Proton Pump Inhibitor Use and Complications of Cirrhosis Are Linked With Distinct Gut Microbial Bacteriophage and Eukaryotic Viral-Like Particle Signatures in Cirrhosis

INTRODUCTION

Proton pump inhibitors (PPIs) modulate the progression of cirrhosis to hepatic encephalopathy (HE) and can affect the bacterial microbiome. However, the impact of PPI on the virome in cirrhosis using viral-like particle (VLP) analysis is unclear.

METHODS

We determined the VLP in the stool microbiome in patients with cirrhosis cross-sectionally (ascites, HE, and PPI use analyzed) who were followed up for 6-month hospitalizations and through 2 clinical trials of PPI withdrawal and initiation.

RESULTS

In a cross-sectional study, PPI users had greater ascites prevalence and 6-month hospitalizations, but VLP α diversity was similar. Among phages, PPI users had lower Autographviridae and higher Streptococcus phages and Herelleviridae than nonusers, whereas opposite trends were seen in ascites and HE. Trends of eukaryotic viruses (higher Adenoviridae and lower Virgaviridae/Smacoviridae) were similar for PPI, HE, and ascites. Twenty-one percent were hospitalized, mostly due to HE. α Diversity was similar in the hospitalized/nonhospitalized/not groups. Higher Gokushovirinae and lower crAssphages were related to hospitalizations such as HE-related cross-sectional VLP changes. As part of the clinical trial, PPIs were added and withdrawn in 2 different decompensated groups over 14 days. No changes in α diversity were observed. Withdrawal reduced crAssphages, and initiation reduced Gokushovirinae and Bacteroides phages.

DISCUSSION

In cirrhosis, PPI use has a gut microbial VLP phage signature that is different from that in HE and ascites, and VLP changes are linked with hospitalizations over 6 months, independent of clinical biomarkers. Eukaryotic viral patterns were consistent across PPI use, HE, and ascites, indicating a relationship with the progression of cirrhosis. PPIs alone showed modest VLP changes with withdrawal or initiation. Distinct phage and eukaryotic viral patterns are associated with the use of PPIs in cirrhosis.

The RIVET RCT: Rifamycin SV MMX improves muscle mass, physical function, and ammonia in cirrhosis and minimal encephalopathy

BACKGROUND

Minimal hepatic encephalopathy (MHE) negatively affects the prognosis of cirrhosis, but treatment is not standard. Rifamycin SV MMX (RiVM) is a nonabsorbable rifampin derivative with colonic action.

METHODS

In a phase 2 placebo-controlled, double-blind randomized clinical trial patients with MHE were randomized to RiVM or placebo for 30 days with a 7-day follow-up. The primary endpoint was a change in stool cirrhosis dysbiosis ratio. Gut-brain (cognition, stool/salivary microbiome, ammonia, brain magnetic resonance spectroscopy), inflammation (stool calprotectin/serum cytokines), patient-reported outcomes (sickness impact profile: total/physical/psychosocial, high = worse), and sarcopenia (handgrip, bioelectric impedance) were secondary. Between/within groups and delta (post-pre) comparisons were performed.

RESULTS

Thirty patients (15/group) were randomized and completed the study without safety concerns. While cirrhosis dysbiosis ratio was statistically similar on repeated measures ANOVA (95% CI: -0.70 to 3.5), ammonia significantly reduced (95% CI: 4.4-29.6) in RiVM with changes in stool microbial α/β-diversity. MHE status was unchanged but only serial dotting (which tests motor strength) improved in RiVM-assigned patients. Delta physical sickness impact profile (95% CI: 0.33 = 8.5), lean mass (95% CI: -3.3 to -0.9), and handgrip strength (95% CI: -8.1 to -1.0) improved in RiVM versus placebo. Stool short-chain fatty acids (propionate, acetate, and butyrate) increased post-RiVM. Serum, urine, and stool bile acid profile changed to nontoxic bile acids (higher hyocholate/ursodeoxycholate and lower deoxycholate/lithocholate) post-RiVM. Serum IL-1β and stool calprotectin decreased while brain magnetic resonance spectroscopy showed higher glutathione concentrations in RiVM.

CONCLUSIONS

RiVM is well tolerated in patients with MHE with changes in stool microbial composition and function, ammonia, inflammation, brain oxidative stress, and sarcopenia-related parameters without improvement in cognition. RiVM modulates the gut-brain axis and gut-muscle axis in cirrhosis.

Alterations in gut virome are associated with cognitive function and minimal hepatic encephalopathy cross-sectionally and longitudinally in cirrhosis

Cognitive dysfunction due to minimal hepatic encephalopathy (MHE) adversely impacts patients with cirrhosis and more precise therapies are needed. Gut-brain axis changes are therapeutic targets, but prior studies have largely focused on bacterial changes. Our aim was to determine linkages between individual cognitive testing results and bacteria with the virome using a cross-sectional and longitudinal approach. We included cross-sectional (n = 138) and longitudinal analyses (n = 36) of patients with cirrhosis tested using three cognitive modalities, which were psychometric hepatic encephalopathy score (PHES), inhibitory control test (ICT), Stroop, and all three. Stool metagenomics with virome and bacteriome were analyzed studied cross-sectionally and in a subset followed for development/reversal of MHE repeated at 6 months (longitudinally only using PHES). Cross-sectional: We found no significant changes in α/β diversity in viruses or bacteria regardless of cognitive testing. Cognitively impaired patients were more likely to have higher relative abundance of bacteriophages linked with Streptococcus, Faecalibacterium, and Lactobacillus, which were distinct based on modality. These were also linked with cognition on correlation networks. Longitudinally, 27 patients remained stable while 9 changed their MHE status. Similar changes in phages that are linked with Streptococcus, Faecalibacterium, and Lactobacillus were seen. These phages can influence ammonia, lactate, and short-chain fatty acid generation, which are neuro-active. In conclusion, we found linkages between bacteriophages and cognitive function likely due to impact on bacteria that produce neuroactive metabolites cross-sectionally and longitudinally. These findings could help explore bacteriophages as options to influence treatment for MHE in cirrhosis.

Detection of SARS-CoV-2 RNA in wastewater from dormitory buildings in a university campus: comparison with individual testing results

Wastewater-based epidemiology (WBE) for monitoring COVID-19 has been largely used to detect the spread of the disease at the community level. From February to December 2022, we collected 24-h composite sewage samples from dormitory buildings in George Mason University (Fairfax, Virginia, USA) housing approximately 5,200 resident students. SARS-CoV-2 RNA extraction was achieved using an automated system based on magnetic nanoparticles. Analysis of SARS-CoV-2 RNA was performed using reverse transcription quantitative PCR based on the Centers for Disease Control and Prevention (CDC) N1 and N2 assays. From the 362 samples collected, 86% showed positive detection of SARS-CoV-2 RNA. Wastewater monitoring was able to detect SARS-CoV-2 RNA in 96% of the samples from buildings housing students with COVID-19. Over the period of study, we observed significant correlations between the SARS-CoV-2 concentration (copy number mL-1) in wastewater and the number of positive cases on campus based on individual saliva testing. Although several reports have been published on the wastewater monitoring of COVID-19 in university campuses, our study is one of the very few that provides results that were obtained during the last phase of the pandemic (roughly the year 2022), when the large majority of students were vaccinated and back on campus.

Longitudinal transkingdom gut microbial approach towards decompensation in outpatients with cirrhosis

OBJECTIVE

First decompensation development is a critical milestone that needs to be predicted. Transkingdom gut microbial interactions, including archaeal methanogens, may be important targets and predictors but a longitudinal approach is needed.

DESIGN

Cirrhosis outpatients who provided stool twice were included. Group 1: compensated, group 2: 1 decompensation (decomp), group 3: >1 decompensationwere followed and divided into those who remained stable or decompensated. Bacteria, viral and archaeal presence, α/β diversity and taxa changes over time adjusted for clinical variables were analysed. Correlation networks between kingdoms were analysed.

RESULTS

157 outpatients (72 group 1, 33 group 2 and 52 group 3) were followed and 28%-47% developed outcomes. Baseline between those who remained stable/developed outcome: While no α/β diversity differences were seen, commensals were lower and pathobionts were higher in those who decompensated. After decompensation: those experiencing their first decompensation showed greater decrease in α/β-diversity, bacterial change (↑Lactobacillus spp, Streptococcus parasanguinis and ↓ beneficial Lachnospiraceae and Eubacterium hallii) and viral change (↑Siphoviridae, ↓ Myoviridae) versus those with further decompensation. Archaea: 19% had Methanobacter brevii, which was similar between/within groups. Correlation networks: Baseline archaeal-viral-bacterial networks were denser and more homogeneous in those who decompensated versus the rest. Archaea-bacterial correlations collapsed post first decompensation. Lactobacillus phage Lc Nu and C2-like viruses were negatively linked with beneficial bacteria.

CONCLUSION

In this longitudinal study of cirrhosis outpatients, the greatest transkingdom gut microbial changes were seen in those reaching the first decompensation, compared with subsequent decompensating events. A transkingdom approach may refine prediction and provide therapeutic targets to prevent cirrhosis progression.

Association of serum metabolites and gut microbiota at hospital admission with nosocomial infection development in patients with cirrhosis

Cirrhosis is complicated by a high rate of nosocomial infections (NIs), which result in poor outcomes and are challenging to predict using clinical variables alone. Our aim was to determine predictors of NI using admission serum metabolomics and gut microbiota in inpatients with cirrhosis. In this multicenter inpatient cirrhosis study, serum was collected on admission for liquid chromatography-mass spectrometry metabolomics, and a subset provided stool for 16SrRNA analysis. Hospital course, including NI development and death, were analyzed. Metabolomic analysis using analysis of covariance (ANCOVA) (demographics, Model for End-Stage Liver Disease [MELD] admission score, white blood count [WBC], rifaximin, and infection status adjusted) and random forest analyses for NI development were performed. Additional values of serum metabolites over clinical variables toward NI were evaluated using logistic regression. Stool microbiota and metabolomic correlations were compared in patients with and without NI development. A total of 602 patients (231 infection admissions) were included; 101 (17%) developed NIs, which resulted in worse inpatient outcomes, including intensive care unit transfer, organ failure, and death. A total of 127 patients also gave stool samples, and 20 of these patients developed NIs. The most common NIs were spontaneous bacterial peritonitis followed by urinary tract infection, Clostridioides difficile, and pneumonia. A total of 247 metabolites were significantly altered on ANCOVA. Higher MELD scores (odds ratio, 1.05; p < 0.0001), admission infection (odds ratio, 3.54; p < 0.0001), and admission WBC (odds ratio, 1.05; p = 0.04) predicted NI (area under the curve, 0.74), which increased to 0.77 (p = 0.05) with lower 1-linolenoyl-glycerolphosphocholine (GPC) and 1-stearoyl-GPC and higher N-acetyltryptophan and N-acetyl isoputreanine. Commensal microbiota were lower and pathobionts were higher in those who developed NIs. Microbial-metabolite correlation networks were complex and dense in patients with NIs, especially sub-networks centered on Ruminococcaceae and Pseudomonadaceae. NIs are common and associated with poor outcomes in cirrhosis. Admission gut microbiota in patients with NIs showed higher pathobionts and lower commensal microbiota. Microbial-metabolomic correlations were more complex, dense, and homogeneous among those who developed NIs, indicating greater linkage strength. Serum metabolites and gut microbiota on admission are associated with NI development in cirrhosis.

