Bile Acid Concentrations Research Articles

Dietary supplementation of poly-dihydromyricetin-fused zinc nanoparticles alleviates fatty liver hemorrhagic syndrome by improving antioxidant capacity, intestinal health and lipid metabolism of laying hens

Fatty liver hemorrhagic syndrome is the main cause of noninfectious death of laying hens and results in substantial economic losses to the poultry industry. This study focused on evaluating the effects of Poly-dihydromyricetin-fused zinc nanoparticles (PDMY-Zn NPs) on antioxidant capacity, liver lipid metabolism, and intestinal health in laying hens. A total of 288 Jingfen laying hens (52 wk old) with similar body weights were randomly divided into 4 dietary groups with 6 replicates in each group for 8 wk. The control group received a basal diet, while the treatment groups were supplemented with PDMY-Zn NPs at levels of 200, 400, and 600 mg/kg, respectively. The results indicate that PDMY-Zn NPs supplementation can enhance antioxidant parameters (P < 0.05) in the blood and liver of laying hens. Simultaneously, it can mitigate vacuolar degeneration and inflammatory necrosis in hepatocytes, improve the relative expression level of related parameters associated with liver lipid metabolism and key regulatory genes (P < 0.05). Furthermore, it has been observed to reshape the composition and diversity of cecum microbes by increasing beneficial probiotics such as Lactobacillus and Prevotella, while also enhancing villi height and villi/crypt ratio in the duodenum and ileum (P < 0.05). Additionally, it elevates liver bile acid content along with the relative expression of key genes involved in liver synthesis (P < 0.05). In summary, PDMY-Zn NPs showed potential to alleviate fatty liver hemorrhagic syndrome by enhancing antioxidant capacity, regulating liver lipid metabolism, and maintaining intestinal health.

740. RABEPRAZOLE PROTECTS REFLUX ESOPHAGITIS DUE TO BILE IN RAT MODEL

Abstract Aims we studied the effect of proton pump inhibitor(PPI)(Rabeprazole) therapy on esophageal bile reflux in esophagitis after total gastrectomy. (Methodology) Sixteen 8-week old male Wistar rats were underwent total gastrectomy and esophagoduodenostomy to induce esophageal reflux of biliary and pancreatic juice. In 5 rats the sham operation induced a midline laparatomy alone (Sham). One week following surgery, they were treated with saline (Control) (n=8) PPI (Rabeprazole)(n=8)(30mg/kg/day) ip for 2 weeks. 3 weeks after operation, all rats were killed and the esophagus was evaluated histologically. Esophageal injury was evaluated by macroscopic, microscopic findings and expression of COX2 and PGE2. We performed the measurement of bile acid in the esophageal lumen and common bile duct. Results At 3 weeks after surgery, duodenal reflux induced esophageal erosions and ulcer formation. The macroscopic ulcer score and microscopic ulcer length were significantly reduced by PPI. The enhanced expression of COX2 and PGE2 in the control group was also markedly inhibited in the PPI group. Really, there is no difference between control group and PPI group in bile acid concentration from the common bile duct. PPI does not inhibit the secretion of bile acid from the common bile duct. But, the bile acid activity in the esophageal lumen was significantly increased in the control group, and this increase was significantly inhibited in the PPI group. Conclusion These results indicate that bile acid, which is inhibited by Rabeprazole, plays an important role in the mucosal damage induced by duodenal reflux.

Bariatric Surgery Is Associated with Lower Concentrations of Fecal Secondary Bile Acids and Their Metabolizing Microbial Enzymes: A Pilot Study.

Excess body fat elevates colorectal cancer risk. While bariatric surgery (BRS) induces significant weight loss, its effects on the fecal stream and colon biology are poorly understood. Specifically, limited data exist on the impact of bariatric surgery (BRS) on fecal secondary bile acids (BA), including lithocholic acid (LCA), a putative promotor of colorectal carcinogenesis. This cross-sectional case-control study included 44 patients with obesity; 15 pre-BRS (controls) vs. 29 at a median of 24.1months post-BRS.We examined the fecal concentrations of 11 BA by liquid chromatography and gene abundance of BA-metabolizing bacterial enzymes through fecal metagenomic sequencing. Differences were quantified using non-parametric tests for BA levels and linear discriminant analysis (LDA) effect size (LEfSe) for genes encoding BA-metabolizing enzymes. Total fecal secondary BA concentrations trended towards lower levels post- vs. pre-BRS controls (p = 0.07). Individually, fecal LCA concentrations were significantly lower post- vs. pre-BRS (8477.0 vs. 11,914.0 uM/mg, p < 0.008). Consistent with this finding, fecal bacterial genes encoding BA-metabolizing enzymes, specifically 3-betahydroxycholanate-3-dehydrogenase (EC 1.1.1.391) and 3-alpha-hydroxycholanate dehydrogenase (EC 1.1.1.52), were also lower post- vs. pre-BRS controls (LDA of - 3.32 and - 2.64, respectively, adjusted p < 0.0001). Post-BRS fecal BA concentrations showed significant inverse correlations with weight loss, a healthy diet quality, and increased physical activity. Concentrations of LCA, a secondary BA, and bacterial genes needed for BA metabolism are lower post-BRS. These changes can impact health and modulate the colorectal cancer cascade. Further research is warranted to examine how surgical alterations and the associated dietary changes impact bile acid metabolism.

