Circulating bile acids as a link between the gut microbiota and cardiovascular health: impact of prebiotics, probiotics and polyphenol-rich foods

The individual response to antibiotics and diet - insights into gut microbial resilience and host metabolism

Antibiotic use disrupts microbial composition and activity in humans, but whether this disruption in turn affects host metabolic health is unclear. Cohort studies show associations between antibiotic use and an increased risk of developing obesity and type 2 diabetes mellitus. Here, we review available clinical trials and show the disruptive effect of antibiotic use on the gut microbiome in humans, as well as its impact on bile acid metabolism and microbial metabolites such as short-chain fatty acids. Placebo-controlled human studies do not show a consistent effect of antibiotic use on body weight and insulin sensitivity at a population level, but rather an individual-specific or subgroup-specific response. This response to antibiotic use is affected by the resistance and resilience of the gut microbiome, factors that determine the extent of disruption and the speed of recovery afterwards. Nutritional strategies to improve the composition and functionality of the gut microbiome, as well as its recovery after antibiotic use (for instance, with prebiotics), require a personalized approach to increase their efficacy. Improved insights into key factors that influence the individual-specific response to antibiotics and dietary intervention may lead to better efficacy in reversing or preventing antibiotic-induced microbial dysbiosis as well as strategies for preventing cardiometabolic diseases.

Dietary supplements: clinical cholesterol-lowering efficacy and potential mechanisms of action

This review aims to analyse the efficacy of dietary supplements in reducing plasma cholesterol levels. Focusing on evidence from meta-analyses of randomised controlled clinical trials, with an emphasis on potential mechanisms of action as supported by human, animal, and cell studies. Certain dietary supplements including phytosterols, berberine, viscous soluble dietary fibres, garlic supplements, soy protein, specific probiotic strains, and certain polyphenol extracts could significantly reduce plasma total and low-density lipoprotein (LDL) cholesterol levels by 3-25% in hypercholesterolemic patients depending on the type of supplement. They tended to be more effective in reducing plasma LDL cholesterol level in hypercholesterolemic individuals than in normocholesterolemic individuals. These supplements worked by various mechanisms, such as enhancing the excretion of bile acids, inhibiting the absorption of cholesterol in the intestines, increasing the expression of hepatic LDL receptors, suppressing the activity of enzymes involved in cholesterol synthesis, and activating the adenosine monophosphate-activated protein kinase signalling pathway.

Structural and functional alteration of the gut microbiota in elderly patients with hyperlipidemia

Objective

To investigate the structure, composition, and functions of the gut microbiota in elderly patients with hyperlipidemia.

Methods

Sixteen older patients diagnosed with hyperlipidemia (M group) and 10 healthy, age-matched normal volunteers (N group) were included. These groups were further subdivided by sex into the male normal (NM, n = 5), female normal (NF, n = 5), male hyperlipidemia (MM, n = 8), and female hyperlipidemia (MF, n = 8) subgroups. Stool samples were collected for high-throughput sequencing of 16S rRNA genes. Blood samples were collected for clinical biochemical index testing.

Results

Alpha- and beta-diversity analyses revealed that the structure and composition of the gut microbiota were significantly different between the M and N groups. The relative abundances of Bacteroides, Parabacteroides, Blautia, Peptococcus, and Bifidobacterium were significantly decreased, while those of Lactobacillus, Helicobacter, and Desulfovibrio were significantly higher in the M group. There were also significant sex-related differences in microbial structure between the NM and NF groups, and between the MM and MF groups. Through functional prediction with PICRUSt 2, we observed distinct between-group variations in metabolic pathways associated with the gut microbiota and their impact on the functionality of the nervous system. Pearson's correlation coefficient was used as a distance metric to build co-abundance networks. A hypergeometric test was used to detect taxonomies with significant enrichment in specific clusters. We speculated that modules with Muribaculaceae and Lachnospiraceae as the core microbes play an important ecological role in the intestinal microbiota of the M group. The relative intestinal abundances of Agathobacter and Faecalibacterium in the M group were positively correlated with serum triglyceride and low-density lipoprotein levels, while the relative abundance of Bifidobacterium was negatively correlated with the serum lipoprotein a level.

Dietary fiber: Still alive

Dietary fiber (DF) was established as a key dietary constituent some decades ago, as were some of its mechanisms of action and health effects. Although there is consolidated evidence on many features regarding DF, at the same time there are still many aspects to be explored in the field, e.g., deeper explorations of the contribution of phenolic compounds linked to cell walls to the biological activities of DF, or of the relevance of the gut-brain axis. At the same time, increasing DF intake should be seen as a major public health problem since worldwide intakes are quite far from recommendations. The awareness of this fact by public bodies should lead, among others, to the assessment of effective strategies for promoting DF intake among general population or specific groups; and to consider potential regulatory modifications in order to clarify several aspects potentially misleading for consumers.

Anthocyanins from Lycium ruthenicum Murray attenuates high-fat diet-induced hypercholesterolemia in ApoE-/- mice are related to the modulation of gut microbiota and the ratio of conjugated to unconjugated bile acids in fecal bile acid profile

Previous findings showed that anthocyanins from Lycium ruthenicum Murray (ACN) reduced HFD-induced hypercholesterolemia by regulating gut microbiota, but the mechanism has not been fully understood. The objective of this research was to know whether the cholesterol-lowering impact of ACN in HFD-induced ApoE-/- mice is related to the gut microbiota-bile acid (BA) metabolism. Twenty-four male ApoE-/- mice were divided into three groups: the Control group, the HFD group, and the HFD + ACN group. Here, we showed that ACN intervention reduced HFD-induced body weight serum concentrations of TC and LDL-C and ameliorated lipid accumulation in the liver and adipose tissues. Besides, ACN altered gut microbiota composition in HFD-fed ApoE-/- mice. Moreover, UHPLC-MS/MS analysis revealed that ACN intervention significantly increased the ratio of conjugated to unconjugated BAs in feces induced by HFD, attributed to the increase in conjugated BAs and decrease in unconjugated BAs. Finally, the correlation analysis indicated that the above changes in fecal BA profile were linked with an increase in Bifidobacterium, Allobaculum and a decrease in Ileibacterium, Helicobacter, Rikenellaceae_RC9_gut_group, Blautia, Odoribacter, and Colidextribacter. In summary, ACN could alleviate HFD-induced hypercholesterolemia in ApoE-/- mice, which was associated with the improvement of gut microbiota and modulation of fecal BA profile.

