Intestinal flora and bilirubin

Intrapartum Maternal Prophylactic Antimicrobial Treatment and Neonatal Jaundice

Intrapartum antibiotics are widely used and may potentially affect bilirubin levels and neurotoxicity in the newborn. The aim of this study was to examine the effect of intrapartum antibiotic exposure on neonatal jaundice. We retrospectively collected data from 972 neonates born to 963 mothers. Five hundred forty-five mothers (56.6%) received intrapartum antibiotics. There were no statistically significant differences in maximum bilirubin level (7.82 ± 3.65 vs 7.63 ± 3.71, P = .43) or need for phototherapy (9 [1.62%] vs 4 [0.94%], P = .52) between exposed and non-exposed newborns. The rate of phototherapy was significantly higher only in the group of infants born to mothers who received broad-spectrum antibiotics at 2 to 3.9 hours prior to delivery (χ2 = 10.453, P = .015) and was not higher in the group of exposure >4 hours, which may represent a short transient effect of antibiotics exposure on bilirubin turnover. Further studies are needed to validate this finding.

Analysis of gut microbiota in rats with bile duct obstruction after biliary drainage

The abundance of specific gut microorganisms is strongly associated with the concentrations of microbially modified bile acids. This study aimed to investigate the composition of intestinal microbiota in rats subjected to bile duct ligation or biliary drainage. Extrahepatic bile duct ligation was conducted to induce bile duct obstruction in rats. The bile was drained via a percutaneous biliary drainage catheter to cause bile deficiency. The total DNA extracted from fecal samples was sequenced with 16S DNA sequencing. Taxonomic classifications were conducted using the Mothur algorithm and SILVA138 database and were presented along with the abundance presented using a heatmap. The inter- and intra-group differences in the intestinal microbiome composition were analyzed by ANOSIM test. The biomarker microorganisms were screened using the Linear discriminant analysis Effect size method. The possible functional pathways were predicted using the Tax4Fun package. A total of 3277 operational taxonomic units (OTUs) were examined, with 2410 in the Kongbai group, 2236 in the Gengzu group, and 1763 in the Yinliu group. The composition of microorganisms at the levels of phylum, class, order, family, and genus was altered in rats with bile duct obstruction. This composition was then restored by biliary drainage. The top 10 predominant microorganisms were identified that led to the inter-group differences. Functional annotation revealed that the potential functions of the microorganisms with significant differences were enriched in metabolism, cellular processes, and genetic and environmental information processing. The intestinal microbial community was significantly changed in rats with bile duct obstruction. The changes in the abundance of intestinal microbiota Prevotellaceae and Enterobacteriaceae were statistically significant after biliary drainage treatment.

The Mutation Hotspots at UGT1A Locus May Be Associated with Gilbert's Syndrome Affecting the Taiwanese Population

Gilbert's syndrome is mainly diagnosed through genetic analysis and is primarily detected through a mutation in the promoter region of the UGT1A1 gene. However, most of the research has been conducted on Caucasian populations. In this study, we studied the Han population in Taiwan to investigate the possibility of other mutations that could cause Gilbert's syndrome. This study comprised a test group of 45 Taiwanese individuals with Gilbert's syndrome and 180 healthy Taiwanese individuals as a control group. We extracted DNA from the blood samples and then used Axiom Genome-Wide TWB 2.0 array plates for genotyping. Out of 302,771 single nucleotide polymorphisms (SNPs) from 225 subjects, we detected 57 SNPs with the most significant shift in allele frequency; 27 SNPs among them were located in the UGT1A region. Most of the detected SNPs highly correlated with each other and are located near the first exon of UGT1A1, UGT1A3, UGT1A6, and UGT1A7. We used these SNPs as an input for the machine learning algorithms and developed prediction models. Our study reveals a good association between the 27 SNPs detected and Gilbert's syndrome. Hence, this study provides a reference for diagnosing Gilbert's syndrome in the Taiwanese population in the future.

Role of ursodeoxycholic acid in neonatal indirect hyperbilirubinemia: a systematic review and meta-analysis of randomized controlled trials

Background

Neonatal jaundice is a transitional phenomenon affecting three out of five full-term newborns globally. Ursodeoxycholic acid could be beneficial in neonatal jaundice needing phototherapy. 

