Modulation of Bile Acid Metabolism to Improve Plasma Lipid and Lipoprotein Profiles

Efficacy and Safety of Ileal Bile Acid Transport Inhibitors in Inherited Cholestatic Liver Disorders: A Meta-analysis of Randomized Controlled Trials

Background

Inherited cholestatic liver disorders such as progressive familial intrahepatic cholestasis (PFIC) and Alagille syndrome result in significant pruritus and increased serum bile acids, necessitating liver transplantation. This study aims to evaluate the efficacy and safety of Ileal bile acid transport inhibitors (IBATIs) in children with PFIC and Alagille syndrome.

Methods

We conducted a comprehensive search across the databases to identify relevant randomized controlled trials (RCTs), and Covidence was used to screen eligible articles. All outcomes data were synthesized using risk ratios (RRs) or mean differences (MDs) with 95% confidence intervals (CIs) in RevMan 5.4. PROSPERO: CRD42024564270.

Results

Four multicenter RCTs involving 215 patients were included. IBATIs were associated with a significant reduction in Itch Observer Reported Outcome (Itch (ObsRo)) score (MD: -0.90, 95% CI [-1.17, -0.63], P < 0.01), serum bile acids (MD: -119.06, 95% CI [-152.37, -85.74], P < 0.01), total bilirubin (MD: -0.73, 95% CI [-1.32, -0.15], P = 0.01), and increased proportion of patients achieving ≥1 score reduction in Itch (ObsRo) score (RR: 2.54, 95% CI [3.83, 1.69], P < 0.01) and bile acid responders (RR: 8.76, 95% CI [2.46, 31.23], P < 0.01) compared with placebo. No differences were observed in any treatment-emergent adverse events (TEAs) (RR: 1.02, 95% CI [1.12, 0.93], P = 0.71), TEAs leading to drug discontinuation (1.03, 95% CI [5.56, 0.19], any serious TEAs, or liver-related TEAs.

Conclusion

IBATIs showed significant improvement in various cholestatic parameters with tolerable safety profile; however, future research on optimal dosage and long-term outcomes is needed.

Reversal of insulin resistance in people with obesity by lifestyle-induced weight loss does not impact the proportion of circulating 12α-hydroxylated bile acids

AIM

Bile acids (BAs) are implicated in the pathogenesis of several metabolic syndrome-related diseases, including insulin resistance (IR) and type 2 diabetes (T2D). It has been reported that IR and T2D are associated with an increased ratio of 12α/non-12α-hydroxylated BAs in the circulating BA pool. It is, however, unknown whether the improvement of insulin sensitivity inversely affects BA composition in humans. Therefore, we assessed whether lifestyle-induced weight loss induces changes in BA metabolism in people with obesity, with or without T2D, and if these changes are associated with metabolic parameters.

MATERIALS AND METHODS

Individual BAs and C4 were quantified by ultra-high-performance liquid chromatography-tandem mass spectrometry in plasma samples collected from two cohorts of people with obesity (OB) and with T2D and obesity (T2D), before and after a lifestyle intervention.

RESULTS

Lifestyle-induced weight loss improved glycaemic control in both cohorts, with plasma BA concentrations not affected by the lifestyle interventions. The ratio of 12α/non-12α-hydroxylated BAs remained unchanged in OB (p = .178) and even slightly increased upon intervention in T2D (p = .0147). Plasma C4 levels were unaffected in OB participants (p = .20) but significantly reduced in T2D after intervention (p = .0003). There were no significant correlations between the ratio of 12α/non-12α-hydroxylated BAs and glucose, insulin, or homeostatic model assessment-IR, nor in plasma triglycerides, low-density lipoprotein cholesterol, lipoprotein (a) in the T2D cohort.

CONCLUSIONS

Lifestyle-induced weight loss did improve glycaemic control but did not affect BA concentrations. Improvements in insulin sensitivity were not associated with changes in BA parameters in people with obesity, with or without T2D.

