Altered gut microbiota and endocannabinoid system tone in obese and diabetic leptin-resistant mice: impact on apelin regulation in adipose tissue

Anti-obesogenic effect of lupin-derived protein hydrolysate through modulation of adiposopathy, insulin resistance and gut dysbiosis in a diet-induced obese mouse

The prevalence of obesity is increasingly widespread, resembling a global epidemic. Lifestyle changes, such as consumption of high-energy-dense diets and physical inactivity, are major contributors to obesity. Common features of this metabolic pathology involve an imbalance in lipid and glucose homeostasis including dyslipidemia, insulin resistance and adipose tissue dysfunction. Moreover, the importance of the gut microbiota in the development and susceptibility to obesity has recently been highlighted. In recent years, new strategies based on the use of functional foods, in particular bioactive peptides, have been proposed to counteract obesity outcomes. In this context, the present study examines the effects of a lupin protein hydrolysate (LPH) on obesity, dyslipidemia and gut dysbiosis in mice fed a high-fat diet (HFD). After 12 weeks of LPH treatment, mice gained less weight and showed decreased adipose dysfunction compared to the HFD-fed group. HFD-induced dyslipidemia (increased triglycerides, cholesterol and LDL concentration) and insulin resistance were both counteracted by LPH consumption. Discriminant analysis differentially distributed LPH-treated mice compared to non-treated mice. HFD reduced gut ecological parameters, promoted the blooming of deleterious taxa and reduced the abundance of commensal members. Some of these changes were corrected in the LPH group. Finally, correlation analysis suggested that changes in this microbial population could be responsible for the improvement in obesity outcomes. In conclusion, this is the first study to show the effect of LPH on improving weight gain, adiposopathy and gut dysbiosis in the context of diet-induced obesity, pointing to the therapeutic potential of bioactive peptides in metabolic diseases.

Adipose thermogenic mechanisms by cold, exercise and intermittent fasting: Similarities, disparities and the application in treatment

Given its nonnegligible role in metabolic homeostasis, adipose tissue has been the target for treating metabolic disorders such as obesity, diabetes and cardiovascular diseases. Besides its lipolytic function, adipose thermogenesis has gained increased interest due to the irreplaceable contribution to dissipating energy to restore equilibrium, and its therapeutic effects have been testified in various animal models. In this review, we will brief about the canonical cold-stimulated adipose thermogenic mechanisms, elucidate on the exercise- and intermittent fasting-induced adipose thermogenic mechanisms, with a focus on the similarities and disparities among these signaling pathways, in an effort to uncover the overlapped and specific targets that may yield potent therapeutic efficacy synergistically in improving metabolic health.

Apelin and the gut microbiome: Potential interaction in human MASLD

BACKGROUND

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a leading cause of chronic liver disease with increasing numbers worldwide. Adipokines like apelin (APLN) can act as key players in the complex pathophysiology of MASLD.

AIMS

Investigating the role of APLN in MASLD.

METHODS

Fecal and blood samples were collected in a MASLD cohort and healthy controls (HC). MASLD patients with liver fibrosis and MASLD-associated hepatocellular carcinoma (HCC) were included into the study. Systemic concentration of Apelin, Apelin receptor (APLNR) and circulating cytokines were measured in serum samples.

RESULTS

Apelin concentration correlated with the Fib-4 score and was elevated in MASLD patients (mild fibrosis, mF (Fib-4 <3.25) and severe fibrosis, sF (Fib-4 >3.25)) as well as in MASLD-associated HCC patients compared to HC. In accordance APLNR and circulating cytokines were also elevated in mF and sF. In contrast apelin levels were negatively associated with liver survival at three and five years. Changes in taxa composition at phylum level showed an increase of Enterobactericae, Prevotellaceae and Lactobacillaceae in patients with sF compared to mF. We could also observe an association between apelin concentrations and bacterial lineages (phyla).

CONCLUSIONS

Circulating apelin is associated with liver fibrosis and HCC. In addition, there might exist an interaction between systemic apelin and the gut microbiome.

