Reshaping faecal gut microbiota composition by the intake of trans-resveratrol and quercetin in high-fat sucrose diet-fed rats

Quercetin Intervention Alleviates Offspring's Oxidative Stress, Inflammation, and Tight Junction Damage in the Colon Induced by Maternal Fine Particulate Matter (PM2.5) Exposure through the Reduction of Bacteroides

The influences of maternal fine particulate matter (PM_2.5) exposure on intestinal oxidative stress, inflammation, tight junctions, and gut microbiota of offspring are not well understood. Moreover, research on the dietary intervention method has not been well studied. In our study, dams received PM_2.5 and quercetin intervention during gestation and lactation, and then inflammation biomarkers, oxidative stress indicators, tight junction proteins, and gut microbiota in the colon of offspring were analyzed. Compared with the control group, lower catalase (CAT) and superoxide dismutase (SOD) activities, higher interleukin-17A (IL-17A) and interleukin-22 (IL-22), decreased ZO-1 and occludin expressions, and higher Bacteroides abundance were observed in the offspring mice of the PM_2.5 group. However, higher CAT and SOD activities, lower IL-17A and IL-22 levels, increased ZO-1 and occludin expressions, and lower Bacteroides abundance were found in the quercetin groups. In addition, there was a negative correlation between Bacteroides abundance and CAT concentration. Additionally, Bacteroides abundance was positively related to IL-17A and IL-22 levels. These findings suggest that maternal PM_2.5 exposure may have some certain effects on intestinal oxidative stress, inflammation, and tight junctions. Quercetin administration may protect the offspring against these adverse effects. Changes of Bacteroides abundance play an important role in the process.

Modulatory effect of Cyclocarya paliurus flavonoids on the intestinal microbiota and liver clock genes of circadian rhythm disorder mice model

Host circadian rhythm and gut microbiota have a bidirectional relationship, indicating that prebiotics or prebiotic-like substance is a possible way to regulate circadian rhythm. The modulatory effect of Cyclocarya paliurus flavonoids (CPF) on the intestinal microbiota and liver clock genes of a circadian rhythm disorder mouse model was investigated in the present study. 16S rDNA sequencing analysis showed that CPF ameliorated the imbalanced intestinal microbial structure induced by circadian rhythm disorder. Compared with the constant darkness (CD) group, the ratio of the relative abundance of Firmicutes to Bacteroidetes was significantly decreased after the intervention of CPF for 4 weeks. In addition, CPF significantly alleviated the disrupted diurnal oscillation and phase shift of the specific intestinal microbes and liver clock genes induced by constant darkness. Moreover, metagenomics analysis of gut microbiota showed that the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways enriched the most differentially expressed genes (DEGs) after CPF administration includes xenobiotics biodegradation and metabolism, carbohydrate metabolism and cell motility. The results suggested that CPF may positively regulate the gut flora disturbed by host circadian rhythm disorder, including its composition, diurnal oscillation and function, as well as affect the expression of liver clock genes, thus improving the host micro-ecology and health.

Involvement of Gut Microbiota, Microbial Metabolites and Interaction with Polyphenol in Host Immunometabolism

Immunological and metabolic processes are inextricably linked and important for maintaining tissue and organismal health. Manipulation of cellular metabolism could be beneficial to immunity and prevent metabolic and degenerative diseases including obesity, diabetes, and cancer. Maintenance of a normal metabolism depends on symbiotic consortium of gut microbes. Gut microbiota contributes to certain xenobiotic metabolisms and bioactive metabolites production. Gut microbiota-derived metabolites have been shown to be involved in inflammatory activation of macrophages and contribute to metabolic diseases. Recent studies have focused on how nutrients affect immunometabolism. Polyphenols, the secondary metabolites of plants, are presented in many foods and beverages. Several studies have demonstrated the antioxidant and anti-inflammatory properties of polyphenols. Many clinical trials and epidemiological studies have also shown that long-term consumption of polyphenol-rich diet protects against chronic metabolic diseases. It is known that polyphenols can modulate the composition of core gut microbiota and interact with the immunometabolism. In the present article, we review the mechanisms of gut microbiota and its metabolites on immunometabolism, summarize recent findings on how the interaction between microbiota and polyphenol modulates host immunometabolism, and discuss future research directions.

Microbial Peer Pressure: The Role of the Gut Microbiota in Hypertension and Its Complications

There is increasing evidence of the influence of the gut microbiota on hypertension and its complications, such as chronic kidney disease, stroke, heart failure, and myocardial infarction. This is not surprising considering that the most common risk factors for hypertension, such as age, sex, medication, and diet, can also impact the gut microbiota. For example, sodium and fermentable fiber have been studied in relation to both hypertension and the gut microbiota. By combining second- and, now, third-generation sequencing with metabolomics approaches, metabolites, such as short-chain fatty acids and trimethylamine N-oxide, and their producers, have been identified and are now known to affect host physiology and the cardiovascular system. The receptors that bind these metabolites have also been explored with positive findings-examples include known short-chain fatty acid receptors, such as G-protein coupled receptors GPR41, GPR43, GPR109a, and OLF78 in mice. GPR41 and OLF78 have been shown to have inverse roles in blood pressure regulation, whereas GPR43 and GPR109A have to date been demonstrated to impact cardiac function. New treatment options in the form of prebiotics (eg, dietary fiber), probiotics (eg, Lactobacillus spp.), and postbiotics (eg, the short-chain fatty acids acetate, propionate, and butyrate) have all been demonstrated to be beneficial in lowering blood pressure in animal models, but the underlying mechanisms remain poorly understood and translation to hypertensive patients is still lacking. Here, we review the evidence for the role of the gut microbiota in hypertension, its risk factors, and cardiorenal complications and identify future directions for this exciting and fast-evolving field.

Natural proteins and polysaccharides in the development of micro/nano delivery systems for the treatment of inflammatory bowel disease

Treatments for inflammatory bowel disease (IBD) are typically immunosuppressive. Despite a range of treatment options, limited efficacy, systemic toxicities like bone marrow suppression, infections and malignancy are their serious setbacks. There exists an unmet medical need for novel therapeutic agents without safety concerns resulting from chronic, systemic immunosuppression. Of late, several natural agents with better therapeutic potential have been reported. It is very likely that restricting the release of the active molecules to the intestine would further improve their clinical efficacy and safety. To this end, novel polymer-based micro/nano formulations protect the drug from gastric environment and slowly release the drug in the colon. However, cost and side-effects associated to synthetic polymers have led to the development of biocompatible, economic and pharmaceutically well-accepted biomacromolecules in exploring their potential in IBD. Since last few years, biological proteins, polysaccharides and their combinations have shown great efficacy in colitis induced animal models. In this review, micro/nano formulations developed using biomacromolecules like chitosan, zein, pectin, casein, alginate, dextran, glucomannan and hyaluronic acid have been reviewed focusing on their potential in protecting active cargo, avoiding premature release, distal colon targeting along with their impact on reshaping the altered gut microbiota and how it can ameliorate the colitis conditions.

