The Potential Role of Gut Microbiota in the Prevention and Treatment of Lipid Metabolism Disorders

Microbiota based personalized nutrition improves hyperglycaemia and hypertension parameters and reduces inflammation: a prospective, open label, controlled, randomized, comparative, proof of concept study

Background

Recent studies suggest that gut microbiota composition, abundance and diversity can influence many chronic diseases such as type 2 diabetes. Modulating gut microbiota through targeted nutrition can provide beneficial effects leading to the concept of personalized nutrition for health improvement. In this prospective clinical trial, we evaluated the impact of a microbiome-based targeted personalized diet on hyperglycaemic and hyperlipidaemic individuals. Specifically, BugSpeaks®-a microbiome profile test that profiles microbiota using next generation sequencing and provides personalized nutritional recommendation based on the individual microbiota profile was evaluated.

Methods

A total of 30 participants with type 2 diabetes and hyperlipidaemia were recruited for this study. The microbiome profile of the 15 participants (test arm) was evaluated using whole genome shotgun metagenomics and personalized nutritional recommendations based on their microbiota profile were provided. The remaining 15 participants (control arm) were provided with diabetic nutritional guidance for 3 months. Clinical and anthropometric parameters such as HbA1c, systolic/diastolic pressure, c-reactive protein levels and microbiota composition were measured and compared during the study.

Results

The test arm (microbiome-based nutrition) showed a statistically significant decrease in HbA1c level from 8.30 (95% confidence interval (CI), [7.74-8.85]) to 6.67 (95% CI [6.2-7.05]), p < 0.001 after 90 days. The test arm also showed a 5% decline in the systolic pressure whereas the control arm showed a 7% increase. Incidentally, a sub-cohort of the test arm of patients with >130 mm Hg systolic pressure showed a statistically significant decrease of systolic pressure by 14%. Interestingly, CRP level was also found to drop by 19.5%. Alpha diversity measures showed a significant increase in Shannon diversity measure (p < 0.05), after the microbiome-based personalized dietary intervention. The intervention led to a minimum two-fold (Log2 fold change increase in species like Phascolarctobacterium succinatutens, Bifidobacterium angulatum, and Levilactobacillus brevis which might have a beneficial role in the current context and a similar decrease in species like Alistipes finegoldii, and Sutterella faecalis which have been earlier shown to have some negative effects in the host. Overall, the study indicated a net positive impact of the microbiota based personalized dietary regime on the gut microbiome and correlated clinical parameters.

Probiotics combined with atorvastatin administration in the treatment of hyperlipidemia: A randomized, double-blind, placebo-controlled clinical trial

BACKGROUND

Hyperlipidemia is a common feature of chronic diseases. The aim of this work was designed to assess the role of probiotics (Lactobacillus casei Zhang, Bifidobactetium animalis subsp. lactis V9, and Lactobacillus plantarum P-8) in the treatment of hyperlipidemia.

METHODS

Thirty three patients with hyperlipidemia were randomly divided into a probiotic group (n = 18) and a control group (n = 15). The probiotic group was administered probiotics (2 g once daily) and atorvastatin 20 mg (once daily), and the control group was administered a placebo (2 g once daily) and atorvastatin 20 mg (once daily). Serum and fecal samples were gathered for subsequent analyses.

RESULTS

Time had a significant effect on the total cholesterol (TC), triglycerides (TG), and low-density lipoprotein-cholesterol (LDL-C) levels in the probiotic and control groups (P < .05). The gut microbial abundance in the probiotic group was markedly higher than that in the control group following 3-month probiotic treatment (P < .05). At the phylum level, probiotics exerted no notable effects on the relative abundance of Firmicutes, Bacteroidetes, and Actinobacteria but elevated that of Tenericutes and reduced Proteobacteria. At the genus level, probiotics increased the relative abundance of Bifidobacterium, Lactobacillus, and Akkermansia, and decreased that of Escherichia, Eggerthella, and Sutterella relative to the control group in months 1, 2, and 3 (P < .05).

CONCLUSIONS

Probiotics optimize the gut microbiota structure and decrease the amount of harmful bacteria in patients with hyperlipidemia. Probiotics can influence the composition of gut microorganisms and increase their diversity and abundance in vivo. It is recommended to use probiotics combined with atorvastatin to treat patients with hyperlipidemia.

