Bile acid metabolism and the pathogenesis of type 2 diabetes

The Gut Microbiota and Diabetes: Research, Translation, and Clinical Applications-2023 Diabetes, Diabetes Care, and Diabetologia Expert Forum

This article summarizes the state of the science on the role of the gut microbiota (GM) in diabetes from a recent international expert forum organized by Diabetes, Diabetes Care, and Diabetologia, which was held at the European Association for the Study of Diabetes 2023 Annual Meeting in Hamburg, Germany. Forum participants included clinicians and basic scientists who are leading investigators in the field of the intestinal microbiome and metabolism. Their conclusions were as follows: 1) the GM may be involved in the pathophysiology of type 2 diabetes, as microbially produced metabolites associate both positively and negatively with the disease, and mechanistic links of GM functions (e.g., genes for butyrate production) with glucose metabolism have recently emerged through the use of Mendelian randomization in humans; 2) the highly individualized nature of the GM poses a major research obstacle, and large cohorts and a deep-sequencing metagenomic approach are required for robust assessments of associations and causation; 3) because single-time point sampling misses intraindividual GM dynamics, future studies with repeated measures within individuals are needed; and 4) much future research will be required to determine the applicability of this expanding knowledge to diabetes diagnosis and treatment, and novel technologies and improved computational tools will be important to achieve this goal.

The gut microbiota and diabetes: research, translation, and clinical applications - 2023 Diabetes, Diabetes Care, and Diabetologia Expert Forum

This article summarises the state of the science on the role of the gut microbiota (GM) in diabetes from a recent international expert forum organised by Diabetes, Diabetes Care, and Diabetologia, which was held at the European Association for the Study of Diabetes 2023 Annual Meeting in Hamburg, Germany. Forum participants included clinicians and basic scientists who are leading investigators in the field of the intestinal microbiome and metabolism. Their conclusions were as follows: (1) the GM may be involved in the pathophysiology of type 2 diabetes, as microbially produced metabolites associate both positively and negatively with the disease, and mechanistic links of GM functions (e.g. genes for butyrate production) with glucose metabolism have recently emerged through the use of Mendelian randomisation in humans; (2) the highly individualised nature of the GM poses a major research obstacle, and large cohorts and a deep-sequencing metagenomic approach are required for robust assessments of associations and causation; (3) because single time point sampling misses intraindividual GM dynamics, future studies with repeated measures within individuals are needed; and (4) much future research will be required to determine the applicability of this expanding knowledge to diabetes diagnosis and treatment, and novel technologies and improved computational tools will be important to achieve this goal.

The Gut Microbiota and Diabetes: Research, Translation, and Clinical Applications-2023 Diabetes, Diabetes Care, and Diabetologia Expert Forum

This article summarizes the state of the science on the role of the gut microbiota (GM) in diabetes from a recent international expert forum organized by Diabetes, Diabetes Care, and Diabetologia, which was held at the European Association for the Study of Diabetes 2023 Annual Meeting in Hamburg, Germany. Forum participants included clinicians and basic scientists who are leading investigators in the field of the intestinal microbiome and metabolism. Their conclusions were as follows: 1) the GM may be involved in the pathophysiology of type 2 diabetes, as microbially produced metabolites associate both positively and negatively with the disease, and mechanistic links of GM functions (e.g., genes for butyrate production) with glucose metabolism have recently emerged through the use of Mendelian randomization in humans; 2) the highly individualized nature of the GM poses a major research obstacle, and large cohorts and a deep-sequencing metagenomic approach are required for robust assessments of associations and causation; 3) because single-time point sampling misses intraindividual GM dynamics, future studies with repeated measures within individuals are needed; and 4) much future research will be required to determine the applicability of this expanding knowledge to diabetes diagnosis and treatment, and novel technologies and improved computational tools will be important to achieve this goal.

The Antidiabetic Potential of Probiotics: A Review

Diabetes has become one of the most prevalent global epidemics, significantly impacting both the economy and the health of individuals. Diabetes is associated with numerous complications, such as obesity; hyperglycemia; hypercholesterolemia; dyslipidemia; metabolic endotoxemia; intestinal barrier damage; insulin-secretion defects; increased oxidative stress; and low-grade, systemic, and chronic inflammation. Diabetes cannot be completely cured; therefore, current research has focused on developing various methods to control diabetes. A promising strategy is the use of probiotics for diabetes intervention. Probiotics are a class of live, non-toxic microorganisms that can colonize the human intestine and help improve the balance of intestinal microbiota. In this review, we summarize the current clinical studies on using probiotics to control diabetes in humans, along with mechanistic studies conducted in animal models. The primary mechanism by which probiotics regulate diabetes is improved intestinal barrier integrity, alleviated oxidative stress, enhanced immune response, increased short-chain fatty acid production, etc. Therefore, probiotic supplementation holds great potential for the prevention and management of diabetes.

Alteration of Fecal Microbiota, Fecal Metabolites, and Serum Metabolites in Dairy Cows with Pre-Retained Placenta

Retained placenta (RP) affects lactation and fertility in dairy cows and causes economic losses to the dairy industry. Therefore, screening for early warning of this disease is important. This study used multi omics techniques to reveal the metabolic differences of dairy cows before RP onset and to find potential warning markers. Fecal samples and serum samples of 90 healthy Holstein cows were collected 7 days pre-calving; 10 healthy and 10 RP cows were enrolled according to normal expulsion of fetal membranes after calving. Fecal samples were subjected to 16S rRNA sequencing and untargeted metabolomics analysis, while plasma was analyzed using targeted metabolomics. Pathogenic bacteria levels increased in the intestines of cows with RP compared to those in healthy cows. Lipid metabolites constituted the largest proportion of differential metabolites between feces and plasma. Six potential warning markers for RP in cows were identified, including two fecal microbiomics markers (Oscillospiraceae UCG-005 and Escherichia-Shigella), one fecal untargeted metabolomics marker (N-acetylmuramic acid), and three plasma targeted metabolomics markers (glycylcholic acid-3 sulfate, 7-ketolithocholic acid, and 12-ketolithocholic acid). These biomarkers can predict RP occurrence in the early perinatal period. These results lay a theoretical foundation for early nutritional intervention and pathogenesis research in dairy cows.

Ji-Ni-De-Xie ameliorates type 2 diabetes mellitus by modulating the bile acids metabolism and FXR/FGF15 signaling pathway

Introduction: Ji-Ni-De-Xie (JNDX) is a traditional herbal preparation in China. It is widely used to treat type 2 diabetes mellitus (T2DM) in traditional Tibetan medicine system. However, its antidiabetic mechanisms have not been elucidated. The aim of this study is to elucidate the underlying mechanism of JNDX on bile acids (BAs) metabolism and FXR/FGF15 signaling pathway in T2DM rats. Methods: High-performance liquid chromatography-triple quadrupole mass spectrometry (HPLC-QQQ-MS) and UPLC-Q-Exactive Orbitrap MS technology were used to identify the constituents in JNDX. High-fat diet (HFD) combined with streptozotocin (45 mg∙kg-1) (STZ) was used to establish a T2DM rat model, and the levels of fasting blood-glucose (FBG), glycosylated serum protein (GSP), homeostasis model assessment of insulin resistance (HOMA-IR), LPS, TNF-α, IL-1β, IL-6, TG, TC, LDL-C, HDL-C, and insulin sensitivity index (ISI) were measured to evaluate the anti-diabetic activity of JNDX. In addition, metagenomic analysis was performed to detect changes in gut microbiota. The metabolic profile of BAs was analyzed by HPLC-QQQ-MS. Moreover, the protein and mRNA expressions of FXR and FGF15 in the colon and the protein expressions of FGF15 and CYP7A1 in the liver of T2DM rats were measured by western blot and RT-qPCR. Results: A total of 12 constituents were identified by HPLC-QQQ-MS in JNDX. Furthermore, 45 chemical components in serum were identified from JNDX via UPLC-Q-Exactive Orbitrap MS technology, including 22 prototype components and 23 metabolites. Using a T2DM rat model, we found that JNDX (0.083, 0.165 and 0.33 g/kg) reduced the levels of FBG, GSP, HOMA-IR, LPS, TNF-α, IL-1β, IL-6, TG, TC, and LDL-C, and increased ISI and HDL-C levels in T2DM rats. Metagenomic results demonstrated that JNDX treatment effectively improved gut microbiota dysbiosis, including altering some bacteria (e.g., Streptococcus and Bacteroides) associated with BAs metabolism. Additionally, JNDX improved BAs disorder in T2DM rats, especially significantly increasing cholic acid (CA) levels and decreasing ursodeoxycholic acid (UDCA) levels. Moreover, the protein and mRNA expressions of FXR and FGF15 of T2DM rats were significantly increased, while the expression of CYP7A1 protein in the liver was markedly inhibited by JNDX. Discussion: JNDX can effectively improve insulin resistance, hyperglycemia, hyperlipidemia, and inflammation in T2DM rats. The mechanism is related to its regulation of BAs metabolism and activation of FXR/FGF15 signaling pathway.

