Dietary Polyphenols Promote Growth of the Gut Bacterium Akkermansia muciniphila and Attenuate High-Fat Diet-Induced Metabolic Syndrome

A comprehensive update on the immunoregulatory mechanisms of Akkermansia muciniphila: insights into active ingredients, metabolites, and nutrient-driven modulation

Akkermansia muciniphila (A. muciniphila) has gained recognition as a pioneering probiotic, exhibiting considerable potential to enhance immune conditions across both humans and animals. The health benefits of A. muciniphila are attributed to its various components, including outer membrane proteins (PilQ and Amuc_1100), secreted proteins (P9 and AmTARS), extracellular vesicles, and metabolites such as SCFAs, ornithine lipids, γ-aminobutyric acid, cobalamin, and inosine. The dynamic control of the mucus layer by A. muciniphila plays a crucial role in regulating intestinal mucosal immunity. Furthermore, A. muciniphila modulates immune function by interacting with macrophages, dendritic cells, T lymphocytes, and Paneth cells. Increasing the abundance of A. muciniphila in the gut through nutritional strategies represents a safe and effective means to augment immune function. Various polyphenols, oligosaccharides, and polysaccharides have been shown to elevate the levels of this bacterium, thereby contributing to favorable immunoregulatory outcomes. This paper delves into the latest research advancements related to the probiotic mechanisms of A. muciniphila and provides an overview of the current understanding of how its abundance responds to nutrients. These insights offer a theoretical foundation for the utilization of A. muciniphila in immunoregulation.

The role of gut microbiota in prostate inflammation and benign prostatic hyperplasia and its therapeutic implications

Background

The gut microbiota thrives in a complex ecological environment and its dynamic balance is closely related to host health. Recent studies have shown that the occurrence of various diseases including prostate inflammation is related to the dysregulation of the gut microbiome.

Objective

This review focus on the mechanisms by which the gut microbiota induces prostate inflammation and benign prostatic hyperplasia and its therapeutic implications.

Materials and methods

Publications related to gut microbiota, prostate inflammation, and benign prostatic hyperplasia (BPH) until April 2023 were systematically reviewed. The research questions were formulated using the Problem, Intervention, Comparison/Control, and Outcome (PICO) frameworks.

Results

Fifteen articles covering the relationship between the gut microbiota and prostate inflammation/BPH, the mechanisms by which the gut microbiota influences prostate inflammation and BPH, and potential therapeutic approaches targeting the gut microbiota for these conditions were included.

Conclusion

Short-chain fatty acids (SCFAs), which are metabolites of the intestinal microbiota, protect the integrity of the intestinal barrier, regulate immunity, and inhibit inflammation. However, dysregulation of the gut microbiota significantly reduces the SCFA content in feces and impairs the integrity of the gut barrier, leading to the translocation of bacteria and bacterial components such as lipopolysaccharide, mediating the development of prostate inflammation through microbe-associated molecular patterns (MAMPs).

Manipulation of feeding patterns in high fat diet fed rats improves microbiota composition dynamics, inflammation and gut-brain signaling

Chronic consumption of high fat (HF) diets has been shown to increase meal size and meal frequency in rodents, resulting in overeating. Reducing meal frequency and establishing periods of fasting, independently of caloric intake, may improve obesity-associated metabolic disorders. Additionally, diet-driven changes in microbiota composition have been shown to play a critical role in the development and maintenance of metabolic disorders. In this study, we used a pair-feeding paradigm to reduce meal frequency and snacking episodes while maintaining overall intake and body weight in HF fed rats. We hypothesized that manipulation of feeding patterns would improve microbiota composition and metabolic outcomes. Male Wistar rats were placed in three groups consuming either a HF, low fat diet (LF, matched for sugar), or pair-fed HF diet for 7 weeks (n = 11-12/group). Pair-fed animals received the same amount of food consumed by the HF fed group once daily before dark onset (HF-PF). Rats underwent oral glucose tolerance and gut peptide cholecystokinin sensitivity tests. Bacterial DNA was extracted from the feces collected during both dark and light cycles and sequenced via Illumina MiSeq sequencing of the 16S V4 region. Our pair-feeding paradigm reduced meal numbers, especially small meals in the inactive phase, without changing total caloric intake. This shift in feeding patterns reduced relative abundances of obesity-associated bacteria and maintained circadian fluctuations in microbial abundances. These changes were associated with improved gastrointestinal (GI) function, reduced inflammation, and improved glucose tolerance and gut to brain signaling. We concluded from these data that targeting snacking may help improve metabolic outcomes, independently of energy content of the diet and hyperphagia.

Dietary Polyphenols, Food Processing and Gut Microbiome: Recent Findings on Bioavailability, Bioactivity, and Gut Microbiome Interplay

Polyphenols are organic chemical compounds naturally present in plants, renowned for their anti-inflammatory, antioxidant, immunomodulatory, anticancer, and cardiovascular protective properties. Their bioactivity and bioavailability can vary widely depending on the methods of food processing and interactions with the gut microbiome. These factors can induce changes in polyphenols, affecting their ability to achieve their intended health benefits. Thus, it is essential to develop and apply food processing methods that optimize polyphenol content while maintaining their bioactivity and bioavailability. This review aims to explore how various food processing techniques affect the quantity, bioactivity, and bioavailability of polyphenols, as well as their interactions with the gut microbiome, which may ultimately determine their health effects.

Strategies for producing probiotic biomass and postbiotics from Akkermansia muciniphila in submerged cultivations incorporating prebiotic sources

This research propounds an innovative technology focused on sustainability to increase the biomass yield of Akkermansia muciniphila, the next-generation probiotic, using prebiotic sources to replace or reduce animal mucin levels. A series of experimental design approaches were developed aiming to optimize the growth of Akkermansiamuciniphila by incorporating extracts of green leafy vegetables and edible mushroom into the cultivation media. Experiments using kale extract (KE), Brassica oleracea L., associated with lyophilized mushroom extract (LME) of Pleurotus ostreatus were the most promising, highlighting the assays with 0.376% KE and 0.423% LME or 1.05% KE and 0.5% LME, in which 3.5 × 1010 CFU (Colony Forming Units) mL- 1 was achieved - higher than in experiments in optimized synthetic media. Such results enhance the potential of using KE and LME not only as mucin substitutes, but also as a source to increase Akkermansia muciniphila biomass yields and release short-chain fatty acids. The work is relevant to the food and pharmaceutical industries in the preparation of the probiotic ingredient.

Metabolomic Applications in Gut Microbiota-Host Interactions in Human Diseases

The human gut microbiota, consisting of trillions of microorganisms, encodes diverse metabolic pathways that impact numerous aspects of host physiology. One key way in which gut bacteria interact with the host is through the production of small metabolites. Several of these microbiota-dependent metabolites, such as short-chain fatty acids, have been shown to modulate host diseases. In this review, we examine how disease-associated metabolic signatures are identified using metabolomic platforms, and where metabolomics is applied in gut microbiota-disease interactions. We further explore how integration of metagenomic and metabolomic data in human studies can facilitate biomarkers discoveries in precision medicine.

Okra extract alleviates lipopolysaccharide-induced inflammation response through the regulation of bile acids, the receptor-mediated pathway, and gut microbiota

BACKGROUND

Okra contains flavonoids and vitamin C as antioxidants and it contains polysaccharides as immunomodulators. Flavonoids regulate the inflammatory response in mice and may be related to gut microbiota. This study therefore aimed to investigate the impact of okra extract (OE) on inflammation in mice and to elucidate its underlying mechanism.

METHOD

Forty male Kunming (KM) mice were categorized into four groups: the control (CON) group, the lipopolysaccharide stimulation (LPS) group, the 5 mg mL-1 OE intervention (LPS + OE) group, and the 5 mg mL-1 OE supplementation plus mixed antibiotics (LPS + OE + ABX) group.