Another renaissance for bile acid gastrointestinal microbiology

The field of bile acid microbiology in the gastrointestinal tract is going through a current rebirth after a peak of activity in the late 1970s and early 1980s. This renewed activity is a result of many factors, including the discovery near the turn of the century that bile acids are potent signalling molecules and technological advances in next-generation sequencing, computation, culturomics, gnotobiology, and metabolomics. We describe the current state of the field with particular emphasis on questions that have remained unanswered for many decades in both bile acid synthesis by the host and metabolism by the gut microbiota. Current knowledge of established enzymatic pathways, including bile salt hydrolase, hydroxysteroid dehydrogenases involved in the oxidation and epimerization of bile acid hydroxy groups, the Hylemon-Bjӧrkhem pathway of bile acid C7-dehydroxylation, and the formation of secondary allo-bile acids, is described. We cover aspects of bile acid conjugation and esterification as well as evidence for bile acid C3-dehydroxylation and C12-dehydroxylation that are less well understood but potentially critical for our understanding of bile acid metabolism in the human gut. The physiological consequences of bile acid metabolism for human health, important caveats and cautionary notes on experimental design and interpretation of data reflecting bile acid metabolism are also explored.

The Potential Harmful Effects of Genetically Engineered Microorganisms (GEMs) on the Intestinal Microbiome and Public Health

Gut luminal dysbiosis and pathobiosis result in compositional and biodiversified alterations in the microbial and host co-metabolites. The primary mechanism of bacterial evolution is horizontal gene transfer (HGT), and the acquisition of new traits can be achieved through the exchange of mobile genetic elements (MGEs). Introducing genetically engineered microbes (GEMs) might break the harmonized balance in the intestinal compartment. The present objectives are: 1. To reveal the role played by the GEMs' horizontal gene transfers in changing the landscape of the enteric microbiome eubiosis 2. To expand on the potential detrimental effects of those changes on the human genome and health. A search of articles published in PubMed/MEDLINE, EMBASE, and Scielo from 2000 to August 2023 using appropriate MeSH entry terms was performed. The GEMs' horizontal gene exchanges might induce multiple human diseases. The new GEMs can change the long-term natural evolution of the enteric pro- or eukaryotic cell inhabitants. The worldwide regulatory authority's safety control of GEMs is not enough to protect public health. Viability, biocontainment, and many other aspects are only partially controlled and harmful consequences for public health should be avoided. It is important to remember that prevention is the most cost-effective strategy and primum non nocere should be the focus.

Bifidobacterium lactis Probio-M8 ameliorated the symptoms of type 2 diabetes mellitus mice by changing ileum FXR-CYP7A1

The aim of this study was to investigate the effect of Bifidobacterium lactis Probio-M8 on glucolipid metabolism and gut microbiota (GM) composition in type 2 diabetes mellitus (T2DM) mice. The glucolipid metabolic profiles were analyzed. The 16S rRNA gene sequencing was employed to investigate GM. The levels of farnesyl X receptor (FXR) and cytochrome p450 7A1 (CYP7A1) were detected by quantitative polymerase chain reaction and western blot assays. The total bile acids (TBAs), ceramide (CE), glucagon-like peptide-1 (GLP-1), and fibroblast growth factor (FGF)-15 were also detected. The morphological features of liver and pancreas were also analyzed. Compared with the model group, Probio-M8 restored body weight, food intake and water intake, as well as improved hyperglycemia symptoms, serum glucolipid parameters, and the composition of intestinal microbes in T2DM diabetic mice. Moreover, the reduced level of FXR and the increased level of CYP7A1 in T2DM mice were reversed by Probio-M8 treatment. The increased levels of TBA and CE and the reduced levels of GLP-1 and FGF-15 in T2DM mice were altered after Probio-M8 stimulation. Besides, the altered morphology of liver and ileum in T2DM mice was alleviated by Probio-M8 treatment. Taken together, we suggested that the symptoms of T2DM could be ameliorated by Probio-M8 in T2DM mice.

