Bifidobacterium adolescentis and Lactobacillus rhamnosus alleviate non-alcoholic fatty liver disease induced by a high-fat, high-cholesterol diet through modulation of different gut microbiota-dependent pathways

Bifidobacterium adolescentis prevents diabetes-induced liver injury via pyroptosis attenuation

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD), along with non-alcoholic steatohepatitis (NASH), lacks definitive therapy and typically remains asymptomatic until reaching advanced stages. Lipid metabolism and inflammation management using probiotics such as Bifidobacterium adolescentis is suggested to alleviate or suppress NAFLD development. Hence, this study aims to investigate the effects of Bifidobacterium adolescentis treatment on mitigating pyroptosis, an inflammatory cell death pathway, in the liver of rats with NAFLD induced by high-fat diet (HFD) and streptozotocin (STZ) administration.

METHODS

Forty 8-week adult male Sprague Dawley rats were divided into four groups. Bifidobacterium adolescentis was administered for 8 and 16 weeks at 4 × 1010 CFU/day to rats fed a high-fat diet (HFD). Subsequently, the mRNA expression levels of pyroptotic-related genes including Cas1, Cas3, Cas11, NLRP3, GSDMD, IL-1β, and NF-κB were quantified in liver tissue using quantitative polymerase chain reaction (qPCR). Histopathological alterations and stereological changes in liver structure, as well as lipid profile (FBG, TG, TC, HDL, LDL), and liver indices (ALT, AST, ALP, LDH), were also evaluated across the different groups.

RESULTS

Bifidobacterium adolescentis administration significantly reduced the expression levels of NF-κB and pyroptotic-related genes. Additionally, this probiotic effectively reversed the adverse effects of the high-fat diet (HFD) on liver volume, Kupffer cell numbers, and hepatocyte nuclei. Furthermore, it improved the lipid profile and liver indices of rats fed with the HFD.

CONCLUSION

This study demonstrates that B. adolescentis supplementation prevents diabetes-induced liver injury by attenuating pyroptosis. These findings suggest that Bifidobacterium adolescentis may be a promising therapeutic approach for managing NAFLD and its associated complications, primarily by modulating key genes associated with pyroptosis and inflammation in rats fed with a high-fat diet.

Therapeutic Role of Probiotics Against Environmental-Induced Hepatotoxicity: Mechanisms, Clinical Perspectives, Limitations, and Future

Hepatotoxicity is one of the biggest health challenges, particularly in the context of liver diseases, often aggravated by gut microbiota dysbiosis. The gut-liver axis has been regarded as a key idea in liver health. It indicates that changes in gut flora caused by various hepatotoxicants, including alcoholism, acetaminophen, carbon tetrachloride, and thioacetamide, can affect the balance of the gut's microflora, which may lead to increased dysbiosis and intestinal permeability. As a result, bacterial endotoxins would eventually enter the bloodstream and liver, causing hepatotoxicity and inducing inflammatory reactions. Many treatments, including liver transplantation and modern drugs, can be used to address these issues. However, because of the many side effects of these approaches, scientists and medical experts are still hoping for a therapeutic approach with fewer side effects and more positive results. Thus, probiotics have become well-known as an adjunctive strategy for managing, preventing, or reducing hepatotoxicity in treating liver injury. By altering the gut microbiota, probiotics offer a secure, non-invasive, and economical way to improve liver health in the treatment of hepatotoxicity. Through various mechanisms such as regulation of gut microbiota, reduction of pathogenic overgrowth, suppression of inflammatory mediators, modification of hepatic lipid metabolism, improvement in the performance of the epithelial barrier of the gut, antioxidative effects, and modulation of mucosal immunity, probiotics play their role in the treatment and prevention of hepatotoxicity. This review highlights the mechanistic effects of probiotics in environmental toxicants-induced hepatotoxicity and current findings on this therapeutic approach's experimental and clinical trials.

Bifidobacterium adolescentis FJSSZ23M10 modulates gut microbiota and metabolism to alleviate obesity through strain-specific genomic features

Obesity is a major global public health challenge, affecting billions and serving as a primary risk factor for many chronic diseases. Certain probiotics have shown promise in regulating energy balance and enhancing fat metabolism, offering potential strategies for managing obesity. In this study, we evaluated three strains of Bifidobacterium adolescentis and identified B. adolescentis FJSSZ23M10 as the most effective in alleviating high-fat diet (HFD)-induced obesity. This strain significantly reduced weight gain, improved abnormal serum biochemical indicators, decreased lipid accumulation in adipocytes, and enhanced energy expenditure. Furthermore, B. adolescentis FJSSZ23M10 treatment modulated the gut microbiota, notably increasing the abundance of Bifidobacterium and Faecalibaculum. Untargeted metabolomic analysis revealed that B. adolescentis FJSSZ23M10 uniquely upregulated beneficial metabolites, such as butyrate and pyruvic acid, suggesting its superior metabolic impact. Genomic analysis indicated that B. adolescentis FJSSZ23M10 harbored the highest abundance of unassigned genes and carbohydrate-active enzymes (CAZymes) compared to the other strains, highlighting its superior functional potential. Combining the shared and unique modifications in gut microbiota, metabolites, and genomic annotations, the study highlights that genomic differences among probiotics could shape their effects on gut microbiota and metabolites. Conclusively, the study underscores the critical role of probiotic genomic characteristics in determining their functional efficacy and suggests that the intake of the B. adolescentis FJSSZ23M10 strain with enriched genomic features, such as CAZymes, could represent a novel genomic-based strategy for alleviating obesity through gut microbiota modulation and metabolic regulation.

Probiotic Bifidobacterium reduces serum TMAO in unstable angina patients via the gut to liver to heart axis

Background and aims

Studies indicate that the gut microbiota and its metabolites are involved in the progression of cardiovascular diseases, and enterohepatic circulation plays an important role in this progression. This study aims to identify potential probiotics for the treatment of unstable angina (UA) and elucidate their mechanisms of action.

Methods

Initially, the gut microbiota from patients with UA and control was analyzed. To directly assess the effects of Bifidobacterium supplementation, 10 patients with UA were enrolled and administered Bifidobacterium (630 mg per intake twice a day for 1 month). The fecal metagenome, serum trimethylamine N-oxide (TMAO) levels, and other laboratory parameters were evaluated before and after Bifidobacterium supplementation.

Results

After supplementing with Bifidobacterium for 1 month, there were statistically significant differences (P < 0.05) in TMAO, aspartate aminotransferase, total cholesterol, and low-density lipoprotein compared to before. Additionally, the abundance of Bifidobacterium longum increased significantly, although the overall abundance of Bifidobacterium did not reach statistical significance. The gut microbiota, metabolites, and gut-liver axis are involved in the progression of UA, and potential mechanisms should be further studied.

Conclusions

Metagenomic analysis demonstrated a reduced abundance of Bifidobacterium in patients with UA. Supplementation with Bifidobacterium restored gut dysbiosis and decreased circulating TMAO levels in patients with UA. This study provides evidence that Bifidobacterium may exert cardiovascular-protective effects through the gut-liver-heart axis.

Clinical trial number

ChiCTR2400093946.

Μetabolic dysfunction-associated steatotic liver disease: a condition of heterogeneous metabolic risk factors, mechanisms and comorbidities requiring holistic treatment

Μetabolic dysfunction-associated steatotic liver disease (MASLD) comprises a heterogeneous condition in the presence of steatotic liver. There can be a hierarchy of metabolic risk factors contributing to the severity of metabolic dysfunction and, thereby, the associated risk of both liver and extrahepatic outcomes, but the precise ranking and combination of metabolic syndrome (MetS) traits that convey the highest risk of major adverse liver outcomes and extrahepatic disease complications remains uncertain. Insulin resistance, low-grade inflammation, atherogenic dyslipidaemia and hypertension are key to the mechanisms of liver and extrahepatic complications. The liver is pivotal in MetS progression as it regulates lipoprotein metabolism and secretes substances that affect insulin sensitivity and inflammation. MASLD affects the kidneys, heart and the vascular system, contributing to hypertension and oxidative stress. To address the global health burden of MASLD, intensified by obesity and type 2 diabetes mellitus epidemics, a holistic, multidisciplinary approach is essential. This approach should focus on both liver disease management and cardiometabolic risk factors. This Review examines the link between metabolic dysfunction and liver dysfunction and extrahepatic disease outcomes, the diverse mechanisms in MASLD due to metabolic dysfunction, and a comprehensive, personalized management model for patients with MASLD.

Debranched Lentil Starch-Sodium Alginate-Based Encapsulated Particles of Lacticaseibacillus rhamnosus GG: Morphology, Structural Characterization, In Vitro Release Behavior, and Storage Stability

Starches with different degrees of debranching (DBS30, DBS60, and DBS90) and sodium alginate were used as the wall material for encapsulating particles of Lacticaseibacillus rhamnosus GG (LGG). The structural characteristics of these encapsulated particles were examined, along with the impact of varying levels of debranching on the encapsulation efficiency, the in vitro release of LGG under the simulated gastrointestinal environment, and the storage stability of the encapsulated particles. The results revealed a transformation in the crystalline polymorph from C- to B+V-type following debranching and retrogradation. This process also resulted in a significant decrease in molecular weight and polydispersity index, accompanied by an increase in amylose and resistant starch levels along with the relative crystallinity of the debranched lentil starch. Comparatively, DBS60-LGG and DBS90-LGG exhibited higher encapsulation efficiency and encapsulation yield than UDBS-LGG and DBS30-LGG. Furthermore, these encapsulated particles provided enhanced protection for LGG in both the simulated gastrointestinal environment and the storage process. It can be inferred that a superior encapsulation performance of the debranched lentil starch-sodium alginate-based encapsulated LGG particles was associated with higher debranching levels, a more uniform molecular weight distribution, and a more ordered multi-scale structure of the debranched lentil starch.