Impact of bacterial infections and spontaneous bacterial peritonitis prophylaxis on phage-bacterial dynamics in cirrhosis

BACKGROUND AND AIMS

Gut microbiota, including bacteria and phages, are altered in cirrhosis, but their role during infections and spontaneous bacterial peritonitis (SBP) prophylaxis is unclear. Our aim was determine metagenomic changes in gut bacteria; phages and their linkages centered around Gram-negative and Gram-positive pathobionts in patients with cirrhosis with/without infections or SBP prophylaxis.

APPROACH AND RESULTS

We included uninfected (n = 231) and infected (n = 30, SBP n = 19 and urinary tract infection n = 11 before antibiotics) patients who gave stool for bacterial and phage metagenomics. We matched uninfected to infected patients 1:1 on a model for end-stage liver disease (MELD). We also analyzed subgroups of patients with ascites matched on an MELD (n = 73) to patients on SBP prophylaxis (n = 7) and then to SBP infection. Phage and bacterial taxa differences (DESeq2) and correlation networks centered around Escherichia coli and Enterococcus faecium were analyzed. Infections were mostly due to Enterobacteriaceae and Enterococcus spp. On metagenomics, higher fold changes of Enterobacteriaceae members, Enterococcus and Streptococcus spp., and Escherichia phages were seen in infected patients. Correlation networks showed more complex bacteria-phage linkages in infected patients compared with uninfected ones overall and centered around E. coli and E. faecium. SBP prophylaxis induced higher Gram-positive bacteria. In SBP, Enterococcus and Escherichia were higher versus ascites. Correlation networks around E. coli were complex in ascites but sparse with SBP prophylaxis, whereas the reverse was seen with E. faecium. Lytic phages and those associated with antibiotic resistance were correlated with E. faecium.

CONCLUSION

In cirrhosis, there are significant changes in phage-bacterial linkages in infected patients and those on SBP prophylaxis compared to the remaining patients. SBP prophylaxis enriches complexity of E. faecium-centered but induces a collapse in E. coli-centered phage-bacterial correlations.

Genetic variation of Borreliella burgdorferi in Fairfax County, Virginia, targeting the OspC gene in white-footed mice

Outer surface protein C (OspC) is a commonly used marker in population studies of Borreliella to differentiate types and establish evolution over time. Investigating the ospC genetic types of Borreliella burgdorferi across multiple organ tissues of white-footed mice has the potential to contribute to our understanding of Lyme disease and the wide spectrum of clinical presentation associated with infection. In this study, five unique tissue types were sampled from 90 mice and screened for B. burgdorferi infections. This initial screening revealed a 63% overall B. burgdorferi infection rate in the mice collected (57/90). A total of 163 tissues (30.4%) tested positive for B. burgdorferi infections and when mapped to Borreliella types, 143,894 of the initial 322,480 reads mapped to 10 of the reference sequences in the ospC strain library constructed for this study at a 97% MOI. Two tissue types, the ear and the tongue, each accounted for 90% of the observed Borreliella sequence diversity in the tissue samples surveyed. The largest amount of variation was observed in an individual ear tissue sample with six ospC sequence types, which is equivalent to 60% of the observed variation seen across all tested specimens, with statistically significant associations observed between tissue type and detected Borreliella. There is strong evidence for genetic variability in B. burgdorferi within local white-footed mouse populations and even within individual hosts by tissue type. These findings may shed light on drivers of infection sequalae in specific tissues in humans and highlights the need for expanded surveillance on the epigenetics of B. burgdorferi across reservoirs, ticks, and infected patients.

Reduced alcohol preference and intake after fecal transplant in patients with alcohol use disorder is transmissible to germ-free mice

Alcohol use disorder is a major cause of morbidity, which requires newer treatment approaches. We previously showed in a randomized clinical trial that alcohol craving and consumption reduces after fecal transplantation. Here, to determine if this could be transmitted through microbial transfer, germ-free male C57BL/6 mice received stool or sterile supernatants collected from the trial participants pre-/post-fecal transplant. We found that mice colonized with post-fecal transplant stool but not supernatants reduced ethanol acceptance, intake and preference versus pre-fecal transplant colonized mice. Microbial taxa that were higher in post-fecal transplant humans were also associated with lower murine alcohol intake and preference. A majority of the differentially expressed genes (immune response, inflammation, oxidative stress response, and epithelial cell proliferation) occurred in the intestine rather than the liver and prefrontal cortex. These findings suggest a potential for therapeutically targeting gut microbiota and the microbial-intestinal interface to alter gut-liver-brain axis and reduce alcohol consumption in humans.

Area Deprivation Index and Gut-Brain Axis in Cirrhosis

INTRODUCTION

Neighborhood deprivation has been associated with chronic diseases and with gut microbial alterations. Although cirrhosis is associated with gut microbiome changes and hepatic encephalopathy (HE), their association is unclear.

METHODS

Demographics and cirrhosis details (model for end-stage liver disease [MELD], prior HE, and medications) were recorded from outpatients with cirrhosis. Area deprivation index (ADI), which ranks neighborhoods by socioeconomic disadvantage, was recorded as state decile and national percentile (high = worse for both) and dichotomized on the median. Patients underwent cognitive testing to diagnose minimal HE (MHE). Stool microbiota was analyzed using 16S ribosomal RNA for α/β-diversity. Multivariable analysis was used to evaluate the factors independently associated with MHE.

RESULTS

A total of 321 people with cirrhosis (60 years, 78% men, 75% non-Hispanic White, 24% non-Hispanic African American, 4% Hispanic) were included. 45% had prior HE and 56% MHE. For ADI, the national percentile was 49.1 ± 21.8 while the state decile was 6.1 ± 2.3. ADI was not associated with race, ethnicity, MELD, or HE-related variables on regression. Regarding microbiota, α-diversity was lower in MHE and prior HE patients but similar across ADI rankings. Low vs high ADIs were associated with different β-diversity in univariable but not multivariable analyses. Multivariable analyses showed positive associations with MELD, prior HE, and lactate producers ( Lactobacillus and Lacticaseibacillus ) and negative associations with short-chain fatty acid producers ( Blautia , Lachnoclostridium , and Anaerobutyricum ) with MHE.

DISCUSSION

Cirrhosis-related variables may be more influential in determining gut microbiome composition and cognitive impairment than ADI. Therefore, the focus should be on improving cirrhosis care, regardless of ADI, but studies evaluating other measures of social determinants are needed in cirrhosis.

Interaction of Microbiome, Diet, and Hospitalizations Between Brazilian and American Patients With Cirrhosis

BACKGROUND & AIMS

Gut microbiota are affected by diet, country, and affect outcomes in cirrhosis. Western diets are associated with dysbiosis. Comparisons with other diets is needed. We aimed to compare cirrhosis patients from the United States with cirrhosis patients from Brazil with respect to diet, microbiota, and impact on hospitalizations.

METHODS

Healthy controls and compensated/decompensated outpatients with cirrhosis from the United States and Brazil underwent dietary recall and stool for 16S ribosomal RNA sequencing. Demographics and medications/cirrhosis details were compared within and between countries. Patients with cirrhosis were followed up for 90-day hospitalizations. Regression for Shannon diversity was performed within cirrhosis. Regression for hospitalizations adjusting for clinical and microbial variables was performed.

RESULTS

Model for end-stage liver disease (MELD), diabetes, ascites, and albumin were similar, but more Americans were men, had higher hepatic encephalopathy and alcohol/hepatitis C etiology, with lower nonalcoholic fatty liver disease than Brazilians. Brazilians had higher cereal, rice, and yogurt intake vs the United States. As disease progressed, cereals, rice/beans, coffee, and chocolate consumption was reduced. Microbial diversity was higher in Brazilians. Within cirrhosis, high diversity was related to Brazilian origin (P < .0001), age, and cereal intake (P = .05), while high MELD scores (P = .009) and ascites (P = .05) did the reverse. Regardless of stage, beneficial taxa and taxa associated with grant and yogurt intake were higher (Ruminococcaceae, Christensenellacae, and Prevotellaceae), while pathobionts (Porphyromonadaceae, Sutterellaceae, and Enterobacteriaceae) were lower in Brazilians. More Americans were hospitalized vs Brazilians (P = .002). On regression, MELD (P = .001) and ascites (P = .001) were associated with higher hospitalizations, while chocolate (P = .03) and Brazilian origin (P = .001) were associated with lower hospitalizations with/without microbiota inclusion.

CONCLUSIONS

Brazilian cirrhotic patients follow a diet richer in cereals and yogurt, which is associated with higher microbial diversity and beneficial microbiota and could contribute toward lower hospitalizations compared with a Western-diet-consuming American cohort.

Stool microbiota are superior to saliva in distinguishing cirrhosis and hepatic encephalopathy using machine learning

BACKGROUND & AIMS

Saliva and stool microbiota are altered in cirrhosis. Since stool is logistically difficult to collect compared to saliva, it is important to determine their relative diagnostic and prognostic capabilities. We aimed to determine the ability of stool vs. saliva microbiota to differentiate between groups based on disease severity using machine learning (ML).

METHODS

Controls and outpatients with cirrhosis underwent saliva and stool microbiome analysis. Controls vs. cirrhosis and within cirrhosis (based on hepatic encephalopathy [HE], proton pump inhibitor [PPI] and rifaximin use) were classified using 4 ML techniques (random forest [RF], support vector machine, logistic regression, and gradient boosting) with AUC comparisons for stool, saliva or both sample types. Individual microbial contributions were computed using feature importance of RF and Shapley additive explanations. Finally, thresholds for including microbiota were varied between 2.5% and 10%, and core microbiome (DESeq2) analysis was performed.

RESULTS

Two hundred and sixty-nine participants, including 87 controls and 182 patients with cirrhosis, of whom 57 had HE, 78 were on PPIs and 29 on rifaximin were included. Regardless of the ML model, stool microbiota had a significantly higher AUC in differentiating groups vs. saliva. Regarding individual microbiota: autochthonous taxa drove the difference between controls vs. patients with cirrhosis, oral-origin microbiota the difference between PPI users/non-users, and pathobionts and autochthonous taxa the difference between rifaximin users/non-users and patients with/without HE. These were consistent with the core microbiome analysis results.

CONCLUSIONS

On ML analysis, stool microbiota composition is significantly more informative in differentiating between controls and patients with cirrhosis, and those with varying cirrhosis severity, compared to saliva. Despite logistic challenges, stool should be preferred over saliva for microbiome analysis.

LAY SUMMARY

Since it is harder to collect stool than saliva, we wanted to test whether microbes from saliva were better than stool in differentiating between healthy people and those with cirrhosis and, among those with cirrhosis, those with more severe disease. Using machine learning, we found that microbes in stool were more accurate than saliva alone or in combination, therefore, stool should be preferred for analysis and collection wherever possible.