The Effect of Enteric-Derived Lipopolysaccharides on Obesity

Endotoxin is a general term for toxic substances in Gram-negative bacteria, whose damaging effects are mainly derived from the lipopolysaccharides (LPS) in the cell walls of Gram-negative bacteria, and is a strong pyrogen. Obesity is a chronic, low-grade inflammatory condition, and LPS are thought to trigger and exacerbate it. The gut flora is the largest source of LPS in the body, and it is increasingly believed that altered intestinal microorganisms can play an essential role in the pathology of different diseases. Today, the complex axis linking gut flora to inflammatory states and adiposity has not been well elucidated. This review summarises the evidence for an interconnection between LPS, obesity, and gut flora, further expanding our understanding of LPS as a mediator of low-grade inflammatory disease and contributing to lessening the effects of obesity and related metabolic disorders. As well as providing targets associated with LPS, obesity, and gut flora, it is hoped that interventions that combine targets with gut flora address the individual differences in gut flora treatment.

Research progress on the microbiota in bladder cancer tumors

The microbiota, also referred to as the microbial community, is a crucial component of the human microenvironment. It is located predominantly in various organs, including the intestines, skin, oral cavity, respiratory tract, and reproductive tract. The microbiota maintains a symbiotic relationship with the human body, influencing physiological and pathological functions to a significant degree. There is increasing evidence linking the microbial flora to human cancers. In contrast to the traditional belief that the urethra and urine of normal individuals are sterile, recent advancements in high-throughput sequencing technology and bacterial cultivation methods have led to the discovery of specific microbial communities in the urethras of healthy individuals. Given the prevalence of bladder cancer (BCa) as a common malignancy of the urinary system, researchers have shifted their focus to exploring the connection between disease development and the unique microbial community within tumors. This shift has led to a deeper investigation into the role of microbiota in the onset, progression, metastasis, prognosis, and potential for early detection of BCa. This article reviews the existing research on the microbiota within BCa tumors and summarizes the findings regarding the roles of different microbes in various aspects of this disease.

Loss of Paneth cells dysregulates gut ILC subsets and enhances weight gain response to high fat diet in a mouse model

Obesity has been associated with dysbiosis, but innate mechanisms linking intestinal epithelial cell subsets and obesity remain poorly understood. Using mice lacking Paneth cells (Sox9 ΔIEC mice), small intestinal epithelial cells specialized in the production of antimicrobial products and cytokines, we show that dysbiosis alone does not induce obesity or metabolic disorders. Loss of Paneth cells reduced ILC3 and increased ILC2 numbers in the intestinal lamina propria. High-fat diet (HFD) induced higher weight gain and more severe metabolic disorders in Sox9 ΔIEC mice. Further, HFD enhances the number of ILC1 in the intestinal lamina propria of Sox9 ΔIEC mice and increases intestinal permeability and the accumulation of immune cells (inflammatory macrophages and T cells, and B cells) in abdominal fat tissues of obese Sox9 ΔIEC . Transplantation of fecal materials from Sox9 ΔIEC mice in germ-free mice before HFD further confirmed the regulatory role of Paneth cells for gut ILC subsets and the development of obesity.

Gut microbiota in overweight and obesity: crosstalk with adipose tissue

Overweight and obesity are characterized by excessive fat mass accumulation produced when energy intake exceeds energy expenditure. One plausible way to control energy expenditure is to modulate thermogenic pathways in white adipose tissue (WAT) and/or brown adipose tissue (BAT). Among the different environmental factors capable of influencing host metabolism and energy balance, the gut microbiota is now considered a key player. Following pioneering studies showing that mice lacking gut microbes (that is, germ-free mice) or depleted of their gut microbiota (that is, using antibiotics) developed less adipose tissue, numerous studies have investigated the complex interactions existing between gut bacteria, some of their membrane components (that is, lipopolysaccharides), and their metabolites (that is, short-chain fatty acids, endocannabinoids, bile acids, aryl hydrocarbon receptor ligands and tryptophan derivatives) as well as their contribution to the browning and/or beiging of WAT and changes in BAT activity. In this Review, we discuss the general physiology of both WAT and BAT. Subsequently, we introduce how gut bacteria and different microbiota-derived metabolites, their receptors and signalling pathways can regulate the development of adipose tissue and its metabolic capacities. Finally, we describe the key challenges in moving from bench to bedside by presenting specific key examples.