Intestinal Stearoyl-CoA Desaturase-1 Regulates Energy Balance via Alterations in Bile Acid Homeostasis

Background and AimsStearoyl-CoA desaturase-1 (SCD1) converts saturated fatty acids into monounsaturated fatty acids and plays an important regulatory role in lipid metabolism. Previous studies have demonstrated that mice deficient in SCD1 are protected from diet-induced obesity and hepatic steatosis due to altered lipid assimilation and increased energy expenditure. Previous studies in our lab have shown that intestinal SCD1 modulates intestinal and plasma lipids and alters cholesterol metabolism. Here we investigated a novel role for intestinal SCD1 in the regulation of systemic energy balance. MethodsTo interrogate the role of intestinal SCD1 in modulating whole body metabolism, intestine- specific Scd1 knockout (iKO) mice were maintained on standard chow diet or challenged with a high-fat diet (HFD). Studies included analyses of bile acid content and composition, metabolic phenotyping including body composition, indirect calorimetry, glucose tolerance analyses, quantification of the composition of the gut microbiome, and assessment of bile acid signaling pathways. ResultsIKO mice displayed elevated plasma and hepatic bile acid content and decreased fecal bile acid excretion, associated with increased expression of the ileal bile acid uptake transporter, Asbt. In addition, the alpha and beta diversity of the gut microbiome was reduced in iKO mice, with several alterations in microbe species being associated with the observed increases in plasma bile acids. These increases in plasma bile acids were associated with increased expression of TGR5 targets, including Dio2 in brown adipose tissue and elevated plasma glucagon-like peptide-1 levels. Upon HFD challenge, iKO mice had reduced metabolic efficiency apparent through decreased weight gain despite higher food intake. Concomitantly, energy expenditure was increased, and glucose tolerance was improved in HFD-fed iKO mice. ConclusionOur results indicate that deletion of intestinal SCD1 has significant impacts on bile acid homeostasis and whole-body energy balance, likely via activation of TGR5.

Comprehensive Analysis of scRNA-Seq and Bulk RNA-Seq Reveals Transcriptional Signatures of Macrophages in Intrahepatic Cholestasis of Pregnancy.

Intrahepatic cholestasis of pregnancy (ICP) is a disorder that characterized by maternal pruritus, abnormal liver function, and an elevation in total bile acid concentrations during pregnancy. Immune factors have been recognized as playing a vital role in the mechanism of ICP. However, the underlying mechanisms regulating dysfunctional immune cells and immune genes remain to be fully elucidated. Single-cell RNA sequencing and bulk RNA sequencing data of the placenta were downloaded from the SRA database. The AUCell package, Monocle package and SCENIC package were utilized to explored immune cell activity, cell trajectory and transcription factor, respectively. GO, KEGG, and GSEA were employed to explore potential biological mechanisms. Cell-cell communications were further investigated using the CellChat package. RT-PCR, and Western blot were used to verify the gene expression in placenta. In placenta cells, macrophages were found to be significantly increased in ICP. Additionally, macrophages exhibited the highest immune gene score and were divided into four subclusters (MF1-4). Our analysis revealed significant elevations in MF2, associated with LPS response and antigen presentation, and MF4, associated with TNF and cytokine production. MF3 displayed an anti-inflammatory phenotype. MF1, closely related to ribosomes and proteins, exhibited a sharp decrease. Although ICP maintained an anti-inflammatory state, macrophage trajectories showed a gradual progression toward inflammation. Subsequently, we confirmed that cytokine- and chemokine-related signaling pathways were emphasized in macrophages. Within the CXCL signaling pathway, the increased expression of CXCL1 in macrophages can interact with CXCR2 in neutrophils, potentially inducing macrophage infiltration, stimulating neutrophil chemotaxis, and leading to an inflammatory response and cellular damage. In conclusion, we firstly revealed the transcriptional signatures of macrophages in ICP and discovered a tendency toward an inflammatory state. This study also provides new evidence that the CXCL1-CXCR2 axis may play an important role in the pathogenesis of ICP.