Effect of Spirulina on the Rumen Microbiota and Serum Biochemical Parameters of Lambs

Spirulina (Arthrospira platensis) is rich in a variety of fermentable fibers and prebiotics, which can promote the proliferation of beneficial flora in the intestinal tract of ruminants and optimize the balance of microorganisms in the rumen. The aim of this study was to evaluate whether dietary supplementation with Spirulina has a beneficial effect on the rumen microbial community and serum indices in lambs. For this purpose, 36 lambs with a mean weight of 21.68 kg (standard deviation 1.04 kg) and an age of approximately 5 months (standard deviation 4 days) were selected for the study. The same scale was used for age standard deviation, i.e., 4 days/30.5 days (1 month) = 0.13 months. All lambs were randomly assigned into two treatments, and received non-Spirulina diet as the control (CK treatment) and the Spirulina added diet (Spirulina was added at a rate of 3% of the fresh weight of the diet). The results indicated that the triacylglycerol (p < 0.0001), alanine transaminase (ALT) (p < 0.0001), aspartate aminotransferase (AST) (p < 0.0001), glucose (p < 0.0001), immunoglobulin G (p = 0.0066) and insulin (p = 0.0025) levels were markedly increased in the Spirulina treatment compared to those in the CK treatment. The principal coordinates analysis showed that the bacterial community did not cluster separately between the CK and Spirulina treatments. Firmicutes, Bacteroidetes and Actinobacteria were the dominant members of the community in two treatments. Prevotella were the primary genera, followed by the Lachnospiraceae_NK3A20_group, Olsenella, Succinivibrionaceae_UCG-001 and Ruminococcus, and a significant (p < 0.05) difference was found in Olsenella between the two treatments. These results suggest that the addition of Spirulina is more beneficial for serum biochemical parameters and rumen microbiota of lambs. Overall, these findings contribute to the development of strategies to improve rumen microbial communities for healthy ecosystems on the Mongolian Plateau and provide a scientific basis for the use of Spirulina in feed.

Dynamic Hydration and Viscosity Control of Konjac Glucomannan Enhance Long-Term Antiobesity Effects by Reducing Food Intake in High-Fat-Diet-Fed Mice

The purpose of this study was to investigate the necessity and importance of dynamic hydration rate and ultimate viscosity control of konjac glucomannan (KGM) for long-term antiobesity effects in C57BL/6J mice on high-fat (HF) diets. KGM supplementation effectively attenuated HF-diet-induced increases in body and tissue weights. The hydration rate and viscosity changes of KGM in the digestive tract were found to have marked impacts on antiobesity effects. KGM with medium hydration and viscosity slowed gastric emptying and intestinal transit, leading to prolonged presence in the lower ileum, increased satiety-related hormones (GLP-1 and PYY), and an 18.27% reduction in daily food intake over 10 weeks (p < 0.05). This resulted in the greatest reduction in weight gain among HF-fed mice. In contrast, KGM with faster hydration and higher viscosity provided only short-term satiety due to rapid dilution. Furthermore, KGM improved metabolic health and altered glycolipid metabolism gene transcription while enriching beneficial gut bacteria; however, no significant differences were observed among the KGM groups in these effects. These findings highlight that synchronizing KGM's hydration rate and viscosity with digestive processes is crucial for regulating satiety and achieving long-term weight loss.

Lactic acid bacteria supplementation: A bioprotective approach to mitigating cadmium-induced toxicity and modulating gene expression in murine models

This study aimed to assess the effects of different strains of lactic acid bacteria, namely LeviLactobacillus brevis (AC10), Lacticaseibacillus rhamnosus (AC11), and Pediococcus acidilactici (AC15), on mice exposed to cadmium-induced oxidative stress. The study assessed weight gain, liver enzymes, antioxidant enzymes, immunoglobulin factors, lipid peroxidation, and gene expression in liver and brain of mice. The findings revealed that the AC10 and AC11 strains had a higher ability to absorb Cd as compared to AC15. The in vivo analysis demonstrated that the dietary dual supplementation of AC10 and AC11 resulted in significant (p < 0.05) improvements, including increased body weight and food intake, reduced cadmium tissue deposition, decreased lipid peroxidation, enhanced cellular antioxidant redox potential, suppressed inflammation genes in the liver and brain tissues, and improved morpho-characteristics of the jejunum in mice challenged by cadmium-induced toxicity. The multiple mechanisms of action, including heavy metal sequestration, antioxidant enhancement, and maintenance of intestinal integrity, highlight the potential of these probiotics' intervention as a viable approach to counteract the deleterious effects of cadmium exposure.

Impact of Lactobacillaceae supplementation on the multi-organ axis during MASLD

The gut-liver axis plays a pivotal role in maintaining body homeostasis. Disruption of the gut-liver axis is linked to a multitude of diseases, including metabolic dysfunction-associated steatotic liver disease (MASLD). Probiotic strains from the Lactobacillaceae family are commonly used to mitigate experimental MASLD. Over the years, numerous studies have demonstrated the efficacy of these probiotics, often focusing on the outcome of liver disease. This review aims to further understand MASLD as a systemic metabolic dysfunction and to highlight the effects of probiotics on multi-organ axis, including organs such as the gastrointestinal tract, pancreas, muscle, adipose tissue, and the immune system. We specifically discuss evidence on how supplementation with Lactobacillaceae strains may alleviate MASLD by not only restoring liver health but also by modulating the physiology of other organ systems.

Chitosan-Stabilized Selenium Nanoparticles Alleviate High-Fat Diet-Induced Non-Alcoholic Fatty Liver Disease (NAFLD) by Modulating the Gut Barrier Function and Microbiota

Low molecular weight chitosan selenium nanoparticles (LCS-SeNPs), a biologically active compound derived from selenium polysaccharides, have demonstrated potential in addressing obesity. However, the mechanism through which LCS-SeNPs alleviate high-fat diet (HFD)-induced non-alcoholic fatty liver disease (NAFLD) remains unclear. Our results elucidated that LCS-SeNPs significantly inhibited fat accumulation and markedly improved the intestinal barrier by increasing mucus secretion from goblet cells. Moreover, LCS-SeNPs reshaped intestinal flora composition by increasing the abundance of mucus-associated microbiota (Bifidobacterium, Akkermansia, and Muribaculaceae_unclassified) and decreasing the abundance of obesity-contributed bacterium (Anaerotruncus, Lachnoclostridium, and Proteus). The modulation of intestinal microbiota by LCS-SeNPs influenced several metabolic pathways, including bile acid secretion, purine metabolites, and tryptophan derivation. Meanwhile, glycocholic acid and tauro-beta-muricholic acid were significantly reduced in the LCS-SeNP group. Our study suggests the crucial role of intestinal microbiota composition and metabolism, providing a new theoretical foundation for utilizing selenium polysaccharides in the intervention of HFD-induced NAFLD.

Lipid-lowering and antioxidant effects of Polygonatum fermented liquor: a study on intestinal microbiota and brain-gut axis in mice

Introduction

This study aims to investigate the effects of Polygonatum fermented liquor (PFL) on improving lipid metabolism and oxidative stress in mice by regulating the gut microbiota.

Methods

Forty SPF-grade male Kunming mice were randomly divided into four groups: normal control group (NC), general liquor group (GC), fresh Polygonatum fermented liquor group (FPC), and nine-steam-nine-bask Polygonatum fermented liquor group (NPC). Each group was administered with sterile water, general liquor, fresh Polygonatum fermented liquor, and nine-steam-nine-bask Polygonatum fermented liquor, respectively, by gavage. The mice's liver, brain tissue, serum, and intestinal contents were collected. The indicators of oxidative stress in the liver, four blood lipid indicators, gamma-aminobutyric acid (GABA), and brain-derived neurotrophic factor (BDNF) levels in the brain tissue were measured, liver hematoxylin and eosin (HE) staining was performed, and the gut microbiota in the small intestine were analyzed using 16S rRNA second-generation sequencing technology.