The Hypolipidemic Effect of Hawthorn Leaf Flavonoids through Modulating Lipid Metabolism and Gut Microbiota in Hyperlipidemic Rats

Objective. The purpose of this study was to explore the potential mechanisms of the lipid-regulating effects and the effect on modulating the gut microbiota of hawthorn leaf flavonoids (HLF) in the high-fat diet-induced hyperlipidemic rats. Methods. The hypolipidemic effect of HLF was investigated in the high-fat diet-induced hyperlipidemic rats. The action targets of HLF in the treatment of hyperlipidemia were predicted by network pharmacology and KEGG enrichment bubble diagram, which were verified by the test of western blotting. Meanwhile, we used 16S rRNA sequencing to evaluate the effects of HLF on the microbes. Results. The results of animal experiments showed that HLF could reduce the body weight and regulate the levels of serum lipid in high-fat diet (HFD) rats. Meanwhile, for the related targets of cholesterol metabolism, HLF could significantly upregulate the expression of LDLR, NR1H3, and ABCG5/ABCG8; reduce the expression of PCSK9; and increase the level of CYP7A1 in the intestinal tissue, whereas cholesterol biosynthetic protein expressions including HMGCR and SCAP were lowered by HLF. In addition, HLF increased the activities of plasma SOD, CAT, and GSH-Px and decreased the levels of Casp 1, NLRP3, IL-1β, IL-18, and TNF-α, improving the degree of hepatocyte steatosis and inflammatory infiltration of rats. Notably, HLF significantly regulated the relative abundance of major bacteria such as g_Lactobacillus, g_Anaerostipes, g_[Eubacterium]_hallii_group, g_Fusicatenibacter, g_Akkermansia, and g_Collinsella. Synchronously, we found that HLF could regulate the disorder of plasma HEPC and TFR levels caused by HFD. Conclusion. This study demonstrates that HLF can regulate metabolic hyperlipidemia syndromes and modulate the relative abundance of major bacteria, which illustrated that it might be associated with the modulation of gut microbiota composition and metabolites.

Neohesperidin Dihydrochalcone Ameliorates High-Fat Diet-Induced Glycolipid Metabolism Disorder in Rats

High-fat diet (HFD) is closely related to the formation of metabolic diseases. Studies have confirmed that neohesperidin dihydrochalcone (NHDC) possesses the biological activity of preventing glycolipid metabolism disorder. To explore the mechanism of its preventive activity against glucolipid metabolism disorder, HFD-treated rats were orally administered with NHDC for 12 weeks continuously. The results showed that, compared with the HFD group, the intervention of 40-80 mg/kg body weight of NHDC effectively downregulated the level of fasting blood glucose. Western blot analysis revealed that the treatment of NHDC alleviated the inhibitory effect of HFD on the expression of hepatic GLUT-4 and IRS-1. Further studies confirmed that NHDC reduced the degree of HFD-stimulated inflammation of ileum through the TLR4/MyD88/NF-κB signaling pathway. Moreover, ileum intestinal flora analysis showed that intragastric administration of NHDC reversed the change of Proteobacteria abundance and the Firmicutes/Bacteroidetes (F/B) ratio caused by HFD. At the generic level, NHDC promoted the relative abundance of Coprococcus, Bifidobacterium, Clostridium, Oscillospira, and [Eubacterium], while reducing the relative abundance of Defluviitalea and Prevotella. Taken together, these findings suggest that NHDC possesses the biological activity of improving HFD-induced glycolipid metabolism disorder.

The Ameliorative Effect of COST on Diet-Induced Lipid Metabolism Disorders by Regulating Intestinal Microbiota

(1) Background: Chitosan oligosaccharides, with an average molecular weight ≤ 1000 Da (COST), is a natural marine product that has the potential to improve intestinal microflora and resist lipid metabolism disorders. (2) Methods: First, by establishing a mice model of lipid metabolism disorder induced by a high fat and high sugar diet, it is proven that COST can reduce lipid metabolism disorder, which may play a role in regulating intestinal microorganisms. Then, the key role of COST in the treatment of intestinal microorganisms is further confirmed through the method of COST-treated feces and fecal bacteria transplantation. (3) Conclusions: intestinal microbiota plays a key role in COST inhibition of lipid metabolism disorder induced by a high fat and high sugar diet. In particular, COST may play a central regulatory role in microbiota, including Bacteroides, Akkermansia, and Desulfovibrio. Taken together, our work suggests that COST may improve the composition of gut microbes, increase the abundance of beneficial bacteria, improve lipid metabolism disorders, and inhibit the development of metabolic disorders.