Ginsenoside Rb1, Compound K and 20(S)-Protopanaxadiol Attenuate High-Fat Diet-Induced Hyperlipidemia in Rats via Modulation of Gut Microbiota and Bile Acid Metabolism

Hyperlipidemia, characterized by elevated serum lipid concentrations resulting from lipid metabolism dysfunction, represents a prevalent global health concern. Ginsenoside Rb1, compound K (CK), and 20(S)-protopanaxadiol (PPD), bioactive constituents derived from Panax ginseng, have shown promise in mitigating lipid metabolism disorders. However, the comparative efficacy and underlying mechanisms of these compounds in hyperlipidemia prevention remain inadequately explored. This study investigates the impact of ginsenoside Rb1, CK, and PPD supplementation on hyperlipidemia in rats induced by a high-fat diet. Our findings demonstrate that ginsenoside Rb1 significantly decreased body weight and body weight gain, ameliorated hepatic steatosis, and improved dyslipidemia in HFD-fed rats, outperforming CK and PPD. Moreover, ginsenoside Rb1, CK, and PPD distinctly modified gut microbiota composition and function. Ginsenoside Rb1 increased the relative abundance of Blautia and Eubacterium, while PPD elevated Akkermansia levels. Both CK and PPD increased Prevotella and Bacteroides, whereas Clostridium-sensu-stricto and Lactobacillus were reduced following treatment with all three compounds. Notably, only ginsenoside Rb1 enhanced lipid metabolism by modulating the PPARγ/ACC/FAS signaling pathway and promoting fatty acid β-oxidation. Additionally, all three ginsenosides markedly improved bile acid enterohepatic circulation via the FXR/CYP7A1 pathway, reducing hepatic and serum total bile acids and modulating bile acid pool composition by decreasing primary/unconjugated bile acids (CA, CDCA, and β-MCA) and increasing conjugated bile acids (TCDCA, GCDCA, GDCA, and TUDCA), correlated with gut microbiota changes. In conclusion, our results suggest that ginsenoside Rb1, CK, and PPD supplementation offer promising prebiotic interventions for managing HFD-induced hyperlipidemia in rats, with ginsenoside Rb1 demonstrating superior efficacy.

Polysaccharides from Phellinus linteus attenuate type 2 diabetes mellitus in rats via modulation of gut microbiota and bile acid metabolism

Type 2 diabetes mellitus (T2DM) is the most prevalent metabolic disorder. Polysaccharides from Phellinus linteus (PLP) have been found to have anti-diabetes effects, but the mechanism has not been elucidated. The purpose of this study was to investigate the mechanism of PLP on T2DM through the gut microbiota and bile acids metabolism. The T2DM rat model was induced by a high-fat high-carbohydrate (HFHC) diet and streptozocin (30 mg/kg). We found that PLP ameliorated diabetes symptoms. Besides, PLP intervention increased the abundance of g_Bacteroides, g_Parabacteroides, and g_Alistioes, which are associated with the biosynthesis of short-chain fatty acids (SCFAs) and bile acids (BAs) metabolism. Meanwhile, untargeted and targeted metabolomics indicated that PLP could regulate the composition of BAs and increase the levels of SCFAs. Real-time quantitative PCR (RT-qPCR) and enzyme-linked immunosorbent assay (ELISA) were performed to analyze the expression levels of BAs metabolism enzymes in the liver. Finally, the results of correlation analysis and Glucagon-like peptide-1 (GLP-1) showed that PLP stimulated the release of GLP-1 by regulating SCFAs and BAs. In conclusion, this study demonstrated that PLP can regulate gut microbiota and BAs metabolism to promote GLP-1 secretion, thereby increasing insulin release, decreasing blood glucose and attenuating T2DM.

Structure-activity relationship of Caulerpa lentillifera polysaccharide in inhibiting lipid digestion

Caulerpa lentillifera polysaccharide (CLP) has been characterized as a sulfated polysaccharide which can effectively inhibit lipid digestion. However, little information was known regarding its inhibitory mechanisms. In the present study, desulfation and degradation were conducted to prepare the derivatives of CLP, and a series of chemical and spectroscopic methods were used to elucidate the structure-activity relationship of CLP on the inhibitory effect of lipid digestion. Results revealed that CLP possessed excellent binding capacities for sodium cholate, sodium glycocholate, and sodium taurocholate. In addition, CLP can effectively inhibit lipase activity by quenching the fluorescence intensity, changing the secondary structure, and decreasing the UV-Vis absorbance. Of note, sulfate groups in CLP took a vital role in inhibiting lipase activity, while the molecular weight of CLP showed a positive correlation with the binding activities of bile acids. Furthermore, adding CLP into the whey protein isolate (WPI) emulsion system also impeded lipid digestion, indicating that CLP can be a potential reduced-fat nutraceutical used in food emulsion systems.

Lacticaseibacillus chiayiensis mediate intestinal microbiome and microbiota-derived metabolites regulating the growth and immunity of chicks

Emerging evidence confirms beneficial properties of probiotics in promoting growth and immunity of farmed chicken. However, the molecular mechanisms underlying the host-microbiome interactions mediated by probiotics are not fully understood. In this study, the internal mechanisms of Lacticaseibacillus chiayiensis-mediated host-microbiome interactions and to elucidate how it promotes host growth were investigated by additional supplementation with L. chiayiensis. We conducted experiments, including intestinal cytokines, digestive enzymes test, intestinal microbiome, metabolome and transcriptome analysis. The results showed that chickens fed L. chiayiensis exhibited higher body weight gain and digestive enzyme activity, and lower pro-inflammatory cytokines, compared to controls. Microbiota sequencing analysis showed that the gut microbiota structure was reshaped with L. chiayiensis supplementation. Specifically, Lactobacillus and Escherichia increased in abundance and Enterococcus, Lactococcus, Corynebacterium, Weissella and Gallicola decreased. In addition, the bacterial community diversity was significantly increased compared to controls. Metabolomic and transcriptomic analyses revealed that higher bile acids and N-acyl amides concentrations and lower carbohydrates concentrations in L. chiayiensis-fed chickens. Meanwhile, the expression of genes related to nutrient transport and absorption in the intestine was upregulated, which reflected the enhanced digestion and absorption of nutrients in chickens supplemented with L. chiayiensis. Moreover, supplementation of L. chiayiensis down-regulated genes involved in inflammation-related, mainly involved in NF-κB signaling pathway and MHC-II mediated antigen presentation process. Cumulatively, these findings highlight that host-microbiota crosstalk enhances the host growth phenotype in two ways: by enhancing bile acid metabolism and digestive enzyme activity, and reducing the occurrence of intestinal inflammation to promote nutrient absorption and maintain intestinal health. This provides a basis for the application of LAB as an alternative to antibiotics in animal husbandry.

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.

Bile acids metabolism involved in the beneficial effects of Danggui Shaoyao San via gut microbiota in the treatment of CCl4 induced hepatic fibrosis

ETHNOPHARMACOLOGICAL RELEVANCE

Danggui Shaoyao San (DSS) is a traditional Chinese medicine (TCM) first recorded in the Synopsis of the Golden Chamber. DSS has proven efficacy in treating hepatic fibrosis (HF). However, the effects and mechanisms of DSS on HF are not clear.

AIM OF THE STUDY

To investigate the effect of DSS on HF via gut microbiota and its metabolites (SCFAs, BAs).

MATERIALS AND METHODS

HF rats were induced with CCl4 and treated with DSS. Firstly, the therapeutic efficacy of DSS in HF rats and the protection of gut barrier were assessed. Then, 16S rRNA gene sequencing and untargeted fecal metabolomics preliminarily explored the mechanism of DSS in treating HF, and identified different microbiota and metabolic pathways. Finally, targeted metabolomics and RT-qPCR were used to further validate the mechanism of DSS for HF based on the metabolism of SCFAs and BAs.