Bifidobacterium longumBL-19 inhibits oxidative stress and inflammatory damage in the liver of mice with NAFLD by regulating the production of butyrate in the intestine

Nonalcoholic fatty liver disease (NAFLD) is a common chronic liver disease, but there is currently no effective treatment method. Probiotics have been used as an adjunct therapy for NAFLD, but the mechanism is not clear. This study used Bifidobacterium longum BL19 (BL-19) to treat the NAFLD mice induced by a high-fat diet, and explored the treatment mechanism through gut microbiota and serum metabolomics techniques. We found that BL-19 effectively prevented rapid weight gain in NAFLD mice and reduced their overall food and energy intake, decreased liver inflammatory factors expressions, and increased the bile acid synthetase enzyme CYP7A1 and superoxide dismutase. After BL-19 treatment, the abundances of butyric acid bacteria (Oscillospira and Coprococcus) in the feces of mice increased significantly, and the concentration of butyric acid also increased significantly. We believe that BL-19 promotes the production of butyrate in the intestines, which in turn regulates the activity of CYP7A1 in the liver and bile acid synthesis, ultimately treating liver inflammation and lipid accumulation in NAFLD mice. Serum metabolomics results indicated that BL-19 affected multiple pathways related to inflammation and lipid metabolism in NAFLD mice. These findings suggest that BL-19 shows promise as an adjunct therapy for NAFLD, as it can significantly improve oxidative stress, reduce inflammation in the liver, and decrease lipid accumulation.

Trends in Immediate Lymphatic Reconstruction

Background and objective Immediate lymphatic reconstruction (ILR) is emerging as a useful adjunct after axillary lymph node dissection (ALND), leading to a decrease in lymphedema rates from 30 to 3-13% in breast cancer patients. ILR requires coordination between two surgical specialties for oncologic ALND and microsurgical axillary lymphatic anastomosis. This study aimed to assess the trends in the frequency of ILR performed after ALND at our institution. Methods This study involved a retrospective review of breast cancer patients undergoing ALND with and without ILR at our institution (2017-2022). Data on patient demographics, tumor characteristics, and treatments received were gathered and analyzed. Results A total of 316 patients underwent ALND at our institution and 30.7% (97/316) of them received ILR. There was no significant difference in clinical breast cancer stages between patients who underwent ALND with or without ILR (p>0.05). Neoadjuvant chemotherapy was given to 51.1% (112/219) of patients with ALND only compared to 60.8% (59/97) of patients who underwent ALND with ILR (p=0.09). All patients received adjuvant radiation therapy. ILR was performed after ALND in 4.2% (2/47) in 2017, 25.8% (3/58) in 2018, 17.6% (12/68) in 2019, 35% (21/60) in 2020, 56.9% (41/72) in 2021, and 54.5% (6/11) in 2022. When comparing the first year of the ILR program with the last year of the study period, the odds ratio of receiving ILR after ALND was 1.8 (p=0.04). Conclusions The frequency of performing ILR after ALND in breast cancer patients at our institution witnessed a substantial increase during the study period. The implementation of an established ILR program at an institution can increase procedure uptake accompanied by continued growth in utilization.

Changes in bile acid composition are correlated with reduced intestinal cholesterol uptake in intestine-specific WASH-deficient mice

The Wiskott-Aldrich syndrome protein and SCAR homolog (WASH) complex is a pentameric protein complex localized at endosomes, where it facilitates the transport of numerous receptors from endosomes toward the plasma membrane. Recent studies have shown that the WASH complex plays an essential role in cholesterol and glucose homeostasis in humans and mice. To investigate the physiological importance of intestinal WASH, we ablated the WASH component WASHC1 specifically in murine enterocytes. Male and female intestine-specific WASHC1-deficient mice (Washc1IKO) were challenged with either a standard chow diet or a high-cholesterol (1.25 %) diet (HCD). Washc1IKO mice fed a standard diet did not present any apparent phenotype, but when fed an HCD, their hepatic cholesterol levels were ~ 50 % lower compared to those observed in control mice. The intestinal cholesterol absorption was almost 2-fold decreased in Washc1IKO mice, which translated into increased fecal neutral sterol loss. The intestinal expression of cholesterogenic genes, such as Hmgcs1, Hmgcr, and Ldlr, was significantly higher in Washc1IKO mice than in control mice and correlated with increased whole-body de novo cholesterol synthesis, likely to compensate for impaired intestinal cholesterol absorption. Unexpectedly, the ratio of biliary 12α-/non-12α-hydroxylated bile acids (BAs) was decreased in Washc1IKO mice and reversing this reduced ratio by feeding the mice with the HCD supplemented with 0.5 % (w/w) sodium cholate normalized the improvement of hepatic cholesterol levels in Washc1IKO mice. Our data indicate that the intestinal WASH complex plays an important role in intestinal cholesterol absorption, likely by modulating biliary BA composition.