RESULTS

The results showed that, compared with the OE group, the expression of inflammatory signaling pathway genes was upregulated and gut barrier genes were inhibited in the OE + ABX group. The Fxr receptor was activated and the abundance of Akkermansia was increased after OE supplementation, whereas the effect was reversed in the OE + ABX group. Meanwhile, Fxr was correlated positively with Akkermansia.

CONCLUSION

The OE supplementation alleviated the inflammatory response in mice under LPS stimulation, accompanied by changes in gut microbiota and bile acid receptors, whereas the addition of antibiotics caused a disturbance to the gut microbiota in the OE group, thus reducing the effect of OE in alleviating the inflammatory response. © 2024 Society of Chemical Industry.

A Critical Review on Akkermansia muciniphila: Functional Mechanisms, Technological Challenges, and Safety Issues

Due to its physiological benefits from in vitro and in vivo points of view, Akkermansia muciniphila, a common colonizer in the human gut mucous layer, has consistently been identified as an option for the next-generation probiotic. A. muciniphila is a significant bacterium that promotes host physiology. However, it also has a great deal of potential to become a probiotic due to its physiological advantages in a variety of therapeutic circumstances. Therefore, it can be established that the abundance of A. muciniphila in the gut environment, which is controlled by many genetic and dietary variables, is related to the biological behaviors of the intestinal microbiota and gut dysbiosis/eubiosis circumstances. Before A. muciniphila is widely utilized as a next-generation probiotic, regulatory obstacles, the necessity for significant clinical trials, and the sustainability of manufacturing must be eliminated. In this review, the outcomes of recent experimental and clinical reports are comprehensively reviewed, and common colonization patterns, main factors involved in the colonization of A. muciniphila in the gut milieu, their functional mechanisms in establishing homeostasis in the metabolic and energy pathways, the promising delivery role of microencapsulation, potential genetic engineering strategies, and eventually safety issues of A. muciniphila have been discussed.

Enhancing optimal molecular interactions during food processing to design starch key structures for regulating quality and nutrition of starch-based foods: an overview from a synergistic regulatory perspective

Charting out personalized and/or optimized diets offers new opportunities in the field of food science, although with inherent challenges. Starch-based foods are a major component of daily energy intake in humans. In addition to being rich in starch, starchy foods also contain a multitude of bioactive substances (e.g., polyphenols, lipids). Food processing including storage affects the consistency and interactions between starch and other food components, which can affect the quality and nutritional characteristics of starch-based foods. This review describes the effects of interactions between starch and other components on the structural evolution of starch during food processing. We ponder upon how the evolution of starch molecular structure affects the quality and nutritional characteristics of starch-based foods vis-a-vis the structure-property relationship. Furthermore, we formulate best practices in processing starchy food to retain the quality and nutritional value by rationally designing starch structural domains. Interestingly, we found that inhibiting the formation of a crystalline structures while promoting the formation of short-range ordered structures and nano-aggregates can synchronously slow down its digestion and retrogradation properties, thus improving the quality and nutritional characteristics of starch-based food. This review provides theoretical guidelines for new researchers and food innovators of starch-based foods.

Digesting the complex metabolic effects of diet on the host and microbiome

The past 50 years of interdisciplinary research in humans and model organisms has delivered unprecedented insights into the mechanisms through which diet affects energy balance. However, translating these results to prevent and treat obesity and its associated diseases remains challenging. Given the vast scope of this literature, we focus this Review on recent conceptual advances in molecular nutrition targeting the management of energy balance, including emerging dietary and pharmaceutical interventions and their interactions with the human gut microbiome. Notably, multiple current dietary patterns of interest embrace moderate-to-high fat intake or prioritize the timing of eating over macronutrient intake. Furthermore, the rapid expansion of microbiome research findings has complicated multiple longstanding tenets of nutrition while also providing new opportunities for intervention. Continued progress promises more precise and reliable dietary recommendations that leverage our growing knowledge of the microbiome, the changing landscape of clinical interventions, and our molecular understanding of human biology.

Anti-diabetic effect of dicaffeoylquinic acids is associated with the modulation of gut microbiota and bile acid metabolism

INTRODUCTION

The human gut microbiome plays a pivotal role in health and disease, notably through its interaction with bile acids (BAs). BAs, synthesized in the liver, undergo transformation by the gut microbiota upon excretion into the intestine, thus influencing host metabolism. However, the potential mechanisms of dicaffeoylquinic acids (DiCQAs) from Ilex kudingcha how to modulate lipid metabolism and inflammation via gut microbiota remain unclear.

OBJECTIVES AND METHODS

The objectives of the present study were to investigate the regulating effects of DiCQAs on diabetes and the potential mechanisms of action. Two mice models were utilized to investigate the anti-diabetic effects of DiCQAs. Additionally, analysis of gut microbiota structure and functions was conducted concurrently with the examination of DiCQAs' impact on gut microbiota carrying the bile salt hydrolase (BSH) gene, as well as on the enterohepatic circulation of BAs and related signaling pathways.

RESULTS

Our findings demonstrated that DiCQAs alleviated diabetic symptoms by modulating gut microbiota carrying the BSH gene. This modulation enhanced intestinal barrier integrity, increased enterohepatic circulation of conjugated BAs, and inhibited the farnesoid X receptor-fibroblast growth factor 15 (FGF15) signaling axis in the ileum. Consequently, the protein expression of hepatic FGFR4 fibroblast growth factor receptor 4 (FGFR4) decreased, accompanied by heightened BA synthesis, reduced hepatic BA stasis, and lowered levels of hepatic and plasma cholesterol. Furthermore, DiCQAs upregulated glucolipid metabolism-related proteins in the liver and muscle, including v-akt murine thymoma viral oncogene homolog (AKT)/glycogen synthase kinase 3-beta (GSK3β) and AMP-activated protein kinase (AMPK), thereby ameliorating hyperglycemia and mitigating inflammation through the down-regulation of the MAPK signaling pathway in the diabetic group.

CONCLUSION

Our study elucidated the anti-diabetic effects and mechanism of DiCQAs from I. kudingcha, highlighting the potential of targeting gut microbiota, particularly Acetatifactor sp011959105 and Acetatifactor muris carrying the BSH gene, as a therapeutic strategy to attenuate FXR-FGF15 signaling and ameliorate diabetes.

Identification of herbal drug extracts that promote growth of Akkermansia muciniphila in high-fat diet fed mice

Disruption of the gut microbiota causes metabolic dysfunction, and intervention in the gut microbiota has the potential to improve host glucose metabolism. Akkermanisa muciniphila is an intestinal bacterium involved in anti-obesity and insulin resistance. Developing interventions to increase A. muciniphla would be useful for new treatment strategies. In this study, we screened herbal drug extracts that promoted the growth of A. muciniphila. Among the 123 herbal drugs, five herbal drug extracts significantly increased A. muciniphila DNA levels compared with that in controls. In particular, Dioscoreae rhizoma extract increased the growth of A. muciniphila in the intestines of mice fed a high-fat diet and improved obesity. It significantly reduced body weight gain, improved glucose tolerance even when the administration was initiated after the induction of dietary obesity. These results suggest that herbal drug extracts, such as Dioscoreae rhizome, that increase A. muciniphila could be a new therapeutic strategy for metabolic syndrome.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13340-024-00713-w.