Laminaria japonica Polysaccharide Regulates Fatty Hepatosis Through Bile Acids and Gut Microbiota in Diabetes Rat.

In this study, we examined the effect of Laminaria japonica polysaccharide (fucoidan) on the regulation of lipid metabolism. A rat model of diabetes mellitus (DM) was established by a high-sugar and high-fat diet combined with streptozotocin. Changes in the rats' body weight and blood glucose level during the experiment were recorded. Before the end of the experiment, an automatic biochemical analyzer was used to detect the fasting blood glucose (FBG), lipid content in serum, and insulin content, and calculate the insulin resistance index. Oil red O staining was used to detect lipid deposition in the liver. H&E staining, Masson staining, and PASM staining were used to observe the pathological structural changes in the liver. 16s RNA sequencing and targeted metabolomics were used to detect intestinal microbiota and bile acid content. The results showed that fucoidan was able to inhibit weight loss in the DM rats and reduce the content of triglycerides (TG), cholesterol (TC), and low-density lipoprotein (LDL-C) in serum. Oil red O staining showed a decrease in liver fat accumulation after fucoidan treatment. 16s RNA sequencing demonstrated that fucoidan increased the abundance of Bacteroidia, Campylobacteria, Clostridia, Gammaproteobacteria, Negativicutes, and Verrucomicrobi. Fucoidan also increased the secretion of secondary bile acids (Nor-DCA, TLCA, β-UDCA) and alleviated lipid metabolism disorders. The expression of α-SMA was inhibited by fucoidan, whereas the expression of FXR and TGR5 was promoted. Fucoidan shows good activity in regulating lipid metabolism by regulating the expression of FXR and TGR5 and acting on the intestinal flora-bile acid axis.

Assessment of Fetal Ventricular Size and Shape in Women With Intrahepatic Cholestasis of Pregnancy Using Speckle Tracking.

To examine the effect of intrahepatic cholestasis of pregnancy (ICP) on fetal heart morphology. This case-control study was conducted with 40 women with ICP and 54 pregnant controls. Fetal heart quantification based on speckle tracking technology was used to assess the morphology of the fetal right and left ventricles. Routine ventricular size parameters, global and 24-segment spherical indices (SIs) were measured and compared between groups. The routine fetal cardiac parameters, global and right-ventricular SIs did not differ between the ICP and control groups. The left-ventricular apical (segments 16-24) SIs were lower in the ICP group than in the control group (P < .05), with no significant difference in the other left-ventricular segments. Subclinical morphological changes were observed in the left ventricular apical segments of the fetal hearts in women with ICP, which indicates an intrauterine environment with high bile acid concentrations. Twenty-four-segment SIs can be used to effectively evaluate these changes.

Effects of wheat-based fermented liquid feed on growth performance, nutrient digestibility, gut microbiota, intestinal morphology, and barrier function in grower-finisher pigs.

Fermented liquid feed (FLF) can improve dietary nutrient absorption levels, degrade anti-nutrient factors in diets, and increase beneficial bacteria abundance in animal guts. However, few systematic studies have been conducted on WFLF in pigs. The present study evaluates the effects of WFLF on the growth performance, nutrient digestibility, gastric volume, intestinal morphology, intestinal health, intestinal barrier function, serum biochemical immunity, gut microbiota, and intestinal microbial diversity of grower-finisher pigs. In total, 80 weaned pigs were randomly allocated to two treatment groups based on their initial body weight: a basal diet with pellet dry feeding (CON) and a basal diet with wheat-based fermented liquid feed (WFLF), with four replicate pens per group. The experiment lasted 82 d. Compared with CON pigs, those fed WFLF were heavier significantly at 60-82 d and had significantly higher average daily feed intake, average daily gain, and gain: feed ratio at 60-82 d and 1-82 d. WFLF pigs had significantly greater jejunum, total tract, and ileal digestibility for all nutrients and amino acids, excluding arginine, than CON pigs. WFLF intake influenced villus height, villus height: crypt depth ratio of the anterior segment of the jejunum(A-jejunum), crypt depth, and redox potential of the posterior segment of the jejunum (P-jejunum) while significantly affecting body weight. Additionally, FLF improved gastric capacity significantly. Furthermore, mRNA expression of occludin and claudin-1 in the mucosa of the ileum and jejunum was significantly higher in WFLF pigs than in CON pigs. WFLF increased serum concentrations of alanine transaminase and reduced low-density lipoprotein cholesterol, total cholesterol, and total bile acid content. The alpha diversity (Shannon and Simpson indices) in the stomachs of WFLF pigs was significantly higher than in CON pigs. Microbial diversity in the stomach, ileum, and cecum, as well as the abundance of lactic acid bacteria, were increased in WFLF pigs compared to CON pigs. In conclusion, WFLF intake may positively influence intestinal ecology by improving digestive tract structure, upregulating intestinal barrier-related genes, and improving intestinal morphology to enhance intestinal digestive function and health. Collectively, the present study shows that WFLF intake can increase growth performance while maintaining beneficial nutrient digestibility in grower-finisher pigs.