High-Fat Diet-Induced Decreased Circulating Bile Acids Contribute to Obesity Associated with Gut Microbiota in Mice

The altered circulating bile acids (BAs) modulate gut microbiota, energy metabolism and various physiological functions. BA profiles in liver, serum, ileum and feces of HFD-fed mice were analyzed with normal chow diet (NCD)-fed mice after 16-week feeding. Furthermore, gut microbiota was analyzed and its correlation analysis with BA was performed. The result showed that long-term HFD feeding significantly decreased hepatic and serum BA levels, mainly attributed to the inhibition of hepatic BA synthesis and the reduced reabsorption efficiency of BAs in enterohepatic circulation. It also significantly impaired glucose and lipid homeostasis and gut microbiota in mice. We found significantly higher bile salt hydrolase activity in ileal microbes and a higher ratio of free BAs to conjugated BA content in ileal contents in HFD groups compared with NCD group mice, which might account for the activated intestinal farnesoid X receptor signaling on liver BA synthesis inhibition and reduced ileal reabsorption. The decreased circulating BAs were associated with the dysregulation of the lipid metabolism according to the decreased TGR5 signaling in the ileum and BAT. In addition, it is astonishing to find extremely high percentages of taurocholate and 12-OH BAs in liver and serum BA profiles of both groups, which was mainly attributed to the high substrate selectivity for 12-OH BAs of the intestinal BAs transporter during the ileal reabsorption of enterohepatic circulation. This study revealed a significant effect of long-term HFD feeding on the decreased circulating BA pool in mice, which impaired lipid homeostasis and gut microbiota, and collectively resulted in metabolic disorders and obesity.

The level of serum total bile acid is related to atherosclerotic lesions, prognosis and gut Lactobacillus in acute coronary syndrome patients

BACKGROUND

Bile acids play crucial roles in various metabolisms, as well as Lactobacillus in the intestine. But studies on their roles in acute coronary syndrome (ACS) are still insufficient. The aim of this study was to investigate their role and potential association with the severity of coronary lesions and the prognosis of ACS.

METHODS

Three hundred and sixty ACS patients were selected. Detection of gut Lactobacillus levels was done through 16S rDNA sequence analysis. Evaluation of the extent of lesions was done using the SYNTAX (SS) score. Mediation analysis was used to assess the relationship between serum total bile acid (TBA), Lactobacillus, atherosclerotic lesions and prognosis of ACS.

RESULTS

Logistic regressive analysis disclosed that serum TBA and Lactobacillus were independent predictors of coronary lesions (high vs. low SS: serum TBA adjusted odds ratio (aOR) = 0.8, 95% confidence interval (CI): 0.6-0.9, p < .01; Lactobacillus: aOR = 0.9, 95% CI: 0.9-1.0, p = .03). According to multivariate Cox regression analysis, they were negatively correlated with the overall risk of all-cause death (serum TBA: adjusted hazard ratio (aHR) = 0.1, 95% CI: 0.0-0.6, p = .02; Lactobacillus: aHR = 0.6, 95% CI: 0.4-0.9, p = .01), especially in acute myocardial infarction (AMI) but not in unstable angina pectoris (UAP). Ulteriorly, mediation analysis showed that serum TBA played an important role as a mediation effect in the following aspects: Lactobacillus (17.0%, p < .05) → SS association (per 1 standard deviation (SD) increase), Lactobacillus (43.0%, p < .05) → all-cause death (per 1 SD increase) and Lactobacillus (45.4%, p < .05) → cardiac death (per 1 SD increase).