The Effect of Coenzyme Q10 Supplementation on Bile Acid Metabolism: Insights from Network Pharmacology, Molecular Docking, and Experimental Validation

SCOPE

Bile acids play a crucial role in lipid absorption and the regulation of lipid, glucose, and energy homeostasis. Coenzyme Q10 (CoQ10), a lipophilic antioxidant, has been recognized for its positive effects on obesity and related glycolipid metabolic disorders. However, the relationship between CoQ10 and bile acids has not yet been evaluated.

METHODS AND RESULTS

This study assesses the impact of CoQ10 treatment on bile acid metabolism in mice on a high-fat diet using Ultra-Performance Liquid Chromatography-tandem Mass Spectrometry. CoQ10 reverses the reduction in serum and colonic total bile acid levels and alters the bile acid profile in mice that are caused by a high-fat diet. Seventeen potential targets of CoQ10 in bile acid metabolism are identified by network pharmacology, with six being central to the mechanism. Molecular docking shows a high binding affinity of CoQ10 to five of these key targets. Further analyses indicate that farnesoid X (FXR) receptor and Takeda G-protein coupled receptor 5 (TGR5) may be crucial targets for CoQ10 to regulate bile acid metabolism and exert beneficial effects.

CONCLUSION

This study sheds light on the impact of CoQ10 in bile acids metabolism and offers a new perspective on the application of CoQ10 in metabolic health.

A Matched Comparative Analysis of Type-2 Diabetes Mellitus Remission Between Roux-en-Y Gastric Bypass and Sleeve Gastrectomy

OBJECTIVE

Multiple scores validate long-term type-2 diabetes mellitus (T2DM) remission after metabolic and bariatric surgery (MBS). However, studies comparing Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) have not adequately controlled for certain parameters, which may influence procedure selection.

METHODS

We conducted a multicenter retrospective review of patients with T2DM who underwent RYGB or SG between 2008 and 2017. Data on demographics, clinical, laboratory, and metabolic values were collected annually for up to 14 years. Each eligible RYGB patient was individually matched to an eligible SG patient based on diabetes severity, weight loss, and follow-up duration.

RESULTS

Among 1149 T2DM patients, 467 were eligible for matching. We found 97 matched pairs who underwent RYGB or SG. RYGB showed significantly higher T2DM remission rates (46.4%) compared to SG (33.0%) after matching. SG patients had higher insulin usage (35.1%) than RYGB patients (20.6%). RYGB patients also experienced greater decreases in HbA1c levels and diabetes medication usage than SG patients.

CONCLUSIONS

RYGB demonstrates higher efficacy for T2DM remission compared to SG, regardless of baseline characteristics, T2DM severity, weight loss, and follow-up duration. Further studies are needed to understand the long-term metabolic effects of MBS and the underlying pathophysiology of T2DM remission after MBS.

Gut microbiome in diabetic retinopathy: A systematic review and meta-analysis

CONTEXT

Changes in the gut microbiome are linked with Type 2diabetes mellitus (T2DM) development, but alterations in patients with diabetic retinopathy (DR) are still being debated.

OBJECTIVE

To investigate the differences in biodiversity and relative abundance of gut microbiome between patients with DR and T2DM.

METHODS

A comprehensive search was performed in five electronic databases (PubMed, EMBASE, Cochrane Central Register of Controlled Trials, Web of Science, and CNKI) from the inception of each database through to August 2023. The standardized mean difference (SMD) and its 95% confidence interval (CI) were estimated using Stata 15.1. Furthermore, the alpha diversity index and relative abundance of the gut microbiome were calculated. The Egger test determined publication bias in the literature.

RESULTS

Seven case-control studies were included in the final dataset, comprising 195 patients with DR and 211 patients with T2DM. Compared to T2DM patients, patients in the DR group had a reduced but not significantly different α-diversity. The analysis of microbial composition at the phylum level revealed a marked increase in the relative abundance of Bacteroidetes(ES = 23.27, 95%CI[8.30, 38.23], P = 0.000) and a decline in Firmicutes(ES = 47.05, 95%CI[36.58, 57.52], P = 0.000), Proteobacteria (ES = 11.08, 95%CI[6.08, 16.07], P = 0.000) and Actinobacteria (ES = 10.43, 95%CI[1.64, 19.22], P = 0.001) in patients with DR when compared to those with T2DM.

CONCLUSIONS

An association exists between alterations in the gut microbiome of T2DM and the development and progression of DR. This suggests that re-establishing homeostasis of the gut microbiome could be a potential way to prevent or treat DR and requires further confirmation in future studies.

REGISTRATION DATABASE

Prospero.

REGISTRATION NUMBER

CRD42023455280.

Correlation between Peptacetobacter hiranonis, the baiCD Gene, and Secondary Bile Acids in Dogs

Bile acid metabolism is a key pathway modulated by intestinal microbiota. Peptacetobacter (Clostridium) hiranonis has been described as the main species responsible for the conversion of primary into secondary fecal unconjugated bile acids (fUBA) in dogs. This multi-step biochemical pathway is encoded by the bile acid-inducible (bai) operon. We aimed to assess the correlation between P. hiranonis abundance, the abundance of one specific gene of the bai operon (baiCD), and secondary fUBA concentrations. In this retrospective study, 133 fecal samples were analyzed from 24 dogs. The abundances of P. hiranonis and baiCD were determined using qPCR. The concentration of fUBA was measured by gas chromatography-mass spectrometry. The baiCD abundance exhibited a strong positive correlation with secondary fUBA (ρ = 0.7377, 95% CI (0.6461, 0.8084), p < 0.0001). Similarly, there was a strong correlation between P. hiranonis and secondary fUBA (ρ = 0.6658, 95% CI (0.5555, 0.7532), p < 0.0001). Animals displaying conversion of fUBA and lacking P. hiranonis were not observed. These results suggest P. hiranonis is the main converter of primary to secondary bile acids in dogs.

Variant of the lactase LCT gene explains association between milk intake and incident type 2 diabetes

Cow's milk is frequently included in the human diet, but the relationship between milk intake and type 2 diabetes (T2D) remains controversial. Here, using data from the Hispanic Community Health Study/Study of Latinos, we show that in both sexes, higher milk intake is associated with lower risk of T2D in lactase non-persistent (LNP) individuals (determined by a variant of the lactase LCT gene, single nucleotide polymorphism rs4988235 ) but not in lactase persistent individuals. We validate this finding in the UK Biobank. Further analyses reveal that among LNP individuals, higher milk intake is associated with alterations in gut microbiota (for example, enriched Bifidobacterium and reduced Prevotella) and circulating metabolites (for example, increased indolepropionate and reduced branched-chain amino acid metabolites). Many of these metabolites are related to the identified milk-associated bacteria and partially mediate the association between milk intake and T2D in LNP individuals. Our study demonstrates a protective association between milk intake and T2D among LNP individuals and a potential involvement of gut microbiota and blood metabolites in this association.