Therapeutic manipulation of the microbiome in liver disease

Myriad associations between the microbiome and various facets of liver physiology and pathology have been described in the literature. Building on descriptive and correlative sequencing studies, metagenomic studies are expanding our collective understanding of the functional and mechanistic role of the microbiome as mediators of the gut-liver axis. Based on these mechanisms, the functional activity of the microbiome represents an attractive, tractable, and precision medicine therapeutic target in several liver diseases. Indeed, several therapeutics have been used in liver disease even before their description as a microbiome-dependent approach. To bring successful microbiome-targeted and microbiome-inspired therapies to the clinic, a comprehensive appreciation of the different approaches to influence, collaborate with, or engineer the gut microbiome to coopt a disease-relevant function of interest in the right patient is key. Herein, we describe the various levels at which the microbiome can be targeted-from prebiotics, probiotics, synbiotics, and antibiotics to microbiome reconstitution and precision microbiome engineering. Assimilating data from preclinical animal models, human studies as well as clinical trials, we describe the potential for and rationale behind studying such therapies across several liver diseases, including metabolic dysfunction-associated steatotic liver disease, alcohol-associated liver disease, cirrhosis, HE as well as liver cancer. Lastly, we discuss lessons learned from previous attempts at developing such therapies, the regulatory framework that needs to be navigated, and the challenges that remain.

Diet-Induced Rodent Obesity Is Prevented and the Fecal Microbiome Is Improved with Elderberry (Sambucus nigra ssp. canadensis) Juice Powder

Anthocyanin-rich edible berries protect against diet-induced obesity in animal models. Prevention is mediated through the bidirectional relationship with the fecal microbiome, and gut-derived phenolic metabolite absorption increases with physical activity, which may influence bioactivity. The objective of this study was to test elderberry juice powder on the development of diet-induced obesity and its influence on the fecal microbiome alone or in combination with physical activity. Male C57BL/6J mice were assigned to one of four treatments, including (1) high-fat diet without wheel access; (2) high-fat diet with unlimited wheel access; (3) high-fat diet supplemented with 10% elderberry juice powder without wheel access; and (4) high-fat diet supplemented with 10% elderberry juice powder with unlimited wheel access. Body weight gain, fat pads, and whole-body fat content in mice fed elderberry juice were significantly less than in mice fed the control diet independent of wheel access. At the end of the study, active mice fed elderberry juice ate significantly more than active mice fed a control diet. There was no difference in the physical activity between active groups. Elderberry juice increasedBifidobacterium, promotedAkkermansia and Anaeroplasma, and prevented the growth of Desulfovibrio. Elderberry juice is a potent inhibitor of diet-induced obesity with action mediated by the gut microbiota.

Insights into the Mechanisms of Action of Akkermansia muciniphila in the Treatment of Non-Communicable Diseases

This comprehensive review delineates the extensive roles of Akkermansia muciniphila in various health domains, spanning from metabolic and inflammatory diseases to neurodegenerative disorders. A. muciniphila, known for its ability to reside in the mucous layer of the intestine, plays a pivotal role in maintaining gut integrity and interacting with host metabolic processes. Its influence extends to modulating immune responses and potentially easing symptoms across several non-communicable diseases, including obesity, diabetes, inflammatory bowel disease, and cancer. Recent studies highlight its capacity to interact with the gut-brain axis, suggesting a possible impact on neuropsychiatric conditions. Despite the promising therapeutic potential of A. muciniphila highlighted in animal and preliminary human studies, challenges remain in its practical application due to stability and cultivation issues. However, the development of pasteurized forms and synthetic mediums offers new avenues for its use in clinical settings, as recognized by regulatory bodies like the European Food Safety Authority. This narrative review serves as a crucial resource for understanding the broad implications of A. muciniphila across different health conditions and its potential integration into therapeutic strategies.

Blautia Coccoides is a Newly Identified Bacterium Increased by Leucine Deprivation and has a Novel Function in Improving Metabolic Disorders

Gut microbiota is linked to human metabolic diseases. The previous work showed that leucine deprivation improved metabolic dysfunction, but whether leucine deprivation alters certain specific species of bacterium that brings these benefits remains unclear. Here, this work finds that leucine deprivation alters gut microbiota composition, which is sufficient and necessary for the metabolic improvements induced by leucine deprivation. Among all the affected bacteria, B. coccoides is markedly increased in the feces of leucine-deprived mice. Moreover, gavage with B. coccoides improves insulin sensitivity and reduces body fat in high-fat diet (HFD) mice, and singly colonization of B. coccoides increases insulin sensitivity in gnotobiotic mice. The effects of B. coccoides are mediated by metabolizing tryptophan into indole-3-acetic acid (I3AA) that activates the aryl hydrocarbon receptor (AhR) in the liver. Finally, this work reveals that reduced fecal B. coccoides and I3AA levels are associated with the clinical metabolic syndrome. These findings suggest that B. coccoides is a newly identified bacterium increased by leucine deprivation, which improves metabolic disorders via metabolizing tryptophan into I3AA.

A View on the Chemical and Biological Attributes of Five Edible Fruits after Finishing Their Shelf Life: Studies on Caco-2 Cells

We studied five common perishable fruits in terms of their polyphenols dynamic, minerals distribution, scavenger activity and the effects of 50% ethanolic extracts on the viability of Caco-2 cells in vitro, over a period of time between T = 0 and T = 5/7 days, typically the end of their shelf life. Altogether, there were few changes found, consisting of either an increase or a decrease in their chemical and biological attributes. A slow decrease was found in the antioxidant activity in apricot (-11%), plum (-6%) and strawberry (-4%) extracts, while cherry and green seedless table grape extracts gained 7% and 2% antioxidant potency, respectively; IC50 values ranged from 1.67 to 5.93 μg GAE/μL test extract. The cytotoxicity MTS assay at 24 h revealed the ability of all 50% ethanol fruit extracts to inhibit the Caco-2 cell viability; the inhibitory effects ranged from 49% to 83% and were measured at 28 µg GAE for strawberry extracts/EES, from 22 µg to 45 µg GAE for cherry extracts/EEC, from 7.58 to 15.16 µg GAE for apricot extracts/EEA, from 12.50 to 25.70 µg GAE for plum extracts/EEP and from 21.51 to 28.68 µg GAE for green table grape extracts/EEG. The MTS anti-proliferative assay (72 h) also revealed a stimulatory potency upon the Caco-2 viability, from 34% (EEA, EEG) and 48% (EEC) to 350% (EES) and 690% (EEP); therefore fruit juices can influence intestinal tumorigenesis in humans.

Optimizing Akkermansia muciniphila Isolation and Cultivation: Insights into Gut Microbiota Composition and Potential Growth Promoters in a Chinese Cohort

The study aims to analyze the composition of the gut microbiota in Chinese individuals using metagenomic sequencing technology, with a particular focus on the abundance of Akkermansia muciniphila (Akk). To improve the efficiency of Akk isolation and identification accuracy, modifications were made to the enrichment culture medium and 16S rRNA universal primers. Additionally, potential growth-promoting factors that stimulate Akk growth were explored through in vitro screening. The research results revealed that the abundance of Akk in Chinese fecal samples ranged from 0.004% to 0.4%. During optimization, a type of animal protein peptide significantly enhanced the enrichment efficiency of Akk, resulting in the isolation of three Akk strains from 14 fecal samples. Furthermore, 17 different growth-promoting factors were compared, and four factors, including galactose, sialic acid, lactose, and chitosan, were identified as significantly promoting Akk growth. Through orthogonal experiments, the optimal ratio of these four growth-promoting factors was determined to be 1:1:2:1. After adding 1.25% of this growth-promoting factor combination to the standard culture medium, Akk was cultivated at 37° for 36 h, achieving an OD600nm value of 1.169, thus realizing efficient proliferation and optimized cultivation of Akk. This study provides important clues for a deeper understanding of the gut microbiota composition in Chinese individuals, while also offering effective methods for the isolation and cultivation of Akk, laying the groundwork for its functional and application research in the human body.