An integrative machine learning approach to discovering multi-level molecular mechanisms of obesity using data from monozygotic twin pairs

We combined clinical, cytokine, genomic, methylation and dietary data from 43 young adult monozygotic twin pairs (aged 22-36 years, 53% female), where 25 of the twin pairs were substantially weight discordant (delta body mass index > 3 kg m^-2). These measurements were originally taken as part of the TwinFat study, a substudy of The Finnish Twin Cohort study. These five large multivariate datasets (comprising 42, 71, 1587, 1605 and 63 variables, respectively) were jointly analysed using an integrative machine learning method called group factor analysis (GFA) to offer new hypotheses into the multi-molecular-level interactions associated with the development of obesity. New potential links between cytokines and weight gain are identified, as well as associations between dietary, inflammatory and epigenetic factors. This encouraging case study aims to enthuse the research community to boldly attempt new machine learning approaches which have the potential to yield novel and unintuitive hypotheses. The source code of the GFA method is publically available as the R package GFA.

Rhubarb Supplementation Prevents Diet-Induced Obesity and Diabetes in Association with Increased Akkermansia muciniphila in Mice

Obesity and obesity-related disorders, such as type 2 diabetes have been progressively increasing worldwide and treatments have failed to counteract their progression. Growing evidence have demonstrated that gut microbiota is associated with the incidence of these pathologies. Hence, the identification of new nutritional compounds, able to improve health through a modulation of gut microbiota, is gaining interest. In this context, the aim of this study was to investigate the gut-driving effects of rhubarb extract in a context of diet-induced obesity and diabetes. Eight weeks old C57BL6/J male mice were fed a control diet (CTRL), a high fat and high sucrose diet (HFHS) or a HFHS diet supplemented with 0.3% (g/g) of rhubarb extract for eight weeks. Rhubarb supplementation fully prevented HFHS-induced obesity, diabetes, visceral adiposity, adipose tissue inflammation and liver triglyceride accumulation, without any modification in food intake. By combining sequencing and qPCR methods, we found that all these effects were associated with a blooming of Akkermansia muciniphila, which is strongly correlated with increased expression of Reg3γ in the colon. Our data showed that rhubarb supplementation is sufficient to protect against metabolic disorders induced by a diet rich in lipid and carbohydrates in association with a reciprocal interaction between Akkermansia muciniphila and Reg3γ.

The role of gut microbiota (GM) and GM-related metabolites in diabetes and obesity. A review of analytical methods used to measure GM-related metabolites in fecal samples with a focus on metabolites' derivatization step

Disruption of gut microbiota (GM) composition is increasingly related to the pathogenesis of various metabolic diseases. Additionally, GM is responsible for the production and transformation of metabolites involved in the development of metabolic disorders, such as obesity and type 2 diabetes mellitus (T2DM). The current state of knowledge regarding the composition of GM and GM-related metabolites in relation to the progress and development of obesity and T2DM is presented in this review. To understand the relationships between GM-related metabolites and the development of metabolic disorders, their accurate qualitative and quantitative measurement in biological samples is needed. Feces represent a valuable biological matrix which composition may reflect the health status of the lower gastrointestinal tract and the whole organism. Mass spectrometry (MS), mainly in combination with gas chromatography (GC) or liquid chromatography (LC), is commonly used to measure fecal metabolites. However, profiling metabolites in such a complex matrix as feces is challenging from both analytical chemistry and biochemistry standpoints. Chemical derivatization is one of the most effective methods used to overcome these problems. In this review, we provide a comprehensive summary of the derivatization methods of GM-related metabolites prior to GC-MS or LC-MS analysis, which have been published in the last five years (2015-2020). Additionally, analytical methods used for the analysis of GM-related metabolites without the derivatization step are also presented.

Probiotics, Prebiotics, Synbiotics, Postbiotics, and Obesity: Current Evidence, Controversies, and Perspectives

PURPOSE OF REVIEW

In this review, we summarize current evidence on gut microbiome and obesity; we discuss the role of probiotics, prebiotics, synbiotics, and postbiotics in obesity prevention and management; and we highlight and analyze main limitations, challenges, and controversies of their use.

RECENT FINDINGS

Overall, the majority of animal studies and meta-analyses of human studies examining the use of probiotics and synbiotics in obesity has shown their beneficial effects on weight reduction and other metabolic parameters via their involvement in gut microbiota modulation. Bifidobacterium and Lactobacillus strains are still the most widely used probiotics in functional foods and dietary supplements, but next generation probiotics, such as Faecalibacterium prausnitzii, Akkermansia muciniphila, or Clostridia strains, have demonstrated promising results. On the contrary, meta-analyses of human studies on the use of prebiotics in obesity have yielded contradictory results. In animal studies, postbiotics, mainly short-chain fatty acids, may increase energy expenditure through induction of thermogenesis in brown adipose tissue as well as browning of the white adipose tissue. The main limitations of studies on biotics in obesity include the paucity of human studies; heterogeneity among the studied subgroups regarding age, gender, and lifestyle; and use of different agents with potential therapeutic effects in different formulations, doses, ratio and different pharmacodynamics/pharmacokinetics. In terms of safety, the supplementation with prebiotics, probiotics, and synbiotics has not been associated with serious adverse effects among immune-competent individuals, with the exception of the use of probiotics and synbiotics in immunocompromised patients. Further large-scale Randomized Controlled Trials (RCTs) in humans are required to evaluate the beneficial properties of probiotics, prebiotics, synbiotics, and postbiotics; their ideal dose; the duration of supplementation; and the durability of their beneficial effects as well as their safety profile in the prevention and management of obesity.

Interactions Between Food and Gut Microbiota: Impact on Human Health

Understanding the relationship between food and the gut microbiota, their interactions, and how each modulates the other is critical for successful promotion of human health. This review seeks to summarize ( a) the current knowledge on the effects of food and food components on gut microbiota and ( b) the association between gut microbiota, consumption of food, and food bioactive components and the resulting beneficial health outcomes. Our goal is to provide state-of-the-art information on food and gut microbiota interactions and to stimulate discussions and research approaches that will move the field forward.

Resveratrol reduces obesity in high-fat diet-fed mice via modulating the composition and metabolic function of the gut microbiota

Resveratrol (RSV) is a natural polyphenol with anti-obesity effects. However, the mechanisms of anti-obesity remain unclear due to its low bioavailability. Recent evidence demonstrates that gut microbiota plays a key role in obesity. This spurred us to investigate whether the anti-obesity effects of RSV are related to modulations in the gut microbiota and metabolic functions. Here, RSV significantly improved metabolic phenotype and intestinal oxidative stress in the high-fat diet (HFD)-fed mice. A multi-omics approach was used to systematically profile the microbial signatures at both the phylogenetic and functional levels using 16S rRNA gene sequencing and metagenome. At the phylogenetic level, RSV treatment significantly modulated the gut microbiota composition in HFD-fed mice, characterized with increased Blautia abundance and decreased Desulfovibrio and Lachnospiraceae_NK4A136_group abundance. At the functional level, RSV significantly decreased the enrichment of pathways linked to host metabolic disease and increased the enrichment of pathways involved in the generation of small metabolites. Besides, the fecal microbiota transplantation experiment showed anti-obesity and microbiota-modulating effects similar to those observed in the oral RSV-feeding experiment. Furthermore, metabolomic analysis and antibiotic treatment verified that 4-hydroxyphenylacetic acid (4-HPA) and 3-hydroxyphenylpropionic acid (3-HPP) were the two gut metabolites of RSV, which contribute to improving lipid metabolism in vitro. Moreover, the content of 4-HPA and 3-HPP exhibited strong correlation with the intestinal oxidative state. We concluded that the RSV-mediated alteration of gut microbiota, related gut metabolites and redox state of the intestinal environment contributed to prevention of metabolic syndrome in HFD-fed mice.