RESULTS

After 8 weeks of administration, DSS significantly reduced the degree of HF. In addition, DSS alleviated inflammation in the ileum and reduced the levels of LPS and D-lactate. Furthermore, DSS altered the structure of gut microbiota, especially Veillonella, Romboutsia, Monoglobus, Parabacteroides, norank_f_Coriobacteriales_Incertae_Sedis. These bacteria have been linked to the production of SCFAs and the metabolism of BAs. Untargeted metabolomics suggested that DSS may play a role via BAs metabolism. Subsequently, targeted metabolomics and RT-qPCR further confirmed the key role of DSS in increasing SCFAs levels and regulating BAs metabolism.

CONCLUSIONS

DSS can alleviate CCl4-induced HF and protect the gut barrier. DSS may exert its beneficial effects on HF by affecting the gut microbiota and its metabolites (SCFAs, BAs).

The supplementation of the multi-strain probiotics WHHPRO™ alleviates high-fat diet-induced metabolic symptoms in rats via gut-liver axis

Metabolic syndrome (MS) has emerged as one of the major global health concerns, accompanied by a series of related complications, such as obesity and type-2 diabetes. The gut-liver axis (GLA) is a bidirectional communication between the gut and the liver. The GLA alterations have been revealed to be closely associated with the development of MS. Probiotics within Lactobacillus and Bifidobacterium confer beneficial effects on improving MS symptoms. WHHPRO™ is a mixture of four probiotic strains, with potential MS-improving abilities. This study aimed to investigate the effects of WHHPRO™ on MS symptoms using a high-fat diet (HFD) rat model. Oral administration of WHHPRO™ for 12 weeks improved glucose tolerance, blood lipid, body weight, and liver index in HFD rats. WHHPRO™ shaped the gut microbiome composition by increasing the abundance of Lactobacillus and Akkermansia and normalized the reduced SCFA levels in HFD rats. Besides, WHHPRO™ modulated the fecal bile acids (BAs) profile, with decreased levels of T-b-MCA and 12-KDCA and increased levels of LCA and ILCA. Meanwhile, WHHPRO™ increased total unconjugated BAs in feces and liver and reduced the accumulation of total hepatic BA pool size in HFD rats. Moreover, WHHPRO™ reversed the expression of genes associated with impaired BA metabolism signaling in the ileum and liver. Our findings suggest that WHHPRO™ exerted beneficial effects on improving MS symptoms, involving the modulation of the gut microbiome composition, SCFAs, and the FXR-FGF15 signaling along the GLA. Supplementation of WHHPRO™ may serve as a novel strategy for improving MS symptoms.

Heat-moisture treatment enhances the ordered degree of starch structure in whole chestnut flour and alters its gut microbiota modulation in mice fed with high-fat diet

Currently, chestnuts attract more attention among consumers due to its rich nutritional functions, but systematic evaluation on the effect of thermal processing on its nutritional value is still limited. In this work, based on results of microstructural properties that heat-moisture treatment (HMT) could enhance the total ordered degree of starch structure in whole chestnut flour (CN) and promote the formation of anti-enzymatic component, in vitro experiment was then conducted and confirmed that HMT could significantly reduce the predicted glycemic index (pGI) of CN from 75.6 to 64.3 and improve its dietary fiber content from 7.06 to 13.42 g/100 g (p < 0.05). Further dietary intervention studies with CN and heat-moisture treated CN (HMT-CN) supplementation on the high-fat diet (HFD) consuming mice were discussed in terms of gut microbiota and its metabolites changes. The results showed that both CN and HMT-CN significantly resisted the weight gain induced by HFD, while HMT-CN had better serum lipid regulation effect. However, they had different effects on the gut metabolism pathways, among which CN inhibited the production of stearamine by promoting the proliferation of Dubosiella, while HMT-CN contributed to the growth of Lachnoclostridium, Desulfovibrio, and Faecalibaculum which stimulated the formation of associated metabolites including jwh-018-d11, valylproline, tetranor-12(S)-HETE, and PA (3:0/18:0). Overall, these discoveries could provide basic data for the effective utilization of CN in food industry processing.

Biodegradation of Cholesterol by Enterococcus faecium YY01

Cholesterol (CHOL) is one of the risk factors causing the blockage of the arterial wall, atherosclerosis, coronary heart disease, and other serious cardiovascular diseases. Here, a promising bacterial strain for biodegrading CHOL was successfully isolated from the gut of healthy individuals and identified as Enterococcus faecium YY01 with an analysis of the 16S rDNA sequence. An initial CHOL of 1.0 g/L was reduced to 0.5 g/L in 5 days, and glucose and beef extract were found to be optimal carbon and nitrogen sources for the rapid growth of YY01, respectively. To gain further insight into the mechanisms underlying CHOL biodegradation, the draft genome of YY01 was sequenced using Illumina HiSeq. Choloylglycine hydrolase, acyltransferase, and alkyl sulfatase was encoded by gene0586, gene1890, and gene2442, which play crucial roles in converting 3α, 7α, 12α-trihydroxy-5β-choranic acid to choline-CoA and then choline-CoA to bile acid. Notably, choloylglycine hydrolase was closely related to the biosynthesis of both primary and secondary bile acid. The findings of this study provide valuable insights into the metabolism pathway of CHOL biodegradation by YY01 and offer a potential avenue for the development of bacterioactive drugs against hypercholesterolemia.

Olive Oil Polyphenols Improve HDL Cholesterol and Promote Maintenance of Lipid Metabolism: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

In 2011, the European Food Safety Authority (EFSA) accorded a health claim to olive oil polyphenols in that they protected LDL particles from oxidative damage. However, limited scientific evidence has so far failed to confer any claim of function on the maintenance of normal lipid metabolism. We performed a systematic review and meta-analysis of human RCTs, evaluating the effect of olive oil polyphenol administration on lipid profiles. Previous literature was acquired from six electronic databases until June 2023. A total of 75 articles were retrieved and screened for inclusion criteria, which resulted in the selection of 10 RCTs that evaluated the effect of daily exposure to olive oil polyphenols on serum lipids in adults. Meta-analyses were built by tertiles of outcomes, as follows: low (0-68 mg/kg), medium (68-320 mg/kg), and high (320-600 mg/kg) polyphenols for HDL and LDL cholesterol (HDL-C and LDL-C, respectively), and low (0-59.3 mg/kg), medium (59.3-268 mg/kg), and high (268-600 mg/kg) polyphenols for total cholesterol (TC). The study protocol was registered on PROSPERO (registration code: CRD42023403383). The study design was predominantly cross-over (n = 8 of 10) but also included parallel (n = 2 of 10). The study population was predominantly European and healthy. Daily consumption of olive oil polyphenols did not affect TC levels and only slightly significantly reduced LDL-C, with WMD statistically significant only for high daily consumption of olive oil polyphenols (WMD -4.28, 95%CI -5.78 to -2.77). Instead, our data found a statistically significant HDL-C enhancing effect (WMD pooled effect model: 1.13, 95%CI 0.45; 1.80, heterogeneity 38%, p = 0.04) with WMD by daily exposure level showing a statistically significant improvement effect for low (WMD 0.66, 95%CI 0.10-1.23), medium (WMD 1.36, 95%CI 0.76-1.95), and high (WMD 1.13, 95%CI 0.45-1.80) olive oil polyphenol consumptions. Olive oil polyphenols contribute toward maintaining lipid metabolism. Thus, food labeling regulations should stress this health feature of olive oil, whereby a declaration of the olive oil polyphenol content should be added to products on the market. Consumers need to be aware of the quality and possible health effects of any products they consume, and enforcement of nutrition labels offers the best way of providing this information.