Results

Compared with the NC group, the NPC group showed significantly increased liver glutathione peroxidase (GSH-Px) content in mice (p < 0.05), reduced number of lipid droplets in the liver cells, and increased GABA and BDNF content in the brain tissues. The NPC group regulated lipid metabolism by lowering low-density lipoprotein cholesterol (LDL-C) and increasing high-density lipoprotein cholesterol (HDL-C) content in the mouse serum. Gut microbiota analysis showed significant changes in the gut microbiota of mice in the FPC and NPC groups, with increased richness and species diversity. These two groups increased the abundance of beneficial bacteria such as Lactobacillus, unclassified Muribaculaceae, unclassified Bacilli, and uncultured Bacteroidales bacterium while reducing the abundance of harmful bacteria such as Candidatus Arthromitus, and Staphylococcus, with a particularly significant reduction in Staphylococcus (p < 0.05). It is speculated that the two types of PFL may exert lipid-lowering and antioxidant effects by modulating the abundance of these dominant bacteria. Further studies showed that various environmental factors are closely related to the dominant gut bacteria. Malondialdehyde (MDA) was significantly negatively correlated with Lactobacillus and unclassified Bacilli, superoxide dismutase (SOD) was significantly negatively correlated with Staphylococcus (p < 0.01) and significantly negatively correlated with Candidatus Arthromitus (p < 0.05), and HDL-C was significantly negatively correlated with Staphylococcus and Facklamia (p < 0.05).

Discussion

The two types of PFL chosen in this study may exert lipid-lowering and antioxidant effects by modulating the composition and function of the gut microbiota, providing guidance for the industrial application of Polygonatum.

Single and Mixed Strains of Probiotics Reduced Hepatic Fat Accumulation and Inflammation and Altered Gut Microbiome in a Nonalcoholic Steatohepatitis Rat Model

As gut dysbiosis has been implicated in the pathogenesis of nonalcoholic steatohepatitis (NASH), probiotic supplementation might be a potential treatment for this condition. The aim of this study was to evaluate the effects of single- and mixed-strain probiotics on the severity of NASH induced by a high-fat, high-fructose (HFHF) diet and their mechanisms of action. Male Sprague-Dawley rats were divided into four groups (n = 7 per group): control group, NASH group, NASH + single-strain group, and NASH + mixed-strain group. In the single-strain and mixed-strain groups, rats received Lactobacillus plantarum B7 and Lactobacillus rhamnosus L34 + Lactobacillus paracasei B13 by oral gavage once daily, respectively. The duration of the study was 6 weeks. Liver tissue was used for histopathology, hepatic fat content was assessed by Oil Red O staining and hepatic free fatty acid (FFA), and hepatic TLR4 and CD14 expression were assessed by immunohistochemistry. Fresh feces was collected for gut microbiota analysis. Liver histology revealed a higher degree of fat accumulation, hepatocyte ballooning, and lobular inflammation in the NASH group, which improved in probiotics-treated groups. The amounts of hepatic fat droplets and hepatic FFA levels were more pronounced in the NASH group than in the control and treatment groups. Serum TNF- α levels were significantly higher in the NASH group than in control and probiotic groups. The expression of CD14 and TLR4 increased in the NASH group as compared with the control and probiotics-treated groups. Alpha diversity was reduced in the NASH group, but increased in both treatment groups. The relative abundance of Lactobacillus significantly decreased in the NASH group, but increased in both treatment groups. The relative abundance of Akkermansia significantly increased in the NASH group, but decreased in both treatment groups. In conclusion, both single-strain and mixed-strain probiotics could improve NASH histology by suppressing inflammatory responses in the liver, with this improvement potentially being associated with changes in the gut microbiota.

Gut microbial metabolites in MASLD: Implications of mitochondrial dysfunction in the pathogenesis and treatment

With an increasing prevalence, metabolic dysfunction-associated steatotic liver disease (MASLD) has become a major global health problem. MASLD is well-known as a multifactorial disease. Mitochondrial dysfunction and alterations in the gut bacteria are 2 vital events in MASLD. Recent studies have highlighted the cross-talk between microbiota and mitochondria, and mitochondria are recognized as pivotal targets of the gut microbiota to modulate the host's physiological state. Mitochondrial dysfunction plays a vital role in MASLD and is associated with multiple pathological changes, including hepatocyte steatosis, oxidative stress, inflammation, and fibrosis. Metabolites are crucial mediators of the gut microbiota that influence extraintestinal organs. Additionally, regulation of the composition of gut bacteria may serve as a promising therapeutic strategy for MASLD. This study reviewed the potential roles of several common metabolites in MASLD, emphasizing their impact on mitochondrial function. Finally, we discuss the current treatments for MASLD, including probiotics, prebiotics, antibiotics, and fecal microbiota transplantation. These methods concentrate on restoring the gut microbiota to promote host health.

Exploring the therapeutic potential of silymarin-based herbal remedy (prebiotic) and probiotic blend in a mouse model of NAFLD: Insights into gut microbiota modulation and liver health

Non-alcoholic fatty liver disease (NAFLD) is a significant consequence of metabolic dysfunction, often associated with changes in the intestinal microbiota. Prebiotics and probiotics have shown promise in NAFLD management. This study evaluated a silymarin-based herbal remedy with piperine and fulvic acid, alongside a probiotic blend of Bifidobacterium adolescentis, Bifidobacterium bifidum, Lactobacillus casei, and Lactobacillus rhamnosus. Using a NAFLD mouse model induced by a high-fat and high-fructose diet, we assessed biochemical parameters, liver function, glucose levels, and conducted histological analysis. Stool samples underwent 16S rRNA metagenomic analysis to explore changes in microbiota composition. Mice on the high-fat diet exhibited elevated lipids, liver enzymes, and glucose, with reduced high-density lipoprotein levels (with p value < 0.001). Treatment, particularly with F3 (silymarin-piperine-fulvic acid herbal remedy and probiotic blend), significantly reduced hepatic fat accumulation and improved gut microbiota composition. This study highlights the potential of silymarin-based therapy combined with probiotics in attenuating NAFLD progression.

NAFLD/MASLD and the Gut-Liver Axis: From Pathogenesis to Treatment Options

Nonalcoholic fatty liver disease (NAFLD) poses an emerging threat topublic health. Nonalcoholic steatohepatitis (NASH) is reported to be the most rapidly rising cause of hepatocellular carcinoma in the western world. Recently, a new term has been proposed: metabolic dysfunction-associated steatotic liver disease (MASLD). The introduction of this new terminology has sparked a debate about the interchangeability of these terms. The pathogenesis of NAFLD/MASLD is thought to be multifactorial, involving both genetic and environmental factors. Among these factors, alterations in gut microbiota and gut dysbiosis have recently garnered significant attention. In this context, this review will further discuss the gut-liver axis, which refers to the bidirectional interaction between the human gut microbiota and the liver. Additionally, the therapeutic potential of probiotics, particularly next-generation probiotics and genetically engineered bacteria, will be explored. Moreover, the role of prebiotics, synbiotics, postbiotics, and phages as well as fecal microbiota transplantation will be analyzed. Particularly for lean patients with NAFLD/MASLD, who have limited treatment options, approaches that modify the diversity and composition of the gut microbiota may hold promise. However, due to ongoing safety concerns with approaches that modulate gut microbiota, further large-scale studies are necessary to better assess their efficacy and safety in treating NAFLD/MASLD.

Chrysanthemum morifolium Ramat extract and probiotics combination ameliorates metabolic disorders through regulating gut microbiota and PPARα subcellular localization

BACKGROUND

Chrysanthemum morifolium Ramat, a traditional Chinese medicine, has the effects on liver clearing, vision improving, and anti-inflammation. C. morifolium and probiotics have been individually studied for their beneficial effects on metabolic diseases. However, the underlying molecular mechanisms were not completely elucidated. This study aims to elucidate the potential molecular mechanisms of C. morifolium and probiotics combination (CP) on alleviating nonalcoholic fatty liver disease (NAFLD) and the dysregulation of glucose metabolism in high-fat diet (HFD)-fed mice.

METHODS

The therapeutic effect of CP on metabolism was evaluated by liver histology and serum biochemical analysis, as well as glucose tolerance test. The impact of CP on gut microbiota was analyzed by 16S rRNA sequencing and fecal microbiota transplantation. Hepatic transcriptomic analysis was performed with the key genes and proteins validated by RT-qPCR and western blotting. In addition, whole body Pparα knockout (Pparα-/-) mice were used to confirm the CP-mediated pathway.

RESULTS

CP supplementation ameliorated metabolic disorders by reducing body weight and hepatic steatosis, and improving glucose intolerance and insulin resistance in HFD fed mice. CP intervention mitigated the HFD-induced gut microbiota dysbiosis, which contributed at least in part, to the beneficial effect of improving glucose metabolism. In addition, hepatic transcriptomic analysis showed that CP modulated the expression of genes associated with lipid metabolism. CP downregulated the mRNA level of lipid droplet-binding proteins, such as Cidea and Cidec in the liver, leading to more substrates for fatty acid oxidation (FAO). Meanwhile, the expression of CPT1α, the rate-limiting enzyme of FAO, was significantly increased upon CP treatment. Mechanistically, though CP didn't affect the total PPARα level, it promoted the nuclear localization of PPARα, which contributed to the reduced expression of Cidea and Cidec, and increased expression of CPT1α, leading to activated FAO. Moreover, whole body PPARα deficiency abolished the anti-NAFLD effect of CP, suggesting the importance of PPARα in CP-mediated beneficial effect.

CONCLUSION

This study revealed the hypoglycemic and hepatoprotective effect of CP by regulating gut microbiota composition and PPARα subcellular localization, highlighting its potential for therapeutic candidate for metabolic disorders.