CONCLUSIONS

The lower serum TBA and Lactobacillus level in ACS patients, especially in AMI, was independently linked to the risk of coronary lesions, all-cause death and cardiac death. In addition, according to our mediation model, serum TBA served as a partial intermediate in predicting coronary lesions and the risk of death by Lactobacillus, which is paramount to further exploring the mechanism of Lactobacillus and bile acids in ACS.KEY MESSAGESLower level of serum total bile acid (TBA) was highly associated with the severity of coronary lesions, myocardial damage, inflammation and gut Lactobacillus in acute coronary syndrome (ACS) patients, especially in acute myocardial infarction (AMI).Lower level of serum TBA was highly associated with mortality (including all-cause death and cardiac death) in patients with ACS, especially with AMI.Serum TBA had a partial mediating effect rather than regulating effect between gut Lactobacillus and coronary lesions and prognosis of ACS.

Inclisiran and cardiovascular events: a comprehensive review of efficacy, safety, and future perspectives

PURPOSE OF REVIEW

This review aims to offer an up-to-date evaluation of Inclisiran's (a small interfering RNA treatment) ability to decrease low-density lipoprotein cholesterol (LDL-C), as well as its safety and potential effects on decreasing cardiovascular risk.

RECENT FINDINGS

Inclisiran significantly lowers LDL-C levels, as shown by phase III studies, by inhibiting hepatic synthesis of proprotein convertase subtilisin kexin 9 (PCSK-9), a protein implicated in the degradation of LDL receptors. Inclisiran has the benefit of subcutaneous injection twice a year, which may reduce patient nonadherence when compared with other LDL-C reducing therapies such as statins and ezetimibe, which require daily dosing. When added on top of statins, a greater proportion of patients achieved recommended cholesterol goals. It has also demonstrated a good safety profile with few adverse effects.

SUMMARY

Inclisiran is a promising treatment for lowering LDL-C levels in people at high risk of atherosclerotic cardiovascular disease. It is a practical and well tolerated option for those who struggle to stick to medication regimes because of its twice-yearly dosage schedule and a good safety profile. Although it has been demonstrated to be effective in decreasing LDL-C, further research is needed to determine its impact on reducing cardiovascular events. Nonetheless, Inclisiran is a significant advancement in lipid-lowering medication and could improve patient outcomes.

Bile Acid Sequestration via Colesevelam Reduces Bile Acid Hydrophobicity and Improves Liver Pathology in Cyp2c70-/- Mice with a Human-like Bile Acid Composition

Bile acids (BAs) and their signaling pathways have been identified as therapeutic targets for liver and metabolic diseases. We generated Cyp2c70-/- (KO) mice that were not able to convert chenodeoxycholic acid into rodent-specific muricholic acids (MCAs) and, hence, possessed a more hydrophobic, human-like BA pool. Recently, we have shown that KO mice display cholangiopathic features with the development of liver fibrosis. The aim of this study was to determine whether BA sequestration modulates liver pathology in Western type-diet (WTD)-fed KO mice. The BA sequestrant colesevelam was mixed into the WTD (2% w/w) of male Cyp2c70+/+ (WT) and KO mice and the effects were evaluated after 3 weeks of treatment. Colesevelam increased fecal BA excretion in WT and KO mice and reduced the hydrophobicity of biliary BAs in KO mice. Colesevelam ameliorated diet-induced hepatic steatosis in WT mice, whereas KO mice were resistant to diet-induced steatosis and BA sequestration had no additional effects on liver fat content. Total cholesterol concentrations in livers of colesevelam-treated WT and KO mice were significantly lower than those of untreated controls. Of particular note, colesevelam treatment normalized plasma levels of liver damage markers in KO mice and markedly decreased hepatic mRNA levels of fibrogenesis-related genes in KO mice. Lastly, colesevelam did not affect glucose excursions and insulin sensitivity in WT or KO mice. Our data show that BA sequestration ameliorates liver pathology in Cyp2c70-/- mice with a human-like bile acid composition without affecting insulin sensitivity.