The Effects of Food Nutrients and Bioactive Compounds on the Gut Microbiota: A Comprehensive Review

It is now widely recognized that gut microbiota plays a critical role not only in the development and progression of diseases, but also in its susceptibility to dietary patterns, food composition, and nutritional intake. In this comprehensive review, we have compiled the latest findings on the effects of food nutrients and bioactive compounds on the gut microbiota. The research indicates that certain components, such as unsaturated fatty acids, dietary fiber, and protein have a significant impact on the composition of bile salts and short-chain fatty acids through catabolic processes, thereby influencing the gut microbiota. Additionally, these compounds also have an effect on the ratio of Firmicutes to Bacteroides, as well as the abundance of specific species like Akkermansia muciniphila. The gut microbiota has been found to play a role in altering the absorption and metabolism of nutrients, bioactive compounds, and drugs, adding another layer of complexity to the interaction between food and gut microbiota, which often requires long-term adaptation to yield substantial outcomes. In conclusion, understanding the relationship between food compounds and gut microbiota can offer valuable insights into the potential therapeutic applications of food and dietary interventions in various diseases and health conditions.

Gestational Diabetes and the Gut Microbiota: Fibre and Polyphenol Supplementation as a Therapeutic Strategy

Gestational diabetes mellitus (GDM) is an escalating public health concern due to its association with short- and long-term adverse maternal and child health outcomes. Dysbiosis of microbiota within the gastrointestinal tract has been linked to the development of GDM. Modification of microbiota dysbiosis through dietary adjustments has attracted considerable attention as adjunct strategies to improve metabolic disease. Diets high in fibre and polyphenol content are associated with increased gut microbiota alpha diversity, reduced inflammation and oxidative processes and improved intestinal barrier function. This review explores the potential of fibre and polyphenol supplementation to prevent GDM by investigating their impact on gut microbiota composition and function.

Mechanism of procyanidins for health functionality by improving the intestinal environment

Procyanidins are one of the polyphenols consisting of multiple flavan-3-ols (eg epicatechin). They have a complex chemical structure, with the degree of polymerization and linked position of flavan-3-ols varying among various foods, such as apples and chocolate. Physiological functional studies of procyanidins have investigated their mechanisms in cells and animals based on their antioxidant effects. Recently, the intestinal environment, including the intestinal microflora, has played an important role in the energy metabolism and health status of the host. Regulation of the intestinal environment by dietary polyphenols is becoming a new concept in health functions, and we have begun to investigate the mechanism of apple procyanidins, focusing on the gut microbiota and metabolites in our functional research. In this minireview, we will discuss the effects of procyanidin ingestion on the gut microbiota and metabolites.

Akkermansia muciniphila: a potential candidate for ameliorating metabolic diseases

Metabolic diseases are comprehensive disease based on obesity. Numerous cumulative studies have shown a certain correlation between the fluctuating abundance of Akkermansia muciniphila and the occurrence of metabolic diseases. A. muciniphila, a potential probiotic candidate colonized in the human intestinal mucus layer, and its derivatives have various physiological functions, including treating metabolic disorders and maintaining human health. This review systematically explicates the abundance change rules of A. muciniphila in metabolic diseases. It also details the high efficacy and specific molecules mechanism of A. muciniphila and its derivatives in treating obesity, type 2 diabetes mellitus, cardiovascular disease, and non-alcoholic fatty liver disease.

(Poly)phenol-related gut metabotypes and human health: an update

Dietary (poly)phenols have received great interest due to their potential role in the prevention and management of non-communicable diseases. In recent years, a high inter-individual variability in the biological response to (poly)phenols has been demonstrated, which could be related to the high variability in (poly)phenol gut microbial metabolism existing within individuals. An interplay between (poly)phenols and the gut microbiota exists, with (poly)phenols being metabolised by the gut microbiota and their metabolites modulating gut microbiota diversity and composition. A number of (poly)phenol metabolising phenotypes or metabotypes have been proposed, however, potential metabotypes for most (poly)phenols have not been investigated, and the relationship between metabotypes and human health remains ambiguous. This review presents updated knowledge on the reciprocal interaction between (poly)phenols and the gut microbiome, associated gut metabotypes, and subsequent impact on human health.

Metformin, Cognitive Function, and Changes in the Gut Microbiome

The decline in cognitive function and the prevalence of neurodegenerative disorders are among the most serious threats to health in old age. The prevalence of dementia has reached 50 million people worldwide and has become a major public health problem. The causes of age-related cognitive impairment are multiple, complex, and difficult to determine. However, type 2 diabetes (T2D) is linked to an enhanced risk of cognitive impairment and dementia. Human studies have shown that patients with T2D exhibit dysbiosis of the gut microbiota. This dysbiosis may contribute to the development of insulin resistance and increased plasma lipopolysaccharide concentrations. Metformin medication mimics some of the benefits of calorie restriction and physical activity, such as greater insulin sensitivity and decreased cholesterol levels, and hence may also have a positive impact on aging in humans. According to recent human investigations, metformin might partially restore gut dysbiosis related to T2D. Likewise, some studies showed that metformin reduced the risk of dementia and improved cognition, although not all studies are concordant. Therefore, this review focused on those human studies describing the effects of metformin on the gut microbiome (specifically the changes in taxonomy, function, and circulating metabolomics), the changes in cognitive function, and their possible bidirectional implications.

Correlation of Gut Microbiota with Children Obesity and Weight Loss

Children obesity is a serious public health problem drawing much attention around the world. Recent research indicated that gut microbiota plays a vital role in children obesity, and disturbed gut microbiota is a prominent characteristic of obese children. Diet and exercise are efficient intervention for weight loss in obesity children, however, how the gut microbiota is modulated which remains largely unknown. To characterize the feature of gut microbiota in obese children and explore the effect of dietary and exercise on gut microbiota in simple obese children, 107 healthy children and 86 obese children were recruited, and among of the obese children 39 received the dietary-exercise combined weight loss intervention (DEI). The gut microbiota composition was detected by the 16S amplicon sequencing method. The gut microbiota composition was significantly different between obese children and the healthy cohort, and DEI significantly reduced the body weight and ameliorated the gut microbiota dysbiosis. After DEI, the abundance of the Akkermansia muciniphila was increased, while the abundance of the Sutterella genus was decreased in simple obese children. Our results may provide theoretical reference for future personalized obesity interventions based on gut microbiota.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12088-023-01088-3.

The Killer's Web: Interconnection between Inflammation, Epigenetics and Nutrition in Cancer

Inflammation is a key contributor to both the initiation and progression of tumors, and it can be triggered by genetic instability within tumors, as well as by lifestyle and dietary factors. The inflammatory response plays a critical role in the genetic and epigenetic reprogramming of tumor cells, as well as in the cells that comprise the tumor microenvironment. Cells in the microenvironment acquire a phenotype that promotes immune evasion, progression, and metastasis. We will review the mechanisms and pathways involved in the interaction between tumors, inflammation, and nutrition, the limitations of current therapies, and discuss potential future therapeutic approaches.

Elemental iron protects gut microbiota against oxygen-induced dysbiosis

Gut dysbiosis induced by oxygen and reactive oxygen species may be related to the development of inflammation, resulting in metabolic syndrome and associated-conditions in the gut. Here we show that elemental iron can serve as an antioxidant and reverse the oxygen-induced dysbiosis. Fecal samples from three healthy donors were fermented with elemental iron and/or oxygen. 16S rRNA analysis revealed that elemental iron reversed the oxygen-induced disruption of Shannon index diversity of the gut microbiota.The bacteria lacking enzymatic antioxidant systems also increased after iron treatment. Inter-individual differences, which corresponded to iron oxidation patterns, were observed for the tested donors. Gut bacteria responding to oxygen and iron treatments were identified as guilds, among which, Escherichia-Shigella was promoted by oxygen and depressed by elemental iron, while changes in bacteria such as Bifidobacterium, Blautia, Eubacterium, Ruminococcaceae, Flavonifractor, Oscillibacter, and Lachnospiraceae were reversed by elemental iron after oxygen treatment. Short-chain fatty acid production was inhibited by oxygen and this effect was partially reversed by elemental iron. These results suggested that elemental iron can regulate the oxygen/ROS state and protect the gut microbiota from oxidative stress.