Bifidobacterium adolescentis-derived hypaphorine alleviates acetaminophen hepatotoxicity by promoting hepatic Cry1 expression

Acetaminophen (APAP)-induced liver injury (AILI) is a pressing public health concern. Although evidence suggests that Bifidobacterium adolescentis (B. adolescentis) can be used to treat liver disease, it is unclear if it can prevent AILI. In this report, we prove that B. adolescentis significantly attenuated AILI in mice, as demonstrated through biochemical analysis, histopathology, and enzyme-linked immunosorbent assays. Based on untargeted metabolomics and in vitro cultures, we found that B. adolescentis generates microbial metabolite hypaphorine. Functionally, hypaphorine inhibits the inflammatory response and hepatic oxidative stress to alleviate AILI in mice. Transcriptomic analysis indicates that Cry1 expression is increased in APAP-treated mice after hypaphorine treatment. Overexpression of Cry1 by its stabilizer KL001 effectively mitigates liver damage arising from oxidative stress in APAP-treated mice. Using the gene expression omnibus (GEO) database, we verified that Cry1 gene expression was also decreased in patients with APAP-induced acute liver failure. In conclusion, this study demonstrates that B. adolescentis inhibits APAP-induced liver injury by generating hypaphorine, which subsequently upregulates Cry1 to decrease inflammation and oxidative stress.

Gestational supplementation of Bifidobacterium, Lactobacillus, and Streptococcus thermophilus attenuates hepatic steatosis in offspring mice through promoting fatty acid β-oxidation

Currently, Bifidobacterium, Lactobacillus, and Streptococcus thermophilus (BLS) are widely recognized as the crucially beneficial bacteria in the gut. Many preclinical and clinical studies have shown their protective effects against non-alcoholic fatty liver disease (NAFLD). However, whether gestational BLS supplementation could alleviate NAFLD in the offspring is still unknown. Kunming mice were given a high-fat diet (HFD) for 4 weeks before mating. They received BLS supplementation by gavage during pregnancy. After weaning, offspring mice were fed with a regular diet up to 5 weeks old. Gestational BLS supplementation significantly increased the abundance of Actinobacteriota, Bifidobacterium, and Faecalibaculum in the gut of dams exposed to HFD. In offspring mice exposed to maternal HFD, maternal BLS intake significantly decreased the ratio of Firmicutes to Bacteroidetes as well as the relative abundance of Prevotella and Streptococcus, but increased the relative abundance of Parabacteroides. In offspring mice, maternal BLS supplementation significantly decreased the hepatic triglyceride content and mitigated hepatic steatosis. Furthermore, maternal BLS supplementation increased the glutathione content and reduced malondialdehyde content in the liver. In addition, mRNA and protein expression levels of key rate-limiting enzymes in mitochondrial β-oxidation (CPT1α, PPARα, and PGC1α) in the livers of offspring mice were significantly increased after gestational BLS supplementation. Thus, gestational BLS supplementation may ameliorate maternal HFD-induced steatosis and oxidative stress in the livers of offspring mice by modulating fatty acid β-oxidation.

Targeting Non-Alcoholic Fatty Liver Disease with Hawthorn Ethanol Extract (HEE): A Comprehensive Examination of Hepatic Lipid Reduction and Gut Microbiota Modulation

Recent studies have highlighted the lipid-lowering ability of hawthorn ethanol extract (HEE) and the role played by gut flora in the efficacy of HEE. Our study sought to explore the effects of HEE on non-alcoholic fatty liver disease (NAFLD) in normal flora and pseudo germ-free mice. The results showed that HEE effectively diminished hepatic lipid accumulation, ameliorated liver function, reduced inflammatory cytokine levels and blood lipid profiles, and regulated blood glucose levels. HEE facilitated triglyceride breakdown, suppressed fatty acid synthesis, and enhanced intestinal health by modulating the diversity of the gut microbiota and the production of short-chain fatty acids in the gut. In addition, HEE apparently helps to increase the presence of beneficial genera of bacteria, thereby influencing the composition of the gut microbiota, and the absence of gut flora affects the efficacy of HEE. These findings reveal the potential of hawthorn for the prevention and treatment of NAFLD and provide new perspectives on the study of functional plants to improve liver health.

Lacticaseibacillus rhamnosus HF01 fermented yogurt alleviated high-fat diet-induced obesity and hepatic steatosis via the gut microbiota-butyric acid-hepatic lipid metabolism axis

The objective of this study was to investigate the anti-obesity effects and underlying mechanism of Lacticaseibacillus rhamnosus HF01 fermented yogurt (HF01-Y). Herein, obesity was induced in mice through a high-fat diet and the changes in the gut microbiota were evaluated using 16S rRNA gene sequencing, combined with the expression levels of the liver AMPK signaling pathway to analyze the potential relationship between HF01-Y-mediated gut microbiota and obesity. The results showed that supplementation with HF01-Y improved obesity-related phenotypes in mice, including reduced body weight, improved serum lipid profiles, and decreased hepatic lipid droplet formation. In addition, HF01-Y altered the composition of the gut microbiota in obese mice, significantly upregulated norank_f__Muribaculaceae, unclassified_c__Clostridia, Blautia, unclassified_o__Bacteroidales, and Rikenellaceae_RC9_gut_group, while downregulating unclassified_f__Desulfovibrionaceae, Colidextribacter, and unclassified_f__Oscillospiraceae. These alterations led to an increase of the cecum butyric acid content, which in turn indirectly promoted the activation of the AMPK signaling pathway, subsequently, inhibited fat synthesis, and promoted fatty acid oxidation related gene expression. Therefore, HF01-Y was likely to alleviate hepatic fat and relieve obesity by modulating the gut microbiota-butyric acid-hepatic lipid metabolism axis, ultimately promoting host health.

Gut microbiome features and metabolites in non-alcoholic fatty liver disease among community-dwelling middle-aged and older adults

BACKGROUND

The specific microbiota and associated metabolites linked to non-alcoholic fatty liver disease (NAFLD) are still controversial. Thus, we aimed to understand how the core gut microbiota and metabolites impact NAFLD.

METHODS

The data for the discovery cohort were collected from the Guangzhou Nutrition and Health Study (GNHS) follow-up conducted between 2014 and 2018. We collected 272 metadata points from 1546 individuals. The metadata were input into four interpretable machine learning models to identify important gut microbiota associated with NAFLD. These models were subsequently applied to two validation cohorts [the internal validation cohort (n = 377), and the prospective validation cohort (n = 749)] to assess generalizability. We constructed an individual microbiome risk score (MRS) based on the identified gut microbiota and conducted animal faecal microbiome transplantation experiment using faecal samples from individuals with different levels of MRS to determine the relationship between MRS and NAFLD. Additionally, we conducted targeted metabolomic sequencing of faecal samples to analyse potential metabolites.

RESULTS

Among the four machine learning models used, the lightGBM algorithm achieved the best performance. A total of 12 taxa-related features of the microbiota were selected by the lightGBM algorithm and further used to calculate the MRS. Increased MRS was positively associated with the presence of NAFLD, with odds ratio (OR) of 1.86 (1.72, 2.02) per 1-unit increase in MRS. An elevated abundance of the faecal microbiota (f__veillonellaceae) was associated with increased NAFLD risk, whereas f__rikenellaceae, f__barnesiellaceae, and s__adolescentis were associated with a decreased presence of NAFLD. Higher levels of specific gut microbiota-derived metabolites of bile acids (taurocholic acid) might be positively associated with both a higher MRS and NAFLD risk. FMT in mice further confirmed a causal association between a higher MRS and the development of NAFLD.

CONCLUSIONS

We confirmed that an alteration in the composition of the core gut microbiota might be biologically relevant to NAFLD development. Our work demonstrated the role of the microbiota in the development of NAFLD.

The Impact of Probiotic Bifidobacterium on Liver Diseases and the Microbiota

Recent studies have shown the promising potential of probiotics, especially the bacterial genus Bifidobacterium, in the treatment of liver diseases. In this work, a systematic review was conducted, with a focus on studies that employed advanced Next Generation Sequencing (NGS) technologies to explore the potential of Bifidobacterium as a probiotic for treating liver pathologies such as Non-Alcoholic Fatty Liver Disease (NAFLD), Non-Alcoholic Steatohepatitis (NASH), Alcoholic Liver Disease (ALD), Cirrhosis, and Hepatocelullar Carcinoma (HCC) and its impact on the microbiota. Our results indicate that Bifidobacterium is a safe and effective probiotic for treating liver lesions. It successfully restored balance to the intestinal microbiota and improved biochemical and clinical parameters in NAFLD, ALD, and Cirrhosis. No significant adverse effects were identified. While more research is needed to establish its efficacy in treating NASH and HCC, the evidence suggests that Bifidobacterium is a promising probiotic for managing liver lesions.

Healthy diet intervention reverses the progression of NASH through gut microbiota modulation

IMPORTANCE

The link between gut microbiota and diet is crucial in the development of non-alcoholic steatohepatitis (NASH). This study underscores the essential role of a healthy diet in preventing and treating NASH by reversing obesity, lipidemia, and gut microbiota dysbiosis. Moreover, the supplementation of functional food or drug to the diet can provide additional advantages by inhibiting hepatic inflammation through the modulation of the hepatic inflammasome signaling pathway and partially mediating the gut microbiota and lipopolysaccharide signaling pathway. This study highlights the importance of adopting healthy dietary habits in treating NASH and proposes that supplementing with ginger essential oil or obeticholic acid may offer additional benefits. Nonetheless, further clinical studies are necessary to validate these findings.