Dairy Intake Modifies the Level of the Bile Acid Precursor and Its Correlation with Serum Proteins Associated with Cholesterol Clearance in Subjects with Hyperinsulinemia

Bile acids regulate glucose homeostasis and lipid metabolism. Further, the levels of bile acids can be influenced by the intake of dairy products. Although the serum proteome can provide information on the biological pathways associated with different metabolites, it is unknown whether the intake of dairy modifies such associations between bile acids and the proteome. The objectives of this study were to examine plasma bile acid profiles, find the correlations between bile acids and lipid as well as glycemic markers, and to uncover the correlation between bile acids and proteins after high dairy (HD) and adequate dairy (AD) intake among 25 overweight individuals with hyperinsulinemia. In this randomized crossover-trial study, hyperinsulinemia adults were randomized to both HD (≥4 servings/day) and AD (≤2 servings/day) for 6 weeks. Measurements and analyses were performed on before- as well as after- AD and HD conditions. The results indicated that plasma 7α-hydroxy-4-cholesten-3-one (7AC4) increased after HD in comparison with before HD intake (p = 0.03). After adjusting for BMI, age, and sex, 7AC4 positively correlated with triglyceride levels in the pre-AD (r = 0.44; p = 0.03) and post-HD (r = 0.42; p = 0.04). Further, 7AC4 correlated positively with proteins associated with high-density lipoprotein particle remodeling pathway and reverse cholesterol transport only after HD consumption. Thus, the consumption of higher dairy intake modifies the association between 7AC4-a biomarker for bile acid synthesis-and serum proteins involved in cholesterol clearance. Overall, higher dairy consumption may have a positive effect on cholesterol metabolism in subjects at risk of type 2 diabetes.

Dietary polyphenols maintain homeostasis via regulating bile acid metabolism: a review of possible mechanisms

The synthesis and metabolism of bile acids (BAs) have been implicated in various metabolic diseases, including obesity and diabetes. Dietary polyphenols, as natural antioxidants, play a vital role in synthesizing and metabolizing bile acids. This paper reviews the mechanism of dietary polyphenols involved in bile acid (BA) synthesis and metabolism. The impact of different gut microorganisms on BA profiles is discussed in detail. The regulation of BA metabolism by dietary polyphenols can be divided into two modes: (1) dietary polyphenols directly activate/inhibit farnesol X receptor (FXR) and Takeda G protein-coupled receptor (TGR5); (2) dietary polyphenols regulate BA synthesis and metabolism through changes in intestinal microorganisms. Research on direct activation/inhibition of FXR and TGR5 by polyphenols should be ramped up. In addition, the effect of dietary polyphenols on intestinal microorganisms has been paid more and more attention and has become a target that cannot be ignored.

High-Performance Liquid Chromatography-Mass Spectrometry-based Metabolic Profiling of Adult Growth Hormone Deficiency

CONTEXT

Patients with adult growth hormone deficiency (AGHD) are at increased risk of metabolic syndrome. Metabolic profiles in AGHD patients have been insufficiently evaluated.

OBJECTIVE

This work aims to explore serum metabolite profiles by metabolomics analysis and assess potential metabolites associated with recombinant human growth hormone (rhGH) treatment.

METHODS

Thirty-one AGHD patients and 31 healthy controls were enrolled. Untargeted ultra-performance liquid chromatography-coupled mass spectroscopy was conducted in all patients and controls at baseline and during 12 months of rhGH treatment in 11 AGHD patients. Data were processed by principal component analysis, variable importance in projection scoring, orthogonal partial least squares-discriminant analysis, and MetaboAnalyst 5.0. We further explored the associations between metabolites and clinical parameters.

RESULTS

Metabolomics indicated a distinct metabolic pattern between AGHD patients and healthy controls. The perturbed pathways mainly include the biosynthesis of unsaturated fatty acids, sphingolipid metabolism, glycerophospholipid metabolism, fatty acid elongation, degradation, and biosynthesis. rhGH treatment increased the levels of specific glycerophospholipids compounds and reduced fatty acid ester compounds. Significant correlations existed between the 40 identified metabolites and insulin-like growth factor-1 SD score (IGF-1 SDS), body composition, and glucose and lipid metabolism plasma markers. During rhGH treatment, there was a statistically significant negative correlation between deoxycholic acid glycine conjugate and waist-to-hip ratio, while a statistically significant positive correlation existed between decanoylcarnitine and serum low-density lipoprotein levels.

CONCLUSION

AGHD patients have unique metabolomic profiles. rhGH treatment alters the serum levels of several fatty acid compounds/amino acids, which may contribute to the improvement of metabolic status in AGHD patients.

How Do Minerals, Vitamins, and Intestinal Microbiota Affect the Development and Progression of Heart Disease in Adult and Pediatric Patients?

Cardiovascular diseases (CVDs) are the leading cause of death worldwide, far ahead of cancer. Epidemiological data emphasize the participation of many risk factors that increase the incidence of CVDs, including genetic factors, age, and sex, but also lifestyle, mainly nutritional irregularities and, connected with them, overweight and obesity, as well as metabolic diseases. Despite the importance of cardiovascular problems in the whole society, the principles of prevention of CVDs are not widely disseminated, especially among the youngest. As a result, nutritional neglect, growing from childhood and adolescence, translates into the occurrence of numerous disease entities, including CVDs, in adult life. This review aimed to draw attention to the role of selected minerals and vitamins in health and the development and progression of CVDs in adults and children. Particular attention was paid to the effects of deficiency and toxicity of the analyzed compounds in the context of the cardiovascular system and to the role of intestinal microorganisms, which by interacting with nutrients, may contribute to the development of cardiovascular disorders. We hope this article will draw the attention of society and the medical community to emphasize promoting healthy eating and proper eating habits in children and adults, translating into increased awareness and a reduced risk of CVD.