Wuwei Qingzhuo San Ameliorates Hyperlipidemia in Mice Fed With HFD by Regulating Metabolomics and Intestinal Flora Composition

Hyperlipidemia is one of the most common metabolic disorders that threaten people’s health. Wuwei Qingzhuo San (WQS) is a traditional Mongolian medicine prescription, which is widely used in Mongolia for the treatment of hyperlipidemia. Our previous studies found that it has hypolipidemic and hepatoprotective effects on hyperlipidemic hamsters. However, the underlying lipid-lowering mechanisms of WQS and its relationship with intestinal flora are not yet clear. In this study, 16 S rRNA gene sequencing and metabolomics were performed to investigate the action mechanism of WQS on hyperlipidemic mice induced by a high-fat diet (HFD). As a result, metabolic pathway enrichment analysis revealed that the intervention of WQS had obviously modulated the metabolism of α-linolenic acid and linoleic acid and the biosynthesis of bile acids. 16 S rRNA sequencing showed that WQS had altered the composition of the intestinal microbiota in hyperlipidemic mice fed with HFD and, especially, adjusted the relative abundance ratio of Firmicutes/Bacteroides. These findings provide new evidence that WQS can improve HFD-induced hyperlipidemia by regulating metabolic disorders and intestinal flora imbalance.

Dietary Influences on Gut Microbiota with a Focus on Metabolic Syndrome

There is a clear correlation between gut microbiota, diet, and metabolic outcomes. A diet high in fiber has been shown to decrease inflammation, increase insulin sensitivity, and reduce dyslipidemias whereas a diet high in fat and sugar leads to dyslipidemia, insulin resistance, and low-grade inflammation. There is recent evidence suggesting that the human gut microbiota has a significant role in the development or the resolution of metabolic syndrome (MetS) and associated conditions. Leading a stressful, sedentary lifestyle with limited or no physical activity and consuming an unhealthy diet high in saturated fat, simple carbohydrates, and sodium and low in dietary fiber and in high-quality protein are some of the contributing factors. Unhealthy diets have been shown to induce alterations in the gut microbiota and contribute to the pathogenesis of MetS by altering microbiota composition and disrupting the intestinal barrier, which leads to low-grade systemic inflammation. In contrast, healthy diets can lead to changes in microbiota that increase gut barrier function and increase the production of anti-inflammatory biomarkers. This review aims at providing a more in-depth discussion of diet-induced dysbiosis of the gut microbiota and its effect on MetS. Here, we discuss the possible mechanisms involved in the development of the metabolic biomarkers that define MetS, with an emphasis on the role of sugar and dietary fiber in microbiome-mediated changes in low-grade systemic inflammation and metabolic dysfunction.

Probiotics and synbiotics show clinical efficacy in treating gestational diabetes mellitus: A meta-analysis

BACKGROUND

This study performed a systematic and meta-analysis of randomized controlled trials (RCTs) to explore the efficacy of probiotic- and symbiotic-based supplements in the treatment of gestational diabetes mellitus (GDM).

METHODS

We performed a meta-analysis to evaluate the efficacy of probiotics/synbiotics in GDM treatment, following a systematic search in Web of Science, PubMed, Cochrane Library, and EBSCO databases for articles published up to July 2020.

RESULTS

In total, 12 RCTs comprising 894 participants, were analyzed. Compared to the placebo, patients administered with probiotic and synbiotic supplements benefited more with regards to glucose and lipid metabolism as well as anti-inflammation and antioxidant capacity including insulin of change (WMD: 3.57, 95%CI: -5.26, -1.88), very-low-density lipoprotein (VLDL) (WMD: -5.03, 95%CI: -8.26, -1.79), nitric oxide (NO) at the end of trial (WMD: 2.31, 95%CI: 0.91, 3.70), total antioxidant capacity (TAC) at the end of trial (SMD: 0.74, 95%CI: 0.21, 1.27), high-sensitivity C-reactive protein (hsCRP) at the end of trial (SMD: -1.23, 95%CI: -1.97, -0.49). Besides, probiotic and synbiotic supplements improved outcomes on fetal hyperbilirubinemia risk (RR: 0.26, 95%CI: 0.12, 0.55), fetal macrosomia risk (RR: 0.47, 95%CI: 0.27, 0.83) and newborn weight (SMD: -0.29, 95%CI: -0.50, -0.09).