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.

Gut microbiota-derived tryptamine and phenethylamine impair insulin sensitivity in metabolic syndrome and irritable bowel syndrome

The incidence of metabolic syndrome is significantly higher in patients with irritable bowel syndrome (IBS), but the mechanisms involved remain unclear. Gut microbiota is causatively linked with the development of both metabolic dysfunctions and gastrointestinal disorders, thus gut dysbiosis in IBS may contribute to the development of metabolic syndrome. Here, we show that human gut bacterium Ruminococcus gnavus-derived tryptamine and phenethylamine play a pathogenic role in gut dysbiosis-induced insulin resistance in type 2 diabetes (T2D) and IBS. We show levels of R. gnavus, tryptamine, and phenethylamine are positively associated with insulin resistance in T2D patients and IBS patients. Monoassociation of R. gnavus impairs insulin sensitivity and glucose control in germ-free mice. Mechanistically, treatment of R. gnavus-derived metabolites tryptamine and phenethylamine directly impair insulin signaling in major metabolic tissues of healthy mice and monkeys and this effect is mediated by the trace amine-associated receptor 1 (TAAR1)-extracellular signal-regulated kinase (ERK) signaling axis. Our findings suggest a causal role for tryptamine/phenethylamine-producers in the development of insulin resistance, provide molecular mechanisms for the increased prevalence of metabolic syndrome in IBS, and highlight the TAAR1 signaling axis as a potential therapeutic target for the management of metabolic syndrome induced by gut dysbiosis.

The TGR5 Agonist INT-777 Promotes Peripheral Nerve Regeneration by Activating cAMP-dependent Protein Kinase A in Schwann Cells

Schwann cell (SC) myelination is a pivotal event in the normal physiological functioning of the peripheral nervous system (PNS), where myelination is finely controlled by a series of factors within SCs to ensure timely onset and correct myelin thickness for saltatory conduction. Among these, cyclic AMP (cAMP) is a promising factor for driving myelin gene expression in SCs. It has been shown that TGR5 activation is often associated with increased production of cAMP. Therefore, we speculated that the G-protein-coupled receptor (TGR5) might be involved in the PNS myelination. To test this hypothesis, sciatic nerve crush-injured mice were treated with INT-777, a specific agonist of TGR5, which significantly improved remyelination and functional recovery. Furthermore, rats that underwent sciatic nerve transection were treated with INT-777, which also promoted nerve regeneration and functional recovery. In primary SCs, the stimulatory effect of INT-777 on myelin gene expression was largely counteracted by H89, a potent inhibitor of cAMP-dependent protein kinase A (PKA). Additionally, INT-777 stimulated cell migration was blunted in the presence of H89. Overall, these data indicate that INT-777 is capable of promoting peripheral nerve regeneration and functional recovery after injury, and these benefits are likely due to the activation of the TGR5/cAMP/PKA axis. As such, INT-777, together with other TGR5 agonists, may hold great therapeutic potential for treating peripheral nerve injury.

Low-dose nano-gel incorporated with bile acids enhanced pharmacology of surgical implants

Aim: Major challenges to islet transplantation in Type 1 diabetes include host-inflammation, which results in failure to maintain survival and functions of transplanted islets. Therefore, this study investigated the applications of encapsulating the bile acid ursodeoxycholic acid (UDCA) with transplanted islets within improved nano-gel systems for Type 1 diabetes treatment. Materials & methods: Islets were harvested from healthy mice, encapsulated using UDCA-nano gel and transplanted into the diabetic mice, while the control group was transplanted encapsulated islets without UDCA. The two groups' survival plot, blood glucose, and inflammation and bile acid profiles were analyzed. Results & conclusion: UDCA-nano gel enhanced survival, glycemia and normalized bile acids' profile, which suggests improved islets functions and potential adjunct treatment for insulin therapy.

Metabolic Signatures of Youth Exposure to Mixtures of Per- and Polyfluoroalkyl Substances: A Multi-Cohort Study

BACKGROUND

Exposure to per- and polyfluoroalkyl substances (PFAS) is ubiquitous and has been associated with an increased risk of several cardiometabolic diseases. However, the metabolic pathways linking PFAS exposure and human disease are unclear.

OBJECTIVE

We examined associations of PFAS mixtures with alterations in metabolic pathways in independent cohorts of adolescents and young adults.

METHODS

Three hundred twelve overweight/obese adolescents from the Study of Latino Adolescents at Risk (SOLAR) and 137 young adults from the Southern California Children's Health Study (CHS) were included in the analysis. Plasma PFAS and the metabolome were determined using liquid-chromatography/high-resolution mass spectrometry. A metabolome-wide association study was performed on log-transformed metabolites using Bayesian regression with a g-prior specification and g-computation for modeling exposure mixtures to estimate the impact of exposure to a mixture of six ubiquitous PFAS (PFOS, PFHxS, PFHpS, PFOA, PFNA, and PFDA). Pathway enrichment analysis was performed using Mummichog and Gene Set Enrichment Analysis. Significance across cohorts was determined using weighted Z -tests.

RESULTS

In the SOLAR and CHS cohorts, PFAS exposure was associated with alterations in tyrosine metabolism (meta-analysis p = 0.00002 ) and de novo fatty acid biosynthesis (p = 0.03 ), among others. For example, when increasing all PFAS in the mixture from low (∼ 30 th percentile) to high (∼ 70 th percentile), thyroxine (T4), a thyroid hormone related to tyrosine metabolism, increased by 0.72 standard deviations (SDs; equivalent to a standardized mean difference) in the SOLAR cohort (95% Bayesian credible interval (BCI): 0.00, 1.20) and 1.60 SD in the CHS cohort (95% BCI: 0.39, 2.80). Similarly, when going from low to high PFAS exposure, arachidonic acid increased by 0.81 SD in the SOLAR cohort (95% BCI: 0.37, 1.30) and 0.67 SD in the CHS cohort (95% BCI: 0.00, 1.50). In general, no individual PFAS appeared to drive the observed associations.

DISCUSSION

Exposure to PFAS is associated with alterations in amino acid metabolism and lipid metabolism in adolescents and young adults. https://doi.org/10.1289/EHP11372.

Medium chain fatty acid supplementation improves animal metabolic and immune status during the transition period: A study on dairy cattle

The transition period is the stage of the high incidence of metabolic and infectious diseases in dairy cows. Improving transition dairy cows' health is crucial for the industry. This study aimed to determine the effects of dietary supplementation medium-chain fatty acids (MCFAs) on immune function, metabolic status, performance of transition dairy cows. Twenty multiparous Holstein cows randomly assigned to two treatments at 35 d before calving. 1) CON (fed the basal 2) MCFA treatment (basal diet was supplemented at an additional 20 g MCFAs mixture every day) until 70 d after calving. The results showed that the serum amyloid A myeloperoxidase concentrations in the blood of cows in MCFA treatment significantly decreased during the early lactation (from 1 d to 28 d after calving) 0.03, 0.04, respectively) compared with the CON, while the tumor necrosis factor concentration was significantly decreased at 56 d after calving (P = 0.02). In addition, the concentration of insulin in the pre-calving (from 21 d before calving to calving) blood of cows in MCFA treatment was significantly decreased (P = 0.04), and concentration of triglyceride also showed a downward trend at 28 d after calving 0.07). Meanwhile, MCFAs supplementation significantly decreased the concentrations of lithocholic acid, hyodeoxycholic acid, and hyocholic acid in the blood at 1 d calving (P = 0.02, < 0.01, < 0.01, respectively), and the level of hyocholic acid taurocholic acid concentrations (P < 0.01, = 0.01, respectively) decreased dramatically at 14 d after calving. However, compared with the CON, the pre-calving dry matter intake and the early lactation milk yield in MCFA treatment were significantly decreased (P = 0.05, 0.02, respectively). In conclusion, MCFAs supplementation transition diet could improve the immune function and metabolic status of dairy cows, and the health of transition cows might be beneficial from the endocrine status.