Gut ecological networks reveal associations between bacteria, exercise, and clinical profile in non-alcoholic fatty liver disease patients

IMPORTANCE

Our study is applying a community-based approach to examine the influence of exercise on gut microbiota (GM) and discover GM structures linked with NAFLD improvements during exercise. The majority of microbiome research has focused on finding specific species that may contribute to the development of human diseases. However, we believe that complex diseases, such as NAFLD, would be more efficiently treated using consortia of species, given that bacterial functionality is based not only on its own genetic information but also on the interaction with other microorganisms. Our results revealed that exercise significantly changes the GM interaction and that structural alterations can be linked with improvements in intrahepatic lipid content and metabolic functions. We believe that the identification of these characteristics in the GM enhances the development of exercise treatment for NAFLD and will attract general interest in this field.

Prebiotics and Probiotics: Therapeutic Tools for Nonalcoholic Fatty Liver Disease

Alterations in the gut-liver axis and changes in the gut microbiome are among the risk factors for the pathogenesis of non-alcoholic fatty liver disease (NAFLD). These patients show increased bacterial overgrowth in the small intestine and impaired intestinal permeability. Therefore, therapeutic options such as probiotics or prebiotics have been investigated to modulate intestinal microbiota composition to improve NAFLD. Most in vivo and in vitro probiotic studies have focused on reducing hepatic fat accumulation. The beneficial effects of probiotics on NAFLD have been demonstrated in animal models, and the most widely used microorganisms are those of the Lactobacillus and Bifidobacterium genera. In animal models, probiotics help restore the intestinal microbiota and improve the integrity of the intestinal barrier. This narrative review summarizes published evidence and the likely benefits of probiotics and prebiotics as a therapeutic option for patients with NAFLD.

Assessment of Auricularia cornea var. Li. polysaccharides potential to improve hepatic, antioxidation and intestinal microecology in rats with non-alcoholic fatty liver disease

Non-alcoholic fatty acid liver disease (NAFLD) is a reputed global health concern, affecting children and young adults. Accumulating evidence suggests that edible fungi polysaccharides have the potential to relieve NAFLD. Our previous study found that Auricularia cornea var. Li. polysaccharides (ACP) could improve immune by regulating gut microbiota. However, its NAFLD-alleviating potentials have been scarcely reported. This study analyzed the protective effects of Auricularia cornea var. Li. polysaccharides on high-fat diet (HFD)-induced NAFLD and mechanistic actions. We first analyzed the histology and hepatic lipid profile of animals to evaluate this variant's ameliorating effects on NAFLD. Then, antioxidant and anti-inflammatory potentials of ACP were studied. Finally, we explored changes in the gut microbiome diversity for mechanistic insights from the gut-liver region. Results showed that supplementation with ACP substantially reduced homeostasis model assessment-insulin resistance (HOMA-IR), body fat, liver index rates and weight gain (p < 0.05). This variant also improved HDL-C levels while decreasing triglyceride (TG), total cholesterol (TC), and low-density lipoprotein cholesterol (LDL-C) levels which were initially triggered by HFD. ACP mediation also decreased the serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels considerably with H&E technique indicating that it can reduce liver lipid accumulation, thus lowering liver damages risks (p < 0.05). The antioxidant potentials of ACP were also demonstrated as it decreased the hepatic levels of malondialdehyde (MDA) and increased the activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-PX). Proinflammatory markers like IL-6, IL-1β and TNF-α concentrations were decreased by ACP supplementation, accompanied with increased IL-4 levels. Finally, ACP supplementation regulated the intestinal microbiota to near normal patterns. In all, ACP protects HFD-induced NAFLD by improving liver characteristics and regulating colonic flora composition, our findings assert that ACP can be a promising strategy in NAFLD therapy.

Harnessing the potential of probiotics in the treatment of alcoholic liver disorders

In the current scenario, prolonged consumption of alcohol across the globe is upsurging an appreciable number of patients with the risk of alcohol-associated liver diseases. According to the recent report, the gut-liver axis is crucial in the progression of alcohol-induced liver diseases, including steatosis, steatohepatitis, fibrosis, cirrhosis, and hepatocellular carcinoma. Despite several factors associated with alcoholic liver diseases, the complexity of the gut microflora and its great interaction with the liver have become a fascinating area for researchers due to the high exposure of the liver to free radicals, bacterial endotoxins, lipopolysaccharides, inflammatory markers, etc. Undoubtedly, alcohol-induced gut microbiota imbalance stimulates dysbiosis, disrupts the intestinal barrier function, and trigger immune as well as inflammatory responses which further aggravate hepatic injury. Since currently available drugs to mitigate liver disorders have significant side effects, hence, probiotics have been widely researched to alleviate alcohol-associated liver diseases and to improve liver health. A broad range of probiotic bacteria like Lactobacillus, Bifidobacteria, Escherichia coli, Sacchromyces, and Lactococcus are used to reduce or halt the progression of alcohol-associated liver diseases. Several underlying mechanisms, including alteration of the gut microbiome, modulation of intestinal barrier function and immune response, reduction in the level of endotoxins, and bacterial translocation, have been implicated through which probiotics can effectively suppress the occurrence of alcohol-induced liver disorders. This review addresses the therapeutic applications of probiotics in the treatment of alcohol-associated liver diseases. Novel insights into the mechanisms by which probiotics prevent alcohol-associated liver diseases have also been elaborated.

Probiotics as Potential Therapy in the Management of Non-Alcoholic Fatty Liver Disease (NAFLD)

Background: Non-alcoholic fatty liver disease (NAFLD) is the most common liver disease, the prevalence of which has increased over the years. The management of this pathology is not clear, and a specific pharmacological drug that can treat NAFLD is not available. In this sense, efforts are focused on the potential use of compounds with a natural origin that can contribute to reversing hepatic steatosis. Supplementation with probiotics, live microorganisms, is a potential strategy for the management of NAFLD. Methods: In the present review, the available information on the potential therapeutic effects of probiotics in NAFLD, mainly in animal models and in some clinical trials, is summarized. Results: Studies carried out using animal models of NAFLD induced by a high-fat diet have shown the beneficial effects of probiotic supplementation in reducing liver steatosis and normalizing the blood lipid profile and liver enzyme activities. In addition, a decrease in lipogenesis and an increase in lipolysis have been observed, together with a reduction in the pro-oxidative and pro-inflammatory state and a normalization of intestinal dysbiosis. Clinical trials have reported a decrease in the serum transaminases and an improved lipid profile, as well as a reduction in inflammatory markers. Conclusions: In conclusion, probiotic supplementation can be used as a potential therapy for the management of NAFLD.

Inulin intervention attenuates hepatic steatosis in rats via modulating gut microbiota and maintaining intestinal barrier function

Increasing evidence has suggested the mitigatory efficacy of prebiotic inulin on nonalcoholic fatty liver disease (NAFLD), nevertheless, its action mechanisms remain elusive. Herein, inulin consumption effectively ameliorated high-sucrose diet-induced hepatic steatosis and inflammation, and rehabilitated liver lipogenesis regulators, including carbohydrate response element-binding protein, stearoyl-CoA desaturase-1 and peroxisome proliferator-activated receptor alpha. Furthermore, inulin supplementation restored the intestinal barrier integrity and function by up-regulating expressions of tight junction proteins (zonula occludens-1, claudin-1 and occludin). High-throughput sequencing demonstrated that inulin administration regulated the gut microbiota composition, wherein abundance of short-chain fatty acid (SCFA)-producers, including Bifidobacterium, Phascolarctobacterium and Blautia, was significantly enhanced in the inulin-treated rats, conversely, opportunistic pathogens, such as Acinetobacter and Corynebacterium_1, were suppressed. SCFA quantitative analysis showed that dietary inulin suppressed faecal acetate levels, but improved propionate and butyrate concentrations in rats with NAFLD. Functional prediction showed that tryptophan metabolism was one of the key metabolic pathways affected by gut microbiota changes. A targeted metabolomics profiling of tryptophan metabolism demonstrated that inulin intervention up-regulated faecal contents of indole-3-acetic acid and kynurenic acid, whereas down-regulated levels of kynurenine and 5-hydoxyindoleacetic acid in NAFLD rats. Therefore, this study demonstrated that inulin intake alleviated hepatic steatosis likely by regulating the gut microbiota composition and function and restoring the intestinal barrier integrity, which may provide a novel notion for the prevention and treatment of NAFLD in future.