Methods

We searched PubMed, EBSCO, ProQuest, and Cochrane Library up to August 21^st, 2021, for articles to be reviewed. Meta-analysis using random-effects model was performed.

Results

Eight studies involving 1116 neonates were chosen in this review; however, only five studies were included for meta-analysis. Phototherapy duration was significantly lower in the interventional group with high heterogeneities. Subgroup analysis of the phototherapy duration based on the risk of bias resulted in a shorter duration (mean difference (MD) = –17.82; 95% CI = –20.17 to –15.47; p =  < 0.001) with low heterogeneity in the treatment group. Secondary outcome focusing on mean total serum bilirubin showed a lower mean total serum bilirubin in 48 h post-treatment (MD = –0.43; 95% CI = –0.64 to –0.22; p =  < 0.0001) with low heterogeneities in Asian countries.”

Conclusions

Ursodeoxycholic acid might be considered as a novel adjuvant therapy in neonatal indirect hyperbilirubinemia to shorten the phototherapy duration and lower the mean total serum bilirubin.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13052-022-01372-w.

Maternal disease factors associated with neonatal jaundice: a case-control study

Background

Neonatal jaundice is common, and despite the considerable medical costs associated with it, there are still few studies on the maternal factors associated with it. Identification of maternal factors associated with neonatal jaundice is very important in terms of prevention, screening and management of neonatal jaundice. The current study aimed to identify maternal disease factors associated with neonatal jaundice.

Methods

We compared the maternal disease diagnostic codes during pregnancy (study A) and 1 year before conception (study B) in mothers whose insurance claims data included newborns treated for neonatal jaundice before birth registration via the National Health Insurance Service–National Sample Cohort (control group). To decrease the effect of confounding variables, the neonatal jaundice and control groups were matched at a ratio of 1:10 via propensity score matching using covariates including age and income.

Results

The matched samples for studies A and B included 4,026 and 3,278 (jaundice group: 366 and 298) delivery cases, respectively. In both studies, the jaundice group had a higher proportion of patients who underwent cesarean section than the control group. In study A, other diseases of the digestive system had the highest odds ratio (OR) (K92; adjusted OR: 14.12, 95% confidence interval [CI]: 2.70–82.26). Meanwhile, gastritis and duodenitis had the lowest OR (K29; adjusted OR: 0.39, 95% CI: 0.22–0.69). In study B, salpingitis and oophoritis had the highest OR (N70; adjusted OR: 3.33, 95% CI: 1.59–6.94). Heartburn had the lowest OR (R12; adjusted OR: 0.29, 95% CI:0.12–0.71).

Conclusions

This study identified maternal disease factors correlated with neonatal jaundice during pregnancy and 1 year before conception. Maternal risk factors for neonatal jaundice included syphilis and leiomyoma during pregnancy, and salpingo-oophoritis before pregnancy. The protective factors included infection, inflammatory diseases, and dyspepsia.

Translational Approach to the Protective Effect of Bilirubin in Diabetic Kidney Disease

Bilirubin has been regarded as a powerful endogenous antioxidant and anti-inflammatory molecule, able to act on cellular pathways as a hormone. Diabetic kidney disease (DKD) is a common chronic complication of diabetes, and it is the leading cause of end-stage renal disease. Here, we will review the clinical and molecular features of mild hyperbilirubinemia in DKD. The pathogenesis of DKD involves oxidative stress, inflammation, fibrosis, and apoptosis. Serum bilirubin levels are positively correlated with the levels of the antioxidative enzymes as superoxide dismutase, catalase, and glutathione peroxidase, while it is inversely correlated with C-reactive protein, TNF-α, interleukin (IL)-2, IL-6, and IL-10 release in diabetic kidney disease. Bilirubin downregulates NADPH oxidase, reduces the induction of pro-fibrotic factor HIF-1α expression, cleaved caspase-3, and cleaved PARP induction showing lower DNA fragmentation. Recent experimental and clinical studies have demonstrated its effects in the development and progression of renal diseases, pointing out that only very mild elevations of bilirubin concentrations result in real clinical benefits. Future controlled studies are needed to explore the precise role of bilirubin in the pathogenesis of DKD and to understand if the use of serum bilirubin levels as a marker of progression or therapeutic target in DKD is feasible and realistic.