The Role of the Gut-Joint Axis in the Care of Psoriatic Arthritis: A Two-Sample Bidirectional Mendelian Randomization Study

INTRODUCTION

Observational studies and clinical trials have supported the association between gut microbiota and psoriatic arthritis. However, the causal link between gut microbiota and psoriatic arthritis is still unclear.

METHODS

A two-sample bi-directional Mendelian randomization analysis was performed using the summary statistics of gut microbiota from the largest available genome-wide association study meta-analysis (n = 13,266) conducted by the MiBioGen consortium. The summary statistics of psoriatic arthritis were extracted directly from the FinnGen consortium, which consists of 3186 psoriatic arthritis patients and 24,086 controls. Sensitivity analyses were conducted to assess the validity of our findings. Enrichment analyses were used to investigate the biofunction and pathways.

RESULTS

Inverse variance weighted (IVW) estimates suggested that family Rikenellaceae (P = 0.032) and genus Ruminococcaceae UCG011 (P = 0.014) had a detrimental effect on psoriatic arthritis. We also noticed the negative association between the class Methanobacteria (P = 0.032), order Methanobacteriales (P = 0.032), family Methanobacteriaceae (P = 0.032), genus Eubacterium fissicatena group (P = 0.010), genus Methanobrevibacter (P = 0.031), and genus Butyricicoccus (P = 0.041) with psoriatic arthritis. Sensitivity analyses showed that genus Butyricicoccus had pleiotropy and heterogeneity. According to the results of reverse MR analysis, the causal effect of psoriatic arthritis was found on six taxa, respectivelyc family Clostridiaceae1, family Defluviitaleaceae, genus Butyrivibrio, genus Defluviitaleaceae UCG011, genus Clostridium sensu stricto1, and genus Ruminococcaceae UCG011.

CONCLUSION

This two-sample bidirectional Mendelian randomization analysis suggested that the gut microbiota had a causal effect on psoriatic arthritis and implied the potential role of probiotics in the management and prevention of psoriatic arthritis.

Local and Systemic Effects of Bioactive Food Ingredients: Is There a Role for Functional Foods to Prime the Gut for Resilience?

Scientific advancements in understanding the impact of bioactive components in foods on the gut microbiota and wider physiology create opportunities for designing targeted functional foods. The selection of bioactive ingredients with potential local or systemic effects holds promise for influencing overall well-being. An abundance of studies demonstrate that gut microbiota show compositional changes that correlate age and disease. However, navigating this field, especially for non-experts, remains challenging, given the abundance of bioactive ingredients with varying levels of scientific substantiation. This narrative review addresses the current knowledge on the potential impact of the gut microbiota on host health, emphasizing gut microbiota resilience. It explores evidence related to the extensive gut health benefits of popular dietary components and bioactive ingredients, such as phytochemicals, fermented greens, fibres, prebiotics, probiotics, and postbiotics. Importantly, this review distinguishes between the potential local and systemic effects of both popular and emerging ingredients. Additionally, it highlights how dietary hormesis promotes gut microbiota resilience, fostering better adaptation to stress-a hallmark of health. By integrating examples of bioactives, this review provides insights to guide the design of evidence-based functional foods aimed at priming the gut for resilience.

Diabetic Vasculopathy: Molecular Mechanisms and Clinical Insights

Clinical and basic studies have documented that both hyperglycemia and insulin-resistance/hyperinsulinemia not only constitute metabolic disorders contributing to cardiometabolic syndrome, but also predispose to diabetic vasculopathy, which refers to diabetes-mellitus-induced microvascular and macrovascular complications, including retinopathy, neuropathy, atherosclerosis, coronary artery disease, hypertension, and peripheral artery disease. The underlying molecular and cellular mechanisms include inappropriate activation of the renin angiotensin-aldosterone system, mitochondrial dysfunction, excessive oxidative stress, inflammation, dyslipidemia, and thrombosis. These abnormalities collectively promote metabolic disorders and further promote diabetic vasculopathy. Recent evidence has revealed that endothelial progenitor cell dysfunction, gut dysbiosis, and the abnormal release of extracellular vesicles and their carried microRNAs also contribute to the development and progression of diabetic vasculopathy. Therefore, clinical control and treatment of diabetes mellitus, as well as the development of novel therapeutic strategies are crucial in preventing cardiometabolic syndrome and related diabetic vasculopathy. The present review focuses on the relationship between insulin resistance and diabetes mellitus in diabetic vasculopathy and related cardiovascular disease, highlighting epidemiology and clinical characteristics, pathophysiology, and molecular mechanisms, as well as management strategies.