Assessing the in vivo ameliorative effects of Lactobacillus acidophilus KLDS1.0901 for induced non-alcoholic fatty liver disease treatment

Reputed as a significant metabolic disorder, non-alcoholic fatty liver disease (NAFLD) is characterized by high-fat deposits in the liver and causes substantial economic challenges to any country's workforce. Previous studies have indicated that some lactic acid bacteria may effectively prevent or treat NAFLD. Overall, L. acidophilus KLDS1.0901 protected against HFD-induced NAFLD by improving liver characteristics and modulating microbiota composition, and thus could be a candidate for improving NAFLD. This study aimed to assess the protective effects of L. acidophilus KLDS1.0901 on a high-fat diet(HFD)-induced NAFLD. First, hepatic lipid profile and histological alterations were determined to study whether L. acidophilus KLDS1.0901 could ameliorate NAFLD. Then, the intestinal permeability and gut barrier were explored. Finally, gut microbiota was analyzed to elucidate the mechanism from the insights of the gut-liver axis. The results showed that Lactobacillus KLDS1.0901 administration significantly decreased body weight, Lee's index body, fat rate, and liver index. L. acidophilus KLDS1.0901 administration significantly improved lipid profiles by decreasing the hepatic levels of total cholesterol (TC), triglyceride (TG), and low-density lipoprotein cholesterol (LDL-C) and by increasing the high-density lipoprotein cholesterol (HDL-C) levels. A conspicuous decrease of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in serum was observed after L. acidophilus KLDS1.0901 administration. Meanwhile, the H&E and Oil Red O-stained staining showed that L. acidophilus KLDS1.0901 significantly reduced liver lipid accumulation of HFD-fed mice by decreasing the NAS score and lipid area per total area. Our results showed that L. acidophilus KLDS1.0901 administration decreased the interleukin-6 (IL-6), interleukin-1β (IL-1β), and tumor necrosis factor-alpha (TNF-α) concentrations accompanied by the increase of interleukin-10 (IL-10). L. acidophilus KLDS1.0901 administration could improve the intestinal barrier function by upregulating the mRNA levels of occludin, claudin-1, ZO-1, and Muc-2, which were coupled to the decreases of the concentration of LPS and D-lactic acid. Notably, L. acidophilus KLDS1.0901 administration modulated the gut microbiota to a near-normal pattern. Hence, our results suggested that L. acidophilus KLDS1.0901 can be used as a candidate to ameliorate NAFLD.

Characteristic alterations of gut microbiota in uncontrolled gout

Microbiome research has been on the rise recently for a more in-depth understanding of gout. Meanwhile, there is a need to understand the gut microbiome related to uric acid-lowering drug resistance. In this study, 16S rRNA gene-based microbiota analysis was performed for a total of 65 stool samples from 17 healthy controls and 48 febuxostat-treated gout patients (including 28 controlled subjects with decreased uric acid levels and 20 uncontrolled subjects with non-reduced uric acid levels). Alpha diversity of bacterial community decreased in the healthy control, controlled, and uncontrolled groups. In the case of beta diversity, the bacterial community was significantly different among groups (healthy control, controlled, and uncontrolled groups). Taxonomic biomarker analysis revealed the increased population of g-Bifidobacterium in healthy controls and g-Prevotella in uncontrolled patients. PCR further confirmed this result at the species level. Additionally, functional metagenomics predictions led to the exploration of various functional biomarkers, including purine metabolism. The results of this study can serve as a basis for developing potential new strategies for diagnosing and treating gout from microbiome prospects.

Strain-specific regulative effects of Lactobacillus plantarum on intestinal barrier dysfunction are associated with their capsular polysaccharides

The intestinal barrier is integral to the host's defense, and disrupting its integrity contributes to gut and systemic diseases. Lactobacillus plantarum has been widely reported to exhibit a protective effect on the gut barrier. However, the strain-specific mechanism of this bacterium's function remains unclear. This study characterized the regulative effects of 55 L. plantarum strains on the intestinal barrier using TNF-α-induced Caco-2 cells and a dextran sulfate sodium-induced colitis animal model and found that the regulative effect is strain-specific. Comparative genomic analysis suggested that the ability of L. plantarum to regulate the intestinal barrier is exerted in part by genes encoding proteins associated with polysaccharide synthesis. This observation was verified using surface protein/capsular polysaccharides separation experiments. Structural analysis of capsular polysaccharides showed that molecular weight and mole ratios of monosaccharide compositions may play important roles in strain-specific protective effects on the gut barrier. This study identified different effects of L. plantarum strains on intestinal barrier dysfunction and proved that this regulative ability relies on the characteristic of the capsular polysaccharides of the strains. Thus, our data provided genetic targets and molecular for screening L. plantarum strains with the ability to protect the gut barrier, and suggested the capsular polysaccharides of L. plantarum may be explored as a potential functional food component against intestinal barrier dysfunction.

Specific Strains of Faecalibacterium prausnitzii Ameliorate Nonalcoholic Fatty Liver Disease in Mice in Association with Gut Microbiota Regulation

Evidence linking Faecalibacterium prausnitzii abundance to nonalcoholic fatty liver disease (NAFLD) is accumulating; however, the causal relationship remains obscure. In this study, 12 F. prausnitzii strains were orally administered to high fat diet fed C57BL/6J mice for 12 weeks to evaluate the protective effects of F. prausnitzii on NAFLD. We found that five F. prausnitzii strains, A2-165, LB8, ZF21, PL45, and LC49, significantly restored serum lipid profiles and ameliorated glucose intolerance, adipose tissue dysfunction, hepatic steatosis, inflammation, and oxidative stress in a mouse model of NAFLD. Moreover, two strains, LC49 and LB8, significantly enhanced short-chain fatty acid (SCFA) production and modulated the gut microbiota. Based on the combined analysis of linear discriminant analysis effect size and microbial communities, the core microbiome related to NAFLD comprised Odoribacter, Roseburia, Erysipelatoclostridium, Tyzzerella, Faecalibaculum, Blautia, and Acetatifactor, and the last five genera can be reversed by treatment with the LC49 and LB8 strains. Additionally, the LC49 and LB8 strains enriched Lactobacillus, Ileibacterium, Faecalibacterium, Dubosiella, and Bifidobacterium and downregulated pathways involving carbohydrate metabolism, amino acid metabolism, and fatty acid biosynthesis. Interestingly, LC49 supplementation also upregulated tryptophan metabolism, glutathione metabolism, and valine, leucine, and isoleucine degradation, which might be related to NAFLD prevention. Collectively, F. prausnitzii LC49 and LB8 exerted considerable anti-NAFLD and microbiota-regulating effects, indicating their potential as probiotic agents for NAFLD treatment.

The clinical effect of probiotics on patients with non-alcoholic fatty liver disease: a meta-analysis

Nonalcoholic fatty liver disease (NAFLD) is a common chronic liver disease. The present study explores the clinical efficacy of probiotics in the treatment of patients with NAFLD by conducting a systematic search of relevant databases. The RevMan 5.4 software was used to evaluate the effects of probiotics on liver function (i.e. alanine aminotransferase [ALT], aspartate aminotransferase [AST], gamma-glutamyl transferase [GGT], lipid metabolism, blood glucose, inflammatory factors [e.g. tumor necrosis factor-α, TNF-α] and body mass index [BMI]) in patients with NAFLD. A total of 18 high-quality studies were included in the final meta-analysis. The results of the meta-analysis showed that the use of probiotics in the adjuvant treatment of patients with NAFLD improved liver function and reduced ALT levels (mean difference [MD]: -0.07; 95% confidence interval [CI]: -12.95, -7.19), AST levels (MD: -11.90; 95% CI: -16.55, -7.25) and GGT levels (MD: -8.61; 95% CI: -14.74, -2.48); additionally, the treatment effect was more obvious when the treatment time exceeded 12 weeks. Probiotic therapy reduced patients' triglyceride levels (MD: -9.71; 95% CI: -18.39, -1.03) and total cholesterol levels (MD: -22.31; 95% CI: -25.41, -19.21). Probiotic treatment improved patients' levels of fasting blood (MD: -8.22; 95% CI: -12.25, -4.20), insulin (MD: -2.68; 95% CI: -4.94, -0.41) and insulin resistance (MD: -0.72; 95% CI: -1.21, -0.24). Probiotic adjuvant therapy for patients with NAFLD reduced their BMI by approximately 1.67 (95% CI: -2.93, -0.41) and TNF-α levels. The adjuvant treatment of NAFLD with probiotics has a positive clinical effect, which is influenced by treatment time.

Just Drink a Glass of Water? Effects of Bicarbonate–Sulfate–Calcium–Magnesium Water on the Gut–Liver Axis

Background and Aim: Fonte Essenziale® water is a bicarbonate–sulfate–calcium–magnesium water, low in sodium, recognized by the Italian health care system in hydropinotherapy and hepatobiliary dyspepsia therapy. We wanted to explore its effects on the gut–liver axis and microbiota in non-alcoholic fatty liver disease patients.

Patients and Methods: We considered enrollment for 70 patients, of which four were excluded. We finally enrolled 55 patients with ultrasound-documented steatosis (SPs+) and 11 patients without it (SPs−). They then drank 400 ml of water for 6 months in the morning on an empty stomach. Routine hematochemical and metabolic parameters, oxidative stress parameters, gastrointestinal hormone levels, and fecal parameters of the gut microbiota were evaluated at three different assessment times, at baseline (T0), after 6 months (T6), and after a further 6 months of water washout (T12). We lost, in follow-up, 4 (T6) and 22 (T12) patients.