Marine Chitosan-Oligosaccharide Ameliorated Plasma Cholesterol in Hypercholesterolemic Hamsters by Modifying the Gut Microflora, Bile Acids, and Short-Chain Fatty Acids

This study evaluated the cholesterol-alleviating effect and underlying mechanisms of chitosan-oligosaccharide (COS) in hypercholesterolemic hamsters. Male hamsters (n = 24) were divided into three groups in a random fashion, and each group was fed one particular diet, namely a non-cholesterol diet (NCD), a high-cholesterol diet (HCD), and an HCD diet substituting 5% of the COS diet for six weeks. Subsequently, alterations in fecal bile acids (BAs), short-chain fatty acids (SCFAs), and gut microflora (GM) were investigated. COS intervention significantly reduced and increased the plasma total cholesterol (TC) and high-density lipoprotein-cholesterol (HDL-C) levels in hypercholesteremic hamsters. Furthermore, Non-HDL-C and total triacylglycerols (TG) levels were also reduced by COS supplementation. Additionally, COS could reduce and increase food intake and fecal SCFAs (acetate), respectively. Moreover, COS had beneficial effects on levels of BAs and GM related to cholesterol metabolism. This study provides novel evidence for the cholesterol-lowering activity of COS.

bsh1 Gene of Lactobacillus plantarum AR113 Plays an Important Role in Ameliorating Western Diet-Aggravated Colitis

Western diet is thought to increase susceptibility to inflammatory bowel disease (IBD), and probiotics are a potential therapeutic agent for IBD. This study revealed the effects of Lactobacillus plantarum AR113 and L. plantarum AR113Δbsh1 on a dextran sulfate sodium (DSS)-induced colitis mouse model under the Western diet (WD). After four weeks of WD and low-sugar and low-fat diet (LD) intervention, induction with 3% DSS, and intragastric administration of probiotics, we found that L. plantarum AR113 could regulate blood glucose and lipid levels and have a certain protective effect on hepatocytes. Our results suggested that the L. plantarum AR113 alleviated DSS-induced colitis under the Western diet by improving dyslipidemia, repairing intestinal barrier dysfunction, and inhibiting the TLR4/Myd88/TRAF-6/NF-κB inflammatory pathway. However, these changes were not demonstrated in the L. plantarum AR113Δbsh1, and therefore, we reasoned that the presence of bsh1 may play a crucial role in the L. plantarum AR113 exerting its anti-inflammatory function. The relationship between bile salt hydrolase (BSH) and colitis was worthy of further exploration.

Dietary Patterns, Gut Microbiota Remodeling, and Cardiometabolic Disease

The cardiovascular and metabolic disorders, collectively known as cardiometabolic disease (CMD), are high morbidity and mortality pathologies associated with lower quality of life and increasing health-care costs. The influence of the gut microbiota (GM) in dictating the interpersonal variability in CMD susceptibility, progression and treatment response is beginning to be deciphered, as is the mutualistic relation established between the GM and diet. In particular, dietary factors emerge as pivotal determinants shaping the architecture and function of resident microorganisms in the human gut. In turn, intestinal microbes influence the absorption, metabolism, and storage of ingested nutrients, with potentially profound effects on host physiology. Herein, we present an updated overview on major effects of dietary components on the GM, highlighting the beneficial and detrimental consequences of diet-microbiota crosstalk in the setting of CMD. We also discuss the promises and challenges of integrating microbiome data in dietary planning aimed at restraining CMD onset and progression with a more personalized nutritional approach.

Diets Enriched in Sugar, Refined, or Whole Grain Differentially Influence Plasma Cholesterol Concentrations and Cholesterol Metabolism Pathways with Concurrent Changes in Bile Acid Profile and Gut Microbiota Composition in ApoE-/- Mice

This study aimed to compare the effects of diets enriched in sugar, refined grain (RG), or whole grain (WG) on circulating cholesterol concentrations and established and emerging mechanisms regulating cholesterol metabolism. Forty-four male ApoE^-/- mice aged 8 weeks were randomly fed an isocaloric sugar-, RG-, or WG-enriched diet for 12 weeks. Compared to WG-enriched diet, fasting plasma LDL-C and HDL-C concentrations were higher and the mRNA expression of intestinal LXR-α was lower in sugar- and RG-enriched diets; plasma TC, non-HDL-C, TG and VLDL-C concentrations, and cecal concentrations of lithocholic acid were higher and the mRNA expression of intestinal ABCG5 was lower in sugar-enriched diet, and the mRNA expression of hepatic IDOL and cecal concentrations of lithocholic and deoxycholic acids was higher in RG-enriched diet. The relative abundance of Akkermansia, Clostridia_UCG-014, Alistipes, and Alloprevotella, which were lower in sugar- and/or RG- than in WG-enriched diet, had inverse correlations with fasting plasma cholesterol concentrations or cecal concentrations of secondary bile acids and positive correlations with gene expressions in intestinal cholesterol efflux. Conversely, the relative abundance of Lactobacillus, Lachnoclostridium, Lachnospiraceae_NK4A136_group, Colidextribacter, and Helicobacter had reverse correlations. Both sugar- and RG-enriched diets had unfavorable effects on cholesterol concentrations; yet, their effects on the gene expressions of cholesterol efflux, uptake, bile acid synthesis, and bile acid concentrations were distinctive and could be partially attributable to the concurrent changes in gut microbiota.

A Novel Symbiotic Formulation Reduces Obesity and Concomitant Metabolic Syndrome in Rats by Raising the Relative Abundance of Blautia

Obesity is regarded as an abnormal or excessive buildup of fat that may be bad for health and is influenced by a combination of intestinal flora, genetic background, physical activity level and environment. Symbiotic supplementation may be a realistic and easy therapy for the reversal of obesity and associated metabolic problems. In this study, we chose two Bifidobacterium species, three Lactobacilli species and four prebiotics to make a new symbiotic formulation. High or low doses of the symbiotic were administered to rats, and biochemical indicators were recorded to assess the biological effects in a high-fat-diet-induced rat model. The underlying mechanisms were explored by integrating 16S rRNA sequencing with an extensively targeted metabolome. High-dose symbiotic supplementation was effective in reducing obesity and concomitant metabolic syndrome. The high-dose symbiotic also significantly increased the abundance of Blautia, which was negatively correlated with taurocholic acid and the main differential metabolites involved in amino acid and bile acid metabolism. While the low-dose symbiotic had some therapeutic effects, they were not as strong as those at the high dose, demonstrating that the effects were dose-dependent. Overall, our novel symbiotic combination improved plasma glucose and lipid levels, shrunk adipocyte size, restored liver function, increased the abundance of Blautia and adjusted bile acid and amino acid metabolism.

The Gut Microbiome, Microbial Metabolites, and Cardiovascular Disease in People Living with HIV

PURPOSE OF REVIEW

To synthesize recent evidence relating the gut microbiome and microbial metabolites to cardiovascular disease (CVD) in people living with HIV (PLWH).

RECENT FINDINGS

A few cross-sectional studies have reported on the gut microbiome and cardiovascular outcomes in the context of HIV, with no consistent patterns emerging. The largest such study found that gut Fusobacterium was associated with carotid artery plaque. More studies have evaluated microbial metabolite trimethylamine N-oxide with CVD risk in PLWH, but results were inconsistent, with recent prospective analyses showing null effects. Studies of other microbial metabolites are scarce. Microbial translocation biomarkers (e.g., lipopolysaccharide binding protein) have been related to incident CVD in PLWH. Microbial translocation may increase CVD risk in PLWH, but there is insufficient and/or inconsistent evidence regarding specific microbial species and microbial metabolites associated with cardiovascular outcomes in PLWH. Further research is needed in large prospective studies integrating the gut microbiome, microbial translocation, and microbial metabolites with cardiovascular outcomes in PLWH.