Bile Acid Composition and Transcriptome Analysis of the Liver and Small Intestine in Different Species.

Bile, a crucial fluid produced continuously by the liver, plays an essential role in digestion within the small intestine. Beyond its primary function in lipid digestion, bile also acts as a pathway for the elimination of various endogenous and exogenous substances. There have been limited studies focusing on interspecies differences. This study offers a comprehensive analysis of bile acid (BA) composition and its correlation with gene expression patterns across six different species, including mammals and poultry, through combining Liquid Chromatography-Mass Spectrometry (LC-MS) and transcriptome sequencing. The BA profiles revealed distinct metabolite clusters: D-glucuronic acid (GLCA) and glycochenodeoxycholic acid (GCDCA) were predominant in mammals, while taurolithocholic acid (TLCA) and T-alpha-MCA were prevalent in poultry, highlighting species-specific BA compositions. Differentially abundant metabolites, particularly GDCA, glycohyodeoxycholic acid (GHDCA) and taurodeoxycholic acid (TDCA) showed significant variations across species, with pigs showing the highest BA content. Transcriptome analysis of the liver and small intestine tissues of 56 cDNA libraries across the six species revealed distinct mRNA expression patterns. These patterns clustered samples into broad categories based on tissue type and phylogenetic relationships. Furthermore, the correlation between gene expression and BA content was examined, identifying the top 20 genes with significant associations. These genes potentially serve as biomarkers for BA regulation.

Multi-Omics Analysis Reveals Dietary Fiber's Impact on Growth, Slaughter Performance, and Gut Microbiome in Durco × Bamei Crossbred Pig.

Dietary fiber (DF) is an important nutrient component in pig's diet that remarkably influences their growth and slaughter performance. The ability of pigs to digest DF depends on the microbial composition of the intestinal tract, particularly in the hindgut. However, studies on how DF alters the growth and slaughter performance of pigs by shaping the gut microbial composition and metabolites are still limited. Therefore, this study aimed to investigate the effects of DF on microbial composition, functions, and metabolites, ultimately altering host growth and slaughter performance using Durco × Bamei crossbred pigs supplemented with 0%, 10%, 17%, and 24% broad bean silage in the basic diet. We found that the final weight, average daily gain, fat, and lean meat weight significantly decreased with increasing DF. Pigs with the lowest slaughter rate and fat weight were observed in the 24% fiber-supplemented group. Gut microbial communities with the highest alpha diversity were formed in the 17% fiber group. The relative abundance of fiber-degrading bacteria, bile acid, and succinate-producing bacteria, including Prevotella sp., Bacteroides sp., Ruminococcus sp., and Parabacteroides sp., and functional pathways, including the butanoate metabolism and the tricarboxylic acid [TCA] cycle, significantly increased in the high-fiber groups. The concentrations of several bile acids significantly decreased in the fiber-supplemented groups, whereas the concentrations of succinate and long-chain fatty acids increased. Our results indicate that a high-fiber diet may alter the growth and slaughter performance of Durco × Bamei crossbred pigs by modulating the composition of Prevotella sp., Bacteroides sp., Ruminococcus sp., Parabacteroides sp., and metabolite pathways of bile acids and succinate.

Dietary bile acids supplementation decreases hepatic fat deposition with the involvement of altered gut microbiota and liver bile acids profile in broiler chickens