Effects of Atorvastatin on Bile Acid Metabolism in High-fat Diet-fed ApoE -/- Mice

ABSTRACT

Statins are considered as the cornerstone of the prevention and treatment of atherosclerotic cardiovascular disease, where pleiotropic effects are thought to contribute greatly in addition to the lipid-lowering effect. Bile acid metabolism has been gradually reported to be involved in the antihyperlipidemic and antiatherosclerotic effects of statins, but with inconsistent results and few studies carried out on animal models of atherosclerosis. The study aimed to examine the possible role of bile acid metabolism in the lipid-lowering and antiatherosclerotic effects of atorvastatin (ATO) in high-fat diet-fed ApoE -/- mice. The results showed that the levels of liver and faecal TC as well as ileal and faecal TBA were significantly increased in mice of the model group after 20 weeks of high-fat diet feeding compared with the control group, with significantly downregulated mRNA expression of liver LXR-α, CYP7A1, BSEP, and NTCP. ATO treatment further increased the levels of ileal and faecal TBA and faecal TC, but no obvious effect was observed on serum and liver TBA. In addition, ATO significantly reversed the mRNA levels of liver CYP7A1 and NTCP, and no obvious changes were observed in the expression of LXR-α and BSEP. Our study suggested that statins may enhance the synthesis of bile acids and facilitate the reabsorption of bile acids from the ileum via portal into the liver, possibly through the upregulation of the expression of CYP7A1 and NTCP. The results are helpful in enriching the theoretical basis for the clinical use of statins and have good translational value.

Bile Acids in Intrahepatic Cholestasis of Pregnancy

Intrahepatic cholestasis of pregnancy (ICP) is the most common, reversible, and closely related to pregnancy condition characterized by elevated levels of bile acids (BAs) in blood serum and an increased risk of adverse perinatal outcomes. Due to the complex interactions between the mother and the fetus in metabolism and transplacental BAs transport, ICP is classified as a fetal-maternal disease. The disease is usually mild in pregnant women, but it can be fatal to the fetus, leading to numerous complications, including intrauterine death. The pathophysiology of the disease is based on inflammatory mechanisms caused by elevated BA levels. Although ICP cannot be completely prevented, its early diagnosis and prompt management significantly reduce the risk of fetal complications, the most serious of which is unexpected intrauterine death. It is worth emphasizing that all diagnostics and management of ICP during pregnancy are based on BA levels. Therefore, it is important to standardize the criteria for diagnosis, as well as recommendations for management depending on the level of BAs, which undoubtedly determines the impact on the fetus. The purpose of this review is to present the potential and importance of BAs in the detection and rules of medical procedure in ICP.

The role of the gut microbiota in health and cardiovascular diseases

The gut microbiota is critical to human health, such as digesting nutrients, forming the intestinal epithelial barrier, regulating immune function, producing vitamins and hormones, and producing metabolites to interact with the host. Meanwhile, increasing evidence indicates that the gut microbiota has a strong correlation with the occurrence, progression and treatment of cardiovascular diseases (CVDs). In patients with CVDs and corresponding risk factors, the composition and ratio of gut microbiota have significant differences compared with their healthy counterparts. Therefore, gut microbiota dysbiosis, gut microbiota-generated metabolites, and the related signaling pathway may serve as explanations for some of the mechanisms about the occurrence and development of CVDs. Several studies have also demonstrated that many traditional and latest therapeutic treatments of CVDs are associated with the gut microbiota and its generated metabolites and related signaling pathways. Given that information, we summarized the latest advances in the current research regarding the effect of gut microbiota on health, the main cardiovascular risk factors, and CVDs, highlighted the roles and mechanisms of several metabolites, and introduced corresponding promising treatments for CVDs regarding the gut microbiota. Therefore, this review mainly focuses on exploring the role of gut microbiota related metabolites and their therapeutic potential in CVDs, which may eventually provide better solutions in the development of therapeutic treatment as well as the prevention of CVDs.

Hepatocellular carcinoma: Novel understandings and therapeutic strategies based on bile acids (Review)

Bile acids (BAs) are the major components of bile and products of cholesterol metabolism. Cholesterol is catalyzed by a variety of enzymes in the liver to form primary BAs, which are excreted into the intestine with bile, and secondary BAs are formed under the modification of the gut microbiota. Most of the BAs return to the liver via the portal vein, completing the process of enterohepatic circulation. BAs have an important role in the development of hepatocellular carcinoma (HCC), which may participate in the progression of HCC by recognizing receptors such as farnesoid X receptor (FXR) and mediating multiple downstream pathways. Certain BAs, such as ursodeoxycholic acid and obeticholic acid, were indicated to be able to delay liver injury and HCC progression. In the present review, the structure and function of BAs were introduced and the metabolism of BAs and the process of enterohepatic circulation were outlined. Furthermore, the mechanisms by which BAs participate in the development of HCC were summarized and possible strategies for targeting BAs and key sites of their metabolic processes to treat HCC were suggested.