Multiple bacterial virulence factors focused on adherence and biofilm formation associate with outcomes in cirrhosis

BACKGROUND & AIMS

Altered gut microbiota is associated with poor outcomes in cirrhosis, including infections and hepatic encephalopathy (HE). However, the role of bacterial virulence factors (VFs) is unclear. Aim: Define association of VFs with cirrhosis severity and infections, their linkage with outcomes, and impact of fecal microbiota transplant (FMT).

METHODS

VF abundances were determined using metagenomic analysis in stools from controls and cirrhosis patients (compensated, HE-only, ascites-only, both and infected). Patients were followed for 90-day hospitalizations and 1-year death. Stool samples collected before/after a placebo-controlled FMT trial were also analyzed. Bacterial species and VFs for all species and selected pathogens (Escherichia, Klebsiella, Pseudomonas, Staphylococcus, Streptococcus, and Enterococcus spp) were compared between groups. Multi-variable analyses were performed for clinical biomarkers and VFs for outcome prediction. Changes in VFs pre/post-FMT and post-FMT/placebo were analyzed. Results: We included 233 subjects (40 controls, 43 compensated, 30 HE-only, 20 ascites-only, 70 both, and 30 infected). Decompensated patients, especially those with infections, had higher VFs coding for siderophores, biofilms, and adhesion factors versus the rest. Biofilm and adhesion VFs from Enterobacteriaceae and Enterococcus spp associated with death and hospitalizations independent of clinical factors regardless of when all VFs or selected pathogens were analyzed. FMT was associated with reduced VF post-FMT versus pre-FMT and post-placebo groups.

CONCLUSIONS

Virulence factors from multiple species focused on adhesion and biofilms increased with decompensation and infections, associated with death and hospitalizations independent of clinical factors, and were attenuated with FMT. Strategies focused on targeting multiple virulence factors could potentially impact outcomes in cirrhosis.

PRESENTATIONS

Portions of this manuscript were an oral presentation in the virtual International Liver Congress 2021.

ABBREVIATIONS

VF: virulence factors, HE: hepatic encephalopathy, FMT: Fecal microbiota transplant, PPI: proton pump inhibitors, LPS: lipopolysaccharides, VFDB: Virulence factor database, OTU: operational taxonomic units, SBP: spontaneous bacterial peritonitis, UTI: urinary tract infections, MRSA: methicillin resistant Staphylococcus aureus, VRE: vancomycin-resistant Enterococcus, MAAsLin2: Microbiome Multivariable Associations with Linear Models, LPS: lipopolysaccharides, AKI: acute kidney injury.

The Presence of Denitrifiers In Bacterial Communities of Urban Stormwater Best Management Practices (BMPs)

Stormwater best management practices (BMPs) are engineered structures that attempt to mitigate the impacts of stormwater, which can include nitrogen inputs from the surrounding drainage area. The goal of this study was to assess bacterial community composition in different types of stormwater BMP soils to establish whether a particular BMP type harbors more denitrification potential. Soil sampling took place over the summer of 2015 following precipitation events. Soils were sampled from four bioretention facilities, four dry ponds, four surface sand filters, and one dry swale. 16S rRNA gene analysis of extracted DNA and RNA amplicons indicated high bacterial diversity in the soils of all BMP types sampled. An abundance of denitrifiers was also indicated in the extracted DNA using presence/absence of nirS, nirK, and nosZ denitrification genes. BMP soil bacterial communities were impacted by the surrounding soil physiochemistry. Based on the identification of a metabolically-active community of denitrifiers, this study has indicated that denitrification could potentially occur under appropriate conditions in all types of BMP sampled, including surface sand filters that are often viewed as providing low potential for denitrification. The carbon content of incoming stormwater could be providing bacterial communities with denitrification conditions. The findings of this study are especially relevant for land managers in watersheds with legacy nitrogen from former agricultural land use.

The Effects of Consuming White Button Mushroom Agaricus bisporus on the Brain and Liver Metabolome Using a Targeted Metabolomic Analysis

A targeted metabolomic analysis was performed on tissues derived from pigs fed diets supplemented with white button mushrooms (WBM) to determine the effect on the liver and brain metabolome. Thirty-one pigs were fed a grower diet alone or supplemented with either three or six servings of freeze-dried WBM for six weeks. Tissue metabolomes were analyzed using targeted liquid chromatography-mass spectrometry (LC-MS) combined with chemical similarity enrichment analysis (ChemRICH) and correlated to WBM-induced changes in fecal microbiome composition. Results indicated that WBM can differentially modulate metabolites in liver, brain cortex and hippocampus of healthy pigs. Within the glycero-phospholipids, there was an increase in alkyl-acyl-phosphatidyl-cholines (PC-O 40:3) in the hippocampus of pigs fed six servings of WBM. A broader change in glycerophospholipids and sphingolipids was detected in the liver with a reduction in several lipid species in pigs fed both WBM diets but with an increase in amino acids known as precursors of neurotransmitters in the cortex of pigs fed six servings of WBM. Metabolomic changes were positively correlated with increased abundance of Cryomorphaceae, Lachnospiraceae, Flammeovirgaceae and Ruminococcaceae in the microbiome suggesting that WBM can also positively impact tissue metabolite composition.

Impact of Antibiotic Resistance Genes in Gut Microbiome of Patients With Cirrhosis

BACKGROUND AND AIMS

Cirrhosis is associated with changes in intestinal microbiota that can lead to hepatic encephalopathy (HE) and infections, especially with antibiotic-resistant organisms. However, the impact of gut microbial antibiotic resistance gene (ARG) burden on clinical outcomes is unclear. The aims of the study were to determine the impact of ARGs in cirrhosis-related gut metagenome on outcomes and disease progression, study the effect of rifaximin on ARG burden, and compare ARGs in cirrhosis with chronic kidney disease (CKD) and diabetes.

METHODS

In outpatients with cirrhosis who underwent metagenomics, we evaluated change in ARG abundances with progression and their multivariable impact on 90-day hospitalizations and deaths over 1 year. We also studied ARGs pre- and 8 weeks post-rifaximin in patients with compensated cirrhosis in an open-label trial. Finally, ARGs from CKD and diabetes studies were compared with cirrhosis on machine learning.

RESULTS

A total of 163 patients with cirrhosis (43 compensated, 20 ascites-only, 30 HE-only, 70 both) and 40 controls were included. ARG abundances were higher in cirrhosis versus controls and worsened with advancing cirrhosis severity; 44 patients were hospitalized and 14 died. ARG abundances were associated with hospitalizations and mortality while controlling for cirrhosis complications, medications, and demographics. Rifaximin trial: ARG abundance patterns were minimally affected in 19 patients post-rifaximin. CKD/diabetes comparison: ARG abundance patterns in cirrhosis are distinguishable on machine learning and include more gram-positive ARGs.

CONCLUSIONS

Cirrhosis is associated with high gut microbial ARG gene burden compared with controls, which worsens with disease progression and may be different from CKD and diabetes. ARGs are not affected by rifaximin and are associated with hospitalizations and death.

Hepatic Branch Vagotomy Modulates the Gut-Liver-Brain Axis in Murine Cirrhosis

Background

Cirrhosis and hepatic encephalopathy (HE) are linked with an altered gut-liver-brain axis, however, the relative contribution of hepatic vagal innervation is unclear. We aimed to determine the impact of hepatic vagotomy on the gut microbiome, brain, and liver in murine cirrhosis.

Methods

10–15-week-old male C57BL/6 mice with and without hepatic vagotomy underwent carbon tetrachloride (CCl4) gavage for 8 weeks. Frontal cortex [inflammation, glial/microglial activation, BDNF (brain-derived neurotrophic factor)], liver [histology including inflammation and steatosis, fatty acid synthesis (sterol-responsive binding protein-1) SREBP-1, insulin-induced gene-2 (Insig2) and BDNF], and colonic mucosal microbiota (16srRNA microbial sequencing) were evaluated on sacrifice. Conventional mice with and without cirrhosis were compared to vagotomized counterparts.

Results

Conventional control vs. cirrhosis: Cirrhosis resulted in dysbiosis, hepatic/neuro-inflammation with glial/microglial activation, and low brain BDNF vs. controls. Conventional control vs. vagotomy controls: Vagotomized control mice had a lower colonic dysbiosis than conventional mice but the rest of the hepatic/brain parameters were similar. Conventional cirrhosis vs. vagotomized cirrhosis: After vagotomy + cirrhosis, we found lower dysbiosis but continuing neuroinflammation in the absence of glial/microglial activation vs. conventional cirrhosis. Vagotomy + Cirrhosis groups showed higher hepatic steatosis due to higher SREBP1 and low Insig2 protein and altered activation of key genes involved in hepatic lipid metabolism and inflammation. BDNF levels in the brain were higher but low in the liver in vagotomy + cirrhosis, likely a protective mechanism.

Conclusions

Hepatic vagal innervation affects the gut microbial composition, hepatic inflammation and steatosis, and cortical inflammation and BDNF expression and could be a critical modulator of the gut-liver-brain axis with consequences for HE development.

Interaction of bacterial metagenome and virome in patients with cirrhosis and hepatic encephalopathy

OBJECTIVE

Altered bacterial composition is associated with disease progression in cirrhosis but the role of virome, especially phages, is unclear.

DESIGN

Cross-sectional and pre/post rifaximin cohorts were enrolled. Cross-sectional: controls and cirrhotic outpatients (compensated, on lactulose (Cirr-L), on rifaximin (Cirr-LR)) were included and followed for 90-day hospitalisations. Pre/post: compensated cirrhotics underwent stool collection pre/post 8 weeks of rifaximin. Stool metagenomics for bacteria and phages and their correlation networks were analysed in controls versus cirrhosis, within cirrhotics, hospitalised/not and pre/post rifaximin.

RESULTS

Cross-sectional: 40 controls and 163 cirrhotics (63 compensated, 43 Cirr-L, 57 Cirr-LR) were enrolled. Cirr-L/LR groups were similar on model for end-stage liver disease (MELD) score but Cirr-L developed greater hospitalisations versus Cirr-LR (56% vs 30%, p=0.008). Bacterial alpha/beta diversity worsened from controls through Cirr-LR. While phage alpha diversity was similar, beta diversity was different between groups. Autochthonous bacteria linked negatively, pathobionts linked positively with MELD but only modest phage-MELD correlations were seen. Phage-bacterial correlation network complexity was highest in controls, lowest in Cirr-L and increased in Cirr-LR. Microviridae and Faecalibacterium phages were linked with autochthonous bacteria in Cirr-LR, but not Cirr-L hospitalised patients had greater pathobionts, lower commensal bacteria and phages focused on Streptococcus, Lactococcus and Myoviridae. Pre/post: No changes in alpha/beta diversity of phages or bacteria were seen postrifaximin. Phage-bacterial linkages centred around urease-producing Streptococcus species collapsed postrifaximin.

CONCLUSION

Unlike bacteria, faecal phages are sparsely linked with cirrhosis characteristics and 90-day outcomes. Phage and bacterial linkages centred on urease-producing, ammonia-generating Streptococcus species were affected by disease progression and rifaximin therapy and were altered in patients who experienced 90-day hospitalisations.