Photomedicine based on heme-derived compounds

Photoimaging and phototherapy have become major platforms for the diagnosis and treatment of various health complications. These applications require a photosensitizer (PS) that is capable of absorbing light from a source and converting it into other energy forms for detection and therapy. While synthetic inorganic materials such as quantum dots and gold nanorods have been widely explored for their medical diagnosis and photodynamic (PDT) and photothermal (PTT) therapy capabilities, translation of these technologies has lagged, primarily owing to potential cytotoxicity and immunogenicity issues. Of the various photoreactive molecules, the naturally occurring endogenous compound heme, a constituent of red blood cells, and its derivatives, porphyrin, biliverdin and bilirubin, have shown immense potential as noteworthy candidates for clinically translatable photoreactive agents, as evidenced by previous reports. While porphyrin-based photomedicines have attracted significant attention and are well documented, research on photomedicines based on two other heme-derived compounds, biliverdin and bilirubin, has been relatively lacking. In this review, we summarize the unique photoproperties of heme-derived compounds and outline recent efforts to use them in biomedical imaging and phototherapy applications.

A Fluorescence-Based Quantitative Analysis for Total Bilirubin in Blood and Urine

BACKGROUND

Bilirubin is a catabolic product of heme metabolism that circulates in the bloodstream in its unconjugated or glucuronide-conjugated form. Because the accumulation of bilirubin in the blood is a common symptom of liver diseases, its measurement in plasma (serum) is important for the diagnosis of these diseases.

METHOD

We developed a method to assess total bilirubin levels in serum and urine, using the fluorescent protein UnaG and β-glucuronidase.

RESULTS

Our results indicate good correlation in serum total bilirubin levels between UnaG and the conventional bilirubin oxidase (BOD) methods. We found low levels of conjugated and unconjugated bilirubin in the urine of healthy subject individuals. Urinary bilirubin levels were elevated in patients with liver or bile duct diseases. A simple spot test of bilirubin using serum and urine showed a strong signal in patients with liver diseases.

CONCLUSION

The proposed method to assess bilirubin levels in serum and urine will contribute to the accurate diagnosis of health conditions such as jaundice, anemia, and liver disease.

Glucuronides Hydrolysis by Intestinal Microbial β-Glucuronidases (GUS) Is Affected by Sampling, Enzyme Preparation, Buffer pH, and Species

Glucuronides hydrolysis by intestinal microbial β-Glucuronidases (GUS) is an important procedure for many endogenous and exogenous compounds. The purpose of this study is to determine the impact of experimental conditions on glucuronide hydrolysis by intestinal microbial GUS. Standard probe 4-Nitrophenyl β-D-glucopyranoside (pNPG) and a natural glucuronide wogonoside were used as the model compounds. Feces collection time, buffer conditions, interindividual, and species variations were evaluated by incubating the substrates with enzymes. The relative reaction activity of pNPG, reaction rates, and reaction kinetics for wogonoside were calculated. Fresh feces showed the highest hydrolysis activities. Sonication increased total protein yield during enzyme preparation. The pH of the reaction system increased the activity in 0.69–1.32-fold, 2.9–12.9-fold, and 0.28–1.56-fold for mouse, rat, and human at three different concentrations of wogonoside, respectively. The Vmax for wogonoside hydrolysis was 2.37 ± 0.06, 4.48 ± 0.11, and 5.17 ± 0.16 μmol/min/mg and Km was 6.51 ± 0.71, 3.04 ± 0.34, and 0.34 ± 0.047 μM for mouse, rat, and human, respectively. The inter-individual difference was significant (4–6-fold) using inbred rats as the model animal. Fresh feces should be used to avoid activity loss and sonication should be utilized in enzyme preparation to increase hydrolysis activity. The buffer pH should be appropriate according to the species. Inter-individual and species variations were significant.

