The influence of probiotics on bile acids in diseases and aging

Causal Analysis Between Gut Microbes, Aging Indicator, and Age-Related Disease, Involving the Discovery and Validation of Biomarkers

The influence of gut microbes on aging has been reported in several studies, but the mediating pathways of gut microbiota, whether there is a causal relationship between the two, and biomarker screening and validation have not been fully discussed. In this study, Mendelian Randomization (MR) and Linkage Disequilibrium Score Regression (LDSC) are used to systematically investigate the associations between gut microbiota, three aging indicators, and 14 age-related diseases. Additionally, this study integrates machine learning algorithms to explore the potential of MR and LDSC methods for biomarker screening. Gut microbiota is found to be a potential risk factor for 14 age-related diseases. The causal effects of gut microbiota on chronic kidney disease, cirrhosis, and heart failure are partially mediated by aging indicators. Additionally, gut microbiota identified through MR and LDSC methods exhibit biomarker properties for disease prediction (average AUC = 0.731). These methods can serve as auxiliary tools for conventional biomarker screening, effectively enhancing the performance of disease models (average AUC increased from 0.808 to 0.832). This study provides evidence that supports the association between the gut microbiota and aging and highlights the potential of genetic correlation and causal relationship analysis in biomarker discovery. These findings may help to develop new approaches for healthy aging detection and intervention.

Gut Microbiota Modulation Through Dietary Approaches Targeting Better Health During Metabolic Disorders

The impact of gut microbiota is known to play a significant role in an individual's metabolism and health. Many harmful food products or dietary imbalance adversely affect human health and changing lifestyle, environmental factors, and food habits may have their effect on gut microbiota. It has emerged that gut microbiota is regarded as an emerging metabolic organ, which is dependent on individual's diet and its composition. This review discusses the significance of lactic acid bacteria as a prominent inhabitant in the gut microbiota and the role of probiotics, prebiotics, and polyphenols to improve human health and metabolism. The role of fermented foods as an important source of probiotics and bioactive molecules is also discussed along with the role of gut microbiota in metabolic disorders like dyslipidemia, obesity, hypercholesterolemia, cancer, and hypertension. Finally, the review gives insights into the effective therapeutic prospects through gut microbiota alterations to tackle these metabolic disorders.

Bi-Directional Relationship Between Bile Acids (BAs) and Gut Microbiota (GM): UDCA/TUDCA, Probiotics, and Dietary Interventions in Elderly People

The gut microbiota (GM), the set of microorganisms that colonizes our intestinal tract, can undergo many changes, some of which are age related. Several studies have shown the importance of maintaining a healthy GM for a good quality of life. In the elderly, maintaining a good GM may become a real defense against infection by pathogens, such as C. difficile. In addition to the GM, bile acids (BAs) have been shown to provide an additional defense mechanism against the proliferation of pathogenic bacteria and to regulate bacterial colonization of the gut. BAs are molecules produced in the host liver and secreted with the bile into the digestive tract, and they are necessary for the digestion of dietary lipids. In the gut, host-produced BAs are metabolized by commensal bacteria to secondary BAs. In general GM and host organisms interact in many ways. This review examines the relationship between GM, BAs, aging, and possible new approaches such as dietary interventions, administration of ursodesoxycholic acid/tauroursodesoxycholic acid (UDCA/TUDCA), and probiotics to enrich the microbial consortia of the GM in the elderly and achieve a eubiotic state necessary for maintaining good health. The presence of Firmicutes and Actinobacteria together with adequate levels of secondary BAs would provide protection and improve the frailty state in the elderly. In fact, an increase in secondary BAs has been observed in centenarians who have reached old age without serious health issues, which may justify their active role in achieving longevity.

Delivery of Probiotic-Loaded Microcapsules in the Gastrointestinal Tract: A Review

Probiotics are live microorganisms that inhabit the gastrointestinal tract and confer health benefits to consumers. However, a sufficient number of viable probiotic cells must be delivered to the specific site of interest in the gastrointestinal tract to exert these benefits. Enhanced viability and tolerance to sublethal gastrointestinal stress can be achieved using appropriate coating materials and food matrices for orally consumed probiotics. The release mechanism and interaction of probiotic microcapsules with the gastrointestinal tract have been minimally explored in the literature to date. To the authors' knowledge, no review has been published to discuss the nature of release and the challenges in the targeted delivery of probiotics. This review addresses gastrointestinal-related complications in the formulation of targeted delivery and controlled release of probiotic strains. It investigates the impacts of environmental stresses during the transition stage and delivery to the target region in the gastrointestinal tract. The influence of factors such as pH levels, enzymatic degradation, and redox conditions on the release mechanisms of probiotics is presented. Finally, the available methods to evaluate the efficiency of a probiotic delivery system, including in vitro and in vivo, are reviewed and assessed. The paper concludes with a discussion highlighting the emerging technologies in the field and emphasising key areas in need of future study.

Achieving healthy aging through gut microbiota-directed dietary intervention: Focusing on microbial biomarkers and host mechanisms

BACKGROUND

Population aging has become a primary global public health issue, and the prevention of age-associated diseases and prolonging healthy life expectancies are of particular importance. Gut microbiota has emerged as a novel target in various host physiological disorders including aging. Comprehensive understanding on changes of gut microbiota during aging, in particular gut microbiota characteristics of centenarians, can provide us possibility to achieving healthy aging or intervene pathological aging through gut microbiota-directed strategies.

AIM OF REVIEW

This review aims to summarize the characteristics of the gut microbiota associated with aging, explore potential biomarkers of aging and address microbiota-associated mechanisms of host aging focusing on intestinal barrier and immune status. By summarizing the existing effective dietary strategies in aging interventions, the probability of developing a diet targeting the gut microbiota in future is provided.

KEY SCIENTIFIC CONCEPTS OF REVIEW

This review is focused on three key notions: Firstly, gut microbiota has become a new target for regulating health status and lifespan, and its changes are closely related to age. Thus, we summarized aging-associated gut microbiota features at the levels of key genus/species and important metabolites through comparing the microbiota differences among centenarians, elderly people and younger people. Secondly, exploring microbiota biomarkers related to aging and discussing future possibility using dietary regime/components targeted to aging-related microbiota biomarkers promote human healthy lifespan. Thirdly, dietary intervention can effectively improve the imbalance of gut microbiota related to aging, such as probiotics, prebiotics, and postbiotics, but their effects vary among.