Targeted therapies of curcumin focus on its therapeutic benefits in cancers and human health: Molecular signaling pathway-based approaches and future perspectives

The curry powder spices turmeric (Curcuma longa L.), which contains curcumin (diferuloylmethane), an orange-yellow chemical. Polyphenols are the most commonly used sources of curcumin. It combats oxidative stress and inflammation in diseases, such as hyperlipidemia, metabolic syndrome, arthritis, and depression. Most of these benefits are due to their anti-inflammatory and antioxidant properties. Curcumin consumption leads to decreased bioavailability, resulting in limited absorption, quick metabolism, and quick excretion, which hinders health improvement. Numerous factors can increase its bioavailability. Piperine enhances bioavailability when combined with curcumin in a complex. When combined with other enhancing agents, curcumin has a wide spectrum of health benefits. This review evaluates the therapeutic potential of curcumin with a specific emphasis on its approach based on molecular signaling pathways. This study investigated its influence on the progression of cancer, inflammation, and many health-related mechanisms, such as cell proliferation, apoptosis, and metastasis. Curcumin has a significant potential for the prevention and treatment of various diseases. Curcumin modulates several biochemical pathways and targets involved in cancer growth. Despite its limited tissue accumulation and bioavailability when administered orally, curcumin has proven useful. This review provides an in-depth analysis of curcumin's therapeutic applications, its molecular signaling pathway-based approach, and its potential for precision medicine in cancer and human health.

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.

Gut Microbiota and Its Role in Anti-aging Phenomenon: Evidence-Based Review

The gut microbiota widely varies from individual to individual, but the variation shows stability over a period of time. The presence of abundant bacterial taxa is a common structure that determines the microbiota of human being. The presence of this microbiota greatly varies from geographic location, sex, food habits and age. Microbiota existing within the gut plays a significant role in nutrient absorption, development of immunity, curing of diseases and various developmental phases. With change in age, chronology diversification and variation of gut microbiota are observed within human being. But it has been observed that with the enhancement of age the richness of the microbial diversity has shown a sharp decline. The enhancement of age also results in the drift of the characteristic of the microbes associated with the microbiota from commensals to pathogenic. Various studies have shown that age associated gut-dysbiosis may result in decrease in tlongevity along with unhealthy aging. The host signalling pathways regulate the presence of the gut microbiota and their longevity. The presence of various nutrients regulates the presence of various microbial species. Innate immunity can be triggered due to the mechanism of gut dysbiosis resulting in the development of various age-related pathological syndromes and early aging. The gut microbiota possesses the ability to communicate with the host system with the help of various types of biomolecules, epigenetic mechanisms and various types of signalling-independent pathways. Drift in this mechanism of communication may affect the life span along with the health of the host. Thus, this review would focus on the use of gut-microbiota in anti-aging and healthy conditions of the host system.

Lactiplantibacillus biofilm and planktonic cells ameliorate ulcerative colitis in mice via immunoregulatory activity, gut metabolism and microbiota modulation

Since ulcerative colitis (UC) has become a global concern, Lactiplantibacillus is considered an effective, safe strategy for alleviating intestinal inflammation in UC patients. The most advanced fourth-generation probiotics involve beneficial bacteria enclosed in biofilms with multiple advantages. However, the difference between the effect of probiotic biofilm and planktonic cells on UC remains unclear. This study indicated that the biofilm cells of Lactiplantibacillus LR-1 were more successful in increasing the colon length, relieving intestinal inflammation, and repairing colon damage, regulating the host immunity than the planktonic cells. Furthermore, the LR-1 biofilm cells helped prevent a decline in the Eubacterium hallii and Salinimicrobium levels and increased Kocuria and Candidatus Bacilloplasma abundance. Untargeted metabolomics analysis results suggested that the LR-1 biofilm was more successful in promoting the intestinal metabolism recovery of the UC mice than the planktonic cells. Finally, the phenotype-microbiota-metabolism network was conducted to reveal the relationship between these factors.