Gut Microbial Signature of Hepatocellular Cancer in Men With Cirrhosis

The gut microbiome is altered in cirrhosis. Recent evidence has suggested a key role for the gut microbiota in the progression of cirrhosis and the development of hepatocellular carcinoma (HCC). We studied the differences in the microbial composition in patients with cirrhosis with prior and future HCC in the context of other complications (eg, infections, hepatic encephalopathy). The following 2 cohorts were recruited prospectively: the prior HCC cohort, in which outpatients with HCC within 2 years were age-matched, sex-matched, and Model for End-Stage Liver Disease (MELD) score-matched with those without HCC; and the future HCC cohort, in which patients were followed for 2 years and divided into future HCC versus no HCC after age, sex, and MELD-score matching and other complications were also recorded. Microbiota composition and predicted function were analyzed with ribosomal RNA sequencing and Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PiCRUST)and compared between (1) prior HCC versus none and (2) future HCC versus none, and in the future cohort, comparisons were also made between those patients who developed (1) HCC only versus without complications, (2) HCC only versus non-HCC complications only, and (3) HCC + other complications versus non-HCC complications only. A total of 142 men (76 total in the prior cohort [38 with/38 without HCC] and 66 total in the future cohort [33 with/33 without future HCC]) were included. The groups had similar etiology, lactulose/rifaximin/proton pump inhibitor use, diabetes mellitus, and non-HCC complications. Microbial diversity was similar between prior HCC/not or future HCC/not. On DESeq2 higher Clostridium sensu stricto and Anaerotruncus were significantly associated with protection from HCC, whereas the reverse was seen with Raoultella and Haemophilus regardless of prior/future HCC comparisons. Functions focused on urea cycle, bioenergetics, tryptophan, and toluene metabolism were different between the groups. Rothia was specific for other complications. Despite age, sex, and MELD-score matching and accounting for other complications, gut microbiota composition and the predicted function are different in men with cirrhosis with and without prior HCC and can be extended toward future HCC development.

A Randomized Clinical Trial of Fecal Microbiota Transplant for Alcohol Use Disorder

BACKGROUND AND AIMS

Alcohol use disorder (AUD) is associated with microbial alterations that worsen with cirrhosis. Fecal microbiota transplant (FMT) could be a promising approach.

APPROACH AND RESULTS

In this phase 1, double-blind, randomized clinical trial, patients with AUD-related cirrhosis with problem drinking (AUDIT-10 > 8) were randomized 1:1 into receiving one placebo or FMT enema from a donor enriched in Lachnospiraceae and Ruminococcaceae. Six-month safety was the primary outcome. Alcohol craving questionnaire, alcohol consumption (urinary ethylglucuronide/creatinine), quality of life, cognition, serum IL-6 and lipopolysaccharide-binding protein, plasma/stool short-chain fatty acids (SCFAs), and stool microbiota were tested at baseline and day 15. A 6-month follow-up with serious adverse event (SAE) analysis was performed. Twenty patients with AUD-related cirrhosis (65 ± 6.4 years, all men, Model for End-Stage Liver Disease 8.9 ± 2.7) with similar demographics, cirrhosis, and AUD severity were included. Craving reduced significantly in 90% of FMT versus 30% in placebo at day 15 (P = 0.02) with lower urinary ethylglucuronide/creatinine (P = 0.03) and improved cognition and psychosocial quality of life. There was reduction in serum IL-6 and lipopolysaccharide-binding protein and increased butyrate/isobutyrate compared with baseline in FMT but not placebo. Microbial diversity increased with higher Ruminococcaceae and other SCFAs, producing taxa following FMT but not placebo, which were linked with SCFA levels. At 6 months, patients with any SAEs (8 vs. 2, P = 0.02), AUD-related SAEs (7 vs. 1, P = 0.02), and SAEs/patient (median [interquartile range], 1.5 [1.25] vs. 0 [0.25] in FMT, P = 0.02) were higher in placebo versus FMT.

CONCLUSIONS

This phase 1 trial shows that FMT is safe and associated with short-term reduction in alcohol craving and consumption with favorable microbial changes versus placebo in patients with alcohol-associated cirrhosis with alcohol misuse. There was also a reduction in AUD-related events over 6 months in patients assigned to FMT.

Comparative study of the hemolymph microbiome between live and recently dead American lobsters Homarus americanus

Lobsters and other crustaceans do not have sterile hemolymph. Despite this, little is known about the microbiome in the hemolymph of the lobster Homarus americanus. The purpose of this study was to characterize the hemolymph microbiome in lobsters. The lobsters were part of a larger study on the effect of temperature on epizootic shell disease, and several died during the course of the study, providing an opportunity to examine differences in the microbiomes between live and recently dead (1-24 h) animals. The hemolymph microbiomes of live lobsters was different from those in dead animals and both were different from the tank microbiome in which the animals had been held. The microbiomes of live lobsters were more diverse and had a different suite of bacteria than those from dead animals. The dominant taxa in live lobsters belonged to Flavobacteriaceae and Rhodobacteraceae, whereas Vibrionaceae and Enterobacteriaceae were predominant in the dead lobsters. Although aquarium microbiomes overlapped with the hemolymph microbiomes, there was less overlap and lower abundance of taxa in comparison with hemolymph from live lobsters. Previous studies reporting bacteria in the digestive tract of lobsters suggested that Vibrionaceae and Enterobacteriaceae had invaded the hemolymph via the gut. Our study suggests that hemolymph bacteria abundant in live lobsters do not originate from the tank milieu and comprise a rich, natural, or native background of bacterial constituents.

Fecal Microbiota Transplant in Cirrhosis Reduces Gut Microbial Antibiotic Resistance Genes: Analysis of Two Trials

Antibiotic resistance leads to poor outcomes in cirrhosis. Fecal microbiota transplant (FMT) is associated with reduction in antibiotic resistance gene (ARG) burden in patients without cirrhosis; however, the impact in cirrhosis is unclear. We aimed to study the effect of capsule and enema FMT on ARG abundance in fecal samples, which were collected during two published FMT trials in patients with cirrhosis on rifaximin, lactulose, and proton pump inhibitors. ARGs were identified using metagenomics and mapped against the Comprehensive Antibiotic Resistance Database. Changes in ARG abundance were studied within/between groups. The capsule FMT trial involved a one-time FMT or placebo capsule administration with stool collection at baseline and week 4 postintervention. Antibiotics+enema FMT included preprocedure antibiotics followed by FMT enema versus standard-of-care (SOC). Stool was collected at baseline, postantibiotics, and day 7/15 postintervention. Both trials included 20 patients each. There was no safety/infection signal linked to FMT. In the capsule trial, beta-lactamase (OXY/LEN) expression decreased post-FMT versus baseline. Compared to placebo, patients who were post-FMT had lower abundance of vancomycin (VanH), beta-lactamase (ACT), and rifamycin ARGs; the latter was associated with cognitive improvement. No changes were seen within patients treated with placebo. In the antibiotics+enema trial for postantibiotics at day 7 versus baseline, there was an increase in vancomycin and beta-lactamase ARGs, which decreased at day 15. However, quinolone resistance increased at day 15 versus baseline. Between SOC and FMT, day 7 had largely lower ARG (CfxA beta-lactamase, VanW, and VanX) that continued at day 15 (cepA beta-lactamase, VanW). No changes were seen within the SOC group. Conclusion: Despite differences in routes of administration and preintervention antibiotics, we found that ARG abundance is largely reduced after FMT compared to pre-FMT baseline and non-FMT groups in decompensated cirrhosis.

Berberine alters gut microbial function through modulation of bile acids

Background

Berberine (BBR) is a plant-based nutraceutical that has been used for millennia to treat diarrheal infections and in contemporary medicine to improve patient lipid profiles. Reduction in lipids, particularly cholesterol, is achieved partly through up-regulation of bile acid synthesis and excretion into the gastrointestinal tract (GI). The efficacy of BBR is also thought to be dependent on structural and functional alterations of the gut microbiome. However, knowledge of the effects of BBR on gut microbiome communities is currently lacking. Distinguishing indirect effects of BBR on bacteria through altered bile acid profiles is particularly important in understanding how dietary nutraceuticals alter the microbiome.

Results

Germfree mice were colonized with a defined minimal gut bacterial consortium capable of functional bile acid metabolism (Bacteroides vulgatus, Bacteroides uniformis, Parabacteroides distasonis, Bilophila wadsworthia, Clostridium hylemonae, Clostridium hiranonis, Blautia producta; B4PC2). Multi-omics (bile acid metabolomics, 16S rDNA sequencing, cecal metatranscriptomics) were performed in order to provide a simple in vivo model from which to identify network-based correlations between bile acids and bacterial transcripts in the presence and absence of dietary BBR. Significant alterations in network topology and connectivity in function were observed, despite similarity in gut microbial alpha diversity (P = 0.30) and beta-diversity (P = 0.123) between control and BBR treatment. BBR increased cecal bile acid concentrations, (P < 0.05), most notably deoxycholic acid (DCA) (P < 0.001). Overall, analysis of transcriptomes and correlation networks indicates both bacterial species-specific responses to BBR, as well as functional commonalities among species, such as up-regulation of Na⁺/H⁺ antiporter, cell wall synthesis/repair, carbohydrate metabolism and amino acid metabolism. Bile acid concentrations in the GI tract increased significantly during BBR treatment and developed extensive correlation networks with expressed genes in the B4PC2 community.

Conclusions

This work has important implications for interpreting the effects of BBR on structure and function of the complex gut microbiome, which may lead to targeted pharmaceutical interventions aimed to achieve the positive physiological effects previously observed with BBR supplementation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12866-020-02020-1.

Sex is associated with differences in gut microbial composition and function in hepatic encephalopathy

BACKGROUND & AIMS

Altered microbiota can affect the gut-liver-brain axis in cirrhosis and hepatic encephalopathy (HE), but the impact of sex on these changes is unclear. We aimed to determine differences in fecal microbiota composition/functionality between men and women with cirrhosis and HE on differing treatments.

METHODS

Cross-sectional stool microbiome composition (16s rRNA sequencing) and microbial functional analyses were performed in men and women with cirrhosis, and controls. Patients with HE on rifaximin+lactulose (HE-Rif), patients with HE on lactulose only (HE-Lac) and those with cirrhosis without HE (No-HE) were compared to controls using random forest classifier. Men and women were also compared.

RESULTS

A total of 761 individuals were included, 619 with cirrhosis (466 men, 153 women) and 142 controls (92 men, 50 women). Men were older and more frequently used proton pump inhibitors (PPIs), but model for end-stage liver disease score, No-HE (n = 319), HE-lac (n = 130) and HE-Rif (n = 170) proportions were similar. PPI/age-adjusted AUC of differentiation between controls vs. all cirrhosis, and controls vs. No-HE were higher within women than men, but the adjusted AUC for No-HE vs. HE-Rif was higher in men. Control vs. HE-Rif differentiation was similar across sexes. Men vs. women were different in all cirrhosis, No-HE and HE-Lac but not HE-Rif on PERMANOVA and AUC analyses. Autochthonous taxa decreased and pathobionts increased with disease progression regardless of sex. In men, Lactobacillaceae were higher in HE-Lac but decreased in HE-Rif, along with Veillonellaceae. Pathways related to glutamate and aromatic compound degradation were higher in men at all stages. Degradation of androstenedione, an estrogenic precursor, was lower in men vs. women in HE-Rif, likely enhancing feminization.