Regulation of bile acids and their receptor FXR in metabolic diseases

High sugar, high-fat diets and unhealthy lifestyles have led to an epidemic of obesity and obesity-related metabolic diseases, seriously placing a huge burden on socio-economic development. A deeper understanding and elucidation of the specific molecular biological mechanisms underlying the onset and development of obesity has become a key to the treatment of metabolic diseases. Recent studies have shown that the changes of bile acid composition are closely linked to the development of metabolic diseases. Bile acids can not only emulsify lipids in the intestine and promote lipid absorption, but also act as signaling molecules that play an indispensable role in regulating bile acid homeostasis, energy expenditure, glucose and lipid metabolism, immunity. Disorders of bile acid metabolism are therefore important risk factors for metabolic diseases. The farnesol X receptor, a member of the nuclear receptor family, is abundantly expressed in liver and intestinal tissues. Bile acids act as endogenous ligands for the farnesol X receptor, and erroneous FXR signaling triggered by bile acid dysregulation contributes to metabolic diseases, including obesity, non-alcoholic fatty liver disease and diabetes. Activation of FXR signaling can reduce lipogenesis and inhibit gluconeogenesis to alleviate metabolic diseases. It has been found that intestinal FXR can regulate hepatic FXR in an organ-wide manner. The crosstalk between intestinal FXR and hepatic FXR provides a new idea for the treatment of metabolic diseases. This review focuses on the relationship between bile acids and metabolic diseases and the current research progress to provide a theoretical basis for further research and clinical applications.

In Vitro Screening of Bacterial Isolates From Dairy Products for Probiotic Properties and Other Health-Promoting Attributes

The present research was aimed to isolate potential probiotic organisms from dairy products locally made in and around the Saurashtra region of Gujarat. A total of 224 colonies were screened for primary attributes. Based on the results, 70 isolates were carried further for secondary screening. Out of these, only 23 isolates were further tested for antioxidant activities. Only 6 potential probiotic strains were found to have all the probiotic attributes. These isolates demonstrated survivability up to 4 h at pH ≤ 3, bile concentration ≥ 1.5%, autoaggregation ability ≥ 81.08%, and cell surface hydrophobicity more than 70% while using toluene as the test hydrocarbon. The promising six isolates were subjected to 16S rRNA sequencing for species-level identification and found to be belonging to the genus Bacillus, Enterococcus, and Lactobacillus. The isolates demonstrated higher antioxidant potential as determined by ABTS, DPPH, and FRAP methods. For all three methods, L. rhamnosus was taken as a positive control that showed 85.61%, 39.56%, and 78.18% reduction of free radicals as determined by the ABTS, DPPH, and FRAP methods, respectively. Compared to this, Limosilactobacillus fermentum BAB 7912 demonstrated the highest reduction of ABTS radicals (83.45%), while Bacillus subtilis BAB 7918 reduced 29.95% DPPH free radicals and Bacillus spizizenii BAB 7915 reduced 80.93% ferric ions as determined by the FRAP method. Isolates were subjected to 16S rRNA sequencing for species-level identification and found to be belonging to genus Bacillus, Enterococcus, and Lactobacillus.

Evaluation of probiotic bifidobacteria strains from Iranian traditional dairy products for their anti-hyperlipidemic potential

This study investigated the therapeutic potential of probiotic bifidobacteria, isolated from Iranian fermented dairy products, in a hyperlipidemic animal model. Bifidobacterium strains were extracted from traditional dairy samples and screened using physiological and phenotypic examinations, 16S rRNA analysis, and probiotic properties such as tolerance to gastrointestinal juice, antimicrobial activity, and antibiotic susceptibility. The ability of the screened bifidobacteria to reduce serum and liver lipids in vivo was tested using male Wistar rats. Six strains of bifidobacteria were isolated from traditional Iranian fermented dairy. These strains showed promising in vitro activity in lowering triglyceride and cholesterol, tolerance to simulated gastrointestinal juice, the ability to adhere to Caco-2 cells, acceptable antibiotic susceptibility, and a broad spectrum of antibacterial activity. The diet supplemented with isolated bifidobacteria significantly reduced serum total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), liver tissue lipid levels, and hepatic enzymes in animals when compared to a high-fat diet without strains (p < 0.01). Additionally, the potential probiotic-supplemented diet significantly increased bile acid excretion in the feces and upregulated hepatic CYP7A1 expression levels (p < 0.05), while NPC1L1, ACAT2, and MTP gene expressions in small intestinal cells were downregulated (p < 0.05). Bifidobacteria isolated from Iranian traditional dairy showed potential for use in the production of fermented foods that have hypolipemic activity in the host.

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.

Lactiplantibacillus plantarum strains KABP011, KABP012, and KABP013 modulate bile acids and cholesterol metabolism in humans

AIMS

Probiotics with high bile salt hydrolase (BSH) activity have shown to promote cardiovascular health. However, their mechanism(s) of action remain poorly understood. Here, we performed a pilot exploratory study to investigate effects of a 4-week intervention with escalating doses of a BSH-active formula containing Lactiplantibacillus plantarum strains KABP011, KABP012, and KABP013 on bile acid (BA), lipid profile, and lipoprotein function.

METHODS AND RESULTS

Healthy overweight individuals were included in this study. The probiotic intake was associated with a progressive decrease of conjugated BAs in serum, due to the reduction of tauro- and glyco-conjugated forms. Plasma levels of fibroblast growth factor-19 were significantly reduced and correlated with BA changes. The probiotic induced significant changes in serum lipids, with reduction in non-HDL cholesterol (non-HDLc) and LDL cholesterol (LDLc) levels. The largest decrease was evidenced in the subgroup with higher baseline LDLc levels (LDLc > 130 mg/dL). Fasting levels of circulating apolipoprotein(Apo) B100 and ApoB48 were significantly reduced. Importantly, the decrease in non-HDLc levels was associated with a significant reduction in small LDL particles. Functional testing indicated that LDL particles had a significantly lower susceptibility to oxidation, while HDL particles gained antioxidant capacity after the probiotic intake. The microbiota profile in faeces collected at the end of the study was enriched with members of class Desulfovibrio, a taurine-consuming bacteria, likely because of the increase in free taurine in the gut due to the BSH activity of the probiotic.