Unconjugated Bilirubin Attenuates DSS-Induced Colitis Potentially via Enhancement of Bilirubin Reabsorption

Studies increasingly show that ulcerative colitis (UC) is a consequence of an imbalance between oxidative stress and antioxidant capacity. Bilirubin exerts an anti-inflammatory effect by scavenging reactive oxygen species (ROS), although the exact mechanism is not completely understood. The aim of this study was to determine the role of serum bilirubin in UC using patient data and a mouse model of dextran sodium sulfate (DSS)-induced colitis. We found that low levels of serum bilirubin correlated to a higher risk of UC in a retrospective case-control population. Pre-treatment with exogenous unconjugated bilirubin (UCB) significantly enhanced colonic bilirubin absorption in mice, and attenuated the DSS-induced body weight loss, colon shortening and histopathological damage. Mechanistically, bilirubin prevented the infiltration of inflammatory cells, and decreased the levels of myeloperoxidase and pro-inflammatory cytokines in the serum and colon. Moreover, bilirubin inhibited ROS and malondialdehyde production, scavenged superoxide anions (O₂^·−) from the colon and enhanced the total antioxidant capacity. In conclusion, exogenous UCB attenuated DSS-induced colitis by directly scavenging O₂^·− and enhancing bilirubin reabsorption in the colon via enterohepatic cycling.

Human gut bacterial β-glucuronidase inhibition: An emerging approach to manage medication therapy

Bacterial β-glucuronidase enzymes (BGUSs) are at the interface of host-microbial metabolic symbiosis, playing an important role in health and disease as well as medication outcomes (efficacy or toxicity) by deconjugating a large number of endogenous and exogenous glucuronides. In recent years, BGUSs inhibition has emerged as a new approach to manage diseases and medication therapy and attracted an increasing research interest. However, a growing body of evidence underlines great genetic diversity, functional promiscuity and varied inhibition propensity of BGUSs, which have posed big challenges to identifying BGUSs involved in a specific pathophysiological or pharmacological process and developing effective inhibition. In this article, we offered a general introduction of the function, in particular the physiological, pathological and pharmacological roles, of BGUSs and their taxonomic distribution in human gut microbiota, highlighting the structural features (active sites and adjacent loop structures) that affecting the protein-substrate (inhibitor) interactions. Recent advances in BGUSs-mediated deconjugation of drugs and carcinogens and the discovery and applications of BGUS inhibitors in management of medication therapy, typically, irinotecan-induced diarrhea and non-steroidal anti-inflammatory drugs (NSAIDs)-induced enteropathy, were also reviewed. At the end, we discussed the perspectives and the challenges of tailoring BGUS inhibition towards precision medicine.

Physicochemical Understanding of Protein-Bound Quantum Dot-Based Sensitive Probing of Bilirubin: Validation with Real Samples and Implications of Protein Conformation in Sensing

Precise and rapid determination of free bilirubin (BR), a key biomarker of pathological conditions of the liver, is important clinical issue. The present study demonstrates that the combination of the strong specific affinic properties of protein, bovine serum albumin (BSA), toward bilirubin and luminescence of well-characterized semiconductor quantum dots (QDs) can offer a simple, fast, and sensitive technique for the determination of free bilirubin through quenching analysis. Here, BSA molecule not only stabilizes the quantum dots in an aqueous environment but also helps bring BR closer to QDs during the interactions of CdSe-BSA QDs with BR. Further, it is revealed through photophysical investigation that the conformation of protein molecule may play an important role in biomolecular sensing considering bilirubin as a model target molecule. The luminescence of CdSe-BSA QDs was highly responsive toward bilirubin, where nearly 90% of emission intensity was quenched on adding only 40 μM bilirubin, suggesting strong interactions involved between synthesized QDs and bilirubin. Solvent polarity dependence on luminescence changes confirms strong electrostatic interaction between the QDs and BR. The applicability of the synthesized quantum dots in sensing bilirubin has been checked in the presence of different possible interfering agents and also with plasma isolated from real blood samples of both normal and hepatitis patients. It was observed that bilirubin as control sample as well as in human serum sample can be optimally measured at pH 7.5, 25 °C. Thus, the proposed strategy being able to measure free BR even at least two orders of magnitude lower than bilirubin level in normal blood may provide a reasonable protocol to determine BR in the pathophysiology of many critical human diseases, like hepatitis and Gilbert's syndrome in the near future.