CONCLUSIONS

There are differences in gut microbial function and composition between men and women with cirrhosis, which could be implicated in differential responses to HE therapies. Further studies linking these differences to sex-specific outcomes are needed.

LAY SUMMARY

Patients with cirrhosis develop changes in their brain function, and men often develop feminization with disease progression. However, the interaction between sex, microbiota and disease severity is unclear. We found that as disease progressed in men, their microbial composition began to approach that observed in women, with changes in specific microbes that are associated with male hormone metabolism.

Distinct gut microbial compositional and functional changes associated with impaired inhibitory control in patients with cirrhosis

Most cirrhosis etiologies, such as alcohol, hepatitis C, and obesity, involve behavior that require the loss of inhibitory control. Once cirrhosis develops, patients can also develop cognitive impairment due to minimal hepatic encephalopathy (MHE). Both processes could have distinct imprints on the gut-liver-brain axis. Determine the impact of inhibitory control versus traditional cirrhosis-related cognitive performance on gut microbial composition and function. Outpatients with cirrhosis underwent two tests for MHE: inhibitory control test (MHEICT, computerized associated with response inhibition) and psychometric hepatic encephalopathy score (MHEPHES, paper-pencil HE-specific associated with subcortical impairment) along with stool collection for metagenomics. MHEICT/not, MHEPHES/not, and discordant (positive on one test but negative on the other) were analyzed for demographics, bacterial species, and gut-brain modules (GBM) using multi-variable analyses. Ninety-seven patients [47 (49%) MHEPHES, 76 (78%) MHEICT, 41 discordant] were enrolled. MHEPHES/not: Cirrhosis severity was worse in MHEPHES without differences in alpha/beta diversity on bacterial species or GBMs. Pathobionts (Enterobacteriaceae) and γ-amino-butryic acid (GABA) synthesis GBM were higher in MHEPHES. MHEICT/not: We found similar cirrhosis severity and metagenomic alpha/beta diversity in MHEICT versus not. However, alpha/beta diversity of GBMs were different in MHEICT versus No-MHE patients. Alistipes ihumii, Prevotella copri, and Eubacterium spp. were higher, while Enterococcus spp. were uniquely lower in MHEICT versus no-MHE and discordant comparisons. GBMs belonging to tryptophan, menaquinone, GABA, glutamate, and short-chain fatty acid synthesis were also unique to MHEICT. Gut microbial signature of impaired inhibitory control, which is associated with addictive disorders that can lead to cirrhosis, is distinct from cirrhosis-related cognitive impairment.

Extensive photobiont sharing in a rapidly radiating cyanolichen clade

Recent studies have uncovered remarkable diversity in Dictyonema s.lat. basidiolichens, here recognized as subtribe Dictyonemateae. This group includes five genera and 148 species, but hundreds more await description. The photobionts of these lichens belong to Rhizonema, a recently resurrected cyanobacterial genus known by a single species. To further investigate photobiont diversity within Dictyonemateae, we generated 765 new cyanobacterial sequences from 635 specimens collected from 18 countries. The ITS barcoding locus supported the recognition of 200 mycobiont (fungal) species among these samples, but the photobiont diversity was comparatively low. Our analyses revealed three main divisions of Rhizonema, with two repeatedly recovered as monophyletic (proposed as new species), and the third mostly paraphyletic. The paraphyletic lineage corresponds to R. interruptum and partnered with mycobionts from all five genera in Dictyonemateae. There was no evidence of photobiont-mycobiont co-speciation, but one of the monophyletic lineages of Rhizonema appears to partner predominantly with one of the two major clades of Cora (mycobiont) with samples collected largely from the northern Andes. Molecular clock estimations indicate the Rhizonema species are much older than the fungal species in the Dictyonemateae, suggesting that these basidiolichens obtained their photobionts from older ascolichen lineages and the photobiont variation in extant lineages of Dictyonemateae is the result of multiple photobiont switches. These results support the hypothesis of lichens representing "fungal farmers," in which diverse mycobiont lineages associate with a substantially lower diversity of photobionts by sharing those photobionts best suited for the lichen symbiosis among multiple and often unrelated mycobiont lineages.

Serum Levels of Metabolites Produced by Intestinal Microbes and Lipid Moieties Independently Associated With Acute-on-Chronic Liver Failure and Death in Patients With Cirrhosis

BACKGROUND & AIMS

Inpatients with cirrhosis have high rates of acute-on-chronic failure (ACLF) development and high mortality within 30 days of admission to the hospital. Better biomarkers are needed to predict these outcomes. We performed metabolomic analyses of serum samples from patients with cirrhosis at multiple centers to determine whether metabolite profiles might identify patients at high risk for ACLF and death.

METHODS

We performed metabolomic analyses, using liquid chromatography, of serum samples collected at time of admission to 12 North American tertiary hepatology centers from 602 patients in the North American Consortium for the Study of End-Stage Liver Disease sites from 2015 through 2017 (mean age, 56 years; 61% men; mean model for end-stage liver disease score, 19.5). We performed analysis of covariance, adjusted for model for end-stage liver disease at time of hospital admission, serum levels of albumin and sodium, and white blood cell count, to identify metabolites that differed between patients who did vs did not develop ACLF and patients who did vs did not die during hospitalization and within 30 days. We performed random forest analysis to identify specific metabolite(s) that were associated with outcomes and area under the curve (AUC) analyses to analyze them in context of clinical parameters. We analyzed microbiomes of stool samples collected from 133 patients collected at the same time and examined associations with serum metabolites.

RESULTS

Of the 602 patients analyzed, 88 developed ACLF (15%), 43 died in the hospital (7%), and 72 died within 30 days (12%). Increased levels of compounds of microbial origin (aromatic compounds, secondary or sulfated bile acids, and benzoate) and estrogen metabolites, as well as decreased levels of phospholipids, were associated with development of ACLF, inpatient, and 30-day mortality and were also associated with fecal microbiomes. Random forest analysis and logistic regression showed that levels of specific microbially produced metabolites identified patients who developed ACLF with an AUC of 0.84 (95% confidence interval [CI] 0.78-0.88; P = .001), patients who died while in the hospital with an AUC of 0.81 (95% CI 0.74-0.85; P = .002), and patients who died within 30 days with an AUC of 0.77 (95% CI 0.73-0.81; P = .02). The metabolites were significantly additive to clinical parameters for predicting these outcomes. Metabolites associated with outcomes were also correlated with microbiomes of stool samples.

CONCLUSIONS

In an analysis of serum metabolites and fecal microbiomes of patients hospitalized with cirrhosis at multiple centers, we associated metabolites of microbial origin and lipid moieties with development of ACLF and death as an inpatient or within 30 days, after controlling for clinical features.

Cathelicidin-related antimicrobial peptide alleviates alcoholic liver disease through inhibiting inflammasome activation

Alcoholic liver disease (ALD) is associated with gut dysbiosis and hepatic inflammasome activation. While it is known that antimicrobial peptides (AMPs) play a critical role in the regulation of bacterial homeostasis in ALD, the functional role of AMPs in the alcohol-induced inflammasome activation is unclear. The aim of this study was to determine the effects of cathelicidin-related antimicrobial peptide (CRAMP) on inflammasome activation in ALD. CRAMP knockout (Camp^-/-) and wild-type (WT) mice were subjected to binge-on-chronic alcohol feeding and synthetic CRAMP peptide was administered. Serum/plasma and hepatic tissue samples from human subjects with alcohol use disorder and/or alcoholic hepatitis were analyzed. CRAMP deficiency exacerbated ALD with enhanced inflammasome activation as shown by elevated serum interleukin (IL)-1β levels. Although Camp^-/- mice had comparable serum endotoxin levels compared to WT mice after alcohol feeding, hepatic lipopolysaccharide (LPS) binding protein (LBP) and cluster of differentiation (CD) 14 were increased. Serum levels of uric acid (UA), a Signal 2 molecule in inflammasome activation, were positively correlated with serum levels of IL-1β in alcohol use disorder patients with ALD and were increased in Camp^-/- mice fed alcohol. In vitro studies showed that CRAMP peptide inhibited LPS binding to macrophages and inflammasome activation stimulated by a combination of LPS and UA. Synthetic CRAMP peptide administration decreased serum UA and IL-1β concentrations and rescued the liver from alcohol-induced damage in both WT and Camp^-/- mice. In summary, CRAMP exhibited a protective role against binge-on-chronic alcohol-induced liver damage via regulation of inflammasome activation by decreasing LPS binding and UA production. CRAMP administration may represent a novel strategy for treating ALD. © 2020 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

BiomMiner: An advanced exploratory microbiome analysis and visualization pipeline

Current microbiome applications require substantial bioinformatics expertise to execute. As microbiome clinical diagnostics are being developed, there is a critical need to implement computational tools and applications that are user-friendly for the medical community to understand microbiome correlation with the health. To address this need, we have developed BiomMiner (pronounced as “biominer”), an automated pipeline that provides a comprehensive analysis of microbiome data. The pipeline finds taxonomic signatures of microbiome data and compiles actionable clinical report that allows clinicians and biomedical scientists to efficiently perform statistical analysis and data mining on the large microbiome datasets. BiomMiner generates web-enabled visualization of the analysis results and is specifically designed to facilitate the use of microbiome datasets in clinical applications.

Cognition and hospitalizations are linked with salivary and faecal microbiota in cirrhosis cohorts from the USA and Mexico

BACKGROUND & AIMS

Gut microbiota are affected by diet and ethnicity, which impacts cognition and hospitalizations in cirrhosis.

AIM

Study interactions of diet with microbiota and impact on hospitalizations and cognition in American and Mexican cohorts.

METHODS

Controls and age-balanced patients with compensated/decompensated cirrhosis were included and followed for 90-day hospitalizations. A subset underwent minimal hepatic encephalopathy (MHE) testing. Parameters such as dietary, salivary and faecal microbiota (diversity, taxa analysis, cirrhosis dysbiosis ratio CDR:high = good) between/within countries were analysed. Regression analyses for hospitalizations and MHE were performed.

RESULTS

In all, 275 age-balanced subjects (133 US [40 Control, 50 Compensated, 43 Decompensated] and 142 Mexican [41 Control, 49 Compensated, 52 Decompensated]) were enrolled. MELD/cirrhosis severity was comparable. Diet showed lower protein and animal fat intake in all decompensated patients, but this was worse in Mexico. Diversity was lower in stool and saliva in decompensated patients, and worse in Mexican cohorts. Prevotellaceae were lower in decompensated cirrhosis, particularly those with lower animal fat/protein consumption across countries. Hospitalizations were higher in Mexico vs the USA (26% vs 14%, P = .04). On regression, Prevotellaceae, Ruminococcaceae and Lachnospiraceae lowered hospitalization risk independent of MELD and ascites. MHE testing was performed in 120 (60/country and 20/subgroup) subjects and MHE rate was similar. MELD and decompensation increased while CDR and Prevotellaceae decreased the risk of MHE.