The Black Box Orchestra of Gut Bacteria and Bile Acids: Who Is the Conductor?

Over the past decades the potential role of the gut microbiome and bile acids in type 2 diabetes mellitus (T2DM) has been revealed, with a special reference to low bacterial alpha diversity. Certain bile acid effects on gut bacteria concern cytotoxicity, or in the case of the microbiome, bacteriotoxicity. Reciprocally, the gut microbiome plays a key role in regulating the bile acid pool by influencing the conversion and (de)conjugation of primary bile acids into secondary bile acids. Three main groups of bacterial enzymes responsible for the conversion of bile acids are bile salt hydrolases (BSHs), hydroxysteroid dehydrogenases (HSDHs) and enzymes encoded in the bile acid inducible (Bai) operon genes. Interventions such as probiotics, antibiotics and fecal microbiome transplantation can impact bile acids levels. Further evidence of the reciprocal interaction between gut microbiota and bile acids comes from a multitude of nutritional interventions including macronutrients, fibers, prebiotics, specific individual products or diets. Finally, anatomical changes after bariatric surgery are important because of their metabolic effects. The heterogeneity of studies, diseases, bacterial species and (epi)genetic influences such as nutrition may challenge establishing specific and detailed interventions that aim to tackle the gut microbiome and bile acids.

Host-microbiome interactions: Gut-Liver axis and its connection with other organs

An understanding of connections between gut microbiome and liver has provided important insights into the pathophysiology of liver diseases. Since gut microbial dysbiosis increases gut permeability, the metabolites biosynthesized by them can reach the liver through portal circulation and affect hepatic immunity and inflammation. The immune cells activated by these metabolites can also reach liver through lymphatic circulation. Liver influences immunity and metabolism in multiple organs in the body, including gut. It releases bile acids and other metabolites into biliary tract from where they enter the systemic circulation. In this review, the bidirectional communication between the gut and the liver and the molecular cross talk between the host and the microbiome has been discussed. This review also provides details into the intricate level of communication and the role of microbiome in Gut-Liver-Brain, Gut-Liver-Kidney, Gut-Liver-Lung, and Gut-Liver-Heart axes. These observations indicate a complex network of interactions between host organs influenced by gut microbiome.

Bile acid metabolism and signaling, the microbiota, and metabolic disease

The diversity, composition, and function of the bacterial community inhabiting the human gastrointestinal tract contributes to host health through its role in producing energy or signaling molecules that regulate metabolic and immunologic functions. Bile acids are potent metabolic and immune signaling molecules synthesized from cholesterol in the liver and then transported to the intestine where they can undergo metabolism by gut bacteria. The combination of host- and microbiota-derived enzymatic activities contribute to the composition of the bile acid pool and thus there can be great diversity in bile acid composition that depends in part on the differences in the gut bacteria species. Bile acids can profoundly impact host metabolic and immunological functions by activating different bile acid receptors to regulate signaling pathways that control a broad range of complex symbiotic metabolic networks, including glucose, lipid, steroid and xenobiotic metabolism, and modulation of energy homeostasis. Disruption of bile acid signaling due to perturbation of the gut microbiota or dysregulation of the gut microbiota-host interaction is associated with the pathogenesis and progression of metabolic disorders. The metabolic and immunological roles of bile acids in human health have led to novel therapeutic approaches to manipulate the bile acid pool size, composition, and function by targeting one or multiple components of the microbiota-bile acid-bile acid receptor axis.

Gut microbiota, bile acids, and nature compounds

Natural compounds (NPs) have historically made a major contribution to pharmacotherapy in various diseases and drug discovery. In the past decades, studies on gut microbiota have shown that the efficacy of NPs can be affected by the interactions between gut microbiota and NPs. On one hand, gut microbiota can metabolize NPs. On the other hand, NPs can influence the metabolism and composition of gut microbiota. Among gut microbiota metabolites, bile acids (BAs) have attracted widespread attention due to their effects on the body homeostasis and the development of diseases. Studies have also confirmed that NPs can regulate the metabolism of BAs and ultimately regulate the physiological function of the body and disease progresses. In this review, we comprehensively summarize the interactions among NPs, gut microbiota, and BAs. In addition, we also discuss the role of microbial BAs metabolism in understanding the toxicity and efficacy of NPs. Furthermore, we present personal insights into the future research directions of NPs and BAs.

Reconstruction of intestinal microecology of type 2 diabetes by fecal microbiota transplantation: Why and how

Type 2 diabetes (T2D) is a chronic metabolic disease characterized by hyperglycemia due to insulin resistance. Mounting evidence has correlated T2D to alterations in the composition of gut microbiota. Accordingly, targeting the gut microbiota has become an emerging strategy for T2D management. The aim of this article is to get a better insight into the rationale for targeting gut microbiota in T2D treatment. Thus, we herein reviewed the change of gut microbiota composition in T2D, factors shaping gut microbiota, and potential mechanisms behind the contribution of gut microbiota to T2D pathogenesis. At present, it has become possible to use intestinal microorganism capsules, bacteria liquid, and other preparations to carry out fecal microbiota transplantation for the treatment and intervention of T2D with insulin resistance and immune-mediated type 1 diabetes (T1D).

Stimulation of the hepatoportal nerve plexus with focused ultrasound restores glucose homoeostasis in diabetic mice, rats and swine

Peripheral neurons that sense glucose relay signals of glucose availability to integrative clusters of neurons in the brain. However, the roles of such signalling pathways in the maintenance of glucose homoeostasis and their contribution to disease are unknown. Here we show that the selective activation of the nerve plexus of the hepatic portal system via peripheral focused ultrasound stimulation (pFUS) improves glucose homoeostasis in mice and rats with insulin-resistant diabetes and in swine subject to hyperinsulinemic-euglycaemic clamps. pFUS modulated the activity of sensory projections to the hypothalamus, altered the concentrations of metabolism-regulating neurotransmitters, and enhanced glucose tolerance and utilization in the three species, whereas physical transection or chemical blocking of the liver-brain nerve pathway abolished the effect of pFUS on glucose tolerance. Longitudinal multi-omic profiling of metabolic tissues from the treated animals confirmed pFUS-induced modifications of key metabolic functions in liver, pancreas, muscle, adipose, kidney and intestinal tissues. Non-invasive ultrasound activation of afferent autonomic nerves may represent a non-pharmacologic therapy for the restoration of glucose homoeostasis in type-2 diabetes and other metabolic diseases.