Resveratrol Modulates the Gut Microbiota and Inflammation to Protect Against Diabetic Nephropathy in Mice

Oral administration of resveratrol is able to ameliorate the progression of diabetic nephropathy (DN); however, its mechanisms of action remain unclear. Recent evidence suggested that the gut microbiota is involved in the metabolism therapeutics. In the current study, we sought to determine whether the anti-DN effects of resveratrol are mediated through modulation of the gut microbiota using the genetic db/db mouse model of DN. We demonstrate that resveratrol treatment of db/db mice relieves a series of clinical indicators of DN. We then show that resveratrol improves intestinal barrier function and ameliorates intestinal permeability and inflammation. The composition of the gut microbiome was significantly altered in db/db mice compared to control db/m mice. Dysbiosis in db/db mice characterized by low abundance levels of Bacteroides, Alistipes, Rikenella, Odoribacter, Parabacteroides, and Alloprevotella genera were reversed by resveratrol treatment, suggesting a potential role for the microbiome in DN progression. Furthermore, fecal microbiota transplantation, derived from healthy resveratrol-treated db/m mice, was sufficient to antagonize the renal dysfunction, rebalance the gut microbiome and improve intestinal permeability and inflammation in recipient db/db mice. These results indicate that resveratrol-mediated changes in the gut microbiome may play an important role in the mechanism of action of resveratrol, which provides supporting evidence for the gut–kidney axis in DN.

Modulation of Chronic Inflammation by Quercetin: The Beneficial Effects on Obesity

Obesity has become a major risk factor for the development of chronic diseases such as insulin resistance, type 2 diabetes mellitus, and cardiovascular disease. Moreover, obesity induces chronic inflammation in adipose tissue, liver, skeletal muscle, and the vascular system. Quercetin is the major representative of the flavonoid subclass of flavonols, which is ubiquitously contained within natural plants such as green tea, and vegetables, including onions and apples. Researchers have focused greater attention to the beneficial physiological roles of quercetin, which has anti-oxidative, anti-inflammatory, and anti-fibrotic effects on insulin resistance and atherosclerosis in obesity-related diseases. Also, the anti-inflammatory effects of quercetin on intestinal microbiota have been demonstrated in obesity. In addition, there is increasing evidence that quercetin is associated with epigenetic activities in cancer, and in maternal undernutrition during gestation and lactation. In this review, we focus on the chemical properties of quercetin, its dietary sources in obesity, and its anti-inflammatory effects on insulin resistance, atherosclerosis, intestinal microbiota, and maternal under-nutrition with epigenetic activity.

Targeting Carbohydrates and Polyphenols for a Healthy Microbiome and Healthy Weight

Purpose of Review

In this review, we focus on microbiota modulation using non-digestible carbohydrate and polyphenols (i.e., prebiotics) that have the potential to modulate body weight.

Recent Findings

Prebiotics derived from plants have gained the interest of public and scientific communities as they may prevent diseases and help maintain health.

Summary

Maintaining a healthy body weight is key to reducing the risk of developing chronic metabolic complications. However, the prevalence of obesity has increased to pandemic proportions and is now ranked globally in the top five risk factors for death. While diet and behavioral modification programs aiming to reduce weight gain and promote weight loss are effective in the short term, they remain insufficient over the long haul as compliance is often low and weight regain is very common. As a result, novel dietary strategies targeting the gut microbiota have been successful in decreasing obesity and metabolic disorders via different molecular mechanisms.

Current and future experimental approaches in the study of grape and wine polyphenols interacting gut microbiota

Interactions between polyphenols and gut microbiota are indeed a major issue of current interest in food science research. Knowledge in this subject is progressing as the experimental procedures and analysis techniques do. The aim of this article is to critically review the more leading-edge approaches that have been applied so far in the study of the interactions between grape/wine polyphenols and gut microbiota. This is the case of in vitro dynamic gastrointestinal simulation models that try to mitigate the limitations of simple static models (batch culture fermentations). More complex approaches include the experimentation with animals (mice, rats, pigs, lambs and chicks) and nutritional intervention studies in humans. Main advantages and limitations as well as the most relevant findings achieved by each approach in the study of how grape/wine polyphenols can modulate the composition and/or functionality of gut microbiota, are detailed. Also, common findings obtained by the three approaches (in vitro, animal models and human nutritional interventions) such as the fact that the Firmicutes/Bacteroidetes ratio tends to decrease after the feed/intake/consumption of grape/wine polyphenols are highlighted. Additionally, a nematode (Caenorhabditis elegans) model, previously used for investigating the mechanisms of processes such as aging, neurodegeneration, oxidative stress and inflammation, is presented as an emerging approach for the study of polyphenols interacting gut microbiota. © 2020 Society of Chemical Industry.

Pleiotropic effects of polyphenols on glucose and lipid metabolism: Focus on clinical trials

Epidemiological evidence from observational studies suggests that dietary polyphenols (PPs) - phytochemicals found in a variety of plant-based foods - can reduce the risk of developing type 2 diabetes mellitus (T2DM). Clinical trials have also indicated that PPs may help manage the two key features of T2DM, hyperglycemia and dyslipidemia. Since the incidence of T2DM is dramatically increasing worldwide, identifying food-based approaches that can reduce the risk of developing it and help manage its main risk factors in early-stage disease has clinical and socioeconomic relevance. After a brief overview of current epidemiological data on the incidence of T2DM in individuals consuming PP-rich diets, we review the evidence from clinical trials investigating PP-enriched foods and/or PP-based nutraceutical compounds, report their main results, and highlight the knowledge gaps that should be bridged to enhance our understanding of the role of PPs in T2DM development and management.