An Updated Perspective on the Dual-Track Model of Enterocyte Fat Metabolism

The small intestinal epithelium has classically been envisioned as a conduit for nutrient absorption, but appreciation is growing for a larger and more dynamic role for enterocytes in lipid metabolism. Considerable gaps remain in our knowledge of this physiology, but it appears that the enterocyte's structural polarization dictates its behavior in fat partitioning, treating fat differently based on its absorption across the apical versus the basolateral membrane. In this review, we synthesize existing data and thought on this dual-track model of enterocyte fat metabolism through the lens of human integrative physiology. The apical track includes the canonical pathway of dietary lipid absorption across the apical brush-border membrane, leading to packaging and secretion of those lipids as chylomicrons. However, this track also reserves a portion of dietary lipid within cytoplasmic lipid droplets for later uses, including the "second-meal effect," which remains poorly understood. At the same time, the enterocyte takes up circulating fats across the basolateral membrane by mechanisms that may include receptor-mediated import of triglyceride-rich lipoproteins or their remnants, local hydrolysis and internalization of free fatty acids, or enterocyte de novo lipogenesis using basolaterally absorbed substrates. The ultimate destinations of basolateral-track fat may include fatty acid oxidation, structural lipid synthesis, storage in cytoplasmic lipid droplets, or ultimate resecretion, although the regulation and purposes of this basolateral track remain mysterious. We propose that the enterocyte integrates lipid flux along both of these tracks in order to calibrate its overall program of lipid metabolism.

Colesevelam - a bile acid sequestrant for treating hypercholesterolemia and improving hyperglycemia

INTRODUCTION

Low density Lipoprotein cholesterol)LDL-C) levels show a clear relationship with cardiovascular disease (CVD). Statins are first line agents to reduce LDL-C and CVD risk. However, combination lipid-lowering therapy is often required to achieve large reductions in LDL-C.

AREA COVERED

Colesevelam HCl is a bile acid sequestrant (BAS), which reduces LDL-C by 16-22% in monotherapy and adds a further 12-14% reduction in LDL-C when combined with other lipid-lowering drugs. Like statins, colesevelam reduces C-reactive protein levels by 16% in monotherapy and additional 6% when added to statins. Colesevelam also reduced HbA_1c by 4mmol/mol (0.5%) when used alone and added to other hypoglycaemic drugs in studies of patients with diabetes .

EXPERT OPINION

Bile acid sequestrants reduce LDL-C and HbA_1c and have some CVD outcome evidence. The uses of these agents are limited in patients with gastrointestinal disease or high triglycerides due to adverse effects on gut function and raising triglycerides and they interfere with the absorption of lipid-soluble drugs. Colesevelam has a higher bile acid binding capacity, and fewer adverse effects than other BAS. Colesevelam may be useful as a third line agent for treatment of hypercholesterolemia with some additional specific benefits on glycemic control.

Effects of Bile Acid Modulation by Dietary Fat, Cholecystectomy, and Bile Acid Sequestrant on Energy, Glucose, and Lipid Metabolism and Gut Microbiota in Mice