CONCLUSIONS

Changes in diet and microbiota, especially related to animal fat and protein intake and Prevotellaceae, are associated with MHE and hospitalizations in Mexican patients with cirrhosis compared to an American cohort. Nutritional counselling to increase protein intake in cirrhosis could help prevent these hospitalizations.

Gut microbiota manipulation during the prepubertal period shapes behavioral abnormalities in a mouse neurodevelopmental disorder model

Previous studies demonstrate an association between activation of the maternal immune system during pregnancy and increased risk of neurodevelopmental psychiatric conditions, such as schizophrenia and autism, in the offspring. Relatively recent findings also suggest that the gut microbiota plays an important role in shaping brain development and behavior. Here we show that maternal immune activation (MIA) accomplished by infection with a mouse-adapted influenza virus during pregnancy induced up-regulation of frontal cortex serotonin 5-HT_2A receptor (5-HT_2AR) density in the adult offspring, a phenotype previously observed in postmortem frontal cortex of schizophrenic subjects. 5-HT_2AR agonist-induced head-twitch behavior was also augmented in this preclinical mouse model. Using the novel object recognition (NOR) test to evaluate cognitive performance, we demonstrate that MIA induced NOR deficits in adult offspring. Oral antibiotic treatment of prepubertal mice prevented this cognitive impairment, but not increased frontal cortex 5-HT_2AR density or psychedelic-induced head-twitch behavior in adult MIA offspring. Additionally, gut microbiota transplantation from MIA mice produced behavioral deficits in antibiotic-treated mock mice. Adult MIA offspring displayed altered gut microbiota, and relative abundance of specific components of the gut microbiota, including Ruminococcaceae, correlated with frontal cortex 5-HT_2AR density. Together, these findings provide a better understanding of basic mechanisms by which prenatal insults impact offspring brain function, and suggest gut-brain axis manipulation as a potential therapeutic approach for neurodevelopmental psychiatric conditions.

Cost-effectiveness of integrating gut microbiota analysis into hospitalisation prediction in cirrhosis

BACKGROUND

Admissions in cirrhosis are expensive and often unpredictable based on purely clinical variables. Admissions could be related to complications associated with gut microbial changes, which can improve prognostication. However, the cost-effectiveness is unclear.

AIMS

Determine cost-effectiveness of adding gut microbiota analysis to clinical parameters in prediction and subsequent reduction of admissions in cirrhosis.

METHODS

Using a Markov model of 1000 cirrhosis patients over 90 days, we modeled microbiota testing using 16srRNA ($250/sample), low-depth ($350/sample) and high-depth ($650/sample) metagenomics added to standard-of-care (SOC) for prevention of admissions using standard outcome costs and rates of development. We generated quality of life years (QALY) and Incremental cost-effectiveness ratios (ICER) for the base scenarios and performed sensitivity analyses by varying costs for outcomes (transplant, death, admission) and admission rates (40%, range 25%-60%).

RESULTS

Using fixed costs of outcomes and outcome rates, microbiota analysis was cost-saving ($47K-$97K) at $250 and $350/sample if admissions were reduced by 5%over SOC and >10% with $650/sample. When costs of LT, death and admissions were varied, these cost-savings remained robust provided there was >2.1% reduction (range 1.3%-3.2%) for $250/sample, >2.9% (range 1.8%-4.4%) for $350/sample and >5.4% (range 3.3%-8.2%) for $650/sample. These cost-savings remained robust even when the assumed admission rate was varied for all sample cost values.

CONCLUSIONS

Gut microbiota analysis is cost-effective for predicting and potentially preventing 90-day admissions in cirrhosis over current standard of care. This cost-saving remained robust even after sensitivity analyses that varied the background admission rates.

Neuroinflammation in Murine Cirrhosis Is Dependent on the Gut Microbiome and Is Attenuated by Fecal Transplant

Cirrhosis and hepatic encephalopathy (HE) is associated with an altered gut-liver-brain axis. Fecal microbial transplant (FMT) after antibiotics improves outcomes in HE, but the impact on brain function is unclear. The aim of this study is to determine the effect of colonization using human donors in germ-free (GF) mice on the gut-liver-brain axis. GF and conventional mice were made cirrhotic using carbon tetrachloride and compared with controls in GF and conventional state. Additional GF mice were colonized with stool from controls (Ctrl-Hum) and patients with cirrhosis (Cirr-Hum). Stools from patients with HE cirrhosis after antibiotics were pooled (pre-FMT). Stools from the same patients 15 days after FMT from a healthy donor were also pooled (post-FMT). Sterile supernatants were created from pre-FMT and post-FMT samples. GF mice were colonized using stools/sterile supernatants. For all mice, frontal cortex, liver, and small/large intestines were collected. Cortical inflammation, synaptic plasticity and gamma-aminobutyric acid (GABA) signaling, and liver inflammation and intestinal 16s ribosomal RNA microbiota sequencing were performed. Conventional cirrhotic mice had higher degrees of neuroinflammation, microglial/glial activation, GABA signaling, and intestinal dysbiosis compared with other groups. Cirr-Hum mice had greater neuroinflammation, microglial/glial activation, and GABA signaling and lower synaptic plasticity compared with Ctrl-Hum mice. This was associated with greater dysbiosis but no change in liver histology. Pre-FMT material colonization was associated with neuroinflammation and microglial activation and dysbiosis, which was reduced significantly with post-FMT samples. Sterile pre-FMT and post-FMT supernatants did not affect brain parameters. Liver inflammation was unaffected. Conclusion: Fecal microbial colonization from patients with cirrhosis results in higher degrees of neuroinflammation and activation of GABAergic and neuronal activation in mice regardless of cirrhosis compared with those from healthy humans. Reduction in neuroinflammation by using samples from post-FMT patients to colonize GF mice shows a direct effect of fecal microbiota independent of active liver inflammation or injury.

Metabolomics and microbial composition increase insight into the impact of dietary differences in cirrhosis

BACKGROUND & AIMS

Dietary changes can modulate gut microbiota and interact with cirrhosis. Our prior study demonstrated that microbial diversity was higher in cirrhotics from Turkish vs the USA, which was associated with lower risk of 90-day hospitalizations. We aimed to define gut microbial functional and metabolomic changes to increase insight into benefits of the Mediterranean compared to Western diets.

METHODS

In all, 139 Turkish (46 controls/50 compensated/43 decompensated) and 157 American subjects (48 controls/59 compensated/50 decompensated) were studied. Turkish subjects consumed a modified Mediterranean diet with daily fermented milk intake, whereas Americans consumed a Western diet. Predicted gut microbial functionalities and plasma metabolomics were compared between/within countries. Correlation network differences between microbiota and metabolites in cirrhotics from Turkey vs the USA were evaluated.

RESULTS

Predicted microbial function showed lower amino acid, bioenergetics and lipid pathways, with functions related to vitamin B, glycan, xenobiotic metabolism, DNA/RNA synthesis, in cirrhotics from Turkey compared to the USA. Plasma metabolomics demonstrated higher relative lactate levels in Turkey vs the USA. The metabolite changes in decompensated cirrhosis, compared to controls, showed similar trends in Turkey and the USA, with reduced lipids and phosphocholines. Phosphocholines were significantly lower in patients hospitalized in 90 days (P = .03). Correlation networks in cirrhotics demonstrated linkage differences between beneficial taxa, Blautia and Oscillispira, and lactate and unsaturated lipids, in Turkey compared to American patients.

CONCLUSIONS

A modified Mediterranean diet was associated with altered plasma metabolomics and beneficially alters microbiota functionality and correlations compared to Western diet in cirrhosis. These altered diet-microbial interactions could potentially affect the 90-day hospitalization risk.

Optimization of tissue sampling for Borrelia burgdorferi in white-footed mice (Peromyscus leucopus)

Peromyscus leucopus (the white-footed mouse) is a known reservoir of the Lyme disease spirochete Borrelia burgdorferi. Sampling of white-footed mice allows for year-round B. burgdorferi surveillance as well as opportunities to establish the diversity of the different variants in a geographic region. This study explores the prevalence of B. burgdorferi infections in the tissues of white-footed mice, investigates the correlations between B. burgdorferi infected tissues, and determines the optimum field methods for surveillance of B. burgdorferi in P. leucopus. A total of 90 mice and 573 tissues (spleen, liver, ear, tongue, tail, heart, and kidney) were screened via nested PCR for B. burgdorferi infections. A large number of infections were found in the 90 mice as well as multiple infections within individual mice. Infections in a single mouse tissue (spleen, liver, ear, tongue and tail) were predictive of concurrent infection in other tissues of the same mouse at a statistically significant level. Ear tissue accounted for 68.4% of detected infections, which increased to 78.9% of the infected mice with the inclusion of tail samples. The use of ear punch or tail snip samples (used individually or in tandem) have multiple advantages over current Lyme disease ecological studies and surveillance methodologies, including lower associated costs, minimization of delays, year-round B. burgdorferi testing opportunities, as well as longitudinal monitoring of B. burgdorferi in defined geographic regions. In the absence of an effective vaccine, personal prevention measures are currently the most effective way to reduce Lyme disease transmission to humans. Thus, the identification and monitoring of environmental reservoirs to inform at-risk populations remains a priority. The sampling methods proposed in this study provide a reasonable estimate of B. burgdorferi in white-footed mice in a timely and cost-effective manner.

Microbial functional change is linked with clinical outcomes after capsular fecal transplant in cirrhosis

BACKGROUNDHepatic encephalopathy (HE) is associated with poor outcomes. A prior randomized, pilot trial demonstrated safety after oral capsular fecal microbial transplant (FMT) in HE, with favorable changes in microbial composition and cognition. However, microbial functional changes are unclear. The aim of this study was to determine the effect of FMT on the gut-brain axis compared with placebo, using microbial function based on bile acids (BAs), inflammation (serum IL-6, LPS-binding protein [LBP]), and their association with EncephalApp.METHODSTwenty cirrhotic patients were randomized 1:1 into groups that received 1-time FMT capsules from a donor enriched in Lachnospiraceae and Ruminococcaceae or placebo capsules, with 5-month follow-up for safety outcomes. Stool microbiota and BA; serum IL-6, BA, and LBP; and EncephalApp were analyzed at baseline and 4 weeks after FMT/placebo. Correlation networks among microbiota, BAs, EncephalApp, IL-6, and LBP were performed before/after FMT.RESULTSFMT-assigned participants had 1 HE recurrence and 2 unrelated infections. Six placebo-assigned participants developed negative outcomes. FMT, but not placebo, was associated with reduced serum IL-6 and LBP and improved EncephalApp. FMT-assigned participants demonstrated higher deconjugation and secondary BA formation in feces and serum compared with baseline. No change was seen in placebo. Correlation networks showed greater complexity after FMT compared with baseline. Beneficial taxa, such as Ruminococcaceae, Verrucomicrobiaceae, and Lachnospiraceae, were correlated with cognitive improvement and decrease in inflammation after FMT. Fecal/serum secondary/primary ratios and PiCRUST secondary BA pathways did not increase in participants who developed poor outcomes.CONCLUSIONGut microbial function in cirrhosis is beneficially affected by capsular FMT, with improved inflammation and cognition. Lower secondary BAs in FMT recipients could select for participants who develop negative outcomes.TRIAL REGISTRATIONClinicaltrials.gov NCT03152188.FUNDINGNational Center for Advancing Translational Sciences NIH grant R21TR002024, VA Merit Review grant 2I0CX001076, the United Kingdom National Institute for Health Research Biomedical Facility at Imperial College London, the British Heart Foundation, Wellcome Trust, and King's College London.