Results: Between T0–T6, we observed a significant Futuin A and Selenoprotein A decrease and a GLP-1 and PYY increase in SPs+ and the same for Futuin A and GLP-1 in SPs−. Effects were lost at T12. In SPs+, between T0–T12 and T6–12, a significant reduction in Blautia was observed; between T0–T12, a reduction of Collinsella unc. was observed; and between T0–T12 and T6–12, an increase in Subdoligranulum and Dorea was observed. None of the bacterial strains we analyzed varied significantly in the SPs− population.

Conclusion: These results indicate beneficial effects of water on gastrointestinal hormones and hence on the gut–liver axis in the period in which subjects drank water both in SPs− and in SPs+.

Lactococcus lactis KF140 Reduces Dietary Absorption of Nε - (Carboxymethyl)lysine in Rats and Humans via β-Galactosidase Activity

Background and Aims

Excessive intake of advanced glycation end products (AGEs), which are formed in foods cooked at high temperatures for long periods of time, has negative health effects, such as inflammatory responses and oxidative stress. N^ε-(Carboxymethyl)lysine (CML) is one of the major dietary AGEs. Given their generally recognized as safe status and probiotic functionalities, lactic acid bacteria may be ideal supplements for blocking intestinal absorption of food toxicants. However, the protective effects of lactic acid bacteria against dietary AGEs have not been fully elucidated.

Materials and Methods

We investigated the effect of treatment with Lactococcus lactis KF140 (LL-KF140), which was isolated from kimchi, on the levels and toxicokinetics of CML. The CML reduction efficacies of the Lactococcus lactis KF140 (LL-KF140), which was isolated from kimchi, were conducted by in vitro test for reducing CML concentration of the casein-lactose reaction product (CLRP) and in vivo test for reducing serum CML level of LL-KF140 administered rats at 2.0 × 10⁸ CFU/kg for14 days. In addition, 12 volunteers consuming LL-KF140 at 2.0 × 10⁹ CFU/1.5 g for 26 days were determined blood CML concentration and compared with that before intake a Parmesan cheese.

Results

Administration of LL-KF140 reduced serum CML levels and hepatic CML absorption in rats that were fed a CML-enriched product. In a human trial, the intake of LL-KF140 prevented increases in the serum levels of CML and alanine aminotransferase after consumption of a CML-rich cheese. LL-KF140 was determined to presence in feces through metagenome analysis. Furthermore, β-galactosidase, one of the L. lactis-produced enzymes, inhibited the absorption of CML and reduced the levels of this AGE, which suggests an indirect inhibitory effect of LL-KF140. This study is the first to demonstrate that an L. lactis strain and its related enzyme contribute to the reduction of dietary absorption of CML.

Whole-Genome Shotgun Metagenomic Sequencing Reveals Distinct Gut Microbiome Signatures of Obese Cats

Overweight and obesity are growing health problems in domestic cats, increasing the risks of insulin resistance, lipid dyscrasias, neoplasia, cardiovascular disease, and decreasing longevity. The signature of obesity in the feline gut microbiota has not been studied at the whole-genome metagenomic level. We performed whole-genome shotgun metagenomic sequencing in the fecal samples of eight overweight/obese and eight normal cats housed in the same research environment. We obtained 271 Gbp of sequences and generated a 961-Mbp de novo reference contig assembly, with 1.14 million annotated microbial genes. In the obese cat microbiome, we discovered a significant reduction in microbial diversity (P < 0.01) and Firmicutes abundance (P = 0.005), as well as decreased Firmicutes/Bacteroidetes ratios (P = 0.02), which is the inverse of obese human/mouse microbiota. Linear discriminant analysis and quantitative PCR (qPCR) validation revealed significant increases of Bifidobacterium sp., Olsenella provencensis, Dialister sp.CAG:486, and Campylobacter upsaliensis as the hallmark of obese microbiota among 400 enriched species, whereas 1,525 bacterial species have decreased abundance in the obese microbiome. Phascolarctobacterium succinatutens and an uncharacterized Erysipelotrichaceae bacterium are highly abundant (>0.05%) in the normal gut with over 400-fold depletion in the obese microbiome. Fatty acid synthesis-related pathways are significantly overrepresented in the obese compared with the normal cat microbiome. In conclusion, we discovered dramatically decreased microbial diversity in obese cat gut microbiota, suggesting potential dysbiosis. A panel of seven significantly altered, highly abundant species can serve as a microbiome indicator of obesity. Our findings in the obese cat microbiome composition, abundance, and functional capacities provide new insights into feline obesity.

IMPORTANCE Obesity affects around 45% of domestic cats, and licensed drugs for treating feline obesity are lacking. Physical exercise and calorie restrictions are commonly used for weight loss but with limited efficacy. Through comprehensive analyses of normal and obese cat gut bacteria flora, we identified dramatic shifts in the obese gut microbiome, including four bacterial species significantly enriched and two species depleted in the obese cats. The key bacterial community and functional capacity alterations discovered from this study will inform new weight management strategies for obese cats, such as evaluations of specific diet formulas that alter the microbiome composition, and the development of prebiotics and probiotics that promote the increase of beneficial species and the depletion of obesity-associated species. Interestingly, these bacteria identified in our study were also reported to affect the weight loss success in human patients, suggesting translational potential in human obesity.

Triclosan targeting of gut microbiome ameliorates hepatic steatosis in high fat diet-fed mice

Antibiotic use provides a promising strategy for the treatment of non-alcoholic fatty liver disease (NAFLD) by regulating the gut microbiota composition. Triclosan, a widely used antibiotic, may improve gut microbiome dysbiosis associated with NAFLD through the suppression of pathogenic gram-negative bacteria. However, the effects of triclosan on gut microbiota and hepatic steatosis and have not been explored in NAFLD mouse model. In this study, C57BL/6J mice were fed with high fat diet (HFD) for continuous 20 weeks and treated with triclosan at 400 mg/kg/d for 8 weeks from week 13. We explored the effects of triclosan on hepatic lipid accumulation and gut microbiome in HFD-fed mice by histological examination and 16 S ribosomal RNA sequencing, respectively. Analysis on the composition of gut microbiota indicated that triclosan suppressed pathogenic gram-negative bacteria, including Helicobacter, Erysipelatoclostridium and Citrobacter, and increased the ratio of Bacteroidetes/Firmicutes in HFD-fed mice. Meanwhile, triclosan increased the relative abundance of beneficial gut microbiomes including Lactobacillus, Bifidobacterium and Lachnospiraceae, which protected against metabolic abnormality. The results of alpha-diversity and beta-diversity also showed the improvement of triclosan on bacterial diversity and richness in HFD-fed mice. Pathway analysis further confirmed that triclosan can regulate nutrient and energy metabolism through the elimination of deleterious bacteria. As a result, triclosan intervention significantly reduced lipid accumulation and alleviated hepatic steatosis in HFD-fed mice. In conclusion, our results suggest that triclosan can alleviate liver steatosis in HFD-fed mice by targeting the gut microbiome.

Lactobacillus rhamnosus Encapsulated in Alginate/Chitosan Microgels Manipulates the Gut Microbiome to Ameliorate Salt-Induced Hepatorenal Injury

As the essential regulator of intestinal bacterial diversity, probiotics are a potential treatment for chronic high-salt diet (HSD)–induced metabolic dysfunction. Probiotic cells entrapped in microgels have been confirmed as being more effective than free cells in protecting bacteria against unfavorable conditions, that is, enhancing their stress resistance. This study explored the physiological mechanism by which probiotic microgels relieve HSD–induced hepatorenal injury. Herein, Lactobacillus rhamnosus was encapsulated in alginate-chitosan microgels which the percentage of alginate/chitosan was applied 1.5:0.5 (w/w) in this system, and the encapsulation significantly improved the probiotic viability in simulated gastrointestinal conditions. Mice were fed an HSD with L. rhamnosus (SDL) or L. rhamnosus microgels (SDEL). After 8 weeks of administration, dietary sodium was confirmed as inducing the hepatic and renal damages in mice, based on indicators, including serum biomarker levels, histopathological features of tissues, and pro-inflammatory cytokine contents in blood levels. However, the serum levels of urea nitrogen, creatinine, uric acid, glutamic-pyruvic transaminase, glutamic-oxalacetic transaminase, and alkaline phosphatase in the SDL and SDEL-fed mice were significantly lowered compared to the HSD-fed mice, especially in the SDEL group. HSD increased the abundances of Anaeroplasma, Enterorhabdus, Parvibacter, and Bacteroides, while the microgels increased the abundances of Lactobacillus, Bifidobacterium, Mucispirillum, and Faecalibaculum. Significant variations of fecal metabolome were validated for SDEL-treated mice, containing those linked to entero-hepatic circulation (e.g., cholic acid), carbohydrate metabolism (i.e., _L-lactic acid), and increased antioxidants including citric acid. Furthermore, the probiotic microgels ameliorated intestinal damage by improving barrier and absorption functions. These results augmented existing knowledge on probiotic application for salt toxicity.