Contribution of the microbiome for better phenotyping of people living with obesity

Obesity has reached epidemic proportion worldwide and in all ages. Available evidence points to a multifactorial pathogenesis involving gene predisposition and environmental factors. Gut microbiota plays a critical role as a major interface between external factors, i.e., diet, lifestyle, toxic chemicals, and internal mechanisms regulating energy and metabolic homeostasis, fat production and storage. A shift in microbiota composition is linked with overweight and obesity, with pathogenic mechanisms involving bacterial products and metabolites (mainly endocannabinoid-related mediators, short-chain fatty acids, bile acids, catabolites of tryptophan, lipopolysaccharides) and subsequent alterations in gut barrier, altered metabolic homeostasis, insulin resistance and chronic, low-grade inflammation. Although animal studies point to the links between an "obesogenic" microbiota and the development of different obesity phenotypes, the translational value of these results in humans is still limited by the heterogeneity among studies, the high variation of gut microbiota over time and the lack of robust longitudinal studies adequately considering inter-individual confounders. Nevertheless, available evidence underscores the existence of several genera predisposing to obesity or, conversely, to lean and metabolically health phenotype (e.g., Akkermansia muciniphila, species from genera Faecalibacterium, Alistipes, Roseburia). Further longitudinal studies using metagenomics, transcriptomics, proteomics, and metabolomics with exact characterization of confounders are needed in this field. Results must confirm that distinct genera and specific microbial-derived metabolites represent effective and precision interventions against overweight and obesity in the long-term.

Impact of intestinal microenvironments in obesity and bariatric surgery on shaping macrophages

Obesity is associated with alterations in tissue composition, systemic cellular metabolism, and low-grade chronic inflammation. Macrophages are heterogenous innate immune cells ubiquitously localized throughout the body and are key components of tissue homeostasis, inflammation, wound healing, and various disease states. Macrophages are highly plastic and can switch their phenotypic polarization and change function in response to their local environments. Here, we discuss how obesity alters the intestinal microenvironment and potential key factors that can influence intestinal macrophages as well as macrophages in other organs, including adipose tissue and hematopoietic organs. As bariatric surgery can induce metabolic adaptation systemically, we discuss the potential mechanisms through which bariatric surgery reshapes macrophages in obesity.

Gut Microbiota and Adipose Tissue Microenvironment Interactions in Obesity

Obesity is an increasingly serious global health problem. Some studies have revealed that the gut microbiota and its metabolites make important contributions to the onset of obesity. The gut microbiota is a dynamic ecosystem composed of diverse microbial communities with key regulatory functions in host metabolism and energy balance. Disruption of the gut microbiota can result in obesity, a chronic metabolic condition characterized by the excessive accumulation of adipose tissue. Host tissues (e.g., adipose, intestinal epithelial, and muscle tissues) can modulate the gut microbiota via microenvironmental interactions that involve hormone and cytokine secretion, changes in nutrient availability, and modifications of the gut environment. The interactions between host tissues and the gut microbiota are complex and bidirectional, with important effects on host health and obesity. This review provides a comprehensive summary of gut microbiota changes associated with obesity, the functional roles of gut microbiota-derived metabolites, and the importance of the complex interactions between the gut microbiota and target tissues in the pathogenesis of obesity. It places particular emphasis on the roles of adipose tissue microenvironment interactions in the onset of obesity.

New Insights and Potential Therapeutic Interventions in Metabolic Diseases

Endocrine homeostasis and metabolic diseases have been the subject of extensive research in recent years. The development of new techniques and insights has led to a deeper understanding of the mechanisms underlying these conditions and opened up new avenues for diagnosis and treatment. In this review, we discussed the rise of metabolic diseases, especially in Western countries, the genetical, psychological, and behavioral basis of metabolic diseases, the role of nutrition and physical activity in the development of metabolic diseases, the role of single-cell transcriptomics, gut microbiota, epigenetics, advanced imaging techniques, and cell-based therapies in metabolic diseases. Finally, practical applications derived from this information are made.

A study of the correlation between stroke and gut microbiota over the last 20years: a bibliometric analysis

Purpose

This study intends to uncover a more thorough knowledge structure, research hotspots, and future trends in the field by presenting an overview of the relationship between stroke and gut microbiota in the past two decades.

Method

Studies on stroke and gut microbiota correlations published between 1st January 2002 and 31st December 2021 were retrieved from the Web of Science Core Collection and then visualized and scientometrically analyzed using CiteSpace V.