Bile acid metabolism, involved with the digestion and absorption of nutrients in the gut, is linked to the gut microbiota community, greatly impacting the host’s metabolism. We examined the hypothesis that the modulation of bile acid metabolism by dietary fat contents, gallbladder removal (GBX; cholecystectomy), and bile acid sequestrant (BAS; cholestyramine) treatment could alter energy, glucose, and lipid metabolism through the changes in the gut microbiota. Mice were randomly assigned to the following six groups: (1) Sham GBX surgery (Sham) + low fat/high carbohydrate diet (LFD), (2) Sham + high fat diet (HFD), (3) Sham + HFD + BAS, (4) GBX + LFD, (5) GBX + HFD, and (6) GBX + HFD + BAS. BAS groups received 2% cholestyramine. After an 8-week intervention, energy, glucose, and lipid metabolism, and the gut microbiota community were measured. HFD groups exhibited higher body weight gain than LFD, and GBX increased the weight gain comped to Sham groups regardless of BAS in HFD (p < 0.05). Homeostatic model assessment for insulin resistance (HOMA-IR) was higher in HFD than LFD, and GBX increased it regardless of BAS. Serum lipid profiles were worsened in GBX + HFD compared to Sham + LFD, whereas BAS alleviated them, except for serum HDL cholesterol. Hepatic tumor-necrosis-factor-α (TNF-α) mRNA expression and lipid peroxide contents increased with GBX and BAS treatment compared to Sham and no BAS treatment (p < 0.05). Hepatic mRNA expression of sterol regulatory element-binding transcription factor 1c (SREBP1c) and peroxisome proliferator-activated receptor gamma (PPAR-γ) exhibited the same trend as that of tumor necrosis factor-α (TNF-α). The α-diversity of gut bacteria decreased in GBX + HFD and increased in GBX + HFD + BAS. Akkermentia, Dehalobacterium, SMB53, and Megamonas were high in the Sham + LFD, and Veillonella and Streptococcus were rich in the Sham + HFD, while Oscillospira and Olsenella were high in Sham + HFD + BAS (p < 0.05). GBX + LFD increased Lactobacillus and Sutterella while GBX + HFD + BAS elevated Clostridium, Alistipes, Blautia, Eubacterium, and Coprobacillus (p < 0.05). In conclusion, the modulation of bile acid metabolism influences energy, glucose, and lipid metabolisms, and it might be linked to changes in the gut microbiota by bile acid metabolism modulation.

The Use of Machine Learning Algorithms and the Mass Spectrometry Lipidomic Profile of Serum for the Evaluation of Tacrolimus Exposure and Toxicity in Kidney Transplant Recipients

Tacrolimus has a narrow therapeutic window; a whole-blood trough target concentration of between 5 and 8 ng/mL is considered a safe level for stable kidney transplant recipients. Tacrolimus serum levels must be closely monitored to obtain a balance between maximizing efficacy and minimizing dose-related toxic effects. Currently, there is no specific tacrolimus toxicity biomarker except a graft biopsy. Our study aimed to identify specific serum metabolites correlated with tacrolinemia levels using serum high-precision liquid chromatography–mass spectrometry and standard laboratory evaluation. Three machine learning algorithms were used (Naïve Bayes, logistic regression, and Random Forest) in 19 patients with high tacrolinemia (8 ng/mL) and 23 patients with low tacrolinemia (5 ng/mL). Using a selected panel of five lipid metabolites (phosphatidylserine, phosphatidylglycerol, phosphatidylethanolamine, arachidyl palmitoleate, and ceramide), Mg2+, and uric acid, all three machine learning algorithms yielded excellent classification accuracies between the two groups. The highest classification accuracy was obtained by Naïve Bayes, with an area under the curve of 0.799 and a classification accuracy of 0.756. Our results show that using our identified five lipid metabolites combined with Mg2+ and uric acid serum levels may provide a novel tool for diagnosing tacrolimus toxicity in kidney transplant recipients. Further validation with targeted MS and biopsy-proven TAC toxicity is needed.

The Role of Bile Acids in Cardiovascular Diseases: from Mechanisms to Clinical Implications

Bile acids (BAs), key regulators in the metabolic network, are not only involved in lipid digestion and absorption but also serve as potential therapeutic targets for metabolic disorders. Studies have shown that cardiac dysfunction is associated with abnormal BA metabolic pathways. As ligands for several nuclear receptors and membrane receptors, BAs systematically regulate the homeostasis of metabolism and participate in cardiovascular diseases (CVDs), such as myocardial infarction, diabetic cardiomyopathy, atherosclerosis, arrhythmia, and heart failure. However, the molecular mechanism by which BAs trigger CVDs remains controversial. Therefore, the regulation of BA signal transduction by modulating the synthesis and composition of BAs is an interesting and novel direction for potential therapies for CVDs. Here, we mainly summarized the metabolism of BAs and their role in cardiomyocytes and noncardiomyocytes in CVDs. Moreover, we comprehensively discussed the clinical prospects of BAs in CVDs and analyzed the clinical diagnostic and application value of BAs. The latest development prospects of BAs in the field of new drug development are also prospected. We aimed to elucidate the underlying mechanism of BAs treatment in CVDs, and the relationship between BAs and CVDs may provide new avenues for the prevention and treatment of these diseases.