CONCLUSION

The intervention with L. plantarum strains induces beneficial effects on BA signature and lipoprotein profile. It reduces ApoB and small LDL levels and LDL susceptibility to oxidation and increases HDL antioxidant capacity. These metabolic profile changes suggest increased protection against atherosclerotic disease.

Probiotic Mixture Ameliorates a Diet-Induced MASLD/MASH Murine Model through the Regulation of Hepatic Lipid Metabolism and the Gut Microbiome

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a prevalent metabolic disease that has no effective treatment. Our proprietary probiotic mixture, Prohep, has been proven in a previous study to be helpful in reducing hepatocellular carcinoma (HCC) in vivo. However, its prospective benefits on the treatment of other liver diseases such as MASLD, which is one of the major risk factors in the development of HCC, are unclear. To investigate the potential of Prohep in modulating the development and progression of MASLD, we first explored the effect of Prohep supplementation via voluntary intake in a high-fat diet (HFD)-induced MASLD/metabolic dysfunction-associated steatohepatitis (MASH) murine model. Our results indicated that Prohep alleviated HFD-induced liver steatosis and reduced excessive hepatic lipid accumulation and improved the plasma lipid profile when compared with HFD-fed control mice through suppressing hepatic de novo lipogenesis and cholesterol biosynthesis gene expressions. In addition, Prohep was able to modulate the gut microbiome, modify the bile acid (BA) profile, and elevate fecal short-chain fatty acid (SCFA) levels. Next, in a prolonged HFD-feeding MASLD/MASH model, we observed the effectiveness of Prohep in preventing the transition from MASLD to MASH via amelioration in hepatic steatosis, inflammation, and fibrosis. Taken together, Prohep could ameliorate HFD-induced MASLD and control the MASLD-to-MASH progression in mice. Our findings provide distinctive insights into the development of novel microbial therapy for the management of MASLD and MASH.

Invitro and Invivo Analysis of Human Milk Lactic Acid Bacteria Isolates for Their Anti-hypercholesterolemia Actions

The aim of this study was to evaluate the cholesterol lowering ability of Lactic Acid Bacteria (LAB) isolated from human breast milk under in vitro and in vivo conditions. Six LAB isolates namely Lacticaseibacillus casei 1A, Lactobacillus gasseri 5A, Enterococcus faecium 2C, Limosilactobacillus fermentum 3D, Pediococcus acidilactici 1C, and Lactiplantibacillus plantarum 7A, were examined for their bile resistance, bile salt hydrolase activity, cholesterol assimilation and viability in cholesterol rich; DeMan Rogosa and Sharpe broth, simulated gastric, small and upper intestinal conditions. During in vivo experiments, two putative LAB isolates were orally gavage to BALB/c mice, fed with normal basal and cholesterol rich (HCD) diets, daily for a period of 4 weeks. Blood serum analysis including total serum cholesterol, triglycerides, high-density and low-density lipoprotein (LDL) cholesterol levels and total fecal LAB counts of the animals were determined. The isolates in study showed bile resistance and bile salt hydrolysis activity, while significant differences (P < 0.05) were seen in their cholesterol assimilation ability. L. gasseri 5A (195.67%) and L. plantarum 7A (193.78%) displayed highest cholesterol removal percentages, respectively. Animals in HCD, fed with L. gasseri 5A and L. plantarum 7A showed decreased levels of total cholesterol and LDL, compared to the control groups. In HCD group liver weight was increased, while fecal LAB counts were decreased. No changes were observed in behavior or body weight in all experimental groups. In conclusion, L. gasseri 5A and L. plantarum 7A isolated from human breast milk demonstrates significant hypocholesterolaemic actions in vitro and in vivo and might be considered a promising candidates for preventing hypercholesterolemia in man and animals.

Reduced liver damage and fibrosis with combined SCD Probiotics and intermittent fasting in aged rat

This study aimed to examine the impact of SCD Probiotics supplementation on liver biomolecule content and histological changes during a 30-day intermittent fasting (IF) program in 24-month-old male Sprague-Dawley rats. Rats underwent 18-h daily fasting and received 1 × 108 CFU of SCD Probiotics daily. Liver tissue biomolecules were analysed using FTIR Spectroscopy, LDA, and SVM techniques, while histopathological evaluations used Haematoxylin and eosin and Masson trichrome-stained tissues. Blood samples were collected for biochemical analysis. Gross alterations in the quantity of biomolecules were observed with individual or combined treatments. LDA and SVM analyses demonstrated a high accuracy in differentiating control and treated groups. The combination treatments led to the most significant reduction in cholesterol ester (1740 cm-1 ) and improved protein phosphorylation (A1239 /A2955 and A1080 /A1545 ) and carbonylation (A1740 /A1545 ). Individually, IF and SCD Probiotics were more effective in enhancing membrane dynamics (Bw2922 /Bw2955 ). In treated groups, histological evaluations showed decreased hepatocyte degeneration, lymphocyticinfiltration, steatosis and fibrosis. Serum ALP, LDH and albumin levels significantly increased in the SCD Probiotics and combined treatment groups. This study offers valuable insights into the potential mechanisms behind the beneficial effects of IF and SCD Probiotics on liver biomolecule content, contributing to the development of personalized nutrition and health strategies.

Replacement of Dietary Fish Protein with Bacterial Protein Results in Decreased Adiposity Coupled with Liver Gene Expression Changes in Female Danio rerio

Background

Effective use of Danio rerio as a preclinical model requires standardization of macronutrient sources to achieve scientific reproducibility across studies and labs.

Objective

Our objective was to evaluate a bacterial-based single-cell protein (SCP) for the production of open-source standardized diets with defined health characteristics for the zebrafish research community.