Fecal Microbial Transplant Capsules Are Safe in Hepatic Encephalopathy: A Phase 1, Randomized, Placebo-Controlled Trial

Hepatic encephalopathy (HE) can cause major morbidity despite standard of care (SOC; rifaximin/lactulose). Fecal microbial transplant (FMT) enemas postantibiotics are safe, but the effect of FMT without antibiotics using the capsular route requires investigation. The aim of this work was to determine the safety, tolerability, and impact on mucosal/stool microbiota and brain function in HE after capsular FMT in a randomized, single-blind, placebo-controlled clinical trial in Virginia. Patients with cirrhosis with recurrent HE with MELD (Model for End-Stage Liver Disease) <17 on SOC were randomized 1:1 into receiving 15 FMT capsules versus placebo from a single donor enriched in Lachnospiraceae and Ruminococcaceae. Endoscopies with duodenal and sigmoid biopsies, stool analysis, cognition, serum lipopolysaccharide-binding protein (LBP), and duodenal antimicrobial peptide (AMP) expression at baseline were used. Clinical follow-up with SOC maintenance was performed until 5 months. FMT-assigned patients underwent repeat endoscopies 4 weeks postenrollment. Twenty subjects on lactulose/rifaximin were randomized 1:1. MELD score was similar at baseline (9.6 vs. 10.2) and study end (10.2 vs. 10.5). Six patients in the placebo group required hospitalizations compared to 1 in FMT, which was deemed unrelated to FMT. Infection/HE episodes were similar between groups. Baseline microbial diversity was similar in all tissues between groups. Post-FMT, duodenal mucosal diversity (P = 0.01) increased with higher Ruminococcaceae and Bifidobacteriaceae and lower Streptococcaceae and Veillonellaceae. Reduction in Veillonellaceae were noted post-FMT in sigmoid (P = 0.04) and stool (P = 0.05). Duodenal E-cadherin (P = 0.03) and defensin alpha 5 (P = 0.03) increased whereas interleukin-6 (P = 0.02) and serum LBP (P = 0.009) reduced post-FMT. EncephalApp performance improved post-FMT only (P = 0.02). Conclusion: In this phase 1 study, oral FMT capsules are safe and well tolerated in patients with cirrhosis and recurrent HE. FMT was associated with improved duodenal mucosal diversity, dysbiosis, and AMP expression, reduced LBP, and improved EncephalApp performance. Further studies are needed to prove efficacy.

Alterations in Skin Microbiomes of Patients With Cirrhosis

BACKGROUND & AIMS

Patients with cirrhosis have intestinal dysbiosis and are prone to itching and skin or soft-tissue infections. The skin microbiome, and its relationship with intestinal microbiome, have not been characterized. We investigated alterations in skin microbiota of patients with cirrhosis and their association with intestinal microbiota and modulators of itch.

METHODS

We collected skin swabs at 7 sites and blood and stool samples from 20 healthy individuals (control subjects; mean age, 59 years) and 50 patients with cirrhosis (mean age, 61 years; mean model for end-stage disease score, 12; 20 with decompensation). Skin and stool samples were analyzed by 16s rRNA sequencing and serum samples were analyzed by liquid chromatography and mass spectrometry for levels of bile acids (BAs) and by an ELISA for autotaxin (an itch modulator). Participants were analyzed by the visual analog itch scale (VAS, 0-10,10 = maximum intensity). Data were compared between groups (cirrhosis vs control subjects, with vs without decompensation, VAS 5 or higher vs less than 5). Correlation networks between serum levels of BAs and skin microbiomes were compared between patients with cirrhosis with vs without itching.

RESULTS

The composition of microbiomes at all skin sites differed between control subjects and patients with cirrhosis and between patients with compensated vs decompensated cirrhosis. Skin microbiomes of patients with cirrhosis (especially those with decompensation) contained a higher relative abundance of Gammaproteobacteria, Streptococaceae, and Staphylococcaceae, and fecal microbiomes contained a higher relative abundance of Gammaproteobacteria, than control subjects. These bacterial taxa were associated with serum levels of autotaxin and BAs, which were higher in patients with VAS scores ≥5. Based on network statistics, microbial and BA interactions at all sites were more complex in patients with greater levels of itching in the shin, the most common site of itch.

CONCLUSIONS

We identified alterations in skin microbiome of patients with cirrhosis (in Gammaproteobacteria, Streptococcaceae, and Staphylococcaceae)-especially in patients with decompensation; fecal microbiomes of patients with cirrhosis had a higher relative abundance of Gammaproteobacteria than control subjects. These specific microbial taxa are associated with itching intensity and itch modulators, such as serum levels of BAs and autotaxin.

Posttraumatic stress disorder is associated with altered gut microbiota that modulates cognitive performance in veterans with cirrhosis

Posttraumatic stress disorder (PTSD) is associated with cirrhosis in veterans, and therapeutic results are suboptimal. An altered gut-liver-brain axis exists in cirrhosis due to hepatic encephalopathy (HE), but the added impact of PTSD is unclear. The aim of this study was to define linkages between gut microbiota and cognition in cirrhosis with/without PTSD. Cirrhotic veterans (with/without prior HE) underwent cognitive testing [PHES, inhibitory control test (ICT), and block design test (BDT)], serum lipopolysaccharide-binding protein (LBP) and stool collection for 16S rRNA microbiota composition, and predicted function analysis (PiCRUST). PTSD was diagnosed using DSM-V criteria. Correlation networks between microbiota and cognition were created. Patients with/without PTSD and with/without HE were compared. Ninety-three combat-exposed male veterans [ (58 yr, MELD 11, 34% HE, 31% combat-PTSD (42 no-HE/PTSD, 19 PTSD-only, 22 HE-only, 10 PTSD+HE)] were included. PTSD patients had similar demographics, alcohol history, MELD, but worse ICT/BDT, and higher antidepressant use and LBP levels. Microbial diversity was lower in PTSD (2.1 ± 0.5 vs. 2.5 ± 0.5, P = 0.03) but unaffected by alcohol/antidepressant use. PTSD (P = 0.02) and MELD (P < 0.001) predicted diversity on regression. PTSD patients showed higher pathobionts (Enterococcus and Escherichia/Shigella) and lower autochthonous genera belonging to Lachnospiraceaeae and Ruminococcaceae regardless of HE. Enterococcus was correlated with poor cognition, while the opposite was true for autochthonous taxa regardless of PTSD/HE. Escherichia/Shigella was only linked with poor cognition in PTSD patients. Gut-brain axis-associated microbiota functionality was altered in PTSD. In male cirrhotic veterans, combat-related PTSD is associated with cognitive impairment, lower microbial diversity, higher pathobionts, and lower autochthonous taxa composition and altered gut-brain axis functionality compared with non-PTSD combat-exposed patients. Cognition was differentially linked to gut microbiota, which could represent a new therapeutic target.NEW & NOTEWORTHY Posttraumatic stress disorder (PTSD) in veterans with cirrhosis was associated with poor cognitive performance. This was associated with lower gut microbial diversity in PTSD with higher pathobionts belonging to Enterococcus and Escherichia/Shigella and lower beneficial taxa belonging to Lachnospiraceaeae and Ruminococcaceae, with functional alterations despite accounting for prior hepatic encephalopathy, psychoactive drug use, or model for end-stage liver disease score. Given the suboptimal response to current therapies for PTSD, targeting the gut microbiota could benefit the altered gut-brain axis in these patients.

Gut microbiome identifies risk for colorectal polyps

Objective

To characterise the gut microbiome in subjects with and without polyps and evaluate the potential of the microbiome as a non-invasive biomarker to screen for risk of colorectal cancer (CRC).

Design

Presurgery rectal swab, home collected stool, and sigmoid biopsy samples were obtained from 231 subjects undergoing screening or surveillance colonoscopy. 16S rRNA analysis was performed on 552 samples (231 rectal swab, 183 stool, 138 biopsy) and operational taxonomic units (OTU) were identified using UPARSE. Non-parametric statistical methods were used to identify OTUs that were significantly different between subjects with and without polyps. These informative OTUs were then used to build classifiers to predict the presence of polyps using advanced machine learning models.

Results

We obtained clinical data on 218 subjects (87 females, 131 males) of which 193 were White, 21 African-American, and 4 Asian-American. Colonoscopy detected polyps in 56% of subjects. Modelling of the non-invasive home stool samples resulted in a classification accuracy >75% for Naïve Bayes and Neural Network models using informative OTUs. A naïve holdout analysis performed on home stool samples resulted in an average false negative rate of 11.5% for the Naïve Bayes and Neural Network models, which was reduced to 5% when the two models were combined.

Conclusion

Gut microbiome analysis combined with advanced machine learning represents a promising approach to screen patients for the presence of polyps, with the potential to optimise the use of colonoscopy, reduce morbidity and mortality associated with CRC, and reduce associated healthcare costs.

The Effect of Dietary Mushroom Agaricus bisporus on Intestinal Microbiota Composition and Host Immunological Function

A study was designed to determine the potential prebiotic effect of dietary mushrooms on the host immune response, and intestinal microbiota composition and function. Thirty-one six-week-old pigs were fed a pig grower diet alone or supplemented with either three or six servings of freeze-dried white button (WB)-mushrooms for six weeks. Host immune response was evaluated in peripheral blood mononuclear cells (PBMC), and alveolar macrophages (AM) after stimulation with Salmonella typhymurium-Lipopolysaccharide (LPS). Isolated DNA from fecal and proximal colon contents were used for 16S rDNA taxonomic analysis and linear discriminant analysis effect size (LEfSe) to determine bacterial abundance and metabolic function. Pigs gained weight with no difference in body composition or intestinal permeability. Feeding mushrooms reduced LPS-induced IL-1β gene expression in AM (P < 0.05) with no change in LPS-stimulated PBMC or the intestinal mucosa transcriptome. LEfSe indicated increases in Lachnospiraceae, Ruminococcaceae within the order Clostridiales with a shift in bacterial carbohydrate metabolism and biosynthesis of secondary metabolites in the mushroom-fed pigs. These results suggested that feeding WB mushrooms significantly reduced the LPS-induced inflammatory response in AM and positively modulated the host microbiota metabolism by increasing the abundance of Clostridiales taxa that are associated with improved intestinal health.