CONCLUSIONS

Findings from this work demonstrate that probiotic/symbiotic-based interventions improve glucose and lipid metabolism, anti-inflammatory and antioxidant ability in diet-controlled GDM patients, and exert beneficial outcomes on fetal hyperbilirubinemia, fetal macrosomia, and newborn weight.

In Vitro and In Vivo Cholesterol Reducing Ability and Safety of Probiotic Candidates Isolated from Korean Fermented Soya Beans

Hypercholesterolemia is a risk factor for cardiovascular diseases, and hence, reducing serum cholesterol levels could reduce the incidence. In this study, we ascertained the cholesterol-reducing potential of lactic acid bacteria (LAB) isolated from Korean fermented soybean paste. Live, resting, and dead cells of all the bacteria reduced cholesterol in liquid media in a strain-dependent manner. Live cells of Weissella cibaria SCCB2306, Pediococcus acidilactici SDL1402, P. acidilactici SDL1406, and Lactobacillus rhamnosus JDFM6 reduced the most cholesterol in liquid media by 78 ± 3%, 72 ± 3%, 76 ± 3%, 75 ± 5%, and 79 ± 2%, respectively. As the cholesterol levels in the media reduced, cell membrane lipids of P. acidilactici SDL1402, P. acidilactici SDL1406, and L. rhamnosus JDFM6 increased by 23.36 mg/mL, 6.53 mg/mL, and 8.14 mg/mL, respectively, indicating that cholesterol was incorporated into the bacteria cell membranes. All the bacteria displayed bile salt hydrolase activities in a strain-dependent manner. Though all four LAB significantly reduced cholesterol levels in Caenorhabditis elegans irrespective of the order of feeding, L. rhamnosus JDFM6 reduced the most cholesterol in vivo (up to 40% of ingested cholesterol). None of the four LAB hydrolyzed mucin or gelatin and none was toxic to C. elegans. The concentrations of phenylethylamine, putrescine, cadaverine, histamine, and tyramine produced by the LAB were below the toxic limits of biogenic amines set by the European Food Safety Authority. Taken together, our results demonstrate that Weissella cibaria SCCB2306, P. acidilactici SDL1402, P. acidilactici SDL1405, and L. rhamnosus JDFM6 could be safe cholesterol-reducing probiotic candidates for preventing or managing hypercholesterolemia.

Linderae Radix Ethanol Extract Alleviates Diet-Induced Hyperlipidemia by Regulating Bile Acid Metabolism Through gut Microbiota

Hyperlipidemia is a common metabolic disorder and regarded as one of the main risk factors for cardiovascular disease. The gut microbiota has been identified as a potential contributor to hyperlipidemia as it can greatly regulate bile acid metabolism. Linderae radix is a natural medicine widely used in the treatment of a variety of diseases and is also a common drug for hyperlipidemia. Recently, the lipid-lowering effect of Linderae radix are receiving increasing attention but the underlying mechanism remains unknown. The study aimed to investigate the effects of Linderae radix ethanol extract (LREE) on gut microbiota in rats with hyperlipidemia syndrome. We established a hyperlipidemia rat model using a high-fat diet and used LREE as the intervention. Blood lipid levels and pathological examination were measured to assess the effects of LREE on hyperlipidemia. The gut microbiota was determined by 16s rDNA sequencing and the bile acid metabolism-related proteins were detected by western blot to discover the underlying correlations. The results show that LREE lowered TC, TG, and LDL levels effectively, and it also alleviated liver injury by reducing ALT and AST activity. Meanwhile, LREE improved gut microbiota disturbance caused by HFD via increasing intestinal microbiota diversity and changing the abundance of the Firmicutes, Bacteroidetes, and Actinobacteria. In addition, LREE can increase bile acid reabsorption and promote fecal excretion through farnesoid X receptor (FXR), apical sodium-dependent bile acid transporter (ASBT), organic solute transporter alpha (OST-α), and cytochrome P450 family 7 Subfamily A Member 1 (CYP7A1) thus restoring abnormal bile acid metabolism caused by hyperlipidemia.