Clinical characteristics influence cultivable-bacteria composition in the meconium of Indonesian neonates

Background

Microbial colonization of a neonate's gastrointestinal tract has significant perinatal and lifetime health consequences. However, information regarding the profile of meconium microbiota in neonates and the influence of clinical parameters are lacking in the Indonesian population. This study aimed to preliminary investigate the profile of cultivable bacterial diversity of meconium isolated from neonates born at Cipto Mangunkusumo Hospital (CMH), Jakarta. The cultivable bacteria were isolated from meconium samples and were then processed for cultivation and molecular identification.

Results

Fourteen neonates were enrolled as described, i.e., seven hyperbilirubinemia (Hyp) and seven non-Hyp with ten neonates delivered by cesarean section (CS) and four others by vaginal route (VR), and with five exclusive breastfeeding (Ebf), four formula milk, and five combinations. Microbiological identification, molecular 16S rDNA PCR-Sanger sequencing, and PCA analysis of cultivable bacteria isolated from meconium showed Firmicutes' predominance (84.41%), with an abundant population of Staphylococcus, which consist of S. hominis, S. epidermidis, and S. haemolyticus. The influence of mode of delivery showed a lower diversity than the CS populates the VR, but their composition was similar. Concurrently, between feeding patterns, the genera profile did not show much difference; in the non-Ebf group, the total amount of Staphylococcus and Bacillus showed a higher amount but a less diverse. Interestingly, the non-Hyp group showed more abundant and diverse Staphylococcus than that of the Hyp group. In contrast, neonates diagnosed with NEC and proven sepsis showed the same pattern of Staphylococcus domination.

Conclusion

Staphylococcus predominated the composition of cultivable bacteria in neonates meconium. Due to the small sample size, only the hyperbilirubinemia parameter significantly influenced the profile, i.e., Staphylococcus's proportion (p = 0.037).

Preventive Effects of Probiotic Supplementation on Neonatal Hyperbilirubinemia Caused by Isoimmunization

OBJECTIVE

Probiotic supplementation can help to improve recovery from jaundice by reducing enterohepatic circulation through the regulation of intestinal microbial flora. The aim of our study was to investigate the effect of probiotic supplementation on neonatal hyperbilirubinemia caused by isoimmunization alone.

STUDY DESIGN

Sixty neonates were randomly divided into a placebo group and a probiotic group (Lactobacillus rhamnosus GG). Serum total bilirubin (STB) levels were measured at birth and at 4, 8, 16, 24, and 36 hours of treatment (and at 48, 60, and 72 hours if necessary). Duration of phototherapy, rephototherapy requirements, and daily meconium evacuation were recorded.

RESULTS

STB and rebound STB levels at 36 hours were lower in the probiotic group than in the placebo group (p = 0.01 and p = 0.006, respectively). Meconium evacuation was more frequent in the probiotic group than in the placebo group on the second and third days of life (p = 0.002 and 0.009, respectively).

CONCLUSION

Probiotics do not affect STB levels in the first 24 hours of life or duration of phototherapy in neonates with jaundice caused by blood group incompatibility. The effect of probiotic supplementation by reducing enterohepatic circulation occurs at 36 hours of life in newborns with isoimmunization.

Molecular Physiology and Pathophysiology of Bilirubin Handling by the Blood, Liver, Intestine, and Brain in the Newborn

Bilirubin is the end product of heme catabolism formed during a process that involves oxidation-reduction reactions and conserves iron body stores. Unconjugated hyperbilirubinemia is common in newborn infants, but rare later in life. The basic physiology of bilirubin metabolism, such as production, transport, and excretion, has been well described. However, in the neonate, numerous variables related to nutrition, ethnicity, and genetic variants at several metabolic steps may be superimposed on the normal physiological hyperbilirubinemia that occurs in the first week of life and results in bilirubin levels that may be toxic to the brain. Bilirubin exists in several isomeric forms that differ in their polarities and is considered a physiologically important antioxidant. Here we review the chemistry of the bilirubin molecule and its metabolism in the body with a particular focus on the processes that impact the newborn infant, and how differences relative to older children and adults contribute to the risk of developing both acute and long-term neurological sequelae in the newborn infant. The final section deals with the interplay between the brain and bilirubin and its entry, clearance, and accumulation. We conclude with a discussion of the current state of knowledge regarding the mechanism(s) of bilirubin neurotoxicity.