BackgroundHigh-fat diets (HFD) are known to enhance feed conversion ratio in broiler chickens, yet they can also result in hepatic fat accumulation. Bile acids (BAs) and gut microbiota also play key roles in the formation of fatty liver. In this study, our objective was to elucidate the mechanisms through which BA supplementation reduces hepatic fat deposition in broiler chickens, with a focus on the involvement of gut microbiota and liver BA composition.ResultsNewly hatched broiler chickens were allocated to either a low-fat diet (LFD) or HFD, supplemented with or without BAs, and subsequently assessed their impacts on gut microbiota, hepatic lipid metabolism, and hepatic BA composition. Our findings showed that BA supplementation significantly reduced plasma and liver tissue triglyceride (TG) levels in 42-day-old broiler chickens (P < 0.05), concurrently with a significant decrease in the expression levels of fatty acid synthase (FAS) in liver tissue (P < 0.05). These results suggest that BA supplementation effectively diminishes hepatic fat deposition. Under the LFD, BAs supplementation increased the BA content and ratio of Non 12-OH BAs/12-OH BAs in the liver and increased the Akkermansia abundance in cecum. Under the HFD, BA supplementation decreased the BAs and increased the relative abundances of chenodeoxycholic acid (CDCA) and cholic acid (CA) in hepatic tissue, while the relative abundances of Bacteroides were dramatically reduced and the Bifidobacterium, Escherichia, and Lactobacillus were increased in cecum. Correlation analyses showed a significant positive correlation between the Akkermansia abundance and Non 12-OH BA content under the LFD, and presented a significant negative correlation between the Bacteroides abundance and CA or CDCA content under the HFD.ConclusionsThe results indicate that supplementation of BAs in both LFD and HFD may ameliorate hepatic fat deposition in broiler chickens with the involvement of differentiated microbiota–bile acid profile pathways.Graphical

Exploring the effects of dietary cholesterol on growth, immunity, and lipid metabolism of juvenile Chinese mitten crabs (Eriocheir sinensis)

This study aims to investigate the nutritional needs and physiological functions of dietary cholesterol in juvenile Chinese mitten crabs (Eriocheir sinensis). In the 8-week feeding experiment, we evaluated the effects of various cholesterol levels (0 control, 0.6, 1.3, 2.6, 5.9, 12.0 g/kg diet) on growth, immune capacity, lipid metabolism, molting, and cholesterol and bile acid metabolism. Crabs (1.06 ± 0.04 g) were divided into six groups with four replicates of 40 crabs per tank. The highest weight gain was found in crabs fed 5.9 g/kg cholesterol (P < 0.05), while the highest molting frequency was observed in the 0.6 g/kg group (P < 0.05). Cholesterol significantly changed fatty acid composition in the hepatopancreas, and 5.9 g/kg cholesterol increased immune enzyme activities (acid phosphatase, alkaline phosphatase, and polyphenol oxidase) (P < 0.05). A 5.9 g/kg cholesterol significantly upregulated lipogenesis- and catabolism-related genes, while higher levels of cholesterol (12.0 g/kg) downregulated lipogenesis-related genes significantly (P < 0.05). Low cholesterol levels upregulated chitinase expression, while ecdysone receptor and molt-inhibiting hormone expressions were upregulated with cholesterol levels (P < 0.05). Cholesterol also upregulated the gene in bile acid metabolism. The total bile acids, the proportion of primary bile acids, and the content of primary bile acids increased significantly compared to the control. Based on quadratic regression model analysis, the optimal dietary cholesterol level for juvenile E. sinensis is 5.74–5.77 g/kg. The study suggests that cholesterol promotes growth and immunity in juvenile E. sinensis by regulating molting frequency, improving lipid and HUFA utilization, and increasing bile acids.

Astragalus polysaccharides-induced gut microbiota play a predominant role in enhancing of intestinal barrier function of broiler chickens

BackgroundThe intestinal barrier is the first line of defense against intestinal invasion by pathogens and foreign antigens and is closely associated with the gut microbiota. Astragalus polysaccharides (APS) have a long history of use in traditional Chinese medicine owing to its protective properties against intestinal barrier function. The mechanism of APS-induced gut microbiota enhancing intestinal barrier function is urgently needed.ResultsDietary polysaccharide deprivation induced intestinal barrier dysfunction, decreased growth performance, altered microbial composition (Faecalibacterium, Dorea, and Coprobacillus), and reduced isobutyrate concentration. The results showed that APS facilitates intestinal barrier function in broiler chickens, including a thicker mucus layer, reduced crypt depth, and the growth of tight junction proteins. We studied the landscape of APS-induced gut microbiota and found that APS selectively promoted the growth of Parabacteroides, a commensal bacterium that plays a predominant role in enhancing intestinal barrier function. An in vitro growth assay further verified that APS selectively increased the abundance of Parabacteroides distasonis and Bacteroides uniformis. Dietary APS supplementation increased the concentrations of isobutyrate and bile acid (mainly chenodeoxycholic acid and deoxycholate acid) and activated signaling pathways related to intestinal barrier function (such as protein processing in the endoplasmic reticulum, tight junctions, and adherens junction signaling pathways).ConclusionsAPS intervention restored the dietary polysaccharide-induced dysfunction of the intestinal barrier by selectively promoting the abundance of Parabacteroides distasonis, and increasing the concentrations of isobutyrate and bile acids (mainly CDCA and DCA). These findings suggest that APS-induced gut microbiota and metabolic niches are promising strategies for enhancing intestinal barrier function.Graphical