Effect of synbiotic yogurt fortified with monk fruit extract on hepatic lipid biomarkers and metabolism in rats with type 2 diabetes

Monk fruit extract (MFE) is widely used as a sweetener in foods. In this study, the effects of the consumption of MFE-sweetened synbiotic yogurt on the lipid biomarkers and metabolism in the livers of type 2 diabetic rats were evaluated. The results revealed that the MFE-sweetened symbiotic yogurt affected the phosphatidylcholines, phosphatidylethanolamines, phosphatidylglycerol, lysophosphatidic acids, lysophosphatidylcholines, lysophosphatidylethanolamines, lysophosphatidylglycerols, lysophosphatidylinositols, lysophosphatidylserines, and fatty acid-hydroxy fatty acids biomarkers in the livers of type 2 diabetic rats. In addition, the consumption of the MFE-sweetened synbiotic yogurt significantly altered 12 hepatic metabolites, which are involved in phenylalanine metabolism, sphingolipid metabolism, bile secretion, and glyoxylate and dicarboxylate metabolism in the liver. Furthermore, a multiomics (metabolomic and transcriptomic) association study revealed that there was a significant correlation between the MFE-sweetened synbiotic yogurt and the metabolites and genes involved in fatty acid biosynthesis, bile secretion, and glyoxylate and dicarboxylate metabolism. The findings of this study will provide new insights on exploring the function of sweeteners for improving type 2 diabetes mellitus liver lipid biomarkers.

The effect of bile salt diet supplementation on genes related to fat metabolism in yellow-feathered broilers

Background and Aim:

As a new feed additive, bile acid (BA) can promote the absorption and transport of lipids and fat-soluble vitamins. In recent years, BAs have been widely used in animal feed to promote fat absorption. Therefore, this study aimed to investigate the effect of bile salt supplementation in the diet of yellow-feathered broilers on messenger RNA (mRNA) expression of sterol regulatory element-binding protein 1 (SREBF1), fatty acid synthase (FAS), acetyl-coenzyme A carboxylase (ACC), and fatty acid transport protein 4 (FATP4).

Materials and Methods:

Four hundred and twenty commercial male chicks were randomly divided into seven groups (with four replicates per group and 15 chickens per replicate). They were fed diets supplemented with bile salts at 0, 1.5, 2.5, 3.5, 4.5, 5.5 mg/kg, and 2 mg/kg tylosin for 30 days. Changes in SREBF1, fatty acid transporter 4, FAS, and acetyl-CoA carboxylase genes in intestinal mucosa and liver of yellow-feathered broilers were determined using a quantitative fluorescence polymerase chain reaction.

Results:

mRNA expression of SREBF1, FAS, ACC, and FATP4 in the small intestine decreased in chicks fed diets supplemented with 3.5 and 4.5 mg/kg bile salts (p<0.05) compared with the control group on 7 days and 14 d. The mRNA expressions of SREBF1, FAS, ACC, and FATP4 in liver tissue decreased in chicks fed diets supplemented with 4.5 and 5.5 mg/kg bile salts (p<0.05) compared to the control group on 7 days. The mRNA expression of SREBF1, FAS, ACC, and FATP4 in the liver at 14 days and the small intestine on 21 days also decreased in chicks fed diets supplemented with 4.5 mg/kg bile salts (p<0.05) compared to the control group. When contrasted with the control group on day 21, the mRNA expression of SRWBF1, FAS, ACC, and FATP4 detected in the liver was lower in chicks fed diets supplemented with bile salts (p<0.05).

Conclusion:

The dietary supplementation of bile salts at 4.5 mg/kg effectively regulates the expression of fat metabolism genes, such as SREBF1, FAS, ACC, and FATP4 mRNA. At this concentration, bile salts promote fat catabolism, inhibit fat synthesis, and play an essential role in improving the fat deposition of broilers.

Investigation of dysregulated lipid metabolism in diabetic mice via targeted metabolomics of bile acids in enterohepatic circulation

RATIONALE

The mechanism of lipid metabolism disorder in type 2 diabetes (T2DM) remains unclear. This study aimed to reveal the mechanism underlying dysregulated lipid metabolism in T2DM through bile acid metabolism.

METHODS

A db/db mouse model was employed to investigate the alteration of bile acid profiles in T2DM. Ultrahigh-performance liquid chromatography with tandem mass spectrometry was used to quantify the detailed bile acid levels in each compartment of enterohepatic circulation. The pathological change of mouse liver was assessed by liver histology and serum biochemical assays. The expression level of bile acid-related transporters and synthases was measured with Western blot analysis.

RESULTS

The results showed that T2DM can result in severe liver fat accumulation and liver damage. In addition, compared to the control group, in T2DM mice, bile acid synthesis is reduced, while the level of bile acids is increased at the storage sites and the reabsorption sites, but there are subtle gender differences. Further, the ratio of conjugated bile acids in total bile acid in the liver of T2DM mice increased significantly relative to the control group for both female and male mice.

CONCLUSIONS

In T2DM, bile acid metabolism is disordered in both male and female mice, which could be the underlying mechanism of dysregulated lipid metabolism in T2DM.

Network Pharmacology Study to Reveal the Potentiality of a Methanol Extract of Caesalpinia sappan L. Wood against Type-2 Diabetes Mellitus

Caesalpinia sappan L. (CS) is widely used to treat diabetic complications in south-east Asia, specifically in traditional Chinese medicine. This study intends to explain the molecular mechanism of how chemical constituents of CS interrelate with different signaling pathways and receptors involved in T2DM. GC-MS was employed to identify the chemical compounds from the methanol extract of CS wood (MECSW). Lipinski's rule of five was applied, and 33 bioactive constituents have been screened from the CS extract. After that, 124 common targets and 26 compounds associated with T2DM were identified by mining several public databases. Protein-protein interactions and compound-target network were constructed using the STRING database and Cytoscape tool. Protein-protein interactions were identified in 121 interconnected nodes active in T2DM and peroxisome proliferator-activated receptor gamma (PPARG) as key target receptors. Furthermore, pathway compound target (PCT) analysis using the merger algorithm plugin of Cytoscape revealed 121 nodes from common T2DM targets, 33 nodes from MECSW compounds and 9 nodes of the KEGG pathway. Moreover, network topology analysis determined "Fisetin tetramethyl ether" as the key chemical compound. The DAVID online tool determined seven signaling receptors, among which PPARG was found most significant in T2DM progression. Gene ontology and KEGG pathway analysis implied the involvement of nine pathways, and the peroxisome proliferator-activated receptor (PPAR) pathway was selected as the hub signaling pathway. Finally, molecular docking and quantum chemistry analysis confirmed the strong binding affinity and reactive chemical nature of fisetin tetramethyl ether with target receptors exceeding that of the conventional drug (metformin), PPARs agonist (rosiglitazone) and co-crystallized ligands, indicating that fisetin could be a potential drug of choice in T2DM management. This study depicts the interrelationship of the bioactive compounds of MECSW with the T2DM-associated signaling pathways and target receptors. It also proposes a more pharmaceutically effective substance, fisetin tetramethyl ether, over the standard drug that activates PPARG protein in the PPAR signaling pathway of T2DM.

Pharmacological Effects of Secondary Bile Acid Microparticles in Diabetic Murine Model

AIM

Examine bile acids effects in Type 2 diabetes.

BACKGROUND

In recent studies, the bile acid ursodeoxycholic acid (UDCA) has shown potent antiinflammatory effects in obese patients while in type 2 diabetics (T2D) levels of the pro-inflammatory bile acid lithocholic acid were increased, and levels of the anti-inflammatory bile acid chenodeoxycholic acid were decreased, in plasma.

OBJECTIVE

Hence, this study aimed to examine applications of novel UDCA microparticles in diabetes.

METHODS

Diabetic balb/c adult mice were divided into three equal groups and gavaged daily with either empty microcapsules, free UDCA, or microencapsulated UDCA over two weeks. Their blood, tissues, urine, and faeces were collected for blood glucose, inflammation, and bile acid analyses. UDCA resulted in modulatory effects on bile acids profile without antidiabetic effects suggesting that bile acid modulation was not directly linked to diabetes treatment.

RESULTS

UDCA resulted in modulatory effects on bile acids profile without antidiabetic effects suggesting that bile acid modulation was not directly linked to diabetes treatment.

CONCLUSION

Bile acids modulated the bile profile without affecting blood glucose levels.