Dietary Strawberries Improve Serum Metabolites of Cardiometabolic Risks in Adults with Features of the Metabolic Syndrome in a Randomized Controlled Crossover Trial

Dietary strawberries have been shown to improve cardiometabolic risks in multiple clinical trials. However, no studies have reported effects on serum metabolomic profiles that may identify the target pathways affected by strawberries as underlying mechanisms. We conducted a 14-week randomized, controlled crossover study in which participants with features of metabolic syndrome were assigned to one of the three arms for four weeks separated by a one-week washout period: control powder, 1 serving (low dose: 13 g strawberry powder/day), or 2.5 servings (high dose: 32 g strawberry powder/day). Blood samples, anthropometric measures, blood pressure, and dietary and physical activity data were collected at baseline and at the end of each four-week phase of intervention. Serum samples were analyzed for primary metabolites and complex lipids using different mass spectrometry methods. Mixed-model ANOVA was used to examine differences in the targeted metabolites between treatment phases, and LASSO logistic regression was used to examine differences in the untargeted metabolites at end of the strawberry intervention vs. the baseline. The findings revealed significant differences in the serum branched-chain amino acids valine and leucine following strawberry intervention (high dose) compared with the low-dose and control phases. Untargeted metabolomic profiles revealed several metabolites, including serum phosphate, benzoic acid, and hydroxyphenyl propionic acid, that represented improved energy-metabolism pathways, compliance measures, and microbial metabolism of strawberry polyphenols, respectively. Thus, dietary supplementation of strawberries significantly improves the serum metabolic profiles of cardiometabolic risks in adults.

Gut microbiota and fecal metabolic signatures in rat models of disuse-induced osteoporosis

Background

Assessing the correlation between gut microbiota (GM) and bone homeostasis has increasingly attracted research interest. Meanwhile, GM dysbiosis has been found to be associated with abnormal bone metabolism. However, the function of GM in disuse-induced osteoporosis (DIO) remains poorly understood. In our research, we evaluated the characteristics of GM and fecal metabolomics to explore their potential correlations with DIO pathogenesis.

Methods

DIO rat models and controls (CON) underwent micro-CT, histological analyses, and three-point bending tests; subsequently, bone microstructures and strength were observed. ELISAs were applied for the measurement of the biochemical markers of bone turnover while GM abundance was observed using 16S rDNA sequencing. Metabolomic analyses were used to analyze alterations fecal metabolites. The potential correlations between GM, metabolites, and bone loss were then assessed.

Results

In the DIO group, the abundance of GM was significantly altered compared to that in the CON group. Moreover, DIO significantly altered fecal metabolites. More specifically, an abnormally active pathway associated with bile acid metabolism, as well as differential bacterial genera related to bone/tissue volume (BV/TV), were identified. Lithocholic acid, which is the main secondary bile acid produced by intestinal bacteria, was then found to have a relationship with multiple differential bacterial genera. Alterations in the intestinal flora and metabolites in feces, therefore, may be responsible for DIO-induced bone loss.

Conclusions

The results indicated that changes in the abundance of GM abundance and fecal metabolites were correlated with DIO-induced bone loss, which might provide new insights into the DIO pathogenesis. The detailed regulatory role of GM and metabolites in DIO-induced bone loss needs to be explored further.

Chardonnay Marc as a New Model for Upcycled Co-products in the Food Industry: Concentration of Diverse Natural Products Chemistry for Consumer Health and Sensory Benefits

Research continues to provide compelling insights into potential health benefits associated with diets rich in plant-based natural products (PBNPs). Coupled with evidence from dietary intervention trials, dietary recommendations increasingly include higher intakes of PBNPs. In addition to health benefits, PBNPs can drive flavor and sensory perceptions in foods and beverages. Chardonnay marc (pomace) is a byproduct of winemaking obtained after fruit pressing that has not undergone fermentation. Recent research has revealed that PBNP diversity within Chardonnay marc has potential relevance to human health and desirable sensory attributes in food and beverage products. This review explores the potential of Chardonnay marc as a valuable new PBNP ingredient in the food system by combining health, sensory, and environmental sustainability benefits that serves as a model for development of future ingredients within a sustainable circular bioeconomy. This includes a discussion on the potential role of computational methods, including artificial intelligence (AI), in accelerating research and development required to discover and commercialize this new source of PBNPs.

The anti-aging effects of Renshen Guben on thyrotoxicosis mice: Improving immunosenescence, hypoproteinemia, lipotoxicity, and intestinal flora

With the rapid aging of the population, the control of age-related disease susceptibility and prognosis faces greater challenges. There is an urgent need for a strategy to maintain the vitality of elderly people. In this study, the effect of Renshen Guben (RSGB) oral liquid was investigated on an accelerated aging mice model of thyrotoxicosis by conventional detection methods combined with multiomics technology. The results showed that RSGB increased the number of neutrophils and lymphocytes, enhanced the function of lymphocytes, and increased the levels of complement and antimicrobial peptides, which indicated that RSGB improved the immunity of thyrotoxicosis mice at the cellular and molecular levels. RSGB corrected malnutrition in thyrotoxicosis mice by improving anemia, hypoalbuminemia, ion transporters, and vitamin-binding proteins. RSGB significantly reduced the lipotoxicity by reducing the level of fatty acids, triglyceride, sphingolipids, and glucocorticoids, thus increasing the level of docosapentaenoic acid (DPA) and bile acids, which contributed to improve immunosenescence. The intestinal defense ability of thyrotoxicosis mice was enhanced with the increase of bile acids and lactic acid bacteria by the RSGB treatment. The plant metabolomics analysis showed that there were various active components in RSGB oral liquid and medicated serum, including terpenoids, phenolic acids, flavonoids, tannin, alkaloids, organic acids, phenolamines, amino acids, and others. They have antioxidant, immune regulation, and anti-aging effects, which was the material basis of RSGB. Totally, RSGB protected the thyrotoxicosis mice against aging by improving immunosenescence, hypoproteinemia, lipotoxicity, and the intestinal flora. It will be beneficial for improving the disease susceptibility and prognosis of the elderly.

Bile acids-gut microbiota crosstalk contributes to the improvement of type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) occurs that cannot effectively use the insulin. Insulin Resistance (IR) is a significant characteristic of T2DM which is also an essential treatment target in blood glucose regulation to prevent T2DM and its complications. Bile acids (BAs) are one group of bioactive metabolites synthesized from cholesterol in liver. BAs play an important role in mutualistic symbiosis between host and gut microbiota. It is shown that T2DM is associated with altered bile acid metabolism which can be regulated by gut microbiota. Simultaneously, BAs also reshape gut microbiota and improve IR and T2DM in the bidirectional communications of the gut-liver axis. This article reviewed the findings on the interaction between BAs and gut microbiota in improving T2DM, which focused on gut microbiota and its debinding function and BAs regulated gut microbiota through FXR/TGR5. Meanwhile, BAs and their derivatives that are effective for improving T2DM and other treatments based on bile acid metabolism were also summarized. This review highlighted that BAs play a critical role in the glucose metabolism and may serve as therapeutic targets in T2DM, providing a reference for discovering and screening novel therapeutic drugs.