Results

A total of 660 papers were included in the study, among which the United States, the United Kingdom, and Germany were the leading research centers. Cleveland Clinic, Southern Medical University, and Chinese Academy of Science were the top three institutions. The NATURE was the most frequently co-cited journal. STANLEY L HAZEN was the most published author, and Tang WHW was the most cited one. The co-occurrence analysis revealed eight clusters (i.e., brain-gut microbiota axis, fecal microbiome transplantation, gut microbiota, hypertension, TMAO, ischemic stroke, neuroinflammation, atopobiosis). "gut microbiota," "Escherichia coli," "cardiovascular disease," "risk," "disease," "ischemic stroke," "stroke," "metabolism," "inflammation," and "phosphatidylcholine" were the most recent keyword explosions.

Conclusion

Findings suggest that in the next 10 years, the number of publications produced annually may increase significantly. Future research trends tend to concentrate on the mechanisms of stroke and gut microbiota, with the inflammation and immunological mechanisms, TMAO, and fecal transplantation as hotspots. And the relationship between these mechanisms and a particular cardiovascular illness may also be a future research trend.

Microbial lipopolysaccharide-induced inflammation contributes to cognitive impairment and white matter lesion progression in diet-induced obese mice with chronic cerebral hypoperfusion

AIMS

White matter lesions (WMLs) are involved in the pathological processes leading to cognitive decline and dementia. We examined the mechanisms underlying the exacerbation of ischemia-induced cognitive impairment and WMLs by diet-induced obesity, including lipopolysaccharide (LPS)-triggered neuroinflammation via toll-like receptor (TLR) 4.

METHODS

Wild-type (WT) and TLR4-knockout (KO) C57BL/6 mice were fed a high-fat diet (HFD) or low-fat diet (LFD), and subjected to bilateral carotid artery stenosis (BCAS). Diet groups were compared for changes in gut microbiota, intestinal permeability, systemic inflammation, neuroinflammation, WML severity, and cognitive dysfunction.

RESULTS

In WT mice, HFD induced obesity and increased cognitive impairment and WML severity compared with LFD-fed mice following BCAS. HFD caused gut dysbiosis and increased intestinal permeability, and plasma LPS and pro-inflammatory cytokine concentrations. Furthermore, HFD-fed mice had higher LPS levels and higher neuroinflammatory status, including increased TLR4 expression, in WMLs. In TLR4-KO mice, HFD also caused obesity and gut dysbiosis but did not increase cognitive impairment or WML severity after BCAS. No difference was found between HFD- and LFD-fed KO mice for LPS levels or inflammatory status in either plasma or WMLs.

CONCLUSION

Inflammation triggered by LPS-TLR4 signaling may mediate obesity-associated exacerbation of cognitive impairment and WMLs from brain ischemia.

Is the Gut Microbiome Implicated in the Excess Risk of Hypertension Associated with Obstructive Sleep Apnea? A Contemporary Review

Obstructive sleep apnea (OSA) is a highly prevalent sleep disorder and an established risk factor for cardiovascular diseases, including hypertension. The pathogenesis of elevated blood pressure (BP) in OSA is multifactorial, including sympathetic overdrive, vascular aberrations, oxidative stress, inflammation, and metabolic dysregulation. Among the mechanisms potentially involved in OSA-induced hypertension, the role of the gut microbiome is gaining increasing attention. Perturbations in the diversity, composition, and function of the gut microbiota have been causally linked to numerous disorders, and robust evidence has identified gut dysbiosis as a determinant of BP elevation in various populations. In this brief review, we summarize the current body of literature on the implications of altered gut microbiota for hypertension risk in OSA. Data from both preclinical models of OSA and patient populations are presented, and potential mechanistic pathways are highlighted, along with therapeutic considerations. Available evidence suggests that gut dysbiosis may promote the development of hypertension in OSA and may thus be a target for interventions aimed at attenuating the adverse consequences of OSA in relation to cardiovascular risk.