Variation in the gut microbial community is associated with the progression of liver regeneration

AIM

To highlight a potential dynamic interaction between intestinal bacteria (IB) and metabolites that might contribute to liver regeneration (LR).

METHODS

Male Sprague-Dawley rats were subjected to surgical removal of two-thirds of the liver and samples were collected over a 14-day period. Intestinal community and metabolic profiles were characterized to establish their potential interactions during liver regeneration.

RESULTS

Partial hepatectomy caused fluctuating changes in the gut microbiome, which paralleled the biological processes of LR. Briefly, the enhanced cell proliferation occurring within 30-48 h was associated with a decreased ratio of Firmicutes to Bacteroidetes reflected by a reduction in Ruminococcaceae and Lachnospiraceae, and an increase in Bacteroidaceae, Rikenellaceae, and Porphyromonadaceae, which was indicative of a lean phenotype. The microbiota derived from rats at 12-24 h and 3-14 days were characterized by elevated F/B ratios, suggesting the differing energy extract behaviors of microbiota during the course of LR. Functional changes of the shifted microbiota revealed by PICRUSt software confirmed the pyrosequencing results. The microbiome derived from hour 12 rats showed overpresentation of metabolism-related modules. In contrast, the microbiome derived from day 2 rats was functionally unique in "replication and repair", "amino acid metabolism," and "nucleoid metabolism." Upon examining the dynamic pattern of metabolic response, the specific pathways, including glycerophospholipid metabolism, taurine, and hypotaurine metabolism, were identified to be attributable to the systemic alterations in LR-related metabolism. Moreover, our data indicated that several key functional bacteria were strongly related to perturbations of the above pathways.

CONCLUSION

Gut flora could play a central role in manipulating metabolic responses in LR.

Balance of saccharolysis and proteolysis underpins improvements in stool quality induced by adding a fiber bundle containing bound polyphenols to either hydrolyzed meat or grain-rich foods

Dietary fiber is a key component in gastrointestinal health maintenance partly due to its fermentation by the gut microbiome. The food-dependent effects of a novel fiber bundle added to hydrolyzed meat (HM) or grain-rich (GR) foods in healthy dogs (n = 16) or those with chronic enteritis/gastroenteritis (n = 16) were examined. Addition of fiber to either food improved stool quality in dogs regardless of health status; microbiome diversity of dogs with chronic enteritis/gastroenteritis became more similar to healthy dogs. The abundance of bacteria mediating beneficial saccharolytic processes (eg, Lachnospiraceae) significantly increased on addition of fiber to the GR food, while those mediating detrimental proteolytic catabolism (eg, Desulfovibrionaceae) significantly decreased. Fiber addition to the HM food led to significant changes in saccharolytic/proteolytic bacteria. Higher levels of free saccharides in feces upon fiber addition to either food indicated increased saccharolysis. Fiber addition to the GR food decreased levels of fecal free amino acids, indicating decreased proteolysis. Addition of fiber decreased fecal pH for both foods but likely by different mechanisms: addition of fiber to the HM food led to increased straight-chain short-chain fatty acids (SCFAs) and no significant change in proteolytic branched-chain SFCAs, while in the GR food, fiber mainly led to decreased proteolytic branched-chain SFCAs. Other postbiotics related to intestinal health were consistently altered when fiber was added to either food. Plant-derived bioactive molecules were enriched in feces from dogs fed either food with added fiber, which could account for the observed modulation of the canine gut microbiome and shifts in metabolic capacity.

The molecular basis of jaundice: An old symptom revisited

Increased serum bilirubin level is a widely used diagnostic marker for hepatic illnesses. Nevertheless, mild elevation of unconjugated serum bilirubin (such as in Gilbert syndrome) has been recently demonstrated to correlate with low risk of chronic inflammatory and/or oxidative stress-mediated diseases. In accord, a low serum bilirubin level has emerged as an important predisposing factor or a biomarker of these pathologic conditions including cardiovascular, tumour, and possibly neurodegenerative diseases. Bilirubin possesses multiple biological actions with interaction in a complex network of enzymatic and signalling pathways. The fact that the liver is the main organ controlling the bioavailability of bilirubin emphasizes the central role of this organ in human health.