Shrub coverage alters the rumen bacterial community of yaks (Bos grunniens) grazing in alpine meadows

Proliferation of shrubs at the expense of native forage in pastures has been associated with large changes in dry-matter intake and dietary components for grazing ruminants. These changes can also affect the animals’ physiology and metabolism. However, little information is available concerning the effect of pastoral-shrub grazing on the rumen bacterial community. To explore rumen bacteria composition in grazing yaks and the response of rumen bacteria to increasing shrub coverage in alpine meadows, 48 yak steers were randomly assigned to four pastures with shrub coverage of 0%, 5.4%, 11.3%, and 20.1% (referred as control, low, middle, and high, respectively), and ruminal fluid was collected from four yaks from each pasture group after 85 days. Rumen fermentation products were measured and microbiota composition determined using Ion S5^TM XL sequencing of the 16S rRNA gene. Principal coordinates analysis (PCoA) and similarity analysis indicated that the degree of shrub coverage correlated with altered rumen bacterial composition of yaks grazing in alpine shrub meadows. At the phyla level, the relative abundance of Firmicutes in rumen increased with increasing shrub coverage, whereas the proportions of Bacteroidetes, Cyanobacteria and Verrucomicrobia decreased. Yaks grazing in the high shrub-coverage pasture had decreased species of the genus Prevotellaceae UCG-001, Lachnospiraceae XPB1014 group, Lachnospiraceae AC2044 group, Lachnospiraceae FCS020 group and Fretibacterium, but increased species of Christensenellaceae R-7 group, Ruminococcaceae NK4A214 group, Ruminococcus 1, Ruminococcaceae UCG-002, Ruminococcaceae UCG-005 and Lachnospiraceae UCG-008. These variations can enhance the animals’ utilization efficiencies of cellulose and hemicellulose from native forage. Meanwhile, yaks grazed in the high shrub-coverage pasture had increased concentrations of ammonia nitrogen (NH₃-N) and branched-chain volatile fatty acids (isobutyrate and isovalerate) in rumen compared with yaks grazing in the pasture without shrubs. These results indicate that yaks grazing in a high shrub-coverage pasture may have improved dietary energy utilization and enhanced resistance to cold stress during the winter. Our findings provide evidence for the influence of shrub coverage on the rumen bacterial community of yaks grazing in alpine meadows as well as insights into the sustainable production of grazing yaks on lands with increasing shrub coverage on the Qinghai-Tibet Plateau.

Consumption of Wild Rice (Zizania latifolia) Prevents Metabolic Associated Fatty Liver Disease through the Modulation of the Gut Microbiota in Mice Model

Metabolic associated fatty liver disease (MAFLD) due to excess weight and obesity threatens public health worldwide. Gut microbiota dysbiosis contributes to obesity and related diseases. The cholesterol-lowering, anti-inflammatory, and antioxidant effects of wild rice have been reported in several studies; however, whether it has beneficial effects on the gut microbiota is unknown. Here, we show that wild rice reduces body weight, liver steatosis, and low-grade inflammation, and improves insulin resistance in high-fat diet (HFD)-fed mice. High-throughput 16S rRNA pyrosequencing demonstrated that wild rice treatment significantly changed the gut microbiota composition in mice fed an HFD. The richness and diversity of the gut microbiota were notably decreased upon wild rice consumption. Compared with a normal chow diet (NCD), HFD feeding altered 117 operational taxonomic units (OTUs), and wild rice supplementation reversed 90 OTUs to the configuration in the NCD group. Overall, our results suggest that wild rice may be used as a probiotic agent to reverse HFD-induced MAFLD through the modulation of the gut microbiota.

Polyphenols, the new frontiers of prebiotics

There is a growing interest in the identification of molecules capable to promote health and with a concurrent potential for technological applications. Prebiotics are functional ingredients naturally occurring in some plant and animal foods that since many decades stimulated considerable attention from the pharmaceutical and food industries due to their positive health effects. Together the well-known biomolecules with ascertained prebiotic effect, in last year new molecules were finally recognized as prebiotics, so capable to improve the health of an organism, also through the positive effect exerted on host microbiota. Among the so-called prebiotics, a special mention should be given to polyphenols, probably the most important, or at least among the most important secondary metabolites produced by the vegetal kingdom. This short chapter wants to emphasize polyphenols and, after briefly describing the individual microbiome, to illustrate how polyphenols can, through their influence on the microbiome, have a positive effect on the health of the individual in general, and on some pathologies in particular, for which the role of a bad status of the individual microbiome has been definitively established.

Gut microbiome: A possible common therapeutic target for treatment of atherosclerosis and cancer

Human gut microbiota is a dynamic and variable system that can change over time and in response to different diets and treatments. There is currently no doubt that gut microbiota can provide interesting therapeutic opportunities, since it can metabolize biologically active molecules, drugs, and their precursors, and control their bioavailability. Moreover, it can produce both beneficial and dangerous metabolites that influence host's health. In this review, we summarize the current knowledge on the involvement of gut microbiota in two chronic human pathologies that represent the greatest challenges of modern medicine: atherosclerosis and cancer. Interesting parallels are observed between the mechanisms and possible treatment approaches of these pathologies. Some of the common effects of therapeutic agents targeting both pathologies, such as anti-inflammatory activity, are partially mediated by the gut microbiota. We will discuss the effects of common drugs (metformin, statins and aspirin) and various nutraceuticals on gut microbiota and outline the pathways of microbial involvement in mediating the pleiotropic beneficial effects of these agents in atherosclerosis and cancer.

Alterations in the Gut Microbiome and Suppression of Histone Deacetylases by Resveratrol Are Associated with Attenuation of Colonic Inflammation and Protection Against Colorectal Cancer

Inflammatory bowel disease (IBD) is known to significantly increase the risk for development of colorectal cancer (CRC), suggesting inflammation and cancer development are closely intertwined. Thus, agents that suppress inflammation may prevent the onset of cancer. In the current study, we used resveratrol, an anti-inflammatory stilbenoid, to study the role of microbiota in preventing inflammation-driven CRC. Resveratrol treatment in the azoxymethane (AOM) and dextran sodium sulphate (DSS) CRC murine model caused an increase in anti-inflammatory CD4 + FOXP3 + (Tregs) and CD4 + IL10 + cells, a decrease in proinflammatory Th1 and Th17 cells, and attenuated CRC development. Gut microbial profile studies demonstrated that resveratrol altered the gut microbiome and short chain fatty acid (SCFA), with modest increases in n-butyric acid and a potential butyrate precursor isobutyric acid. Fecal transfer from resveratrol-treated CRC mice and butyrate supplementation resulted in attenuation of disease and suppression of the inflammatory T cell response. Data also revealed both resveratrol and sodium butyrate (BUT) were capable of inhibiting histone deacetylases (HDACs), correlating with Treg induction. Analysis of The Cancer Genome Atlas (TCGA) datasets revealed increased expression of Treg-specific transcription factor FoxP3 or anti-inflammatory IL-10 resulted in an increase in 5-year survival of patients with CRC. These data suggest that alterations in the gut microbiome lead to an anti-inflammatory T cell response, leading to attenuation of inflammation-driven CRC.

Biotransformation of dietary phytoestrogens by gut microbes: A review on bidirectional interaction between phytoestrogen metabolism and gut microbiota

Phytoestrogens are a class of plant produced polyphenolic compounds with diphenolic structure, which is similar to 17β-estradiol. These phytoestrogens preferentially bind to estrogen receptors, however, with weak affinity. Recently, many studies have found that these phytoestrogens can be transformed by gut microbiota through novel enzymatic reactions into metabolites with altered bioactivity. Recent studies have also implied that these metabolites could possibly modulate the host gut ecosystem, gene expression, metabolism and the immune system. Thus, isolating gut microbes capable of biotransforming phytoestrogens and characterizing the novel enzymatic reactions involved are principal to understand the mechanisms of beneficial effects brought by gut microbiota and their metabolism on phytoestrogens, and to provide the theoretical knowledge for the development of functional probiotics. In the present review, we summarized works on gut microbial biotransformation of phytoestrogens, including daidzin (isoflavone), phenylnaringenin (prenylflavonoid), lignans, resveratrol (stilbene) and ellagitannins. We mainly focus on gut bacterial isolation, metabolic pathway characterization, and the bidirectional interaction of phytoestrogens with gut microbes to illustrate the novel metabolic capability of gut microbiota and the methods used in these studies.