Specific alterations of gut microbiota in diabetic microvascular complications: A systematic review and meta-analysis

BACKGROUND

The role of gut microbiota in diabetes mellitus (DM) and its complications has been widely accepted. However, the alternation of gut microbiota in diabetic microvascular complications (DC) remains to be determined.

METHODS

Publications (till August 20^th, 2022) on gut microbiota in patients with DC were retrieved from PubMed, Web of Science, Embase and Cochrane. Review Manager 5.3 was performed to estimate the standardized mean difference (SMD) and 95% confidence interval (CI) and calculate alpha diversity indices and the relative abundance of gut microbiota between patients in DC v.s. DM and DC v.s. healthy controls (HC).

RESULTS

We included 13 studies assessing 329 patients with DC, 232 DM patients without DC, and 241 HC. Compared to DM, patients with DC shared a significantly lower Simpson index (SMD = -0.59, 95% CI [-0.82, -0.36], p < 0.00001), but a higher ACE index (SMD = 0.42, 95% CI[0.11, 0.74], p = 0.009). Compared to HC, DC patients held a lower ACE index (SMD = -0.61, 95% CI[-1.20, -0.02], p = 0.04). The relative abundances of phylum Proteobacteria (SMD = 0.03, 95% CI[0.01, 0.04], p = 0.003, v.s. HC) and genus Klebsiella (SMD = 0.00, 95% CI[0.00, 0.00], p < 0.00001, v.s. HC) were enriched, accompanying with depleted abundances of phylum Firmicutes (SMD = -0.06, 95% CI[-0.11, -0.01], p = 0.02, v.s. HC), genera Bifidobacterium (SMD = -0.01, 95% CI[-0.02,-0.01], p < 0.0001, v.s. DM), Faecalibacterium (SMD = -0.01, 95% CI[-0.02, -0.00], p = 0.009, v.s. DM; SMD = -0.02, 95% CI[-0.02, -0.01], p < 0.00001, v.s. HC) and Lactobacillus (SMD = 0.00, 95% CI[-0.00, -0.00], p < 0.00001, v.s. HC) in DC.

CONCLUSIONS

Gut microbiota perturbations with the depletion of alpha diversity and certain short-chain fatty acids (SCFAs)-producing bacteria were associated with the pathology of DC. Therefore, gut microbiota might serve as a promising approach for the diagnosis and treatment of DC. Further investigations are required to study the mechanisms by which gut dysbiosis acts on the onset and progression of DC.

Colon cancer checks in when bile acids check out: the bile acid-nuclear receptor axis in colon cancer

Bile acids (BAs) are a class of hepatically derived metabolite-hormones with prominent roles in nutrient absorption, metabolic and immune homeostasis in the intestine. BAs are ligands for multiple nuclear receptors (NRs), through which they confer transcriptional regulation on target genes that form an enterohepatic hormonal feedback loop to regulate BA synthesis and maintain lipid homeostasis. Endogenous BAs made by the host undergo significant biotransformation by the gut microbiota in the intestine, which diversifies the intestinal BA pool and facilitate host–microbiota cross-talk through BA-mediated signaling. BAs dysregulation contributes to development of metabolic diseases, pathological inflammation and colon cancer. This review provides a brief historic perspective of the study of NR-mediated BA signaling transduction, with a focus on recent advancements in understanding the active role the gut microbiome plays in reshaping intestinal BA landscape, and the implications of novel microbially derived BAs in modulating immune homeostasis and cancer development in the host. Targeting the BA–NR signaling axis for pharmacological intervention provides ample opportunities in the prevention and treatment of intestinal diseases.

Artificial Cell Encapsulation for Biomaterials and Tissue Bio-Nanoengineering: History, Achievements, Limitations, and Future Work for Potential Clinical Applications and Transplantation

Pancreatic β-cell loss and failure with subsequent deficiency of insulin production is the hallmark of type 1 diabetes (T1D) and late-stage type 2 diabetes (T2D). Despite the availability of parental insulin, serious complications of both types are profound and endemic. One approach to therapy and a potential cure is the immunoisolation of β cells via artificial cell microencapsulation (ACM), with ongoing promising results in human and animal studies that do not depend on immunosuppressive regimens. However, significant challenges remain in the formulation and delivery platforms and potential immunogenicity issues. Additionally, the level of impact on key metabolic and disease biomarkers and long-term benefits from human and animal studies stemming from the encapsulation and delivery of these cells is a subject of continuing debate. The purpose of this review is to summarise key advances in this field of islet transplantation using ACM and to explore future strategies, limitations, and hurdles as well as upcoming developments utilising bioengineering and current clinical trials.

Gut-Microbial Metabolites, Probiotics and Their Roles in Type 2 Diabetes

Type 2 diabetes (T2D) is a worldwide prevalent metabolic disorder defined by high blood glucose levels due to insulin resistance (IR) and impaired insulin secretion. Understanding the mechanism of insulin action is of great importance to the continuing development of novel therapeutic strategies for the treatment of T2D. Disturbances of gut microbiota have been widely found in T2D patients and contribute to the development of IR. In the present article, we reviewed the pathological role of gut microbial metabolites including gaseous products, branched-chain amino acids (BCAAs) products, aromatic amino acids (AAAs) products, bile acids (BA) products, choline products and bacterial toxins in regulating insulin sensitivity in T2D. Following that, we summarized probiotics-based therapeutic strategy for the treatment of T2D with a focus on modulating gut microbiota in both animal and human studies. These results indicate that gut-microbial metabolites are involved in the pathogenesis of T2D and supplementation of probiotics could be beneficial to alleviate IR in T2D via modulation of gut microbiota.

Prenatal exposure to poly-/per-fluoroalkyl substances is associated with alteration of lipid profiles in cord-blood

INTRODUCTION

Poly-/per-fluoroalkyl substances (PFAS) are widespread environmental pollutants that may induce metabolic perturbations in humans, including particularly alterations in lipid profiles. Prenatal exposure to PFAS can cause lasting effects on offspring metabolic health, however, the underlying mechanisms are still unknown.

OBJECTIVES

The goal of the study was to investigate the impact of prenatal PFAS exposure on the lipid profiles in cord blood.

METHODS

Herein, we combined determination of bile acids (BAs) and molecular lipids by liquid chromatography with ultra-high-resolution mass spectrometry, and separately quantified cord blood concentrations of sixteen PFAS in a cohort of Chinese infants (104 subjects) in a cross-sectional study. We then evaluated associations between PFAS concentration and lipidome using partial correlation network analysis, debiased sparse partial correlation, linear regression analysis and correlation analysis.

RESULTS

PFAS levels showed significant associations with the lipid profiles; specifically, PFAS exposure was positively correlated with triacylgycerols (TG) and several bile acids. Importantly, exposure to perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), perfluorononanoic acid (PFNA) and perfluorohexane sulfonic acid (PFHxS) were associated with increased levels of TGs with saturated fatty acids while multiple classes of phospholipids were decreased. In addition, several free fatty acids showed significant positive correlations with PFOS.

CONCLUSIONS

Our results indicated that prenatal exposure to PFAS mediated metabolic changes, which may explain the associations reported between PFAS exposure and metabolic health later in life.

Chemotherapy-induced hearing loss: the applications of bio-nanotechnologies and bile acid-based delivery matrices

Advancement in the prevention of chemotherapy-induced hearing loss has proposed new nano-based delivery matrices that can target inner ear regions most damaged by chemotherapy. Chemotherapy agents (e.g., cisplatin) induce increased reactive oxygen species formation in the inner ear that damage sensory hair cells and result in irreversible hearing impairment. Exogenous antioxidants (e.g., Probucol and metformin) have been shown to block the formation of these reactive oxygen species. Delivery of these drugs in effective concentrations remains a challenge. Microencapsulation in combination with drug excipients provides one technique to effectively deliver these drugs. This paper investigates the use of probucol and metformin in combination with drug excipients for novel, inner ear, delivery.