The fecal microbiota of patients with primary biliary cholangitis (PBC) causes PBC-like liver lesions in mice and exacerbates liver damage in a mouse model of PBC

ABSTRACT The role of the gut microbiota in the occurrence and progression of primary biliary cholangitis (PBC) is not fully understood. First, the fecal microbiota of patients with PBC (n = 4) (PBC-FMT) or healthy individuals (n = 3) (HC-FMT) was transplanted into pseudo germ-free mice or 2OA-BSA–induced PBC models. The functions, histology and transcriptome of the liver, and microbiota and metabolome of the feces were analyzed. Second, the liver transcriptomes of PBC patients (n = 7) and normal individuals (n = 7) were analyzed. Third, the liver transcriptomes of patients with other liver diseases were collected from online databases and compared with our human and mouse data. Our results showed that PBC-FMT increased the serum ALP concentration, total bile acid content, liver injury and number of disease-related pathways enriched with upregulated liver genes in pseudo germ-free mice and increased the serum glycylproline dipeptidyl aminopeptidase level and liver damage in a 2OA-BSA–induced PBC model. The gut microbiota and metabolome differed between PBC-FMT and HC-FMT mice and reflected those of their donors. PBC-FMT tended to upregulate hepatic immune and signal transduction pathways but downregulate metabolic pathways, as in some PBC patients. The hematopoietic cell lineage, Toll-like receptor, and PPAR signaling pathway were not affected in patients with alcoholic hepatitis, HBV, HCV, HCV cirrhosis, or NASH, indicating their potential roles in the gut microbiota affecting PBC. In conclusion, the altered gut microbiota of PBC patients plays an important role in the occurrence and progression of PBC. The improvement of the gut microbiota is worthy of in-depth research and promotion as a critical aspect of PBC prevention and treatment.

Abstract Mo041: Bile Acid Dysregulation in Response to Right Heart Failure and Hepatic Congestion

Introduction: Right heart failure (RHF), the result of impaired RV contractility and/or severe right-sided valvulopathies, is a clinical syndrome that commonly results in chronically elevated central venous pressures and hepatic congestion. Hepatic dysfunction in patients with heart failure portends a poor prognosis. In part, this may be due to the liver’s pivotal role in bile acid synthesis and processing. In addition to the classic role of a digestive surfactant, bile acids serve as important and dynamic signaling molecule. The present study characterizes a unique bile acid profile found in patients with RHF. Research Question: We hypothesize that RHF and hepatic congestion results in a dysregulation of bile acids. These untoward changes in bile acids concentrations may provide both important prognostic value and novel mechanistic pathways in congestive liver disease. Aims: 1) To characterize systemic and hepatic vein bile acid concentrations in patients with right heart failure. 2) To phenotype a mouse model of hepatic congestion and understand the mechanistic effects of specific bile acids on liver biology Methods: We enrolled a total of 60 patients who were referred for right heart catheterization (RHC). Patient demographics, echocardiograms, and routine laboratory tests were captured at enrollment. Blood was sampled from the IVC and hepatic vein during RHC. Bile acids were quantified from serum using liquid chromatography-tandem mass spectrometry. To model hepatic congestion, mice underwent ligation of the IVC. Blood and tissue samples were harvested and underwent mass spectrometry evaluation for the bile acid composition and immunohistochemistry was performed to characterize the immune landscape, respectively. Results: We captured a total of 12 control samples from patients with normal filling pressures, 25 patients with left heart failure (LHF), and 23 patients with RF. Patients with RHF had poorer survival outcomes compared to control or LHF. Patients with RHF had significant increases in specific conjugated bile acids when compared to control or LHF (Figure 1). Conclusions: In this study, we identified several conjugated bile acids that are uniquely elevated in patients with RHF compared to LHF and control. Additionally, patients with RHF had poorer survival. Collectively, these data suggest bile acids may serve as important biomarkers and signaling molecules in the pathogenesis of cardiogenic liver disease.

Changes in the Bile Acid Pool and Timing of Female Puberty: Potential Novel Role of Hypothalamic TGR5.