Paraprobiotic derived from Bacillus velezensis GV1 improves immune response and gut microbiota composition in cyclophosphamide-treated immunosuppressed mice

Paraprobiotics that benefit human health have the capacity to modulate innate and adaptive immune systems. In this study, we prepared the paraprobiotic from Bacillus velezensis GV1 using the heat-killing method and investigated its effects on immunity and gut microbiota in vitro and in vivo. The morphology of inactivated strain GV1 was observed using scanning electron microscopy. Treatment with GV1 promoted nitric oxide production and augmented cytokine (IL-6, IL-1β, and TNF-α) expression and secretion in RAW 264.7 macrophages. Moreover, the strain GV1 could alleviate cyclophosphamide monohydrate (CTX)-induced immunosuppression by reversing spleen damage and restoring the immune organ index, as well as by increasing the expression of immune-related cytokines (TNF-α, IL-1β, IFN-γ, and IL-2) in the spleen and thymus, respectively. Furthermore, GV1 treatment dramatically healed the CTX-damaged colon and regulated gut microbiota by increasing the relative abundance of beneficial bacterial families (Lactobacillaceae, Akkermansiaceae, and Coriobacteriaceae) and decreasing that of harmful bacterial families (Desulfovibrionaceae, Erysipelotrichaceae, and Staphylococcaceae). Thus, the heat-killed GV1 can be considered a potential immunoregulatory agent for use as a functional food or immune-enhancing medicine.

Naringin ameliorates obesity via stimulating adipose thermogenesis and browning, and modulating gut microbiota in diet-induced obese mice

Naringin, a natural flavanone primarily found in citrus fruits, has garnered increased attention due to its recognized antioxidative, anti-inflammatory, and cardioprotective attributes. However, the functions of naringin in regulating energy expenditure are poorly understood. In the present study, we observed that twelve weeks of naringin supplementation substantially reshaped the metabolic profile of high-fat diet (HFD)-fed mice, by inhibiting body weight gain, reducing liver weight, and altering body compositions. Notably, naringin exhibited a remarkable capacity to augment whole-body energy expenditure of the tested mice by enhancing the thermogenic activity of brown adipose tissue (BAT) and stimulating browning of inguinal white adipose tissue (iWAT). Furthermore, our results showed naringin supplementation modified gut microbiota composition, specifically increasing the abundance of Bifidobacterium and Lachnospiraceae_bacterium_28-4, while reducing the abundance of Lachnospiraceae_bacterium_DW59 and Dubosiella_newyorkensis. Subsequently, we also found naringin supplementation altered fecal metabolite profile, by significantly promoting the production of taurine, tyrosol, and thymol, which act as potent activators of thermoregulation. Interestingly, the metabolic effects of naringin were abolished upon gut microbiota depletion through antibiotic intervention, concurrently leading the disappearance of naringin-induced thermogenesis and protective actions on diet-induced obesity. This discovery revealed a novel food-driven cross-sectional communication between gut bacteria and adipose tissues. Collectively, our data indicate that naringin supplementation stimulates BAT thermogenesis, alters fat distribution, promotes the browning process, and consequently inhibits body weight gain; importantly these metabolic effects require the participation of gut bacteria.

[Use of microbiological data for the purposes of forensic medical examination]

The study objective was to describe the formation of forensic microbiological examination as an analysis of a new type, defined as the detection and registration of reliably measured environmental and physiological changes within the microbial community of corpse in order to substantiate the possibility of using microbiological parameters to establish the prescription of death coming. It has been determined that the knowledge of the patterns of interaction of a human and his corpse with endogenous and exogenous flora provides the basis for solving a number of traditional and new application-oriented expert tasks and the allocation of such a variety of forensic examination as forensic microbiological examination. Endogenous and exogenous human flora and its interaction with living and dead biological tissues are the objects of this kind of examination, and the dynamic patterns of such interaction are the subject of study. One of the initial relevant tasks of forensic microbiological examination consists in development of methods, adequate for the expert task to be solved, choice of the research «target», «models» for comparative analysis and medium, adequate for task in hand, as well as certification of these methods and standardization of assessment criteria for the obtained results.

The gut microbiome in the fight against obesity: The potential of dietary factors

Obesity as a global public health burden has experienced a drastic growing trend recently. The management of obesity is challenging because of its complex etiology, and various factors are involved in its development, such as genetic and environmental factors. Different approaches are available to treat and/or manage obesity, including diet, physical activity, lifestyle changes, medications, and surgery. However, some of these approaches have inherent limitations and are closely associated with adverse effects. Therefore, probing into a novel/safe approach to treat and/or manage obesity is of fundamental importance. One such approach gaining renewed interest is the potential role of gut microbiota in obesity and its effectiveness in treating this condition. However, there is a dearth of comprehensive compilation of data on the potential role of the gut microbiome in obesity, particularly regarding dietary factors as a therapeutic approach. Therefore, this review aims to provide an updated overview of the role of gut microbiota in obesity, further highlighting the importance of dietary factors, particularly diet, prebiotics, and probiotics, as potential complementary and/or alternative therapeutic options. Moreover, the association of gut microbiota with obese or lean individuals has also been discussed.

Dietary components regulate chronic diseases through gut microbiota: a review

In recent years, gut microbiota as an immune organ has gradually become the mainstream of research. When the composition of the gut microbiota is changed significantly, this may affect human health. This review details the major microbiota composition and metabolites in the gut and discusses chronic diseases based on gut dysbiosis, including obesity, liver injury, colon cancer, atherosclerosis, and central nervous system diseases. We comprehensively summarize the changes in abundance of relevant gut microbiota by ingesting different diet components (such as food additives, dietary polyphenols, polysaccharides, fats, proteins) and their influence on the microbial quorum sensing system, thereby regulating related diseases. We believe that quorum sensing can be used as a new entry point to explain the mechanism of ingesting dietary components to improve gut microbiota and thereby regulate related diseases. This review hopes to provide a theoretical basis for future research on improving disease symptoms by ingesting functional foods containing dietary components. © 2023 Society of Chemical Industry.

Astaxanthin attenuated the stress-induced intestinal motility disorder via altering the gut microbiota

Gut microbiota and short-chain fatty acids (SCFAs) are recognized as key factors in the pathophysiology of irritable bowel syndrome. Astaxanthin is a carotenoid with strong antioxidant and anti-inflammatory activities. In this study, we examined the effects of astaxanthin on gut microbiota-, SCFAs-, and corticotropin-releasing factor (CRH)-induced intestinal hypermotility. Male Wistar rats (n=12 per group) were fed a diet with or without 0. 02% (w/w) astaxanthin for four weeks and CRH or saline was administered intravenously. The number of fecal pellets was counted 2 h after injection. Then the rats were sacrificed, and the cecal content were collected 3 h after injection. The number of feces was significantly increased by CRH injection in the control group (2.0 vs. 6.5; p=0.028), but not in the astaxanthin group (1.0 vs. 2.2; p=0.229) (n=6 per group). The cecal microbiota in the astaxanthin group was significantly altered compared with that in the control group. The concentrations of acetic acid (81.1 μmol/g vs. 103.9 μmol/g; p=0.015) and butyric acid (13.4 μmol/g vs. 39.2 μmol/g; p<0.001) in the astaxanthin group were significantly lower than that in the control group (n=12 per group). Astaxanthin attenuates CRH-induced intestinal hypermotility and alters the composition of gut microbiota and SCFAs.

Is there a role for microbiome-based approach in common variable immunodeficiency?