Myocardial Infarction and Coronary Artery Disease in Menopausal Women With Type 2 Diabetes Mellitus Negatively Correlate With Total Serum Bile Acids

Background

As metabolic molecules, bile acids (BAs) not only promote the absorption of fat-soluble nutrients, but they also regulate many metabolic processes, including the homeostasis of glucose and lipids. Although total serum BA (TBA) measurement is a readily available clinical test related to coronary artery disease (CAD), myocardial infarction (MI), and type 2 diabetes mellitus (T2DM), the relationship between TBA and these pathological conditions remain unclear, and research on this topic is inconclusive.

Methods

This study enrolled 20,255 menopausal women aged over 50 years, including 6,421 T2DM patients. The study population was divided into different groups according to the median TBA level in order to explore the clinical characteristics of menopausal women with different TBA levels. Spline analyses, generalized additive model (GAM) model and regression analyses based on TBA level were used to explore the relationship between TBA and different diseases independently, including CAD and MI, or in combination with T2DM.

Results

Both in the general population and in the T2DM subgroup, the TBA level was significantly lower in CAD patients than in non-CAD patients. Spline analyses indicated that within normal clinical range of TBA concentration (0-10 µmol/L), the presence of CAD and MI showed similar trends in total and T2DM population. Similarly, the GAM model indicated that within the 0-10 μmol/L clinical range, the predicted probability for CAD and MI alone and in combination with T2DM was negatively correlated with TBA concentration. Multivariate regression analysis suggested that low TBA level was positively associated with the occurrence of CAD combined with T2DM (OR: 1.451; 95%CI: 1.141-1.847).

Conclusions

In menopausal women, TBA may represent a valuable clinical serum marker with negative correlation for CAD and MI in patients with T2DM.

Pharmacological and Biological Study of Microencapsulated Probucol-Secondary Bile Acid in a Diseased Mouse Model

Probucol (PB) is a highly lipophilic drug with potential protective effects on pancreatic β-cells from inflammation and oxidation. PB has poor bioavailability and solubility, and despite many attempts, significant improvement in antidiabetic effects or absorption has yet to be discovered. Recently, the role of bile acids has been established in significant drug formulation stabilisation effects and as cell-penetrating agents. Promising results in pharmaceutical formulation studies on drug stability and release patterns when lithocholic acid (LCA) is conjugated with PB and sodium alginate (SA) have been demonstrated. Thus, this study aimed to develop and characterise PB microcapsules incorporating LCA and examine the biological effects of the microcapsules in vitro and in vivo. PB/LCA microcapsules were prepared using an encapsulation method, ionic gelation vibrational jet flow technology. LCA incorporation in PB microcapsules showed positive effects on β-cells with improved insulin release, antioxidant activity, and PB intracellular uptake. Diabetic mice gavaged LCA-PB microcapsules showed a significant reduction in diabetes signs and symptoms, better survival rate, reduced blood glucose levels, and pro-inflammatory cytokines, with an increase PB level in blood and tissues suggesting a potential therapy for treating diabetes mellitus.

Supplementation of Bile Acids and Lipase in Broiler Diets for Better Nutrient Utilization and Performance: Potential Effects and Future Implications – A Review

Bile acids are used for better emulsification, digestion and absorption of dietary fat in chicken, especially in early life. Similarly, exogenous lipases have also been used for the improvement of physiological limitation of the chicken digestive system. Owing to potential of both bile acids and lipases, their use has been increased in recent years, for better emulsification of dietary fat and improvement of growth performance in broilers. In the past, pancreatic lipases were used for supplementation, but recently, microbial lipase is getting attention in poultry industry as a hydrolysis catalyst. Bile acids strengthen the defence mechanism of body against bacterial endotoxins and also play a key role in lipid regulation and sugar metabolism as signaling molecules. It has been demonstrated that bile acids and lipases may improve feed efficiency by enhancing digestive enzyme activity and ultimately leading to better fat digestion and absorption. Wide supplemental range of bile acids (0.004% to 0.25%) and lipases (0.01% to 0.1%) has been used in broiler diets for improvement of fat digestibility and their performance. Combinations of different bile acids have shown more potential to improve feed efficiency (by 7.14%) even at low (0.008%) levels as compared to any individual bile acid. Lipases at a lower level of 0.03% have exhibited more promising potential to improve fat digestibility and feed efficiency. However, contradicting results have been published in literature, which needs further investigations to elucidate various nutritional aspects of bile acids and lipase supplementation in broiler diet. This review focuses on providing insight on the mechanism of action and potential application of bile acids and lipases in broiler diets. Moreover, future implications of these additives in poultry nutrition for enhancing nutrient utilization and absorption are also discussed.

Enhanced Bilosomal Properties Resulted in Optimum Pharmacological Effects by Increased Acidification Pathways

INTRODUCTION

Recent studies in our laboratory have shown that some bile acids, such as chenodeoxycholic acid (CDCA), can exert cellular protective effects when encapsulated with viable β-cells via anti-inflammatory and anti-oxidative stress mechanisms. However, to explore their full potential, formulating such bile acids (that are intrinsically lipophilic) can be challenging, particularly if larger doses are required for optimal pharmacological effects. One promising approach is the development of nano gels. Accordingly, this study aimed to examine biological effects of various concentrations of CDCA using various solubilising nano gel systems on encapsulated β-cells.

METHODS

Using our established cellular encapsulation system, the Ionic Gelation Vibrational Jet Flow technology, a wide range of CDCA β-cell capsules were produced and examined for morphological, biological, and inflammatory profiles.

RESULTS AND CONCLUSION

Capsules' morphology and topographic characteristics remained similar, regardless of CDCA or nano gel concentrations. The best pharmacological, anti-inflammatory, and cellular respiration, metabolism, and energy production effects were observed at high CDCA and nano gel concentrations, suggesting dose-dependent cellular protective and positive effects of CDCA when incorporated with high loading nano gel.

Gut Microbiome Critically Impacts PCB-induced Changes in Metabolic Fingerprints and the Hepatic Transcriptome in Mice

Polychlorinated biphenyls (PCBs) are ubiquitously detected and have been linked to metabolic diseases. Gut microbiome is recognized as a critical regulator of disease susceptibility; however, little is known how PCBs and gut microbiome interact to modulate hepatic xenobiotic and intermediary metabolism. We hypothesized the gut microbiome regulates PCB-mediated changes in the metabolic fingerprints and hepatic transcriptome. Ninety-day-old female conventional and germ-free mice were orally exposed to the Fox River Mixture (synthetic PCB mixture, 6 or 30 mg/kg) or corn oil (vehicle control, 10 ml/kg), once daily for 3 consecutive days. RNA-seq was conducted in liver, and endogenous metabolites were measured in liver and serum by LC-MS. Prototypical target genes of aryl hydrocarbon receptor, pregnane X receptor, and constitutive androstane receptor were more readily upregulated by PCBs in conventional conditions, indicating PCBs, to the hepatic transcriptome, act partly through the gut microbiome. In a gut microbiome-dependent manner, xenobiotic, and steroid metabolism pathways were upregulated, whereas response to misfolded proteins-related pathways was downregulated by PCBs. At the high PCB dose, NADP, and arginine appear to interact with drug-metabolizing enzymes (ie, Cyp1-3 family), which are highly correlated with Ruminiclostridium and Roseburia, providing a novel explanation of gut-liver interaction from PCB-exposure. Utilizing the Library of Integrated Network-based Cellular Signatures L1000 database, therapeutics targeting anti-inflammatory and endoplasmic reticulum stress pathways are predicted to be remedies that can mitigate PCB toxicity. Our findings demonstrate that habitation of the gut microbiota drives PCB-mediated hepatic responses. Our study adds knowledge of physiological response differences from PCB exposure and considerations for further investigations for gut microbiome-dependent therapeutics.