Methods

We completed a 16-wk feeding trial using juvenile D. rerio 31 d postfertilization (10 tanks per diet and 14 D. rerio per tank) with formulated diets containing either a typical fish protein ingredient [standard reference (SR) diet] or a novel bacterial SCP source [bacterial protein (BP) diet]. At the end of the feeding trial, growth metrics, body composition, reproductive success, and bulk transcriptomics of the liver (RNAseq on female D. rerio with confirmatory rtPCR) were performed for each diet treatment.

Results

D. rerio fed the BP diet had body weight gains equivalent to the D. rerio fed fish protein, and females had significantly lower total carcass lipid, indicating reduced adiposity. Reproductive success was similar between treatments, suggesting normal physiological function. Genes differentially expressed in female D. rerio fed the BP diet compared with females fed the SR diet were overrepresented in the gene ontologies of metabolism, biosynthesis of cholesterol precursors and products, and protein unfolding responses.

Conclusion

Protein source substantially affected body growth metrics and composition as well as gene expression. These data support the development of an open-source diet utilizing an ingredient that correlates with improved health profiles and reduced variability in notable outcomes.

The Protective Effect of Roseburia faecis Against Repeated Water Avoidance Stress-induced Irritable Bowel Syndrome in a Wister Rat Model

Roseburia faecis, a butyrate-producing, gram-positive anaerobic bacterium, was evaluated for its usefulness against repeated water avoidance stress (WAS)-induced irritable bowel syndrome (IBS) in a rat model, and the underlying mechanism was explored. We divided the subjects into three groups: one without stress exposure, another subjected to daily 1-hour WAS for 10 days, and a third exposed to the same WAS regimen while also receiving two different R. faecis strains (BBH024 or R22-12-24) via oral gavage for the same 10-day duration. Fecal pellet output (FPO), a toluidine blue assay for mast cell infiltration, and fecal microbiota analyses were conducted using 16S rRNA metagenomic sequencing. Predictive functional profiling of microbial communities in metabolism was also conducted. FPO and colonic mucosal mast cell counts were significantly higher in the WAS group than in the control group (male, P = 0.004; female, P = 0.027). The administration of both BBH024 (male, P = 0.015; female, P = 0.022) and R22-12-24 (male, P = 0.003; female, P = 0.040) significantly reduced FPO. Submucosal mast cell infiltration in the colon showed a similar pattern in males. In case of fecal microbiota, the WAS with R. faecis group showed increased abundance of the Roseburia genus compared to WAS alone. Moreover, the expression of a gene encoding a D-methionine transport system substrate-binding protein was significantly elevated in the WAS with R. faecis group compared to that in the WAS (male, P = 0.028; female, P = 0.025) group. These results indicate that R. faecis is a useful probiotic for treating IBS and colonic microinflammation.

Mechanisms of action of coffee bioactive compounds - a key to unveil the coffee paradox

The knowledge of the relationship between the chemical structure of food components with their mechanisms of action is crucial for the understanding of diet health benefits. This review relates the chemical variability present in coffee beverages with the mechanisms involved in key physiological events, supporting coffee as a polyvalent functional food. Coffee intake has been related with several health-promoting properties such as neuroprotective (caffeine, chlorogenic acids and melanoidins), anti-inflammatory (caffeine, chlorogenic acids, melanoidins, diterpenes), microbiota modulation (polysaccharides, melanoidins, chlorogenic acids), immunostimulatory (polysaccharides), antidiabetic (trigonelline, chlorogenic acids), antihypertensive (chlorogenic acids) and hypocholesterolemic (polysaccharides, chlorogenic acids, lipids). Nevertheless, caffeine and diterpenes are coffee components with ambivalent effects on health. Additionally, a large range of potentially harmful compounds, including acrylamide, hydroxymethylfurfural, furan, and advanced glycation end products, are formed during the roasting of coffee and are present in the beverages. However, coffee beverages are part of the daily human dietary healthy habits, configuring a coffee paradox.

Prevention of High-Fat-Diet-Induced Dyslipidemia by Lactobacillus plantarum LP104 through Mediating Bile Acid Enterohepatic Axis Circulation and Intestinal Flora

This work aimed to investigate the alleviative mechanism of Lactobacillus plantarum LP104 (LP104) isolated from kimchi on high-fat-diet-induced dyslipidemia by targeting the intestinal flora and bile acid (BA) metabolism. Oral administration of LP104 over 8 weeks reduced body weight gain and body fat, as well as ameliorating serum and hepatic dyslipidemia in HFD-fed C57BL/6N mice significantly. LP104 intervention also increased the ileal tauro-α/β-muricholic acid sodium salt (T-α-MCA or T-β-MCA) and tauroursodeoxycholic acid (TUDCA) concentrations to suppress the enterohepatic farnesoid X receptor/fibroblast growth factor 15-fibroblast growth factor receptor 4 (FXR/FGF15-FGFR4) signaling pathway, which stimulated the hepatic cholic acid (CA) and chenodeoxycholic acid (CDCA) de novo synthesis through using cholesterol. Then, LP104 treatment accelerated BA excretion with the feces and cholesterol efflux to improve HFD-caused hyperlipidemia effectively. The 16S rRNA gene high-throughput sequencing revealed that LP104 promoted intestinal flora rebalance by increasing the abundances of Bacteroides, Akkermansia, Lactobacillus, and Clostridium and decreasing the abundance of Oscillospira and Coprococcus. Meanwhile, Spearman correlation analysis demonstrated that the differential flora were closely related to BA signaling molecules including CA, CDCA, T-α-MCA, T-β-MCA, and TUDCA after LP104 intervention. These findings provided new evidence that LP104 had the potential to be used as a naturally functional food for the prevention of dyslipidemia.

The Expression Levels of Genes Responsible for the Enzymatic Activity of Bile Salt Hydrolase (BSH) and the Relationship of Cholesterol Assimilation in L. plantarum and L. paracasei

The bile salt hydrolase (BSH) activity is responsible for the cholesterol-lowering effect of the probiotic strains. The present study aimed to investigate the relationship between bsh gene-expression (GE) levels responsible for the BSH activity and the parameters of bile salt resistance of different Lactobacillaceae species. Accordingly, 11 Lactobacillaceae family strains with high cholesterol assimilation ratio (49.21-68.22%) determined by the o-phthalaldehyde method selected from 46 Lactobacillaceae species was evaluated for their features including acid tolerance, bile tolerance, and BSH activity. All tested strains survived at pH 2 medium and 0.3% (w/v) bile salt and showed positive BSH activity for glycocholic acid (GCA) and taurocholic acid (TCA). BSH gene expression was performed to provide clear information and to identify the key genes responsible for BSH activity. bsh3 genes were found highest GE level (P < 0.05) in Lactiplantibacillus plantarum and Lacticaseibacillus paracasei strains. The results showed that high cholesterol assimilation ratio were closely correlated with BSH activity and the parameters of bile salt resistance. The results of this study will support the development of a new approach based on phenotypic and genetic analysis to determine the bile salt parameters. The study will be useful for the selection of Lactobacillus strains with high bile salt resistance.