Common variable immunodeficiency (CVID) is a primary immunodeficiency characterized by low levels of serum immunoglobulins and increased susceptibility to infections, autoimmune disorders and cancer. CVID embraces a plethora of heterogeneous manifestations linked to complex immune dysregulation. While CVID is thought to be due to genetic defects, the exact cause of this immune disorder is unknown in the large majority of cases. Compelling evidences support a linkage between the gut microbiome and the CVID pathogenesis, therefore a potential for microbiome-based treatments to be a therapeutic pathway for this disorder. Here we discuss the potential of treating CVID patients by developing a gut microbiome-based personalized approach, including diet, prebiotics, probiotics, postbiotics and fecal microbiota transplantation. We also highlight the need for a better understanding of microbiota-host interactions in CVID patients to prime the development of improved preventive strategies and specific therapeutic targets.

Interactions between gut microbiota and polyphenols: A mechanistic and metabolomic review

BACKGROUND

Polyphenols are a class of naturally sourced compounds with widespread distribution and an extensive array of bioactivities. However, due to their complex constituents and weak absorption, a convincing explanation for their remarkable bioactivity remains elusive for a long time. In recent years, interaction with gut microbiota is hypothesized to be a reasonable explanation of the potential mechanisms for natural compounds especially polyphenols.

OBJECTIVES

This review aims to present a persuasive explanation for the contradiction between the limited bioavailability and the remarkable bioactivities of polyphenols by examining their interactions with gut microbiota.

METHODS

We assessed literatures published before April 10, 2023, from several databases, including Scopus, PubMed, Google Scholar, and Web of Science. The keywords used include "polyphenols", "gut microbiota", "short-chain fatty acids", "bile acids", "trimethylamine N-oxide", "lipopolysaccharides" "tryptophan", "dopamine", "intestinal barrier", "central nervous system", "lung", "anthocyanin", "proanthocyanidin", "baicalein", "caffeic acid", "curcumin", "epigallocatechin-3-gallate", "ferulic acid", "genistein", "kaempferol", "luteolin", "myricetin", "naringenin", "procyanidins", "protocatechuic acid", "pterostilbene", "quercetin", "resveratrol", etc. RESULTS: The review first demonstrates that polyphenols significantly alter gut microbiota diversity (α- and β-diversity) and the abundance of specific microorganisms. Polyphenols either promote or inhibit microorganisms, with various factors influencing their effects, such as dosage, treatment duration, and chemical structure of polyphenols. Furthermore, the review reveals that polyphenols regulate several gut microbiota metabolites, including short-chain fatty acids, dopamine, trimethylamine N-oxide, bile acids, and lipopolysaccharides. Polyphenols affect these metabolites by altering gut microbiota composition, modifying microbial enzyme activity, and other potential mechanisms. The changed microbial metabolites induced by polyphenols subsequently trigger host responses in various ways, such as acting as intestinal acid-base homeostasis regulators and activating on specific target receptors. Additionally, polyphenols are transformed into microbial derivatives by gut microbiota and these polyphenols' microbial derivatives have many potential advantages (e.g., increased bioactivity, improved absorption). Lastly, the review shows polyphenols maintain intestinal barrier, central nervous system, and lung function homeostasis by regulating gut microbiota.

CONCLUSION

The interaction between polyphenols and gut microbiota provides a credible explanation for the exceptional bioactivities of polyphenols. This review aids our understanding of the underlying mechanisms behind the bioactivity of polyphenols.

Recent insights of obesity-induced gut and adipose tissue dysbiosis in type 2 diabetes

An imbalance in microbial homeostasis, referred to as dysbiosis, is critically associated with the progression of obesity-induced metabolic disorders including type 2 diabetes (T2D). Alteration in gut microbial diversity and the abundance of pathogenic bacteria disrupt metabolic homeostasis and potentiate chronic inflammation, due to intestinal leakage or release of a diverse range of microbial metabolites. The obesity-associated shifts in gut microbial diversity worsen the triglyceride and cholesterol level that regulates adipogenesis, lipolysis, and fatty acid oxidation. Moreover, an intricate interaction of the gut-brain axis coupled with the altered microbiome profile and microbiome-derived metabolites disrupt bidirectional communication for instigating insulin resistance. Furthermore, a distinct microbial community within visceral adipose tissue is associated with its dysfunction in obese T2D individuals. The specific bacterial signature was found in the mesenteric adipose tissue of T2D patients. Recently, it has been shown that in Crohn's disease, the gut-derived bacterium Clostridium innocuum translocated to the mesenteric adipose tissue and modulates its function by inducing M2 macrophage polarization, increasing adipogenesis, and promoting microbial surveillance. Considering these facts, modulation of microbiota in the gut and adipose tissue could serve as one of the contemporary approaches to manage T2D by using prebiotics, probiotics, or faecal microbial transplantation. Altogether, this review consolidates the current knowledge on gut and adipose tissue dysbiosis and its role in the development and progression of obesity-induced T2D. It emphasizes the significance of the gut microbiota and its metabolites as well as the alteration of adipose tissue microbiome profile for promoting adipose tissue dysfunction, and identifying novel therapeutic strategies, providing valuable insights and directions for future research and potential clinical interventions.

Protective Effect of Akkermansia muciniphila on the Preeclampsia-Like Mouse Model

Preeclampsia (PE) is known as a metabolism-related complication of pregnancy related to gut dysbiosis including the decreased abundance of Akkermansia muciniphila (A. muciniphila). However, the modulatory role of A. muciniphila as a supplement for PE remains ambiguous. This study investigated the effect of A. muciniphila administration on PE-like mice and its underlying mechanisms. A total of twenty-four C57BL/6 mice were randomly assigned into three groups. PE-like symptoms were induced by continuous injection of L-NAME intraperitoneally from gestational day (GD) 11 to GD18 combined with oral administration of pasteurized A. muciniphila during GD14-18 or not. Mice were sacrificed at GD19 to collect for further evaluation. Decreased A. muciniphila was observed in a successfully established PE-like model than normotensive pregnant control (NP), inversely correlated to increased systolic blood pressure blood and 24-h proteinuria. After supplementing with A. muciniphila, mice showed significantly minimized blood pressure and protein expression in urine, increased number of pups and weight of both embryos and placentas. In addition, colonies of bacteria, inflammatory cytokines (TNF-α and IL-6), and metabolic products of lipids including TC, FC, and TG were alleviated by A. muciniphila in the placentas. Among proteins linked with bowel barrier functions, diminished 2-AG and growing ZO-1 and occludin were attributable to A. muciniphila. Also, enhanced Treg/Th17 ratios were found in the intestines of mice treated with A. muciniphila. A. muciniphila facilitated alleviating PE-like symptoms and was beneficial as a novel probiotic therapeutic agent for PE.

The Role of Green Tea on the Regulation of Gut Microbes and Prevention of High-Fat Diet-Induced Metabolic Syndrome in Mice

Green tea is a popular non-alcoholic beverage consumed worldwide and has been shown to be beneficial for human health. However, further exploration is needed to fully understand its function in reducing obesity and regulating gut microbes. Here, we investigated the modulatory effects of green tea and its functional components on high-fat diet (HF)-induced metabolic alterations and gut microbiota in obese mice. Our results showed that 1%, 2%, and 4% of green tea promotes weight loss, with the 2% and 4% groups exhibiting distinct gut microflora clusters compared to the HF group. These results were comparable to those observed in the tea polyphenols (TPP)-treated group, suggesting the TPP in green tea plays a crucial role in body weight control and gut microbiota regulation. Additionally, 32 bacteria were identified as potential obesity markers via 16S rRNA gene sequencing. The 16SrDNA gene is a chromosomal gene present in all bacterial species, highly conserved in structure and function, that can reflect the differences between different taxa. The 16S rRNA-based analysis revealed that Akkermansia, a gut-beneficial bacteria, significantly increased in the TPP group.