Gut Microbiota: A Pivotal Hub for Polyphenols as Antidepressants

Polyphenols, present in a broad range of plants, have been thought to be responsible for many beneficial health effects, such as an antidepressant. Despite that polyphenols can be absorbed in the small intestine directly, most of them have low bioavailability and reach the large intestine without any modifications due to their complex structures. The interaction between microbial communities and polyphenols in the intestine is important for the latter to exert antidepressant effects. Gut microbiota can improve the bioavailability of polyphenols; in turn, polyphenols can maintain the intestinal barrier as well as the community of the gut microbiota in normal status. Furthermore, gut microbita catabolize polyphenols to more active, better-absorbed metabolites, further ameliorating depression through the microbial-gut-brain (MGB) axis. Based on this evidence, the review illustrates the potential role of gut microbiota in the processes of polyphenols or their metabolites acting as antidepressants and further envisions the gut microbiota as therapeutic targets for depression.

Diet-Derived Phytochemicals Targeting Colon Cancer Stem Cells and Microbiota in Colorectal Cancer

Colorectal cancer (CRC) is a fatal disease caused by the uncontrolled propagation and endurance of atypical colon cells. A person's lifestyle and eating pattern have significant impacts on the CRC in a positive and/or negative way. Diet-derived phytochemicals modulate the microbiome as well as targeting colon cancer stem cells (CSCs) that are found to offer significant protective effects against CRC, which were organized in an appropriate spot on the paper. All information on dietary phytochemicals, gut microbiome, CSCs, and their influence on CRC were accessed from the various databases and electronic search engines. The effectiveness of CRC can be reduced using various dietary phytochemicals or modulating microbiome that reduces or inverses the progression of a tumor as well as CSCs, which could be a promising and efficient way to reduce the burden of CRC. Phytochemicals with modulation of gut microbiome continue to be auspicious investigations in CRC through noticeable anti-tumorigenic effects and goals to CSCs, which provides new openings for cancer inhibition and treatment.

The Targeted Impact of Flavones on Obesity-Induced Inflammation and the Potential Synergistic Role in Cancer and the Gut Microbiota

Obesity is an inflammatory disease that is approaching pandemic levels, affecting nearly 30% of the world's total population. Obesity increases the risk of diabetes, cardiovascular disorders, and cancer, consequentially impacting the quality of life and imposing a serious socioeconomic burden. Hence, reducing obesity and related life-threatening conditions has become a paramount health challenge. The chronic systemic inflammation characteristic of obesity promotes adipose tissue remodeling and metabolic changes. Macrophages, the major culprits in obesity-induced inflammation, contribute to sustaining a dysregulated immune function, which creates a vicious adipocyte-macrophage crosstalk, leading to insulin resistance and metabolic disorders. Therefore, targeting regulatory inflammatory pathways has attracted great attention to overcome obesity and its related conditions. However, the lack of clinical efficacy and the undesirable side-effects of available therapeutic options for obesity provide compelling reasons for the need to identify additional approaches for the prevention and treatment of obesity-induced inflammation. Plant-based active metabolites or nutraceuticals and diets with an increased content of these compounds are emerging as subjects of intense scientific investigation, due to their ability to ameliorate inflammatory conditions and offer safe and cost-effective opportunities to improve health. Flavones are a class of flavonoids with anti-obesogenic, anti-inflammatory and anti-carcinogenic properties. Preclinical studies have laid foundations by establishing the potential role of flavones in suppressing adipogenesis, inducing browning, modulating immune responses in the adipose tissues, and hindering obesity-induced inflammation. Nonetheless, the understanding of the molecular mechanisms responsible for the anti-obesogenic activity of flavones remains scarce and requires further investigations. This review recapitulates the molecular aspects of obesity-induced inflammation and the crosstalk between adipocytes and macrophages, while focusing on the current evidence on the health benefits of flavones against obesity and chronic inflammation, which has been positively correlated with an enhanced cancer incidence. We conclude the review by highlighting the areas of research warranting a deeper investigation, with an emphasis on flavones and their potential impact on the crosstalk between adipocytes, the immune system, the gut microbiome, and their role in the regulation of obesity.

Modulation of the human gut microbiota by phenolics and phenolic fiber-rich foods

The gut microbiota plays a prominent role in human health. Alterations in the gut microbiota are linked to the development of chronic diseases such as obesity, inflammatory bowel disease, metabolic syndrome, and certain cancers. We know that diet plays an important role to initiate, shape, and modulate the gut microbiota. Long-term dietary patterns are shown to be closely related with the gut microbiota enterotypes, specifically long-term consumption of carbohydrates (related to Prevotella abundance) or a diet rich in protein and animal fats (correlated to Bacteroides). Short-term consumption of solely animal- or plant-based diets have rapid and reproducible modulatory effects on the human gut microbiota. These alterations in microbiota profile by dietary alterations can be due to impact of different dietary macronutrients, carbohydrates, protein, and fat, which have diverse modulatory effects on gut microbial composition. Food-derived phenolics, which encompass structural variants of flavonoids, hydroxybenzoic acids, hydroxycinnamic acids, coumarins, stilbenes, ellagitannins, and lignans can modify the gut microbiota. Gut microbes have been shown to act on dietary fibers and phenolics to produce functional metabolites that contribute to gut health. Here, we discuss recent studies on the impacts of phenolics and phenolic fiber-rich foods on the human gut microbiota and provide an insight into potential synergistic roles between their bacterial metabolic products in the regulation of the intestinal microbiota.

Protective effect of quercetin on streptozotocin-induced diabetic peripheral neuropathy rats through modulating gut microbiota and reactive oxygen species level

OBJECTIVE

Diabetic peripheral neuropathy (DPN) is a prevalent complication of diabetes with no effective drug currently. As a powerful antioxidant, the flavonoid quercetin has been demonstrated to have potential neuroprotective and prebiotic capacity. But the mechanism of its neuroprotective function and the link to the gut microbiota remains to be elucidated.

METHODS

The neuroprotective effect of quercetin was evaluated on streptozotocin(STZ)-induced DPN rats through electrophysiology, behavioristic, and pathomorphology studies. Serum and urine reactive oxygen species (ROS) production levels and fecal gut microbiota compositions were detected, and the relationship between them was analyzed by Spearman's correlation.

RESULTS

Quercetin not only reversed the decreased mechanical withdraw thresholds and intraepidermal nerve fiber densities in DPN rats, but also improved neurological morphology of sciatic nerves, accompanied with up-regulated percentage of paranodes at paranodal junctions, and down-regulated amyloid precursor protein and ionized calcium-binding adaptor molecule 1 in DPN rats. More importantly, quercetin rescued gut dysbiosis in DPN rats by decreasing four potential pathogenic species and enriching two prebiotic species associated with DPN phenotypes and ROS production levels.