The impact of castration on physiological responses to exertional heat stroke in mice

INTRODUCTION

The capability of male mice to exercise in hot environments without succumbing to exertional heat stroke (EHS) is markedly blunted compared to females. Epidemiological evidence in humans and other mammals also suggests some degree of greater vulnerability to heat stroke in males compared to females. The origins of these differences are unknown, but testosterone has previously been shown to induce faster elevations in core temperature during acute, passive heat exposure. In this study, we tested the hypothesis that loss of testosterone and related sex hormones through castration would improve the performance and heat tolerance of male mice during EHS exposure.

METHODS

Twenty-four male mice were randomly divided into 3 groups, untreated EHS mice (SHAM-EHS), castrated EHS mice (CAS+EHS) and naïve exercise controls (NAIVE). Exercise performance and physiological responses in the heat were monitored during EHS and early recovery. Two weeks later, blood and tissues were collected and analyzed for biomarkers of cardiac damage and testosterone.

RESULTS

Core temperature in CAS+EHS rose faster to 39.5°C in the early stages of the EHS trial (P<0.0001). However, both EHS groups ran similar distances, exhibited similar peak core temperatures and achieved similar exercise times in the heat, prior to symptom limitation (unconsciousness). CAS+EHS mice had ~10.5% lower body mass at the time of EHS, but this provided no apparent advantage in performance. There was no evidence of myocardial damage in any group, and testosterone levels were undetectable in CAS+EHS after gonadectomy.

CONCLUSIONS

The results of these experiments exclude the hypothesis that reduced performance of male mice during EHS trials is due to the effects of male sex hormones or intact gonads. However, the results are consistent with a role of male sex hormones or intact gonads in suppressing the early and rapid rise in core temperature during the early stages of exercise in the heat.

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.

Impact of Blueberry Consumption on the Human Fecal Bileacidome: A Pilot Study of Bile Acid Modulation by Freeze-Dried Blueberry

Cholesterol-derived bile acids (BAs) affect numerous physiological functions such as glucose homeostasis, lipid metabolism and absorption, intestinal inflammation and immunity, as well as intestinal microbiota diversity. Diet influences the composition of the BA pool. In the present study, we analyzed the impact of a dietary supplementation with a freeze-dried blueberry powder (BBP) on the fecal BA pool composition. The diet of 11 men and 13 women at risk of metabolic syndrome was supplemented with 50 g/day of BBP for 8 weeks, and feces were harvested before (pre) and after (post) BBP consumption. BAs were profiled using liquid chromatography coupled with tandem mass spectrometry. No significant changes in total BAs were detected when comparing pre- vs. post-BBP consumption samples. However, post-BBP consumption samples exhibited significant accumulations of glycine-conjugated BAs (p = 0.04), glycochenodeoxycholic (p = 0.01), and glycoursodeoxycholic (p = 0.01) acids, as well as a significant reduction (p = 0.03) in the secondary BA levels compared with pre-BBP feces. In conclusion, the fecal bileacidome is significantly altered after the consumption of BBP for 8 weeks. While additional studies are needed to fully understand the underlying mechanisms and physiological implications of these changes, our data suggest that the consumption of blueberries can modulate toxic BA elimination.

Dietary Modulation of the Human Gut Microbiota and Metabolome with Flaxseed Preparations

Flaxseeds are typically consumed either as whole flaxseed, ground flaxseed, flaxseed oil, partially defatted flaxseed meal, or as a milk alternative. They are considered a rich source of vitamins, minerals, proteins and peptides, lipids, carbohydrates, lignans, and dietary fiber, which have shown hypolipidemic, antiatherogenic, anticholesterolemic, and anti-inflammatory property activity. Here, an in vitro batch culture model was used to investigate the influence of whole milled flaxseed and partially defatted milled flaxseed press cake on the gut microbiota and the liberation of flaxseed bioactives. Microbial communities were profiled using 16S rRNA gene-based high-throughput sequencing with targeted mass spectrometry measuring lignan, cyclolinopeptide, and bile acid content and HPLC for short-chain fatty acid profiles. Flaxseed supplementation decreased gut microbiota richness with Firmicutes, Proteobacteria, and Bacteroidetes becoming the predominant phyla. Secoisolariciresinol, enterodiol, and enterolactone were rapidly produced with acetic acid, butyric acid, and propionic acid being the predominant acids after 24 h of fermentation. The flaxseed press cake and whole flaxseed were equivalent in microbiota changes and functionality. However, press cake may be superior as a functional additive in a variety of foods in terms of consumer acceptance as it would be more resistant to oxidative changes.

Regular exercise combined with ferulic acid exhibits antiobesity effect and regulates metabolic profiles in high-fat diet-induced mice

Exercise (Ex) has been recognized as an effective way of obesity prevention, but it shows a dual effect on the body's antioxidant system. Ferulic acid (FA) is a kind of phenolic acid with well-known antioxidant capacity and numerous health benefits. Therefore, the aim of the study was to compare the antiobesity effect of Ex, FA, and Ex combined with FA (Ex-FA) in vivo and to illustrate the potential mechanisms. Mice were fed a high-fat diet (HFD) with or without administration of Ex, FA, and Ex-FA for 13 weeks. The body weight, antioxidant ability, Ex performance, and lipid profiles in the serum, liver, and skeletal muscle were compared among the groups, and serum metabolomics analysis was conducted. The results showed that Ex, FA, and Ex-FA exhibited a similar effect on body weight management. Ex had a more beneficial function by alleviating HFD-induced dyslipidemia than FA, while FA exerted a more efficient effect in mitigating lipid deposition in the liver and skeletal muscle. Ex-FA showed comprehensive effects in the regulation of the lipid contents in serum, liver, and skeletal muscle, and provoked enhancement effects on antioxidant ability and Ex capacity. Mice administered with Ex, FA, and Ex-FA showed different metabolic profiles, which might be achieved through different metabolic pathways. The findings of this research implied that Ex coupled with FA could become an effective and safe remedy for the management of dietary-induced obesity.

Ultra-performance chromatography-electrospray tandem mass spectrometry analysis of bile acid profiles in the enterohepatic circulation following geniposide and acetaminophen-induced liver injury

Bile acids (BAs) play an important role in pre-diagnosing drug-induced liver injury (DILI). However, in clinical practice, different types of liver injury are characterized by different pathogeneses and pathological manifestations. Therefore, whether BAs can be used as biomarkers across different DILIs remains unclear. In this study, an ultra-performance chromatography-mass spectrometry (MS)/MS-based technique was developed for the simultaneous quantitative analysis of 31 BAs in the serum, liver, feces, urine, and intestinal contents of rats treated with acetaminophen (APAP) and geniposide to induce liver injury. The total extraction recovery for representative analytes ranged between 80.60% and 99.23% in the serum, urine, liver, feces, and intestinal contents. The correlation coefficients for all standard curves of the different matrices were at least 0.99. Validation of the BA analytical method including selectivity, residue, lower limit of quantification, accuracy, precision, matrix effect, and stability conformed with the biospecimen quality control standards of the Chinese Pharmacopoeia (version 2020). Serum biochemical and pathohistological analyses revealed APAP- and geniposide-induced hepatocellular and cholestatic DILI, respectively, with different effects on BA profiles in the enterohepatic circulation. Metabolomics further revealed that the trends in BA changes in the serum, feces, urine, and intestinal tissues were consistent between the geniposide- and APAP-treated groups. However, in the liver, the total BAs (TBA) concentration increased by 1.70 fold in the geniposide group but decreased by 43% in the APAP group compared with the control group. Multivariate analysis revealed differentially expressed BAs, including TCA, CA, and GCA, which are potential biomarkers for DILI, in the serum, liver, and urine following treatment with geniposide. Interestingly, the differentially expressed BAs in the APAP group were similar to those in the control group. Additionally, the magnitude of changes in the TBA in the urine (3.3 fold and 15.5 fold in the APAP and geniposide groups, respectively) was higher than that in the blood (290 fold and 640 fold in the APAP and geniposide groups, respectively). However, given the BA profiles after geniposide- and APAP-induced liver injury, BAs were found to be more suitable as biomarkers for diagnosing cholestatic liver injury. Overall, the BA assay developed in this study is rapid, simple, accurate, validated, sensitive, and suitable for analyzing the levels and distribution of BAs in various parts of the enterohepatic circulation.