Connecting the Gut Microbiota and Neurodegenerative Diseases: the Role of Bile Acids

With the acceleration of global population aging, neurodegenerative diseases (NDs) will become the second leading cause of death in the world, which seriously threatens human life and health. Alzheimer's disease and Parkinson's disease are the most common and typical NDs. The exact mechanisms of the NDs occurrence and development remain unclear, which may be related to immune, oxidative stress, and abnormal aggregation of pathogenic proteins. Studies have suggested that gut microbiota (GM) influences brain function and plays an important role in regulating emotional and cognitive function. Recently, bile acids (BAs) have become the "star molecule" in the microbiota-gut-brain (MGB) axis research. BAs have been reported to exert anti-inflammatory, antioxidant, and neuroprotective activities in NDs. However, the role of BAs in the connection between GM and the central nervous system (CNS) is still unclear. In this review, we will review the possible mechanisms of BAs between GM and NDs and explore the function of BAs to provide ideas for the prevention and treatment of NDs in the future.

Enterococcus faecium R-026 combined with Bacillus subtilis R-179 alleviate hypercholesterolemia and modulate the gut microbiota in C57BL/6 mice

Probiotics have been demonstrated to lower total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) in individuals with mild hypercholesterolemia. Our previous study found that intervention with Bacillus subtilis R-179 and Enterococcus faecium R-026, well-known probiotics, improved obesity-associated dyslipidemia through ameliorating the gut microbiota, but similar studies on hypercholesterolemia have not been reported to date. Here, we investigated the therapeutic effect of live combined B. subtilis R-179 and E. faecium R-026 (LCBE) in a C57BL/6 mouse model of hypercholesterolemia. A total of 40 mice were administered with a high-cholesterol diet (containing 1.2% cholesterol) to establish a state of hypercholesterolemia for 4 weeks. Then, mice were divided into one model group (group M) and three treatment groups (n = 10 per group), which were administered with LCBE at 0.023 g/mouse/day (group L) or 0.230 g/mouse/day (group H), or atorvastatin 0.010 g/kg/day (group A), for 5 weeks while on a high-cholesterol diet. LCBE at high doses significantly alleviated the symptoms of group M and reduced serum TC, LDL-C, and lipopolysaccharide (LPS). LCBE improved liver steatosis and adipocyte enlargement caused by a high-cholesterol diet. In addition, the administration of LCBE regulated the change in gut microbiota and diversity (Shannon index). Compared with group M, the relative abundance of Actinobacteriota, Colidextribacter, and Dubosiella dramatically decreased in the treatment groups, which were positively correlated with serum TC and LPS. These findings indicated that the mechanism of action of LCBE in treating hypercholesterolemia may be modulation of the gut microbiota. In conclusion, LCBE ameliorated lipid accumulation, reduced inflammation, and alleviated the gut microbiota imbalance in hypercholesterolemic mice. These findings support the probiotic role of LCBE as a clinical candidate for the treatment of hypercholesterolemia.

Biological tuners to reshape the bile acid pool for therapeutic purposes in non-alcoholic fatty liver disease

Bile acids synthesized within the hepatocytes are transformed by gut microorganisms and reabsorbed into the portal circulation. During their enterohepatic cycling, bile acids act as signaling molecules by interacting with receptors to regulate pathways involved in many physiological processes. The bile acid pool, composed of a variety of bile acid species, has been shown to be altered in diseases, hence contributing to disease pathogenesis. Thus, understanding the changes in bile acid pool size and composition in pathological processes will help to elaborate effective pharmacological treatments. Five crucial steps along the enterohepatic cycle shape the bile acid pool size and composition, offering five possible targets for therapeutic intervention. In this review, we provide an insight on the strategies to modulate the bile acid pool, and then we discuss the potential benefits in non-alcoholic fatty liver disease.

Comparative plasma and urine metabolomics analysis of juvenile and adult canines

Background and aims

The metabolomic profile of a biofluid can be affected by age, and thus provides detailed information about the metabolic alterations in biological processes and reflects the in trinsic rule regulating the growth and developmental processes.

Methods

To systemically investigate the characteristics of multiple metabolic profiles associated with canine growth, we analyzed the metabolomics in the plasma and urine samples from 15 young and 15 adult beagle dogs via UHPLC-Q-TOFMS-based metabolomics. Blood routine and serum biochemical analyses were also performed on fasting blood samples.

Results

The metabolomics results showed remarkable differences in metabolite fingerprints both in plasma and urine between the young and adult groups. The most obvious age-related metabolite alterations include decreased serumlevels of oxoglutaric acid and essential amino acids and derivatives but increased levels of urine levels of O-acetylserine. These changes primarily involved in amino acid metabolism and bile secretion pathways. We also found that the levels of glutamine were consistently higher in both serum and urine of adults, while N-acetylhistamine and uracil concentrations were much lower in the adult group compared to younger ones.

Conclusion

Our study provides a whole metabolic profile of serum and urine characteristics of young and adult canines, identifying several metabolites that were significantly associated with age change, which provides theoretical support for the nutrition-related research and age-related homeostasis maintenance in dogs.