CONCLUSIONS

Quercetin exerts neuroprotective effect and modulates gut microbiota associated with DPN phenotypes and ROS production levels in STZ-induced DPN rats, suggesting the therapeutic application of quercetin for DPN prevention and treatment.

Effect of resveratrol on intestinal tight junction proteins and the gut microbiome in high-fat diet-fed insulin resistant mice

High-fat diet (HFD)-feeding induces changes in the microbiome and increases intestinal permeability by impairing tight junction (TJ) protein function, which may explain the insulin resistance (IR) and associated pathologies. We aimed to determine the effects of resveratrol (RES) on the gut microbiome and intestinal TJ proteins. Results showed that RES administration improved the lipid profile, and ameliorated the endotoxemia, inflammation, intestinal barrier defect and glucose intolerance in the HFD-fed mice. Furthermore, it modified the gut microbial composition, reducing the proportion of Firmicutes and the Firmicutes-to-Bacteroidetes ratio. Moreover, Verrucomicrobia and Akkermansia were much more abundant in the HFD + RES group. RES also significantly reduced the abundance of Bilophila and Ruminococcus. These findings suggest that RES may be useful for the treatment of IR and associated metabolic diseases.

Physiological relevance of food antioxidants

Dietary antioxidants are associated with prevention of oxidative stress related chronic diseases including certain types of cancer, cardiovascular diseases, diabetes, and neurodegenerative diseases. In recent years, there has been a growing interest in extending the knowledge on their physiological effects in human body. There are numbers of epidemiological, clinical, meta-analysis, and in vitro studies to explain formation mechanisms of each chronic diseases as well as the potential effects of dietary antioxidants on these diseases and gut health. Comprehensive studies for food antioxidants' journey from dietary intake to target tissues/organs deserve a serious consideration to have a clear understanding on the physiological effects of dietary antioxidants. Therefore, absorption and metabolism of dietary antioxidants, and the factors affecting their absorption, such as solubility of antioxidants, food matrix, and interaction between antioxidants have been evaluated in several research articles. This chapter provides an overview about potential health effects of dietary antioxidants considering with their absorption and metabolism in human body.

Dietary Ginkgo biloba leaf extracts supplementation improved immunity and intestinal morphology, antioxidant ability and tight junction proteins mRNA expression of hybrid groupers (Epinephelus lanceolatus ♂ × Epinephelus fuscoguttatus ♀) fed high lipid diets

For many years, Ginkgo biloba has been used as a traditional Chinese medicine because of its antioxidant, anti-inflammatory and hepatoprotective effects. The present study aimed to investigate the effects of dietary Ginkgo biloba leaf extract (GBLE) supplementation on immune response, intestinal morphology, antioxidant ability and tight junction proteins mRNA expression of hybrid groupers fed high lipid diets. Basal diets supplemented with GBLE at 0, 0.50, 1.00, 2.00, 4.00 and 10.00 g/kg were fed to hybrid grouper for 8 weeks. The study showed that dietary GBLE supplementation significantly improved immune ability by increasing plasma complement 3, complement 4 and Immunoglobulin M content. Dietary supplementation of 0.50-2.00 g/kg GBLE improved intestinal morphology and increased the expression of zonula occludens 1, zonula occludens 2, zonula occludens 3, occludin and claudin 3a. Dietary supplementation of 0.50-2.00 g/kg GBLE improved antioxidant ability by increasing activities and expressions of glutathione peroxidase, catalase and glutathione reductase, suppressed inflammatory by increasing expression of interleukin 10, transforming growth factor β1 and target of rapamycin, and decreased apoptotic responses by reducing the expression of caspase 3, caspase 8 and caspase 9 in the intestine of hybrid grouper fed high lipid diets. This study indicated that dietary GBLE supplementation was clearly beneficial for intestinal health and immunity in hybrid groupers fed high lipid diets and it could be used as a functional feed additive in aquaculture to promote the application of high lipid diets.

Function of Akkermansia muciniphila in Obesity: Interactions With Lipid Metabolism, Immune Response and Gut Systems

Obesity and its metabolic syndrome, including liver disorders and type 2 diabetes, are a worldwide epidemic and are intimately linked to diet. The gut microbiota interaction has been pointed to as a hot topic of research in the treatment of obesity and related metabolic diseases by influencing energy metabolism and the immune system. In terms of the novel beneficial microbes identified, Akkermansia muciniphila (A. muciniphila) colonizes the mucosa layer of the gut and modulates basal metabolism. A. muciniphila is consistently correlated with obesity. The causal beneficial impact of A. muciniphila treatment on obesity is coming to light, having been proved by a variety of animal models and human studies. A. muciniphila has been characterized as a beneficial player in body metabolism and has great prospects for treatments of the metabolic disorders associated with obesity, as well as being considered for next-generation therapeutic agents. This paper aimed to investigate the basic mechanism underlying the relation of A. muciniphila to obesity and its host interactions, as identified in recent discoveries, facilitating the establishment of the causal relationship in A. muciniphila-associated therapeutic supplement in humans.

Modulation of gut microbiota by spent coffee grounds attenuates diet-induced metabolic syndrome in rats

Coffee brewing produces spent coffee grounds as waste; few studies have investigated the health benefits of these grounds. This study investigated responses to spent coffee grounds in a diet-induced rat model of metabolic syndrome. Male Wistar rats aged 8-9 weeks were fed either corn starch-rich diet or high-carbohydrate, high-fat diet for 16 weeks, which were supplemented with 5% spent coffee grounds during the last 8 weeks. Rats fed non-supplemented diets were used as controls. High-carbohydrate, high-fat diet-fed rats developed metabolic syndrome including abdominal obesity, impaired glucose tolerance, dyslipidemia, and cardiovascular and liver damage. Body weight, abdominal fat, total body fat mass, systolic blood pressure, and concentrations of plasma triglycerides and non-esterified fatty acids were reduced by spent coffee grounds along with improved glucose tolerance and structure and function of heart and liver. Spent coffee grounds increased the diversity of the gut microbiota and decreased the ratio of Firmicutes to Bacteroidetes. Changes in gut microbiota correlated with the reduction in obesity and improvement in glucose tolerance and systolic blood pressure. These findings indicate that intervention with spent coffee grounds may be useful for managing obesity and metabolic syndrome by altering the gut microbiota, thus increasing the value of this food waste.