Periodontal therapy favorably modulates the oral-gut-hepatic axis in cirrhosis

Cirrhosis is associated with a systemic proinflammatory milieu, endotoxemia, and gut dysbiosis. The oral cavity could be an additional source of inflammation. We aimed to determine the effect of periodontal therapy in cirrhosis through evaluating endotoxemia, inflammation, cognition, and quality of life (QOL). Age-matched cirrhotic and noncirrhotic subjects exhibiting chronic gingivitis and/or mild or moderate periodontitis underwent periodontal therapy with follow-up at 30 days. Saliva/stool for microbial composition and serum for Model for End-stage Liver Disease (MELD) score, endotoxin and lipopolysaccharide binding protein (LBP) and immune-inflammatory markers (IL-1β; IL-6; histatins 1, 3, 5; and lysozyme) were collected at baseline and day 30. The cognitive function and QOL were also evaluated similarly. A separate group of cirrhotic patients were followed for the same duration without periodontal therapy. Cirrhotics, especially those with hepatic encephalopathy (HE), demonstrated improved dysbiosis in stool and saliva, and improved endotoxin, LBP, and salivary and serum inflammatory mediators following periodontal therapy. These parameters, which were higher in HE at baseline, became statistically similar posttherapy. Pretherapy vs. posttherapy QOL and cognition also improved in HE patients following oral interventions. On the other hand, LBP and endotoxin increased over time in cirrhotic patients not receiving therapy, but the rest of the parameters, including microbiota remained similar over time in the no-therapy group. This proof-of-concept study demonstrates that periodontal therapy in cirrhosis, especially in those with HE, is associated with improved oral and gut dysbiosis, systemic inflammation, MELD score, and cognitive function, which was not observed in those who did not receive therapy over the same time period. NEW & NOTEWORTHY Systematic periodontal therapy in cirrhotic outpatients improved endotoxemia, as well as systemic and local inflammation, and modulated salivary and stool microbial dysbiosis over 30 days. This was associated with improved quality of life and cognition in patients with prior hepatic encephalopathy. In a cirrhotic group that was not provided periodontal therapy, there was an increase in endotoxin and lipopolysaccharide binding protein in the same duration. The oral cavity could be an important underdefined source of inflammation in cirrhosis.

Antibiotic-Associated Disruption of Microbiota Composition and Function in Cirrhosis Is Restored by Fecal Transplant

Patients with cirrhosis are often exposed to antibiotics that can lead to resistance and fungal overgrowth. The role of fecal microbial transplant (FMT) in restoring gut microbial function is unclear in cirrhosis. In a Food and Drug Administration-monitored phase 1 clinical safety trial, patients with decompensated cirrhosis on standard therapies (lactulose and rifaximin) were randomized to standard-of-care (SOC, no antibiotics/FMT) or 5 days of broad-spectrum antibiotics followed by FMT from a donor enriched in Lachnospiraceae and Ruminococcaceae. Microbial composition (diversity, family-level relative abundances), function (fecal bile acid [BA] deconjugation, 7α-dehydroxylation, short-chain fatty acids [SCFAs]), and correlations between Lachnospiraceae, Ruminococcaceae, and clinical variables were analyzed at baseline, postantibiotics, and 15 days post-FMT. FMT was well tolerated. Postantibiotics, there was a reduced microbial diversity and autochthonous taxa relative abundance. This was associated with an altered fecal SCFA and BA profile. Correlation linkage changes from beneficial at baseline to negative after antibiotics. All of these parameters became statistically similar post-FMT to baseline levels. No changes were seen in the SOC group.

CONCLUSION

In patients with advanced cirrhosis on lactulose and rifaximin, FMT restored antibiotic-associated disruption in microbial diversity and function. (Hepatology 2018; 00:000-000).

Proton Pump Inhibitor Initiation and Withdrawal affects Gut Microbiota and Readmission Risk in Cirrhosis

OBJECTIVES

Cirrhosis is associated with gut microbial dysbiosis, high readmissions and proton pump inhibitor (PPI) overuse, which could be inter-linked. Our aim was to determine the effect of PPI use, initiation and withdrawl on gut microbiota and readmissions in cirrhosis.

METHODS

Four cohorts were enrolled. Readmissions study: Cirrhotic inpatients were followed throughout the hospitalization and 30/90-days post-discharge. PPI initiation, withdrawal/continuation patterns were analyzed between those with/without readmissions. Cross-sectional microbiota study: Cirrhotic outpatients and controls underwent stool microbiota analysis. Beneficial autochthonous and oral-origin taxa analysis vis-à-vis PPI use was performed. Longitudinal studies: Two cohorts of decompensated cirrhotic outpatients were enrolled. Patients on chronic unindicated PPI use were withdrawn for 14 days. Patients not on PPI were started on omeprazole for 14 days. Microbial analysis for oral-origin taxa was performed pre/post-intervention.

RESULTS

Readmissions study: 343 inpatients (151 on admission PPI) were enrolled. 21 were withdrawn and 45 were initiated on PPI resulting in a PPI use increase of 21%. PPIs were associated with higher 30 (p = 0.002) and 90-day readmissions (p = 0.008) independent of comorbidities, medications, MELD and age. Cross-sectional microbiota: 137 cirrhotics (59 on PPI) and 45 controls (17 on PPI) were included. PPI users regardless of cirrhosis had higher oral-origin microbiota while cirrhotics on PPI had lower autochthonous taxa compared to the rest. Longitudinal studies: Fifteen decompensated cirrhotics tolerated omeprazole initiation with an increase in oral-origin microbial taxa compared to baseline. PPIs were withdrawn from an additional 15 outpatients, which resulted in a significant reduction of oral-origin taxa compared to baseline.

CONCLUSIONS

PPIs modulate readmission risk and microbiota composition in cirrhosis, which responds to withdrawal. The systematic withdrawal and judicious use of PPIs is needed from a clinical and microbiological perspective in decompensated cirrhosis.

Diet affects gut microbiota and modulates hospitalization risk differentially in an international cirrhosis cohort

The relative ranking of cirrhosis-related deaths differs between high-/middle-income countries. Gut microbiome is affected in cirrhosis and is related to diet. Our aim was to determine the effect of differing dietary habits on gut microbiota and clinical outcomes. Outpatient compensated/decompensated patients with cirrhosis and controls from Turkey and the United States underwent dietary and stool microbiota analysis. Patients with cirrhosis were followed till 90-day hospitalizations. Shannon diversity and multivariable determinants (Cox and binary logistic) of microbial diversity and hospitalizations were studied within/between groups. Two hundred ninety-six subjects (157 U.S.: 48 controls, 59 compensated, 50 decompensated; 139 Turkey: 46 controls, 50 compensated, 43 decompensated) were included. Patients with cirrhosis between cohorts had similar Model for End-Stage Liver Disease (MELD) scores. American patients with cirrhosis had more men, greater rifaximin/lactulose use, and higher hepatitis C/alcohol etiologies. Coffee intake was higher in Americans whereas tea, fermented milk, and chocolate intake were higher in Turkey. The entire Turkish cohort had a significantly higher microbial diversity than Americans, which did not change between their controls and patients with cirrhosis. In contrast, microbial diversity changed in the U.S.-based cohort and was the lowest in decompensated patients. Coffee, tea, vegetable, chocolate, and fermented milk intake predicted a higher diversity whereas MELD score, lactulose use, and carbonated beverage use predicted a lower microbial diversity. The Turkish cohort had a lower risk of 90-day hospitalizations. On Cox and binary logistic regression, microbial diversity was protective against 90-day hospitalizations, along with coffee/tea, vegetable, and cereal intake.

CONCLUSION

In this study of patients with cirrhosis and healthy controls from the United States and Turkey, a diet rich in fermented milk, vegetables, cereals, coffee, and tea is associated with a higher microbial diversity. Microbial diversity was associated with an independently lower risk of 90-day hospitalizations. (Hepatology 2018;68:234-247).

Fungal dysbiosis in cirrhosis

OBJECTIVE

Cirrhotics have a high rate of infections, which are increasingly fungal or culture-negative in nature. While infected cirrhotics have bacterial dysbiosis, the role of fungi is unclear. We aimed to evaluate gut bacterial and fungal dysbiosis in cross-sectional and longitudinal analyses of outpatient and inpatient cirrhotics and prediction of hospitalisations.

METHODS

Cross-sectional: Age-matched controls, outpatients (with/without antibiotics) and hospitalised uninfected, culture-negative and culture-positive cirrhotics were included and followed for 90 days. Longitudinal: Three studies were conducted: (1) cirrhotics followed over 6 months, (2) outpatient cirrhotics administered antibiotics per standard of care for 5 days and (3) cirrhotics and controls administered omeprazole over 14 days. In all studies, stool bacterial/fungal profiles were analysed.

RESULTS

Cross-sectional: In 143 cirrhotics and 26 controls, bacterial and fungal diversities were significantly linked. Outpatients on antibiotics and patients with culture-positive infections had the lowest diversities. Bacterial and fungal correlations were complex in uninfected, outpatient and control groups but were markedly skewed in infected patients. 21% were admitted on 90-day follow-up. A lower Bacteroidetes/Ascomycota ratio was associated with lower hospitalisations. Longitudinal: Fungal and bacterial profiles were stable on follow-up (5 days and 6 months). After antibiotics, a significantly reduced bacterial and fungal diversity, higher Candida and lower autochthonous bacterial relative abundance were seen. After omeprazole, changes in bacterial diversity and composition were seen but fungal metrics remained stable.

CONCLUSION

There is a significant fungal dysbiosis in cirrhosis, which changes differentially with antibiotics and proton pump inhibitor use, but is otherwise stable over time. A combined bacterial-fungal dysbiosis metric, Bacteroidetes/Ascomycota ratio, can independently predict 90-day hospitalisations in patients with cirrhosis.

CLINICAL TRIAL NUMBER

NCT01458990.

A Distinctive Urinary Metabolomic Fingerprint Is Linked With Endoscopic Postoperative Disease Recurrence in Crohn's Disease Patients

BACKGROUND

Crohn's disease (CD) patients who undergo ileocolonic resection frequently have disease recurrence. The aim of this preliminary study was to identify urinary metabolomic profiles associated with disease recurrence in order to identify underlying mechanisms of recurrence and possible disease biomarkers.

METHODS

Biopsies from the neoterminal ileum were collected from CD patients (n = 38) after ileocolonic resection in order to assess mucosa-associated microbiota using 16S rRNA multitag pyrosequencing. Urine samples were collected, and metabolomic profiling was done using high-resolution nuclear magnetic resolution spectroscopy and a combined direct infusion liquid chromatography tandem mass spectrometry. The Rutgeerts scoring system was used to assess endoscopic postoperative recurrence of CD.

RESULTS

There were 28 (73.7%) patients with endoscopic CD recurrence. CD patients who were in endoscopic remission had a higher abundance of Bacteroidetes and lower abundance of Fusobacteria and Proteobacteria in comparison with CD patients who had endoscopic recurrence. In addition, metabolomic profiling could also discriminate between these 2 groups of patients. Endoscopic recurrence was associated with increased concentration of urinary levoglucosan. Rutgeerts score was positively correlated with levoglucosan and propylene glycol levels.

CONCLUSIONS

CD patients who present with endoscopic disease recurrence after surgery have a unique urinary metabolomic fingerprint that can differentiate them from CD patients who are in endoscopic remission after ileocolonic resection. In addition, mucosal-associated microbiota in CD patients with or without disease recurrence after surgery differs and correlates with some urinary metabolites.