Urinary metabolite profiling offers potential for differentiation of liver-kidney yin deficiency and dampness-heat internal smoldering syndromes in posthepatitis B cirrhosis patients

Zheng is the basic theory and essence of traditional Chinese medicine (TCM) in diagnosing diseases. However, there are no biological evidences to support TCM Zheng differentiation. In this study we elucidated the biological alteration of cirrhosis with TCM “Liver-Kidney Yin Deficiency (YX)” or “Dampness-Heat Internal Smoldering (SR)” Zheng and the potential of urine metabonomics in TCM Zheng differentiation. Differential metabolites contributing to the intergroup variation between healthy controls and liver cirrhosis patients were investigated, respectively, and mainly participated in energy metabolism, gut microbiota metabolism, oxidative stress, and bile acid metabolism. Three metabolites, aconitate, citrate, and 2-pentendioate, altered significantly in YX Zheng only, representing the abnormal energy metabolism. Contrarily, hippurate and 4-pyridinecarboxylate altered significantly in SR Zheng only, representing the abnormalities of gut microbiota metabolism. Moreover, there were significant differences between two TCM Zhengs in three metabolites, glycoursodeoxycholate, cortolone-3-glucuronide, and L-aspartyl-4-phosphate, among all differential metabolites. Metabonomic profiling, as a powerful approach, provides support to the understanding of biological mechanisms of TCM Zheng stratification. The altered urinary metabolites constitute a panel of reliable biological evidence for TCM Zheng differentiation in patients with posthepatitis B cirrhosis and may be used for the potential biomarkers of TCM Zheng stratification.

Distinct signatures of host-microbial meta-metabolome and gut microbiome in two C57BL/6 strains under high-fat diet

A combinatory approach using metabolomics and gut microbiome analysis techniques was performed to unravel the nature and specificity of metabolic profiles related to gut ecology in obesity. This study focused on gut and liver metabolomics of two different mouse strains, the C57BL/6J (C57J) and the C57BL/6N (C57N) fed with high-fat diet (HFD) for 3 weeks, causing diet-induced obesity in C57N, but not in C57J mice. Furthermore, a 16S-ribosomal RNA comparative sequence analysis using 454 pyrosequencing detected significant differences between the microbiome of the two strains on phylum level for Firmicutes, Deferribacteres and Proteobacteria that propose an essential role of the microbiome in obesity susceptibility. Gut microbial and liver metabolomics were followed by a combinatory approach using Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) and ultra performance liquid chromatography time of tlight MS/MS with subsequent multivariate statistical analysis, revealing distinctive host and microbial metabolome patterns between the C57J and the C57N strain. Many taurine-conjugated bile acids (TBAs) were significantly elevated in the cecum and decreased in liver samples from the C57J phenotype likely displaying different energy utilization behavior by the bacterial community and the host. Furthermore, several metabolite groups could specifically be associated with the C57N phenotype involving fatty acids, eicosanoids and urobilinoids. The mass differences based metabolite network approach enabled to extend the range of known metabolites to important bile acids (BAs) and novel taurine conjugates specific for both strains. In summary, our study showed clear alterations of the metabolome in the gastrointestinal tract and liver within a HFD-induced obesity mouse model in relation to the host-microbial nutritional adaptation.