Based on urine metabolomics to study the mechanism of Qi-deficiency affecting type 2 diabetes rats using ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry

Qi-deficiency also called energy deficiency, which approximates to the term of sub-health in contemporary medical theory. Diabetes is similar to the symptoms of "xiaoke" in traditional Chinese medicine (TCM) which is linked with Qi-deficiency. However, the mechanism of Qi-deficiency on type 2 diabetes (T2D) has not been completely elucidated. In this study, a model on Qi-deficiency T2D rat was established by using diet with high fat and high sugar and small-dose STZ induction combined with exhaustive swimming, and the model was evaluated by pathological section, hematological index and serum biochemical parameters. Applying urine metabolomics based on ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry to explore the underlying molecular mechanism of Qi-deficiency on T2D and 32 urinary metabolites were identified as prospective biomarkers for Qi-deficiency T2D rats. Metabolic pathway analysis indicated that synthesis and degradation of ketone bodies, starch and sucrose metabolism, phenylalanine metabolism, arachidonic acid metabolism, butanoate metabolism and TCA cycle, etc., were closely related to potential mechanisms of Qi-deficiency on T2D. The metabolomics results can provide reliable data support for complex TCM syndrome diagnosis.

Synthesis of Yakuchinone B-Inspired Inhibitors against Islet Amyloid Polypeptide Aggregation

Type 2 diabetes mellitus (T2DM) is associated with pancreatic β-cell dysfunction and insulin resistance. Islet amyloid polypeptide (IAPP) aggregation is found to induce islet β-cell death in T2DM patients. Recently, we demonstrated that yakuchinone B derivative 1 exhibited inhibitory activity against IAPP aggregation. Thus, in this study, a series of synthesized yakuchinone B-inspired compounds were tested for their anti-IAPP aggregation activity. Four of these compounds, 4e-h, showed greater activity than the lead compound 1, in the sub-μM range (IC₅₀ = 0.7-0.8 μM). The molecular docking analysis revealed crucial hydrogen bonds between the compounds and residues S19 and N22 and important hydrophobic interactions with residue I26. Notably, compounds 4g and 4h significantly protected β-cells against IAPP-induced toxicity with EC₅₀ values of 0.1 and 0.2 μM, respectively. In contrast, the protective activities of compounds 4e and 4f were weak. Overall, these results suggest that the compounds exhibiting IAPP aggregation-inhibiting activity have the potential to treat T2DM.

Sleep and Circadian Disruption and the Gut Microbiome-Possible Links to Dysregulated Metabolism

Insufficient sleep and circadian misalignment are associated with adverse metabolic health outcomes. Alterations in gut microbial diversity occur with insufficient sleep and circadian misalignment, which can lead to modifications in microbial structure and function. Changes in microbially produced and modified metabolites such as short chain fatty acids and secondary bile acids may contribute to chronic inflammation, positive energy balance and endocrine changes, and represent potential mechanisms linking insufficient sleep and circadian misalignment with metabolic dysregulation. Literature primarily from the last two years is reviewed here, examining the impact of sleep and circadian rhythms and their disruption on the gut microbiome in human and non-human models, with an emphasis on the hypothesis that the altered gut microbiome may be one pathway by which insufficient sleep and circadian misalignment dysregulate metabolism.

Diet-Related Alterations of Gut Bile Salt Hydrolases Determined Using a Metagenomic Analysis of the Human Microbiome

The metabolism of bile acid by the gut microbiota is associated with host health. Bile salt hydrolases (BSHs) play a crucial role in controlling microbial bile acid metabolism. Herein, we conducted a comparative study to investigate the alterations in the abundance of BSHs using data from three human studies involving dietary interventions, which included a ketogenetic diet (KD) versus baseline diet (BD), overfeeding diet (OFD) versus underfeeding diet, and low-carbohydrate diet (LCD) versus BD. The KD increased BSH abundance compared to the BD, while the OFD and LCD did not change the total abundance of BSHs in the human gut. BSHs can be classified into seven clusters; Clusters 1 to 4 are relatively abundant in the gut. In the KD cohort, the levels of BSHs from Clusters 1, 3, and 4 increased significantly, whereas there was no notable change in the levels of BSHs from the clusters in the OFD and LCD cohorts. Taxonomic studies showed that members of the phyla Bacteroidetes, Firmicutes, and Actinobacteria predominantly produced BSHs. The KD altered the community structure of BSH-active bacteria, causing an increase in the abundance of Bacteroidetes and decrease in Actinobacteria. In contrast, the abundance of BSH-active Bacteroidetes decreased in the OFD cohort, and no significant change was observed in the LCD cohort. These results highlight that dietary patterns are associated with the abundance of BSHs and community structure of BSH-active bacteria and demonstrate the possibility of manipulating the composition of BSHs in the gut through dietary interventions to impact human health.

Unravelling the involvement of gut microbiota in type 2 diabetes mellitus

Type 2 diabetes mellitus is the most prevalent metabolic disorder characterized by hyperglycemia, hyperlipidemia as well as insulin resistance and is affecting the lives of a huge population across the globe. Genetic mutations, obesity and lack of physical activity constitute the possible factors that can lead to onset and progression of this disorder. However, there is another major factor that can be the root cause of type 2 diabetes mellitus and that is an imbalance in the microorganisms that inhabit the gut. The gut microbiome is a vital component that needs to be given significant attention because any "dysbiosis" in the colonic microorganisms can transform the host from a state of health to a state of disease. This transformation is quite obvious since the gut barrier integrity, host metabolism such as sensitivity to insulin and maintaining blood glucose level are carried out by the tiny organisms inhabiting our intestine. In fact, the normal functioning of the human body is accredited to the microbes, particularly the bacteria, because they generate their metabolites that communicate with host cells and maintain normal physiology. Giving importance to gut health is, therefore, necessary to prevent metabolic diseases that can be maintained by the intake of prebiotics, probiotics, synbiotics along with healthy diet. The tiny microorganisms in the gut that keep our body free of disorders such as type 2 diabetes mellitus need to be in a state of 'eubiosis', else the consequences of disturbance in gut microbes can progress to serious complications in the host.

Saffron offers hepatoprotection via up-regulation of hepatic farnesoid-X-activated receptors in a rat model of acetaminophen-induced hepatotoxicity

OBJECTIVES

The most important toxicity of acetaminophen is hepatotoxicity. Farnesoid X-activated receptors (FXR) are one of the nuclear receptor superfamily members which have a pivotal role in the bile acid regulation. The objective of the present study was to examine the role of FXR in mediating the hepatoprotective effects of saffron.

METHODS

Male Wister rats were randomly allocated into five groups including a control, vehicle, acetaminophen and two saffron extract groups of 150 and 300 mg/kg/day. The liver function and hepatic FXR expression were evaluated using biochemical assay and real time RT-PCR, respectively. Data analysis was performed using the one-way ANOVA followed by Duncan's multiple range test.

RESULTS

Levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP) and lactate dehydrogenase (LDH) of the acetaminophen group were significantly higher than the control group whereas those of the extract-treated groups were significantly lower than those of the acetaminophen group. The real time RT-PCR findings showed a non-significant down-regulation of FXR mRNA expression, however, a dose-dependent FXR up-regulation was seen in the groups treated with 150 and 300 mg/kg of the extract for 2.67 (p=0.002) and 10.22 (p=0.0001) fold, respectively.

CONCLUSION

The main finding of the present study was that the hepatic FXR up-regulation had an important role in saffron hepatoprotective activity.