Probiotic Regulation to Modulate Aging Gut and Brain Health: A Concise Review

The human gastrointestinal (GI) tract contains a diverse mixture of commensal and pathogenic microbes, forming the gut microbiome. These gut microbes and their potential to improve human health are a topic of great interest to the scientific community. Many intestinal and age-related complications are linked to dysbiosis of the gut microbiome, often associated with a weakened immune system. A decrease in beneficial microbes, generally, along with decreased microbial diversity in the gut, can, in many cases, result in disease, particularly in older individuals. Probiotics, which are ingestible beneficial microorganisms, have the potential to positively modulate the indigenous gut microbiota. There are two predominant and conventional classes of lactic acid bacterial probiotics, lactobacilli and bifidobacteria, which have been confirmed for their health benefits and role in preventing certain gut-related disorders. The proper use of probiotics and/or supplements, along with a consistently healthy lifestyle, is a promising holistic approach to maintaining or improving gut health and minimizing other age-linked disorders. There are many properties that bacterial probiotics possess, which may allow for these beneficial effects in the gut. For instance, probiotics have adhesion capacities (capability to stay in GI tract) that are effective in excluding pathogens, while other probiotics have the potential to stimulate or modulate the intestinal immune system by regulating genes that reside within and outside of the gut environment. This review discussed the possible underlying mechanics of probiotics, evidence of probiotic-based mitigation of age-related disease, and the role of probiotics in modulating gut health and, in turn, maintaining brain health.

Probiotics protect against hepatic steatosis in tris (2-chloroethyl) phosphate-induced metabolic disorder of mice via FXR signaling

Tris (2-chloroethyl) phosphate (TCEP), the most widely useful and most frequently detective organophosphate flame retardants in environment, has been shown potential relationship with adolescent weight. Probiotics is an effective therapy for metabolic diseases such as obesity and NAFLD with gut microbiota dysregulation. This study aims to explore the protective effects of probiotics against lipid metabolic disorder induced by chronic TCEP exposure and demonstrate the mechanism of this event. The data showed that dietary complex probiotics supplement attenuated TCEP-induced obesity, hyperlipidemia, liver dysfunction, and hepatic steatosis. In addition, dietary complex probiotics suppressed TCEP-promoted ileal FXR signaling, and upregulated hepatic FXR/SHP pathway inhibited by TCEP. Moreover, dietary complex probiotics stimulated PPARα-mediated lipid oxidation and suppressed SREBP1c/PPARγ-mediated lipid synthesis via regulation of FXR signaling. Therefore, this study indicates that dietary complex probiotics could protect against hepatic steatosis via FXR-mediated signaling pathway in TCEP-induced metabolism disorder in mice, resulting in attenuation of systemic lipid accumulation.

Age-Related NAFLD: The Use of Probiotics as a Supportive Therapeutic Intervention

Human aging, a natural process characterized by structural and physiological changes, leads to alterations of homeostatic mechanisms, decline of biological functions, and subsequently, the organism becomes vulnerable to external stress or damage. In fact, the elderly population is prone to develop diseases due to deterioration of physiological and biological systems. With aging, the production of reactive oxygen species (ROS) increases, and this causes lipid, protein, and DNA damage, leading to cellular dysfunction and altered cellular processes. Indeed, oxidative stress plays a key role in the pathogenesis of several chronic disorders, including hepatic diseases, such as non-alcoholic fatty liver disease (NAFLD). NAFLD, the most common liver disorder in the Western world, is characterized by intrahepatic lipid accumulation; is highly prevalent in the aging population; and is closely associated with obesity, insulin resistance, hypertension, and dyslipidemia. Among the risk factors involved in the pathogenesis of NAFLD, the dysbiotic gut microbiota plays an essential role, leading to low-grade chronic inflammation, oxidative stress, and production of various toxic metabolites. The intestinal microbiota is a dynamic ecosystem of microbes involved in the maintenance of physiological homeostasis; the alteration of its composition and function, during aging, is implicated in different liver diseases. Therefore, gut microbiota restoration might be a complementary approach for treating NAFLD. The administration of probiotics, which can relieve oxidative stress and elicit several anti-aging properties, could be a strategy to modify the composition and restore a healthy gut microbiota. Indeed, probiotics could represent a valid supplement to prevent and/or help treating some diseases, such as NAFLD, thus improving the already available pharmacological intervention. Moreover, in aging, intervention of prebiotics and fecal microbiota transplantation, as well as probiotics, will provide novel therapeutic approaches. However, the relevant research is limited, and several scientific research works need to be done in the near future to confirm their efficacy.

Probiotics Administration in Cystic Fibrosis: What Is the Evidence?

In the last 20 years, gut microbiota in patients with cystic fibrosis (CF) has become an object of interest. It was shown that these patients had gut dysbiosis and this could explain not only the intestinal manifestations of the disease but also part of those involving the respiratory tract. The acquisition of previously unknown information about the importance of some bacteria, i.e., those partially or totally disappeared in the gut of CF patients, in the regulation of the activity and function of the gut and the lung was the base to suggest the use of probiotics in CF patients. The main aim of this paper is to discuss the biological basis for probiotic administration to CF patients and which results could be expected. Literature analysis showed that CF intestinal dysbiosis depends on the same genetic mutations that condition the clinical picture of the diseases and is aggravated by a series of therapeutic interventions, such as dietary modifications, the use of antibiotics, and the administration of antacids. All this translates into a significant worsening of the structure and function of organs, including the lung and intestine, already deeply penalized by the genetic alterations of CF. Probiotics can intervene on dysbiosis, reducing the negative effects derived from it. However, the available data cannot be considered sufficient to indicate that these bacteria are essential elements of CF therapy. Further studies that take into account the still unsolved aspects on how to use probiotics are absolutely necessary.

Quantitative Profiling of Bile Acids in Feces of Humans and Rodents by Ultra-High-Performance Liquid Chromatography–Quadrupole Time-of-Flight Mass Spectrometry

A simple, sensitive, and reliable quantification and identification method was developed and validated for simultaneous analysis of 58 bile acids (BAs) in human and rodent (mouse and rat) fecal samples. The method involves an extraction step with a 5% ammonium–ethanol aqueous solution; the BAs were quantified by high-resolution mass spectrometry (ultra-high-performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry, UPLC–Q-TOF). The recoveries were 80.05–120.83%, with coefficient variations (CVs) of 0.01–9.82% for three biological species. The limits of detection (LODs) were in the range of 0.01–0.24 μg/kg, and the limits of quantification (LOQs) ranged from 0.03 to 0.81 μg/kg. In addition, the analytical method was used to identify and quantify BAs in end-stage renal disease (ESRD) patients, C57BL/6 mice, and Sprague-Dawley (SD) rats. The fecal BA profile and analysis of BA indices in these samples provide valuable information for further BA metabolic disorder research.