Grape Polyphenols May Prevent High-Fat Diet-Induced Dampening of the Hypothalamic-Pituitary-Adrenal Axis in Male Mice

Context 

Chronic high-fat diet (HFD) consumption causes obesity associated with retention of bile acids (BAs) that suppress important regulatory axes, such as the hypothalamic-pituitary-adrenal axis (HPAA). HFD impairs nutrient sensing and energy balance due to a dampening of the HPAA and reduced production and peripheral metabolism of corticosterone (CORT).

Objective

We assessed whether proanthocyanidin-rich grape polyphenol (GP) extract can prevent HFD-induced energy imbalance and HPAA dysregulation.

Methods

Male C57BL6/J mice were fed HFD or HFD supplemented with 0.5% w/w GPs (HFD-GP) for 17 weeks.

Results

GP supplementation reduced body weight gain and liver fat while increasing circadian rhythms of energy expenditure and HPAA-regulating hormones, CORT, leptin, and PYY. GP-induced improvements were accompanied by reduced mRNA levels of Il6, Il1b, and Tnfa in ileal or hepatic tissues and lower cecal abundance of Firmicutes, including known BA metabolizers. GP-supplemented mice had lower concentrations of circulating BAs, including hydrophobic and HPAA-inhibiting BAs, but higher cecal levels of taurine-conjugated BAs antagonistic to farnesoid X receptor (FXR). Compared with HFD-fed mice, GP-supplemented mice had increased mRNA levels of hepatic Cyp7a1 and Cyp27a1, suggesting reduced FXR activation and more BA synthesis. GP-supplemented mice also had reduced hepatic Abcc3 and ileal Ibabp and Ostβ, indicative of less BA transfer into enterocytes and circulation. Relative to HFD-fed mice, CORT and BA metabolizing enzymes (Akr1d1 and Srd5a1) were increased, and Hsd11b1 was decreased in GP supplemented mice.

Conclusion

GPs may attenuate HFD-induced weight gain by improving hormonal control of the HPAA and inducing a BA profile with less cytotoxicity and HPAA inhibition, but greater FXR antagonism.

Bile acid metabolism and signaling: Emerging pharmacological targets of dietary polyphenols

Beyond their role as emulsifiers of lipophilic compounds, bile acids (BAs) are signaling endocrine molecules that show differential affinity and specificity for a variety of canonical and non-canonical BA receptors. Primary BAs (PBAs) are synthesized in the liver while secondary BAs (SBAs) are gut microbial metabolites of PBA species. PBAs and SBAs signal to BA receptors that regulate downstream pathways of inflammation and energy metabolism. Dysregulation of BA metabolism or signaling has emerged as a feature of chronic disease. Dietary polyphenols are non-nutritive plant-derived compounds associated with decreased risk of metabolic syndrome, type-2 diabetes, hepatobiliary and cardiovascular disease. Evidence suggests that the health promoting effects of dietary polyphenols are linked to their ability to alter the gut microbial community, the BA pool, and BA signaling. In this review we provide an overview of BA metabolism and summarize studies that link the cardiometabolic improvements of dietary polyphenols to their modulation of BA metabolism and signaling pathways, and the gut microbiota. Finally, we discuss approaches and challenges in deciphering cause-effect relationships between dietary polyphenols, BAs, and gut microbes.

Dietary polyphenols drive dose-dependent behavioral and molecular alterations to repeated morphine

Opioid Use Disorder (OUD) is associated with tremendous morbidity and mortality. Despite this burden, current pharmacotherapies for OUD are ineffective or intolerable for many patients. As such, interventions aimed at promoting resilience against OUD are of immense clinical interest. Treatment with a Bioactive Dietary Polyphenol Preparation (BDPP) promotes resilience and adaptive neuroplasticity in multiple models of neuropsychiatric disease. Here, we assessed effects of BDPP treatment on behavioral and molecular responses to repeated morphine treatment in male mice. BDPP pre-treatment alters responses for both locomotor sensitization and conditioned place preference. Most notably, polyphenol treatment consistently reduced formation of preference at low dose (5 mg/kg) morphine but enhanced it at high dose (15 mg/kg). In parallel, we performed transcriptomic profiling of the nucleus accumbens, which again showed a dose × polyphenol interaction. We also profiled microbiome composition and function, as polyphenols are metabolized by the microbiome and can act as prebiotics. The profile revealed polyphenol treatment markedly altered microbiome composition and function. Finally, we investigated involvement of the SIRT1 deacetylase, and the role of polyphenol metabolites in behavioral responses. These results demonstrate polyphenols have robust dose-dependent effects on behavioral and physiological responses to morphine and lay the foundation for future translational work.

Beer-gut microbiome alliance: a discussion of beer-mediated immunomodulation via the gut microbiome

As a long-established fermented beverage, beer is rich in many essential amino acids, vitamins, trace elements, and bioactive substances that are involved in the regulation of many human physiological functions. The polyphenols in the malt and hops of beer are also important active compounds that interact in both directions with the gut microbiome. This review summarizes the mechanisms by which polyphenols, fiber, and other beneficial components of beer are fermentatively broken down by the intestinal microbiome to initiate the mucosal immune barrier and thus participate in immune regulation. Beer degradation products have anti-inflammatory, anticoagulant, antioxidant, and glucolipid metabolism-modulating potential. We have categorized and summarized reported data on changes in disease indicators and in vivo gut microbiota abundance following alcoholic and non-alcoholic beer consumption. The positive effects of bioactive substances in beer in cancer prevention, reduction of cardiovascular events, and modulation of metabolic syndrome make it one of the candidates for microecological modulators.

Impact of High Fat Diet and Sex in a Rabbit Model of Carpal Tunnel Syndrome

Carpal tunnel syndrome (CTS) is a common musculoskeletal disorder, characterized by fibrosis of the subsynovial connective tissue (SSCT) mediated by transforming growth factor beta (TGF-β). Risk factors for CTS include metabolic dysfunction and age. Additionally, the incidence of CTS is higher in women. In this study we hypothesized that a high-fat diet (HFD), a common driver of metabolic dysfunction, would promote SSCT fibrosis found in CTS and that this response would be sex dependent. To test this, we examined the effects of HFD and sex on SSCT fibrosis using our established rabbit model of CTS. Forty-eight (24 male, 24 female) adult rabbits were divided into four groups including HFD or standard diet with and without CTS induction. SSCT was collected for histological and gene expression analysis. HFD promoted SSCT thickening and upregulated profibrotic genes, including TGF-β. Fibrotic genes were differentially expressed in males and females. Interestingly while the prevalence of CTS is greater in women than in men, the converse is observed in the presence of metabolic dysfunction. This work recapitulates this clinical observation and begins to elucidate the sex-based differences found in SSCT fibrosis. This knowledge should drive further research and may lead to metabolic and sex specific therapeutic strategies for the treatment of patients with CTS.

Nutritional Metabolomics in Diet-Breast Cancer Relations: Current Research, Challenges, and Future Directions-A Review

Breast cancer is one of the most common types of cancer in women worldwide, and its incidence is increasing. Diet has been identified as a modifiable risk factor for breast cancer, but the complex interplay between diet, metabolism, and cancer development is not fully understood. Nutritional metabolomics is a rapidly evolving field that can provide insights into the metabolic changes associated with dietary factors and their impact on breast cancer risk. The review's objective is to provide a comprehensive overview of the current research on the application of nutritional metabolomics in understanding the relationship between diet and breast cancer. The search strategy involved querying several electronic databases, including PubMed, Scopus, Web of Science, and Google Scholar. The search terms included combinations of relevant keywords such as "nutritional metabolomics", "diet", "breast cancer", "metabolites", and "biomarkers". In this review, both in vivo and in vitro studies were included, and we summarize the current state of knowledge on the role of nutritional metabolomics in understanding the diet-breast cancer relationship, including identifying specific metabolites and metabolic pathways associated with breast cancer risk. We also discuss the challenges associated with nutritional metabolomics research, including standardization of analytical methods, interpretation of complex data, and integration of multiple-omics approaches. Finally, we highlight future directions for nutritional metabolomics research in studying diet-breast cancer relations, including investigating the role of gut microbiota and integrating multiple-omics approaches. The application of nutritional metabolomics in the study of diet-breast cancer relations, including 2-amino-4-cyano butanoic acid, piperine, caprate, rosten-3β,17β-diol-monosulfate, and γ-carboxyethyl hydrochroman, among others, holds great promise for advancing our understanding of the role of diet in breast cancer development and identifying personalized dietary recommendations for breast cancer prevention, control, and treatment.