Gut Microbiota and Sex Hormones: Crosstalking Players in Cardiometabolic and Cardiovascular Disease

The available evidence indicates a close connection between gut microbiota (GM) disturbance and increased risk of cardiometabolic (CM) disorders and cardiovascular (CV) disease. One major objective of this narrative review is to discuss the key contribution of dietary regimen in determining the GM biodiversity and the implications of GM dysbiosis for the overall health of the CV system. In particular, emerging molecular pathways are presented, linking microbiota-derived signals to the local activation of the immune system as the driver of a systemic proinflammatory state and permissive condition for the onset and progression of CM and CV disease. We further outline how the cross-talk between sex hormones and GM impacts disease susceptibility, thereby offering a mechanistic insight into sexual dimorphism observed in CVD. A better understanding of these relationships could help unravel novel disease targets and pave the way to the development of innovative, low-risk therapeutic strategies based on diet interventions, GM manipulation, and sex hormone analogues.

Exercise and Interorgan Communication: Short-Term Exercise Training Blunts Differences in Consecutive Daily Urine 1H-NMR Metabolomic Signatures between Physically Active and Inactive Individuals

Physical inactivity is a worldwide health problem, an important risk for global mortality and is associated with chronic noncommunicable diseases. The aim of this study was to explore the differences in systemic urine ¹H-NMR metabolomes between physically active and inactive healthy young males enrolled in the X-Adapt project in response to controlled exercise (before and after the 3-day exercise testing and 10-day training protocol) in normoxic (21% O₂), normobaric (~1000 hPa) and normal-temperature (23 °C) conditions at 1 h of 50% maximal pedaling power output (W_peak) per day. Interrogation of the exercise database established from past X-Adapt results showed that significant multivariate differences existed in physiological traits between trained and untrained groups before and after training sessions and were mirrored in significant differences in urine pH, salinity, total dissolved solids and conductivity. Cholate, tartrate, cadaverine, lysine and N6-acetyllisine were the most important metabolites distinguishing trained and untrained groups. The relatively little effort of 1 h 50% W_peak per day invested by the untrained effectively modified their resting urine metabolome into one indistinguishable from the trained group, which hence provides a good basis for the planning of future recommendations for health maintenance in adults, irrespective of the starting fitness value. Finally, the 3-day sessions of morning urine samples represent a good candidate biological matrix for future delineations of active and inactive lifestyles detecting differences unobservable by single-day sampling due to day-to-day variability.

Bile Acid Detection Techniques and Bile Acid-Related Diseases

Bile acid is a derivative of cholinergic acid (steroidal parent nucleus) that plays an important role in digestion, absorption, and metabolism. In recent years, bile acids have been identified as signaling molecules that regulate self-metabolism, lipid metabolism, energy balance, and glucose metabolism. The detection of fine changes in bile acids caused by metabolism, disease, or individual differences has become a research hotspot. At present, there are many related techniques, such as enzyme analysis, immunoassays, and chromatography, that are used for bile acid detection. These methods have been applied in clinical practice and laboratory research to varying degrees. However, mainstream detection technology is constantly updated and replaced with the passage of time, proffering new detection technologies. Previously, gas chromatography (GS) and gas chromatography-mass spectrometry (GC-MS) were the most commonly used for bile acid detection. In recent years, high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) has developed rapidly and has gradually become the mainstream bile acid sample separation and detection technology. In this review, the basic principles, development and progress of technology, applicability, advantages, and disadvantages of various detection techniques are discussed and the changes in bile acids caused by related diseases are summarized.

Chlorogenic Acid Inhibits Lipid Deposition by Regulating the Enterohepatic FXR-FGF15 Pathway

Aim

Chlorogenic acid (CGA) is a natural polyphenolic compound found in human dietary products. Previous studies have confirmed that CGA has many biological activities, such as regulating glucose and lipid metabolism and improving insulin resistance. However, its underlying mechanisms of action remains unclear. Here, we demonstrate the protective effects and molecular mechanisms of action of CGA in reducing weight gain and hyperlipidemia in mice fed with a high-fat diet (HFD).

Methods and Results

C57BL/6 mice were fed with normal chow or HFD; half of the mice in each group received CGA treatment by oral gavage for 16 weeks. CGA treatment was found to significantly inhibit HFD-induced weight gain and hyperlipidemia and increased energy expenditure by promoting the expression of genes involved in thermogenesis and mitochondrial biogenesis. Furthermore, CGA was shown to inhibit the enterohepatic farnesoid X receptor (FXR) fibroblast growth factor 15 (FGF15) pathway and changes serum bile acid (BA) pool, thereby contributing to the increased expression of cholesterol 7 α-hydroxylase (CYP7A1).

Conclusions

CGA increases the metabolic elimination of cholesterol by inhibiting the enterohepatic FXR/FGF15 pathway.

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.

Bile Acids as Key Modulators of the Brain-Gut-Microbiota Axis in Alzheimer's Disease

Recently, the concept of the brain-gut-microbiota (BGM) axis disturbances in the pathogenesis of Alzheimer's disease (AD) has been receiving growing attention. At the same time, accumulating data revealing complex interplay between bile acids (BAs), gut microbiota, and host metabolism have shed new light on a potential impact of BAs on the BGM axis. The crosstalk between BAs and gut microbiota is based on reciprocal interactions since microbiota determines BA metabolism, while BAs affect gut microbiota composition. Secondary BAs as microbe-derived neuroactive molecules may affect each of three main routes through which interactions within the BGM axis occur including neural, immune, and neuroendocrine pathways. BAs participate in the regulation of multiple gut-derived molecule release since their receptors are expressed on various cells. The presence of BAs and their receptors in the brain implies a direct effect of BAs on the regulation of neurological functions. Experimental and clinical data confirm that disturbances in BA signaling are present in the course of AD. Disturbed ratio of primary to secondary BAs as well as alterations in BA concertation in serum and brain samples have been reported. An age-related shift in the gut microbiota composition associated with its decreased diversity and stability observed in AD patients may significantly affect BA metabolism and signaling. Given recent evidence on BA neuroprotective and anti-inflammatory effects, new therapeutic targets have been explored including gut microbiota modulation by probiotics and dietary interventions, ursodeoxycholic acid supplementation, and use of BA receptor agonists.