Metabolites of Gut Microbiota and Possible Implication in Development of Diabetes Mellitus

Diabetes mellitus is characterized by having a disorder of glucose metabolism. The types of diabetes mellitus include type 1 diabetes mellitus, type 2 diabetes mellitus, gestational diabetes mellitus, and other specific types of diabetes mellitus. Many risk factors contribute to diabetes mellitus mainly including genetics, environment, obesity, and diet. In the recent years, gut microbiota has been shown to be linked to the development of diabetes. It has been reported that the gut microbiota composition of diabetic patients is different from that of healthy people. Although the mechanism behind the abnormality remains to be explored, most hypotheses focus on the inflammation response and leaky gut in relation to the changes in production of endotoxins and metabolites derived from the intestinal flora. Consequently, the above-mentioned abnormalities trigger a series of metabolic changes, gradually leading to development of hyperglycemia, insulin resistance, and diabetes. This review is (i) to summarize the differences in gut microbiota between diabetic patients and healthy people, (ii) to discuss the underlying mechanism(s) by which how lipopolysaccharide, diet, and metabolites of the gut microbiota affect diabetes, and (iii) to provide a new insight in the prevention and treatment of diabetes.

Limosilactobacillus reuteri in Health and Disease

Limosilactobacillus reuteri is a microorganism with valuable probiotic qualities that has been widely employed in humans to promote health. It is a well-studied probiotic bacterium that exerts beneficial health effects due to several metabolic mechanisms that enhance the production of anti-inflammatory cytochines and modulate the gut microbiota by the production of antimicrobial molecules, including reuterin. This review provides an overview of the data that support the role of probiotic properties, and the antimicrobial and immunomodulatory effects of some L. reuteri strains in relation to their metabolite production profile on the amelioration of many diseases and disorders. Although the results discussed in this paper are strain dependent, they show that L. reuteri, by different mechanisms and various metabolites, may control body weight and obesity, improve insulin sensitivity and glucose homeostasis, increase gut integrity and immunomodulation, and attenuate hepatic disorders. Gut microbiota modulation by ingesting probiotic L. reuteri strains could be a promising preventative and therapeutic approach against many diseases and disorders.

The Impact of Lab4 Probiotic Supplementation in a 90-Day Study in Wistar Rats

The anti-inflammatory and cholesterol lowering capabilities of probiotic bacteria highlight them as potential prophylactics against chronic inflammatory diseases, particularly cardiovascular disease. Previous studies in silico, in vitro, and in vivo suggest that the Lab4 probiotic consortium may harbour such capabilities and in the current study, we assessed plasma levels of cytokines/chemokines, short chain fatty acids and lipids and faecal levels of bile acids in a subpopulation of healthy Wistar rats included in 90-day repeat dose oral toxicity study. In the rats receiving Lab4, circulating levels of pro-inflammatory interleukin-6, tumour necrosis factor-α and keratinocyte chemoattractant/growth regulated oncogene were significantly lower compared to the control group demonstrating a systemic anti-inflammatory effect. These changes occurred alongside significant reductions in plasma low density lipoprotein cholesterol and increases in faecal bile acid excretion implying the ability to lower circulating cholesterol via the deconjugation of intestinal bile acids. Correlative analysis identified significant associations between plasma tumour necrosis factor-α and the plasma total cholesterol:high density lipoprotein cholesterol ratio and faecal levels of bifidobacteria in the Lab4 rats. Together, these data highlight Lab4 supplementation as a holistic approach to CVD prevention and encourages further studies in humans.

Polygoni Multiflori Radix Praeparata Ethanol Extract Exerts a Protective Effect Against High-Fat Diet Induced Non-Alcoholic Fatty Liver Disease in Mice by Remodeling Intestinal Microbial Structure and Maintaining Metabolic Homeostasis of Bile Acids

In the prescription of Traditional Chinese Medicine for lipid metabolism, Polygoni Multiflori Radix Preparata (ZhiHeShouWu, RPMP) was widely used. In recent years, RPMP ethanol extract has been reported for the treatment of non-alcoholic fatty liver disease (NAFLD). However, the role of RPMP ethanol extract in the treatment of NAFLD has not been fully elucidated. Therefore, we examined the optimal therapeutic dose of RPMP ethanol extracts. Afterward, a mouse model of non-alcoholic fatty liver induced by a high-fat diet (HFD) was treated with RPMP ethanol extract to further evaluate the mechanism of action of RPMP ethanol extract treatment. And the serum lipid metabolism indexes and liver function indexes showed that the RPMP ethanol extract in the 1.35 g/kg dose group exhibited better therapeutic effects than the 2.70 g/kg dose group. Meanwhile, RPMP ethanol extract can regulate the biochemical indicators of serum and liver to normal levels, and effectively reduce liver steatosis and lipid deposition. RPMP ethanol extract treatment restored HFD-induced disruption of the compositional structure of the intestinal microbial (IM) and bile acids (BAs) pools. And restore the reduced expression of intestinal barrier-related genes caused by HFD administration, which also effectively regulates the expression of genes related to the metabolism of BAs in mice. Thus, RPMP ethanol extract can effectively improve the abnormal lipid metabolism and hepatic lipid accumulation caused by HFD, which may be related to the regulation of IM composition, maintenance of intestinal barrier function, and normal cholesterol metabolism in the body.

Fostering next-generation probiotics in human gut by targeted dietary modulation: An emerging perspective

Emerging evidence and an in-depth understanding of the microbiome have helped in identifying beneficial commensals and their therapeutic potentials. Specific commensal taxa/ strains of the human gut microbiome have been positively associated with human health and recently termed as next-generation probiotics (NGPs). Of these, Akkermansia muciniphila, Ruminococcus bromii, Faecalibacterium prausnitzii, Anaerobutyricum hallii, and Roseburia intestinalis are the five most relevant gut-derived NGPs that have demonstrated therapeutic potential in managing metabolic diseases. Specific and natural dietary interventions can modulate the abundance and activity of these beneficial bacteria in the gut. Hence, the understanding of targeted stimulation of specific NGP by specific probiotic-targeted diets (PTD) is indispensable for the rational application of their combination. The supplementation of NGP with its specific PTD will help the strain(s) to compete with harmful microbes and acquire its niche. This combination would enhance the effectiveness of NGPs to be used as "live biotherapeutic products" or food nutraceuticals. Under the current milieu, we review various PTDs that influence the abundance of specific potential NGPs, and contemplates potential interactions between diet, microbes, and their effects on host health. Taking into account the study mentioned, we propose that combining NGPs will provide an alternate solution for developing the new diet in conjunction with PTD.