The regulation of pubertal timing and reproductive axis maturation is influenced by a myriad of physiologic and environmental inputs yet remains incompletely understood. To contrast differences in bile acid isoform profiles across defined stages of reproductive maturity in humans and a rat model of puberty and to characterize the role of bile acid signaling via hypothalamic expression of bile acid receptor populations in the rodent model. Secondary analysis and pilot studies of clinical cohorts, rodent models, ex vivo analyses of rodent hypothalamic tissues. Bile acid concentrations is the main outcome measure. Lower circulatory conjugated:deconjugated bile acid concentrations and higher total secondary bile acids were observed in postmenarcheal vs pre-/early pubertal adolescents, with similar shifts observed in infantile (postnatal day [PN]14) vs early juvenile (PN21) rats alongside increased tgr5 receptor mRNA expression within the mediobasal hypothalamus of female rats. 16S rRNA gene sequencing of the rodent gut microbiome across postnatal life revealed changes in the gut microbial composition predicted to have bile salt hydrolase activity, which was observed in parallel with the increased deconjugated and increased concentrations of secondary bile acids. We show that TGR5-stimulated GnRH release from hypothalamic explants is mediated through kisspeptin receptors and that early overexpression of human-TGR5 within the arcuate nucleus accelerates pubertal onset in female rats. Bile acid isoform shifts along stages of reproductive maturation are conserved across rodents and humans, with preclinical models providing mechanistic insight for the neuroendocrine-hepatic-gut microbiome axis as a potential moderator of pubertal timing in females.

Liver structure and function in yellowtail kingfish, Seriola lalandi, in response to alternative oils in feed

The inclusion of low cholesterol alternatives to fish oil (FO) in aquaculture diets could result in alterations to the biosynthesis and availability of bile acids for the digestions and absorption of dietary lipids. In this study the effects of graded substitution of FO with poultry oil (PO) and the replacement of PO with canola oil (CO) in formulated feeds on Yellowtail Kingfish (1.45 ± 0.12 kg; n = 342) liver function was investigated over 84 days. Dietary FO was replaced with PO at 100%, 75% and 50% inclusion levels (Diets 1, 2 and 3, respectively). The lipid source (PO) was further replaced with CO at 0%, 33.3%, 66.7% and 100% (Diets 2, 4, 5 and 6, respectively). The liver vacuole volume as a proportion of the liver cell volume (VPLC%) was significantly increased (P = 0.008) in fish fed the 100% PO diet (Diet 1) compared to that of fish fed diets with greater levels of FO inclusion (Diets 2 and 3). Regression analyses showed that: 1) liver VPLC% increased as FO decreased (r2 = 0.588; P = 0.016), 2) total bile acid concentration in liver tissue decreased with increasing CO and decreasing PO (r2 = 0.402; P = 0.027), and 3) liver CYP7A1 concentration increased with increasing PO and decreasing FO (r2 = 0.506; P = 0.032). No statistically significant differences were observed in any of the blood biochemistry parameters measured from fish fed diets with decreasing FO and increasing PO nor from fish fed diets formulated with FO and a graded PO and CO blend. Yellowtail Kingfish may be able to be fed a formulated diet containing: 1) ∼25% dietary lipid level (2.12 g 100 g−1 of ƩLC n-3 PUFA) with up to 100% of the FO component replaced by PO; and 2) ∼25% dietary lipid level (2.12 g 100 g−1 of ƩLC n-3 PUFA) with up to 100% of the commercially used alternative lipid source (PO) replaced with CO without an apparent negative impact on any of the parameters measured in this study.

Enhanced cholesterol utilization and impact on growth through taurine supplementation in high plant-based diets of Pacific white shrimp, Penaeus vannamei in biofloc system

Cholesterol is vital for the optimal growth and physiological function of Pacific white shrimp, Penaeus vannamei. Due to limited availability of fish meal, plant-based ingredients are increasingly added in the shrimp diet which limit the availability and utilization of cholesterol. This study investigated the synergistic effects of dietary taurine and cholesterol supplementation on growth and physio-metabolic responses of Pacific white shrimp, Penaeus vannamei fed with high plant-based protein diets reared in a biofloc system for 60 days. A basal diet (control) comprised 82.55 % plant-based ingredients and 36 % crude protein. Five isonitrogenous and isolipidic diets were prepared (T1-T5) with cholesterol and taurine supplements at inclusion levels of 0.15 % and 0.16 % in T1 and T2, respectively. In the rest of the treatments, T3, T4, and T5, the combinations of cholesterol and taurine were 0.15 % and 0.16 %; 0.05 % and 0.24 %; 0.25 % and 0.08 %, respectively. The experimental diets were allocated to triplicate groups of 100 shrimp per tank following a completely randomized design. The results showed that shrimp fed T3 diet have a significantly (P < 0.05) higher percentage of weight gain, specific growth rate (SGR), percentage of survival, and protein efficiency ratio (PER) with efficient feed conversion ratio (FCR) (1.14±0.06) compared to other treatments. The hematological, antioxidant, and digestive enzyme activities, except amylase activity, were significantly (P < 0.05) higher in shrimp fed T1 and T3. Total bile acid content in T3 fed shrimp was higher than in other dietary treatments (P < 0.05). The results indicated that supplementing a combination of 0.15 % cholesterol and 0.16 % taurine in a high plant-based diet significantly improved growth performance, nutrient utilization, and physio-metabolic responses of P. vannamei.