Molecular mechanisms linking environmental toxicants to cancer development: Significance for protective interventions with polyphenols

Human exposure to environmental toxicants with diverse mechanisms of action is a growing concern. In addition to well-recognized carcinogens, various chemicals in environmental and occupational settings have been suggested to impact health, increasing susceptibility to cancer by inducing genetic and epigenetic changes. Accordingly, in this review, we have discussed recent insights into the pathological mechanisms of these chemicals, namely their effects on cell redox and calcium homeostasis, mitochondria and inflammatory signaling, with a focus on the possible implications for multi-stage carcinogenesis and its reversal by polyphenols. Plant-derived polyphenols, such as epigallocatechin-gallate, resveratrol, curcumin and anthocyanins reduce the incidence of cancer and can be useful nutraceuticals for alleviating the detrimental outcomes of harmful pollutants. However, development of therapies based on polyphenol administration requires further studies to validate the biological efficacy, identifying effective doses, mode of action and new delivery forms. Innovative microphysiological testing models are presented and specific proposals for future trials are given. Merging the current knowledge of multifactorial actions of specific polyphenols and chief environmental toxicants, this work aims to potentiate the delivery of phytochemical-based protective treatments to individuals at high-risk due to environmental exposure.

Exploration of the Relationship Between Gut Microbiota and Polycystic Ovary Syndrome (PCOS): a Review

Polycystic ovary syndrome (PCOS) is an endocrine and metabolic syndrome (MS) with a complex etiology, and its pathogenesis is not yet clear. In recent years, the correlation between gut microbiota (GM) and metabolic disease has become a hot topic in research, leading to a number of new ideas about the etiology and pathological mechanisms of PCOS. The literature shows that GM can cause insulin resistance, hyperandrogenism, chronic inflammation and metabolic syndrome (obesity, diabetes) and may contribute to the development of PCOS by influencing energy absorption, the pathways of short chain fatty acids (SCFA), lipopolysaccharides, choline and bile acids, intestinal permeability and the brain-gut axis. As part of the treatment of PCOS, fecal microbiota transplantation, supplementation with prebiotics and traditional Chinese medicine can be used to regulate GM and treat disorders. This article reviews possible mechanisms and treatment options for PCOS, based on methods which target the GM, and offers new ideas for the treatment of PCOS.

Role of Dietary Nutrients in the Modulation of Gut Microbiota: A Narrative Review

Understanding how dietary nutrients modulate the gut microbiome is of great interest for the development of food products and eating patterns for combatting the global burden of non-communicable diseases. In this narrative review we assess scientific studies published from 2005 to 2019 that evaluated the effect of micro- and macro-nutrients on the composition of the gut microbiome using in vitro and in vivo models, and human clinical trials. The clinical evidence for micronutrients is less clear and generally lacking. However, preclinical evidence suggests that red wine- and tea-derived polyphenols and vitamin D can modulate potentially beneficial bacteria. Current research shows consistent clinical evidence that dietary fibers, including arabinoxylans, galacto-oligosaccharides, inulin, and oligofructose, promote a range of beneficial bacteria and suppress potentially detrimental species. The preclinical evidence suggests that both the quantity and type of fat modulate both beneficial and potentially detrimental microbes, as well as the Firmicutes/Bacteroides ratio in the gut. Clinical and preclinical studies suggest that the type and amount of proteins in the diet has substantial and differential effects on the gut microbiota. Further clinical investigation of the effect of micronutrients and macronutrients on the microbiome and metabolome is warranted, along with understanding how this influences host health.

Hydroxycinnamic acids and human health: recent advances

There is an urgent need to improve human diet globally. Compelling evidence gathered over the past several decades suggests that a suboptimal diet is associated with many chronic diseases and may be responsible for more deaths than any other risks worldwide. The main components in our diet that need higher intake are whole grains, fruit and vegetables, and nuts and seeds; all of these are important sources of dietary fiber and polyphenols. The health benefits of dietary fiber and polyphenols are also supported by several decades of valuable research. However, the conclusions drawn from interventional human trials are not straightforward and the action mechanisms in improving human health are not fully understood. Moreover, there is a great inter-individual variation caused by different individual capabilities of processing, absorbing and using these compounds effectively. Data on the bioavailability and bioefficacy of hydroxycinnamic acids (HCAs) are limited when compared to other classes of polyphenols (e.g. anthocyanins). This review aims to summarize the latest research advances related to HCA bioavailability and their biological effects revealed by epidemiological data, pre-clinical and clinical studies. Moreover, we aim to review the effects of HCAs on gut microbiota diversity and function and its respective influence on host health. © 2019 Society of Chemical Industry.

Dietary resveratrol attenuated colitis and modulated gut microbiota in dextran sulfate sodium-treated mice

Accumulating evidence suggests that the gut microbiota plays an important role in the pathogenesis of colitis and that its composition could be modulated by exposure to dietary components. Thus, it may be possible to ameliorate the severity of colitis through administration of dietary components. Herein, we determined the effects of orally administered resveratrol on the gut microbiota composition and the resulting inflammatory status of a dextran sodium sulfate (DSS)-induced colitis mouse model. Our results supported our hypothesis that dietary resveratrol altered the microbial composition and restored microbial community diversity in DSS-treated mice. Specifically, resveratrol effectively decreased the abundance of the genera Akkermansia, Dorea, Sutterella and Bilophila, and increased the proportion of Bifidobacterium in colitic mice. Resveratrol was also able to prevent mouse body weight loss, reduce the disease activity index, attenuate tissue damage, and down-regulate the expression of pro-inflammatory cytokines such as IL-2, IFN-γ, GM-CSF, IL-1β, IL-6, KC/GRO, and TNF-α in the colon of DSS-treated mice. Pearson's correlation analysis indicated significant correlations between the relative levels of these pro-inflammatory cytokines and alterations of the gut microbiota. Our results demonstrated that dietary resveratrol attenuated the inflammatory status and alleviated gut microbiota dysbiosis in a colitis mouse model.

Beneficial Effects of Dietary Polyphenols on High-Fat Diet-Induced Obesity Linking with Modulation of Gut Microbiota

Obesity is caused by an imbalance of energy intake and expenditure. It is characterized by a higher accumulation of body fat with a chronic low-grade inflammation. Many reports have shown that gut microbiota in the host plays a pivotal role in mediating the interaction between consumption of a high-fat diet (HFD) and onset of obesity. Accumulative evidence has suggested that the changes in the composition of gut microbiota may affect the host's energy homeostasis, systemic inflammation, lipid metabolism, and insulin sensitivity. As one of the major components in human diet, polyphenols have demonstrated to be capable of modulating the composition of gut microbiota and reducing the HFD-induced obesity. The present review summarizes the findings of recent studies on dietary polyphenols regarding their metabolism and interaction with bacteria in the intestine as well as the underlying mechanisms by which they modulate the gut microbiota and alleviate the HFD-induced obesity.