Lactobacillus reuteri CCFM8631 Alleviates Hypercholesterolaemia Caused by the Paigen Atherogenic Diet by Regulating the Gut Microbiota

Cardiovascular disease has one of the highest global incidences and mortality rates. Atherosclerosis is the main cause of cardiovascular disease, and hypercholesterolaemia and hyperlipidaemia are the main risk factors for the development of atherosclerosis. Decreasing serum cholesterol and triglyceride concentrations is considered to be an effective strategy to prevent atherosclerotic cardiovascular disease. Previous studies have shown that many diseases are related to gut microbiota dysbiosis. The positive regulation of the gut microbiota by probiotics may prevent or treat certain diseases. In this study, Lactobacillus reuteri CCFM8631 treatment was shown to decrease plasma total cholesterol (TC), low-density lipoprotein–cholesterol, aspartate transaminase, alanine transaminase and trimethylamine N-oxide concentrations, decrease liver TC and malondialdehyde concentrations and recover liver superoxide dismutase concentrations in mice fed a Paigen atherogenic diet. In addition, L. reuteri increased the faecal short-chain fatty acid content (acetate, propionate and butyrate), which was accompanied by an increase in the relative abundance of faecal Deferribacteres, Lachnospiraceae NK4A136 group, Lactobacillus and Dubosiella; a decrease in the relative abundance of Erysipelatoclostridium and Romboutsia and the activation of butanoate and vitamin B6 metabolism, leading to the alleviation of hypercholesterolaemia.

Bifidobacterium breve and Bifidobacterium longum Attenuate Choline-Induced Plasma Trimethylamine N-Oxide Production by Modulating Gut Microbiota in Mice

Atherosclerosis is the main cause of myocardial infarction and stroke, and the morbidity and mortality rates of cardiovascular disease are among the highest of any disease worldwide. Excessive plasma trimethylamine-N-oxide (TMAO), an intestinal metabolite, promotes the development of atherosclerosis. Therefore, effective measures for reducing plasma TMAO production can contribute to preventing atherosclerosis. Probiotics are living microorganisms that are beneficial to the human body, and some of them can attenuate plasma TMAO production. To explore the effects of probiotic supplementation on plasma TMAO in choline-fed mice, we intragastrically administered eight strains of Bifidobacterium breve and eight strains of Bifidobacterium longum to mice for 6 weeks. B. breve Bb4 and B. longum BL1 and BL7 significantly reduced plasma TMAO and plasma and cecal trimethylamine concentrations. However, hepatic flavin monooxygenase (FMO) activity, flavin-containing monooxygenase 3 (FMO3), farnesoid X receptor (FXR) protein expression and TMAO fractional excretion were not significantly affected by Bifidobacterium supplementation. The treatment of Bifidobacterium strains modulated the abundances of several genera such as Ruminococcaceae UCG-009, Ruminococcaceae UCG-010, which belong to the Firmicutes that has been reported with cut gene clusters, which may be related to the reduction in intestinal TMA and plasma TMAO. Additionally, a reduction in Ruminococcaceae indicates a reduction in circulating glucose and lipids, which may be another pathway by which Bifidobacterium strains reduce the risk of atherosclerosis. The effect of Bifidobacterium strains on Bacteroides also suggests a relationship between the abundance of this genus and TMA concentrations in the gut. Therefore, the mechanism underlying these changes might be gut microbiota regulation. These Bifidobacterium strains may have therapeutic potential for alleviating TMAO-related diseases.

Bifidobacterium bifidum Shows More Diversified Ways of Relieving Non-Alcoholic Fatty Liver Compared with Bifidobacterium adolescentis

The occurrence of non-alcoholic fatty liver disease (NAFLD) is closely related to intestinal microbiota disturbance, and probiotics has become a new strategy to assist in alleviating NAFLD. In order to investigate the effect of Bifidobacterium on NAFLD and the possible pathway, a NAFLD model was established by using a high-fat diet (HFD) for 18 weeks. Fourteen strains of Bifidobacterium were selected (seven Bifidobacterium adolescentis and seven Bifidobacterium bifidum) for intervention. The effects of different bifidobacteria on NAFLD were evaluated from liver cell injury, liver fat deposition, liver inflammatory state and liver histopathology, and were taken as entry points to explore the mitigation approaches of bifidobacteria through energy intake, lipid metabolism, glucose metabolism and intestinal permeability. The results showed that Bifidobacterium exerts species-specific effects on NAFLD. B. bifidum exerted these effects mainly through regulating the intestinal microbiota, increasing the relative abundance of Faecalibaculum and Lactobacillus, decreasing the relative abundance of Tyzzerella, Escherichia-Shigella, Intestinimonas, Osillibacter and Ruminiclostridium, and further increasing the contents of propionic acid and butyric acid, regulating lipid metabolism and intestinal permeability, and ultimately inhibiting liver inflammation and fat accumulation to alleviate NAFLD. B. adolescentis exerted its effects mainly through changing the intestinal microbiota, increasing the content of propionic acid, regulating lipid metabolism and ultimately inhibiting liver inflammation to alleviate NAFLD.

Lipid-Lowering Effects of Inonotus obliquus Polysaccharide In Vivo and In Vitro

Excessive lipid intake will cause hyperlipidemia, fatty liver metabolism disease, and endanger people’s health. Edible fungus polysaccharide is a natural active substance for lipid lowering. In this study, the HepG2 cell model induced by oleic acid and mice model induced by a high-fat diet was established. The lipid-lowering effects of Inonotus obliquus polysaccharide (IOP) was investigated in vivo and in vitro. Glucose (251.33 mg/g), rhamnose (11.53 mg/g), ribose (5.10 mg/g), glucuronic acid (6.30 mg/g), and galacturonic acid (2.95 mg/g) are present in IOP, at a ratio of 85.2:3.91:1.73:2.14:1. The molecular weight of IOP is 42.28 kDa. Treatment with 60 mg/L of IOP showed a significant lipid-lowering effect in HepG2 cells compared with the oleic acid-treated group. In the oil red O-stained images, the red fat droplets in the IOP-treated groups were significantly reduced. TC and TG levels of IOP-treated groups decreased. IOP can alleviate the lipid deposition in the mice liver due to high-fat diet, and significantly reduce their serum TC, TG, and LDL-C contents. IOP could activate AMPK but decrease the SREBP-1C, FAS, and ACC protein expression related to adipose synthesis in mice. IOP has a certain potential for lipid-lowering effects both in vivo and in vitro.

Dietary Fat Effect on the Gut Microbiome, and Its Role in the Modulation of Gastrointestinal Disorders in Children with Autism Spectrum Disorder

Children with autism spectrum disorder (ASD) report a higher frequency and severity of gastrointestinal disorders (GID) than typically developing (TD) children. GID-associated discomfort increases feelings of anxiety and frustration, contributing to the severity of ASD. Emerging evidence supports the biological intersection of neurodevelopment and microbiome, indicating the integral contribution of GM in the development and function of the nervous system, and mental health, and disease balance. Dysbiotic GM could be a contributing factor in the pathogenesis of GID in children with ASD. High-fat diets may modulate GM through accelerated growth of bile-tolerant bacteria, altered bacterial ratios, and reduced bacterial diversity, which may increase the risk of GID. Notably, saturated fatty acids are considered to have a pronounced effect on the increase of bile-tolerant bacteria and reduction in microbial diversity. Additionally, omega-3 exerts a favorable impact on GM and gut health due to its anti-inflammatory properties. Despite inconsistencies in the data elaborated in the review, the dietary fat composition, as part of an overall dietary intervention, plays a role in modulating GID, specifically in ASD, due to the altered microbiome profile. This review emphasizes the need to conduct future experimental studies investigating the effect of diets with varying fatty acid compositions on GID-specific microbiome profiles in children with ASD.

Distribution of Genes Related to Probiotic Effects Across Lacticaseibacillus rhamnosus Revealed by Population Structure

The Gram-positive Lacticaseibacillus rhamnosus has been broadly reported as capable of exerting beneficial health effects. Bacterial genomic diversity may promote niche specialization, thus creating subpatterns within populations. As L. rhamnosus advantageous effects have been widely reported at strain level and few is known regarding the distribution of beneficial genes among L. rhamnosus strains, we investigated all publicly available genomes of Lactobacillus and Lacticaseibacillus genera to study the pangenome and general population structure of L. rhamnosus. Core genome multilocus sequence typing detected eight L. rhamnosus phylogroups (PG1 to PG8). L. rhamnosus harbors an open pangenome; PG1, PG3, PG4, and PG5 exhibited highly conserved gene distribution patterns. Genes significantly associated to the PG1, which comprises L. rhamnosus GG, are mainly phage-related. The adhesion operon spaCBA-srtC1 was found in 44 (24.7%) genomes; however, considering only the PG1, the prevalence was of 65%. In PG2 the spaCBA-srtC1 prevalence was of 43%. Nevertheless, both human and milk-derived strains harbored this operon. Further, two main types of bacteriocin clusters were found (Bact1 and Bact2). Bact1 predictions indicate the presence of garQ, encoding the class II bacteriocin garvieacin Q, that is mainly present in the closely related PG8A and a PG2 subcluster. PG2 harbors two distinct subclusters, harboring either spaCBA-srtC1 or Bact1. Our findings provide novel insights on the distribution of biotechnological relevant genes across L. rhamnosus population, uncovering intra-species patterns that may bring forth the development of more efficient probiotic products.