70% men, 44% previous HE, median MELD 12, 49% veterans) and their caregivers (66% women, 77% married, relationship duration 32±14 years) were included. Cirrhosis severely impacted the family unit with respect to work (only 56% employed), finances, and adherence. Those with previous HE had worse unemployment (87.5 vs. 19%, P=0.0001) and financial status (85 vs. 61%, P=0.019) and posed a higher caregiver burden; PCB (75 vs. 65, P=0.019) and ZBI (16 vs. 11, P=0.015) compared with others. Cognitive performance and MELD score were significantly correlated with employment and caregiver burden. Veterans and non-veterans were equally affected. On regression, depression score, MELD, and cognitive tests predicted both PCB and ZBI score.CONCLUSIONS:Previous HE and cognitive dysfunction are associated with worse employment, financial status, and caregiver burden. Cirrhosis-related expenses impact the family units daily functioning and medical adherence. A multidisciplinary approach to address this burden is required.

Randomised clinical trial: Lactobacillus GG modulates gut microbiome, metabolome and endotoxemia in patients with cirrhosis.

Safety of individual probiotic strains approved under Investigational New Drug (IND) policies in cirrhosis with minimal hepatic encephalopathy (MHE) is not clear.

The Stroop smartphone application is a short and valid method to screen for minimal hepatic encephalopathy

Minimal hepatic encephalopathy (MHE) detection is difficult because of the unavailability of short screening tools. Therefore, MHE patients can remain undiagnosed and untreated. The aim of this study was to use a Stroop smartphone application (app) (EncephalApp_Stroop) to screen for MHE. The app and standard psychometric tests (SPTs; 2 of 4 abnormal is MHE, gold standard), psychometric hepatic encephalopathy score (PHES), and inhibitory control tests (ICTs) were administered to patients with cirrhosis (with or without previous overt hepatic encephalopathy; OHE) and age‐matched controls from two centers; a subset underwent retesting. A separate validation cohort was also recruited. Stroop has an “off” state with neutral stimuli and an “on” state with incongruent stimuli. Outcomes included time to complete five correct runs as well as number of trials needed in on (Ontime) and off (Offtime) states. Stroop results were compared between controls and patients with cirrhosis with or without OHE and those with or without MHE (using SPTs, ICTs, and PHES). Receiver operating characteristic analysis was performed to diagnose MHE in patients with cirrhosis with or without previous OHE. One hundred and twenty‐five patients with cirrhosis (43 previous OHE) and 134 controls were included in the original cohort. App times were correlated with Model for End‐Stage Liver Disease (Offtime: r = 0.57; Ontime: r = 0.61; P < 0.0001) and were worst in previous OHE patients, compared to the rest and controls. Stroop performance was also significantly impaired in those with MHE, compared to those without MHE, according to SPTs, ICTs, and PHES (all P < 0.0001). A cutoff of >274.9 seconds (Ontime plus Offtime) had an area under the curve of 0.89 in all patients and 0.84 in patients without previous OHE for MHE diagnosis using SPT as the gold standard. The validation cohort showed 78% sensitivity and 90% specificity with the >274.9‐seconds Ontime plus Offtime cutoff. App result patterns were similar between the centers. Test‐retest reliability in controls and those without previous OHE was good; a learning effect on Ontime in patients with cirrhosis without previous OHE was noted. Conclusion: The Stroop smartphone app is a short, valid, and reliable tool for screening of MHE. (Hepatology 2013;58:1122‐1132)

Systems biology analysis of omeprazole therapy in cirrhosis demonstrates significant shifts in gut microbiota composition and function

Proton pump inhibitors (PPI) have been associated with infectious complications in cirrhosis, but their impact on distal gut microbiota composition and function is unclear. We aimed to evaluate changes in stool microbiota composition and function in patients with cirrhosis and healthy controls after omeprazole therapy. Both 15 compensated cirrhotic patients and 15 age-matched controls underwent serum gastrin measurement, stool microbiota profiling with multitagged pyrosequencing, and urinary metabolic profiling with NMR spectroscopy to assess microbial cometabolites before/after a 14-day course of 40 mg/day omeprazole under constant diet conditions. Results before (pre) and after PPI were compared in both groups, compared with baseline by systems biology techniques. Adherence was >95% without changes in diet or MELD (model for end-stage liver disease) score during the study. Serum gastrin concentrations significantly increased after PPI in cirrhosis (pre 38.3 ± 35.8 vs. 115.6 ± 79.3 pg/ml P < 0.0001) and controls (pre 29.9 ± 14.5 vs. 116.0 ± 74.0 pg/ml, P = 0.001). A significant microbiota change was seen in both controls and cirrhosis after omeprazole (QIIME P < 0.0001). Relative Streptococcaceae abundance, normally abundant in saliva, significantly increased postomeprazole in controls (1 vs. 5%) and cirrhosis (0 vs. 9%) and was correlated with serum gastrin levels (r = 0.4, P = 0.005). We found significantly reduced hippurate in cirrhosis vs. controls both pre- and postomeprazole and increased lactate in both groups post vs. preomeprazole, whereas dimethylamine (DMA) decreased in cirrhosis only. On correlation network analysis, significant changes in linkages of bacteria with metabolites (hippurate/DMA/lactate) were found postomeprazole, compared with pre-PPI in cirrhosis patients. In conclusion, omeprazole is associated with a microbiota shift and functional change in the distal gut in patients with compensated cirrhosis that could set the stage for bacterial overgrowth.

Covert Hepatic Encephalopathy Is Independently Associated With Poor Survival and Increased Risk of Hospitalization

OBJECTIVES:Despite the high prevalence of covert hepatic encephalopathy (CHE) in cirrhotics without previous overt HE (OHE), its independent impact on predicting clinically relevant outcomes is unclear. The aim of this study was to define the impact of CHE on time to OHE, hospitalization, and death/transplant in prospectively followed up patients without previous OHE.METHODS:Outpatient cirrhotics without OHE were enrolled and were administered a standard paper–pencil cognitive battery for CHE diagnosis. They were systematically followed up and time to first OHE development, hospitalization (liver-related/unrelated), and transplant/death were compared between CHE and no-CHE patients at baseline using Cox regression.RESULTS:A total of 170 cirrhotic patients (55 years, 58% men, 14 years of education, Model for End-Stage Liver Disease (MELD 9), 53% hepatitis C virus (HCV), 20% nonalcoholic etiology) were included, of whom 56% had CHE. The entire population was followed up for 13.0±14.6 months, during which time 30% developed their first OHE episode, 42% were hospitalized, and 19% had a composite death/transplant outcome. Age, gender, etiology, the MELD score, and CHE status were included in Cox regression models for time to first OHE episode, hospitalization, death, and composite death/transplant outcomes. On Cox regression, despite controlling for MELD, those with CHE had a higher risk of developing OHE (hazard ratio: 2.1, 95% confidence interval 1.01–4.5), hospitalization (hazard ratio: 2.5, 95% confidence interval 1.4–4.5), and death/transplant (hazard ratio: 3.4, 95% confidence interval 1.2–9.7) in the follow-up period.CONCLUSIONS:Covert HE is associated with worsened survival and increased risk of hospitalization and OHE development, despite controlling for the MELD score. Strategies to detect and treat CHE may improve these risks.

PROMIS computerised adaptive tests are dynamic instruments to measure health-related quality of life in patients with cirrhosis.

Aliment Pharmacol Ther 2011; 34: 1123–1132