The Regulation of Host Intestinal Microbiota by Polyphenols in the Development and Prevention of Chronic Kidney Disease

Polyphenols are essential antioxidants in our regular diet, and have shown potential antibacterial effects. Other important biological effects, such as anticancer or antibacterial activities, have been demonstrated by some polyphenols. In recent years, the benefits of polyphenols to human health have attracted increasing attention from the scientific community. Recent studies have shown that polyphenols such as anthocyanin, catechin, chlorogenic acid, and resveratrol can inhibit pathogenic bacteria such as Escherichia coli and Salmonella to help regulate intestinal microflora. An imbalance of intestinal microflora and the destruction of intestinal barrier function have been found to have a potential relationship with the occurrence of chronic kidney disease (CKD). Specifically, they can aberrantly trigger the immune system to cause inflammation, increase the production of uremic toxins, and further worsen the condition of CKD. Therefore, the maintenance of intestinal microflora and the intestinal tract in a stable and healthy state may be able to "immunize" patients against CKD, and treat pre-existing disease. The use of common antibiotics may lead to drug resistance in pathogens, and thus beneficial polyphenols may be suitable natural substitutes for antibiotics. Herein we review the ability of different polyphenols, such as anthocyanin, catechin, chlorogenic acid, and resveratrol, to regulate intestinal microorganisms, inhibit pathogenic bacteria, and improve inflammation. In addition, we review the ability of different polyphenols to reduce kidney injury, as described in recent studies.

Ethanol extract of propolis prevents high-fat diet-induced insulin resistance and obesity in association with modulation of gut microbiota in mice

Propolis has beneficial effects anti-inflammatory, anti-diabetes and anti-obesity in human or murine models, but its mechanism has not been fully elucidated. This study was to investigate the effects of ethanol extract of propolis (EEP) on the gut microbiota, and to analyze the associations between these alterations of gut microbiota and insulin resistance and obesity in high fat diet (HFD)-fed mice. Male C57BL/6J mice were fed with chow diet, high-fat diet, and high-fat diet supplemented with 1% EEP or 2%EEP. EEP supplementation reduced HFD-induced weight gain and liver fat accumulation, proinflammatory cytokines and insulin resistance, and improved glucose tolerance and lipid profile. Meanwhile, EEP supplementation in HFD-fed mice increased anti-obesity and anti-inflammatory bacteria such as genera Roseburia and Intestinimonas and species Parabacteroides goldsteinii and Parabacteroides distasonis, and reduced pro-inflammatory bacteria such as genera Faecalibaculum and Prevotella and species Bacteroides vulgatus. These dominant bacterial taxa altered by EEP were significantly associated with the metabolic parameters of insulin resistance and obesityin HFD-fed mice. The results in this study indicated that EEP reduced HFD-induced obesity and insulin resistant, which may be mediated by modulating the composition and function of gut microbiota.

Mutual Interactions among Exercise, Sport Supplements and Microbiota

The adult gut microbiota contains trillions of microorganisms of thousands of different species. Only one third of gut microbiota are common to most people; the rest are specific and contribute to enhancing genetic variation. Gut microorganisms significantly affect host nutrition, metabolic function, immune system, and redox levels, and may be modulated by several environmental conditions, including physical activity and exercise. Microbiota also act like an endocrine organ and is sensitive to the homeostatic and physiological changes associated with training; in turn, exercise has been demonstrated to increase microbiota diversity, consequently improving the metabolic profile and immunological responses. On the other side, adaptation to exercise might be influenced by the individual gut microbiota that regulates the energetic balance and participates to the control of inflammatory, redox, and hydration status. Intense endurance exercise causes physiological and biochemical demands, and requires adequate measures to counteract oxidative stress, intestinal permeability, electrolyte imbalance, glycogen depletion, frequent upper respiratory tract infections, systemic inflammation and immune responses. Microbiota could be an important tool to improve overall general health, performance, and energy availability while controlling inflammation and redox levels in endurance athletes. The relationship among gut microbiota, general health, training adaptation and performance, along with a focus on sport supplements which are known to exert some influence on the microbiota, will be discussed.

Exploring the Pharmacological Mechanism of Quercetin-Resveratrol Combination for Polycystic Ovary Syndrome: A Systematic Pharmacological Strategy-Based Research

Resveratrol and quercetin have effects on polycystic ovary syndrome (PCOS). Hence, resveratrol combined with quercetin may have better effects on it. However, because of the limitations in animal and human experiments, the pharmacological and molecular mechanism of quercetin-resveratrol combination (QRC) remains to be clarified. In this research, a systematic pharmacological approach comprising multiple compound target collection, multiple potential target prediction, and network analysis was used for comparing the characteristic of resveratrol, quercetin and QRC, and exploring the mechanism of QRC. After that, four networks were constructed and analyzed: (1) compound-compound target network; (2) compound-potential target network; (3) QRC-PCOS PPI network; (4) QRC-PCOS-other human proteins (protein-protein interaction) PPI network. Through GO and pathway enrichment analysis, it can be found that three compounds focus on different biological processes and pathways; and it seems that QRC combines the characteristics of resveratrol and quercetin. The in-depth study of QRC further showed  more PCOS-related biological processes and pathways. Hence, this research not only offers clues to the researcher who is interested in comparing the differences among resveratrol, quercetin and QRC, but also provides hints for the researcher who wants to explore QRC's various synergies and its pharmacological and molecular mechanism.

A New Perspective on the Health Benefits of Moderate Beer Consumption: Involvement of the Gut Microbiota

Beer is the most widely consumed fermented beverage in the world. A moderate consumption of beer has been related to important healthy outcomes, although the mechanisms have not been fully understood. Beer contains only a few raw ingredients but transformations that occur during the brewing process turn beer into a beverage that is enriched in micronutrients. Beer also contains an important number of phenolic compounds and it could be considered to be a source of dietary polyphenols. On the other hand, gut microbiota is now attracting special attention due to its metabolic effects and as because polyphenols are known to interact with gut microbiota. Among others, ferulic acid, xanthohumol, catechins, epicatechins, proanthocyanidins, quercetin, and rutin are some of the beer polyphenols that have been related to microbiota. However, scarce literature exists about the effects of moderate beer consumption on gut microbiota. In this review, we focus on the relationship between beer polyphenols and gut microbiota, with special emphasis on the health outcomes.

Sex-Dependent Effects of PM2.5 Maternal Exposure and Quercetin Intervention on Offspring's Short Chain Fatty Acids

Short chain fatty acids (SCFAs) are produced by the colonic microbiota through fermentation. Influences of maternal PM2.5 exposure on SCFAs of the offspring have not been well understood. Additionally, studies of dietary intervention have not been carried out yet. Here we performed a study that dams were received PM2.5 and quercetin intervention during gestation and lactation. SCFAs in colon of dams and their offspring (on postnatal day 21 and 35) were analyzed using gas chromatography. For male offspring, when compared with the control group levels of acetic acid, butyric acid, and valeric acid were lower in the PM2.5 group (p < 0.05), however, levels of isobutyric acid and isovaleric acid were higher in the PM2.5 group (p < 0.05). For female offspring, as compared with the control group, propanoic acid was lower in the PM2.5 group, however isovaleric acid was higher in the PM2.5 group (p < 0.05). 100 mg/kg and 200 mg/kg quercetin intervention could inhibit SCFAs production of male offspring, especially in isobutyric acid and isovaleric acid (p < 0.05). 100 mg/kg quercetin intervention could upgrade the level of propanoic acid of female offspring (p < 0.05). Taken together, these results suggest that PM2.5 tracheal exposure during gestation and lactation could influence SCFAs of offspring. Quercetin administration might have the potential to offset the effects of mater PM2.5 exposure on SCFAs in the offspring to some extent. The above effects were showed in a sex-dependent manner.