Ex vivo metabolism kinetics of primary to secondary bile acids via a physiologically relevant human faecal microbiota model

Bile acids (BA) are synthesized in the human liver and undergo metabolism by host gut bacteria. In diseased states, gut microbial dysbiosis may lead to high primary unconjugated BA concentrations and significant perturbations to secondary BA. Hence, it is important to understand the microbial-mediated formation kinetics of secondary bile acids using physiologically relevant ex vivo human faecal microbiota models. Here, we optimized an ex vivo human faecal microbiota model to recapitulate the metabolic kinetics of primary unconjugated BA and applied it to investigate the formation kinetics of novel secondary BA metabolites and their sequential pathways. We demonstrated (1) first-order depletion of primary BA, cholic acid (CA) and chenodeoxycholic acid (CDCA), under non-saturable conditions and (2) saturable Michaelis-Menten kinetics for secondary BA metabolite formation with increasing substrate concentration. Notably, relatively lower Michaelis constants (Km) were associated with the formation of deoxycholic acid (DCA, 14.3 μM) and lithocholic acid (LCA, 140 μM) versus 3-oxo CA (>1000 μM), 7-keto DCA (443 μM) and 7-keto LCA (>1000 μM), thereby recapitulating clinically observed saturation of 7α-dehydroxylation relative to oxidation of primary BA. Congruently, metagenomics revealed higher relative abundance of functional genes related to the oxidation pathway as compared to the 7α-dehydroxylation pathway. In addition, we demonstrated gut microbial-mediated hyocholic acid (HCA) and hyodeoxycholic acid (HDCA) formation from CDCA. In conclusion, we optimized a physiologically relevant ex vivo human faecal microbiota model to investigate gut microbial-mediated metabolism of primary BA and present a novel gut microbial-catalysed two-step pathway from CDCA to HCA and, subsequently, HDCA.

Recent solid-phase microextraction-based analytical approaches for the profiling of biliary bile acids in pre-transplant assessments of liver grafts subjected to normothermic ex vivo liver perfusion

BackgroundLiver transplantation is the definitive treatment for end-stage liver failure, but the scarcity of donor organs remains a significant challenge. Leveraging organs from extended criteria donors (ECD) offers a potential avenue to address worldwide shortages, though these organs are more susceptible to post-reperfusion injury. This study explores the use of normothermic ex vivo liver perfusion (NEVLP) as a method for organ preservation – an approach that sustains liver metabolism and facilitates pre-transplant assessments of organ viability via bile analysis. The focal point of this study revolves on the development of analytical methods for determining the bile acid profile throughout the peritransplantation period as a potential indicator of liver function and viability. ResultsThe study optimized and validated a high-throughput analytical method to quantify selected bile acids in bile samples using a thin-film microextraction-liquid chromatography-mass spectrometry (TFME-LC-MS) platform. Furthermore, it introduced a solid-phase microextraction-microfluidic open interface-mass spectrometry (SPME-MOI-MS) method for rapid direct analysis of bile acid isobar groups. In the animal study, discernible variations in the concentrations of specific bile acids were observed between donors after circulatory death (DCD) and heart-beating donors (HBD), particularly following normothermic perfusion and reperfusion. Noteworthy fluctuations in individual bile acid concentrations were observed throughout the entire organ transplantation process, with taurocholic acid (TCA), glycocholic acid (GCA), and glycochenodeoxycholic acid (GCDCA) emerging as promising indicators of organ quality. The efficacy of the SPME-MOI-MS platform in corroborating these trends highlights its potential for real-time bile acid analysis during liver transplantation procedures. SignificanceOur findings underscore the efficacy of NEVLP in tandem with advanced bile acid analysis methods as a reliable strategy for pre-transplant assessments of organ viability, potentially increasing the use of ECD organs and reducing organ shortages. The ability to monitor bile acid profiles in real-time provides crucial insights into liver function and ischemic injury, making significant strides in improving transplant outcomes and patient survival rates.