Function of Akkermansia muciniphila in type 2 diabetes and related diseases

The prevalence of type 2 diabetes (T2D) is increasing worldwide, with many patients developing long-term complications that affect their cardiovascular, urinary, alimentary, and other systems. A growing body of literature has reported the crucial role of gut microbiota in metabolic diseases, one of which, Akkermansia muciniphila, is considered the "next-generation probiotic" for alleviating metabolic disorders and the inflammatory response. Although extensive research has been conducted on A. muciniphila, none has summarized its regulation in T2D. Hence, this review provides an overview of the effects and multifaceted mechanisms of A. muciniphila on T2D and related diseases, including improving metabolism, alleviating inflammation, enhancing intestinal barrier function, and maintaining microbiota homeostasis. Furthermore, this review summarizes dietary strategies for increasing intestinal A. muciniphila abundance and effective gastrointestinal delivery.

A comprehensive systematic review of the effectiveness of Akkermansia muciniphila, a member of the gut microbiome, for the management of obesity and associated metabolic disorders

AIMS AND BACKGROUND

Obesity is recognised as a significant public health burden worldwide. Recently the cross-talk between gut microbiota and obesity has attracted much attention. To that end, Akkermansia muciniphila has been proposed as a promising microbe to manage obesity. In the present systematic review, we evaluated evidence on the effectiveness and mechanisms of action of Akkermansia muciniphila supplementation in the management of obesity.

METHODS

Electronic databases of MEDLINE, PubMed, Scopus, Web of Science, and Google Scholar were searched thought March 2020 to identify relevant published articles, and eligible articles were systematically reviewed.

RESULTS AND CONCLUSIONS

Fifteen studies were included in the present study. Findings from the present review, which included human and animal (rodent) models support the effectiveness of Akkermansia supplementation as a novel therapeutic approach for the management of obesity and metabolic complications associated with obesity. However, future clinical trials are warranted to verify these outcomes.

The role of intestinal microbiota and microRNAs in the anti-inflammatory effects of cranberry: from pre-clinical to clinical studies

Cranberries have known anti-inflammatory properties, which extend their benefits in the context of several chronic diseases. These benefits highly rely on the polyphenol profile of cranberries, one of few foods rich in A-type proanthocyanidin (PAC). A-type PAC comprises flavan-3-ol subunits with an additional interflavan ether bond in the conformational structure of the molecule, separating them from the more commonly found B-type PAC. PACs with a degree of polymerization higher than three are known to reach the colon intact, where they can be catabolyzed by the gut microbiota and biotransformed into lower molecular weight organic acids that are available for host absorption. Gut microbiota-derived metabolites have garnered much attention in the past decade as mediators of the health effects of parent compounds. Though, the mechanisms underlying this phenomenon remain underexplored. In this review, we highlight emerging evidence that postulates that polyphenols, including ones derived from cranberries, and their metabolites could exert anti-inflammatory effects by modulating host microRNAs. Our review first describes the chemical structure of cranberry PACs and a pathway for how they are biotransformed by the gut microbiota. We then provide a brief overview of the benefits of microbial metabolites of cranberry in the intestinal tract, at homeostasis and in inflammatory conditions. Finally, we discuss the role of microRNAs in intestinal health and in response to cranberry PAC and how they could be used as targets for the maintenance of intestinal homeostasis. Most of this research is pre-clinical and we recognize that conducting clinical trials in this context has been hampered by the lack of reliable biomarkers. Our review discusses the use of miRNA as biomarkers in this context.

Dietary (poly)phenols mitigate inflammatory bowel disease: Therapeutic targets, mechanisms of action, and clinical observations

Inflammatory bowel diseases (IBD), which include Crohn's disease and ulcerative colitis, are a rapidly growing public health concern worldwide. These diseases are heterogeneous at the clinical, immunological, molecular, genetic, and microbial level, but characteristically involve a disrupted immune-microbiome axis. Shortcomings in conventional treatment options warrant the need for novel therapeutic strategies to mitigate these life-long and relapsing disorders of the gastrointestinal tract. Polyphenols, a diverse group of phytochemicals, have gained attention as candidate treatments due to their array of biological effects. Polyphenols exert broad anti-inflammatory and antioxidant effects through the modulation of cellular signaling pathways and transcription factors important in IBD progression. Polyphenols also bidirectionally modulate the gut microbiome, supporting commensals and inhibiting pathogens. One of the primary means by which gut microbiota interface with the host is through the production of metabolites, which are small molecules produced as intermediate or end products of metabolism. There is growing evidence to support that modulation of the gut microbiome by polyphenols restores microbially derived metabolites critical to the maintenance of intestinal homeostasis that are adversely disrupted in IBD. This review aims to define the therapeutic targets of polyphenols that may be important for mitigation of IBD symptoms, as well as to collate evidence for their clinical use from randomized clinical trials.

Role of flavonoids in controlling obesity: molecular targets and mechanisms

Obesity presents a major health challenge that increases the risk of several non-communicable illnesses, such as but not limited to diabetes, hypertension, cardiovascular diseases, musculoskeletal and neurological disorders, sleep disorders, and cancers. Accounting for nearly 8% of global deaths (4.7 million) in 2017, obesity leads to diminishing quality of life and a higher premature mortality rate among affected individuals. Although essentially dubbed as a modifiable and preventable health concern, prevention, and treatment strategies against obesity, such as calorie intake restriction and increasing calorie burning, have gained little long-term success. In this manuscript, we detail the pathophysiology of obesity as a multifactorial, oxidative stress-dependent inflammatory disease. Current anti-obesity treatment strategies, and the effect of flavonoid-based therapeutic interventions on digestion and absorption, macronutrient metabolism, inflammation and oxidative stress and gut microbiota has been evaluated. The use of several naturally occurring flavonoids to prevent and treat obesity with a long-term efficacy, is also described.

Lower blood lipid level from the administration of plant tannins via altering the gut microbiota diversity and structure

Twenty-four Tan sheep were randomly assigned into 4 groups to study the capability of tannin supplementation (0.5% in dietary DM) to lower blood lipid levels mediated through the gut microbiota. The control (NC) group was offered a basic diet, while the 3 treatment groups were the TA group, which received supplementary tannic acid (TA); GSPE group, which received supplementary procyanidins (GSPE); and the TA + GSPE group, which received supplementary TA and GSPE, besides being supplied with the basic diet for 8 weeks feeding. At the end of the experiment, the serum glucose, insulin, lipids, and cytokines were measured, and the short-chain fatty acids (SCFAs) in the colon were tested by GC/MS. Moreover, the jejunal and colonic microbiota were detected by 16S rRNA sequencing. Significant reductions in serum triacylglycerol, cholesterol, and high density lipoprotein were found in all treatments. The total SCFAs decreased, while the iso-acids were significantly increased in the TA and TA + GSPE groups. The sheep showed noticeably lower MCP-1 and higher COX-2 levels in the GSPE group than that in the NC group. IL-6 was increased in the sheep fed with TA. The tannins still caused a noticeable shift in the colonic microbiota, with significant increases in the abundances of Adlercreutzia and Oscillospira. Ultimately, it was found that the diet with low levels of tannin could reduce blood triacylglycerol and cholesterol in sheep significantly by affecting the composition of the gut microbiota.