Mesobiliverdin IXα Enhances Rat Pancreatic Islet Yield and Function

The aims of this study were to produce mesobiliverdin IXα, an analog of anti-inflammatory biliverdin IXα, and to test its ability to enhance rat pancreatic islet yield for allograft transplantation into diabetic recipients. Mesobiliverdin IXα was synthesized from phycocyanobilin derived from cyanobacteria, and its identity and purity were analyzed by chromatographic and spectroscopic methods. Mesobiliverdin IXα was a substrate for human NADPH biliverdin reductase. Excised Lewis rat pancreata infused with mesobiliverdin IXα and biliverdin IXα-HCl (1-100 μM) yielded islet equivalents as high as 86.7 and 36.5%, respectively, above those from non-treated controls, and the islets showed a high degree of viability based on dithizone staining. When transplanted into livers of streptozotocin-induced diabetic rats, islets from pancreata infused with mesobiliverdin IXα lowered non-fasting blood glucose (BG) levels in 55.6% of the recipients and in 22.2% of control recipients. In intravenous glucose tolerance tests, fasting BG levels of 56 post-operative day recipients with islets from mesobiliverdin IXα infused pancreata were lower than those for controls and showed responses that indicate recovery of insulin-dependent function. In conclusion, mesobiliverdin IXα infusion of pancreata enhanced yields of functional islets capable of reversing insulin dysfunction in diabetic recipients. Since its production is scalable, mesobiliverdin IXα has clinical potential as a protectant of pancreatic islets for allograft transplantation.

Effective treatment of unconjugated hyperbilirubinemia with oral bile salts in Gunn rats

BACKGROUND & AIMS

We tested the hypothesis that oral administration of bile salts, which are known to increase the biliary excretion of unconjugated bilirubin (UCB), decreases unconjugated hyperbilirubinemia in the Gunn rat model.

METHODS

Adult Gunn rats were fed a standard diet or the same diet supplemented with 0.5 weight % ursodeoxycholic acid (UDCA) or cholic acid (CA) for 1 or 6 weeks. UCB and urobilinoids, a family of intestinal UCB breakdown products, were determined in plasma, feces, or both. After 6 weeks of treatment, tracer 3H-UCB was administered intravenously to determine steady-state UCB kinetics over the next 60 hours.

RESULTS

One-week treatment with UDCA or CA decreased plasma UCB concentrations by 21% and 30%, respectively (each P < .01). During the first 4 days of treatment, both UDCA and CA increased the combined fecal excretion of UCB and urobilinoids (+52% and +32%, respectively; each P < .01). Prolongation of treatment to 6 weeks caused a persistent decrease in plasma UCB concentrations to approximately 40% below baseline (each bile salt P < .001). (3)H-UCB kinetic studies showed that UDCA and CA administration decreased UCB pool size (-33% and -32%, respectively; each P < .05) and increased UCB fractional turnover (+33% and +25%, respectively; each P < .05).

CONCLUSIONS

Dietary bile salt administration induces a large, persistent decrease in plasma UCB concentrations in Gunn rats. Both UDCA and CA enhance UCB turnover by increasing its fecal disposal. These results support the application of oral bile salt treatment in patients with unconjugated hyperbilirubinemia.

Novel kinetic insights into treatment of unconjugated hyperbilirubinemia: phototherapy and orlistat treatment in Gunn rats

Treatment with phototherapy or with the lipase inhibitor orlistat decreases plasma unconjugated bilirubin (UCB) concentrations in hyperbilirubinemic Gunn rats. We investigated the mechanism(s) underlying the effects of orlistat, phototherapy, and combined treatment, using steady-state 3H-UCB kinetics. After three weeks of treatment with orlistat (200 mg/kg chow), phototherapy (19 microW/cm2/nm) or combined treatment, tracer 3H-UCB was administered IV to treated and untreated (control) Gunn rats. Plasma samples and feces were collected every 12h for 60h, and bile for 30 min at 60h. The following results were obtained: 1) each treatment decreased plasma bilirubin levels compared with controls: orlistat- 19%, phototherapy-32%, combined treatment-53%; 2) plasma bilirubin concentrations were strongly, negatively correlated with fractional bilirubin turnover; 3) orlistat treatment induced net transmucosal excretion of UCB into the intestinal lumen, whereas phototherapy increased biliary UCB excretion rate; 4) all treatments profoundly increased the enterohepatic circulation of UCB derivatives, indicating enhanced metabolism by intestinal bacteria. In conclusion, orlistat and phototherapy lower plasma bilirubin concentrations in Gunn rats by increasing (net) intestinal influx of UCB, either by transmucosal excretion (orlistat), or increased biliary secretion (phototherapy). The mechanism of phototherapy and orlistat treatment involves increasing the availability of UCB in the intestinal lumen for fecal excretion and for metabolism by intestinal bacteria.