Nutritional and Health Potential of Probiotics: A Review

Several products consist of probiotics that are available in markets, and their potential uses are growing day by day, mainly because some strains of probiotics promote the health of gut microbiota, especially Furmicutes and Bacteroidetes, and may prevent certain gastrointestinal tract (GIT) problems. Some common diseases are inversely linked with the consumption of probiotics, i.e., obesity, type 2 diabetes, autism, osteoporosis, and some immunological disorders, for which the disease progression gets delayed. In addition to disease mitigating properties, these microbes also improve oral, nutritional, and intestinal health, followed by a robust defensive mechanism against particular gut pathogens, specifically by antimicrobial substances and peptides producing probiotics (AMPs). All these positive attributes of probiotics depend upon the type of microbial strains dispensed. Lactic acid bacteria (LAB) and Bifidobacteria are the most common microbes used, but many other microbes are available, and their use depends upon origin and health-promoting properties. This review article focuses on the most common probiotics, their health benefits, and the alleviating mechanisms against chronic kidney diseases (CKD), type 1 diabetes (T1D), type 2 diabetes (T2D), gestational diabetes mellitus (GDM), and obesity.

Polysaccharide Structures and Their Hypocholesterolemic Potential

Several classes of polysaccharides have been described to have hypocholesterolemic potential, namely cholesterol bioaccessibility and bioavailability. This review will highlight the main mechanisms by which polysaccharides are known to affect cholesterol homeostasis at the intestine, namely the effect (i) of polysaccharide viscosity and its influence on cholesterol bioaccessibility; (ii) on bile salt sequestration and its dependence on the structural diversity of polysaccharides; (iii) of bio-transformations of polysaccharides and bile salts by the gut microbiota. Different quantitative structure–hypocholesterolemic activity relationships have been explored depending on the mechanism involved, and these were based on polysaccharide physicochemical properties, such as sugar composition and ramification degree, linkage type, size/molecular weight, and charge. The information gathered will support the rationalization of polysaccharides’ effect on cholesterol homeostasis and highlight predictive rules towards the development of customized hypocholesterolemic functional food.

The Administration of Probiotics against Hypercholesterolemia: A Systematic Review

Hypercholesterolemia is a key factor in the progression of atherosclerosis and cardiovascular disease (CVD). CVD is a significant public health concern with a high death rate. Some of the main factors linked to CVD include genetics and lifestyle. Dyslipidemia has been one of the factors related to the onset of several CVD-related diseases. Several clinicopathological studies have shown a correlation between high cholesterol levels, particularly low-density lipoprotein cholesterol (LDL-c), and CVD development. Probiotics have received a lot of attention for various beneficial effects, especially their ability to reduce blood cholesterol in humans. Probiotics were shown in several investigations to affect hypercholesterolemia by influencing cholesterol biosynthesis. The current review focuses on the human dietary interventions with probiotics and their effects on CVD risk factors and hypercholesterolemia. The outcomes are debatable and consider various parameters such as probiotic strain, dosing frequency, therapeutic response, dietary changes, and so forth. As a result, probiotics have the propensity to become dietary supplements in moderate/severe hypercholesterolemic patients, which significantly reduces the CVD risk.

Probiotic Potential and Cholesterol-Lowering Capabilities of Bacterial Strains Isolated from Pericarpium Citri Reticulatae 'Chachiensis'

Pericarpium Citri Reticulatae 'Chachiensis' (PCR-Chachiensis), the pericarps of Citri Reticulatae Blanco cv. Chachiensis, is a food condiment and traditional medicine in southeast and eastern Asia. Its rich and various bacterial community awaits exploration. The present study is the first report on probiotic screening and characterization of bacteria from PCR-Chachiensis. Based on 64 culturable bacterial isolates, 8 strains were screened out to have great survival in the simulated gastrointestinal stressful condition, being nonhemolytic and without biogenic amine formation. They were identified by 16S rRNA gene sequencing as two Bacillus, three Lactobacillus, and three strains from Bacillales. Their probiotic properties, cholesterol-lowering potential and carbohydrate utilization capability were further investigated. Though these eight strains all displayed distinct cholesterol removal potential, Bacillus licheniformis N17-02 showed both remarkable cholesterol removal capability and presence of bile salt hydrolase gene, as well as possessing most of the desirable probiotic attributes. Thus, it could be a good probiotic candidate with hypocholesterolemic potential. Bacillus megaterium N17-12 displayed the widest carbohydrate utilization profile and the strongest antimicrobial activity. Hence, it was promising to be used as a probiotic in a host and as a fermentation starter in fermented food or feed.

Gut dysbiosis and age-related neurological diseases; an innovative approach for therapeutic interventions

The gut microbiota is a complex ecosystem of bacteria, fungi, and viruses that acts as a critical regulator in microbial, metabolic, and immune responses in the host organism. Imbalances in the gut microbiota, termed "dysbiosis," often induce aberrant immune responses, which in turn disrupt the local and systemic homeostasis of the host. Emerging evidence has highlighted the importance of gut microbiota in intestinal diseases, and more recently, in age-related central nervous systems diseases, for example, stroke and Alzheimer's disease. It is now generally recognized that gut microbiota significantly influences host behaviors and modulates the interaction between microbiota, gut, and brain, via the "microbiota-gut-brain axis." Several approaches have been utilized to reduce age-related dysbiosis in experimental models and in clinical studies. These include strategies to manipulate the microbiome via fecal microbiota transplantation, administration of prebiotics and probiotics, and dietary interventions. In this review, we explore both clinical and preclinical therapies for treating age-related dysbiosis.