Research progress of gut microbiota and obesity caused by high-fat diet

Obesity, a chronic metabolic disorder caused by an energy imbalance, has been increasingly prevalent and poses a global health concern. The multifactorial etiology of obesity includes genetics factors, high-fat diet, gut microbiota, and other factors. Among these factors, the implication of gut microbiota in the pathogenesis of obesity has been prominently acknowledged. This study endeavors to investigate the potential contribution of gut microbiota to the development of high-fat diet induced obesity, as well as the current state of probiotic intervention therapy research, in order to provide novel insights for the prevention and management of obesity.

Dietary metabolizable energy and crude protein levels affect pectoral muscle composition and gut microbiota in native growing chickens

The experiment aimed to study effects of dietary metabolizable energy (ME) and crude protein (CP) levels alone and in interaction on performance, pectoral muscle composition and gut microbiota in native growing chickens. A total of 648 10-wks-old Beijing-You Chicken (BYC) female chickens were randomly allocated to 9 groups with 6 replicates per group and 12 chickens per replicate, and the chickens were fed with a 3 × 3 factorial diets (3 levels of dietary ME: 11.31 MJ/kg, 11.51 MJ/kg, 11.71 MJ/kg; and 3 levels of dietary CP: 14%, 15%, 16%). The results showed that dietary ME and CP levels didn't affect average feed intake (AFI), body weight gain, feed gain ratio (P > 0.05), but ME level significantly affected the AFI (P < 0.05); mortality rate of 11.31 MJ/kg group was the highest (P < 0.05). Dietary ME, CP levels, and the interaction significantly affected pectoral CP and crude fat (CF) content of the growing chickens (P < 0.01). Dietary CP level had opposite effects on pectoral CP and CF content (P < 0.01). The 16% CP increased the pectoral CF content, which may have a negative impact on meat flavor. Dietary ME level affected 11 types of pectoral free amino acids (FAA) contents, including aspartic acid, L-threonine (P < 0.05), also amino acid classification, for example, total amino acid (TAA) and essential amino acid (EAA) content (P < 0.05). The 11.51 MJ/kg group had the highest TAA, EAA, delicious amino acid (DAA) content and EAA percentage (P < 0.05), while 11.31 MJ/kg group had the lowest bitter amino acid (BAA) content and BAA percentage and the highest fresh and sweet amino acid (FSAA) percentage (P < 0.05). Dietary CP level significantly affected glutamine and tyrosine content (P < 0.05). The interaction of dietary ME and CP level affected C20:3n6 content, saturated fatty acid (SFA), and unsaturated fatty acid (UFA) percentage (P < 0.05). The CP level significantly affected SFA percentage (P < 0.05). The 16% CP level increased the diversity of gut microbiota, but at the same time increased the relative abundance of Proteobacteria (P < 0.05), which is a sign of microbiota disorder. The increase of dietary ME level resulted in a gradual decrease in the diversity and relative abundance of gut microbiota. In conclusion, the present study suggested that the medium dietary ME (11.51 MJ/kg) and low CP (14-15%) levels can be helpful for enhancing pectoral muscle composition, increase meat quality such as flavor and nutritional value, and benefit for gut microbiota in native growing chickens.

Zuogui Jiangtang Shuxin formula Ameliorates diabetic cardiomyopathy mice via modulating gut-heart axis

BACKGROUND

There is growing evidence demonstrating that the gut microbiota plays a crucial role in multiple endocrine disorders, including diabetic cardiomyopathy (DCM). Research shows that the Chinese herb reduces disease occurrence by regulating gut microbiota. Zuogui Jiangtang Shuxin formula (ZGJTSXF), a Chinese medicinal formula, has been clinically used for treatment of DCM for many years. However, there is still no clear understanding of how ZGJTSXF treatment contributes to the prevention and treatment of DCM through its interaction with gut microbiota and metabolism.

METHODS

In this study, mice models of DCM were established, and ZGJTSXF's therapeutic effects were assessed. Specifically, serum glycolipid, echocardiography, histological staining, myocardial apoptosis rate were assessed. Using 16s rRNA sequencing and high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), we determined the impact of ZGJTSXF on the structure of gut microbiota and content of its metabolite TMAO. The mechanism of ZGJTSXF action on DCM was analyzed using quantitative real-time PCR and western blots.

RESULTS

We found that ZGJTSXF significantly ameliorated DCM mice by modulating gut-heart axis: ZGJTSXF administration improved glycolipid levels, heart function, cardiac morphological changes, inhibited cardiomyocytes apoptosis, and regulate the gut microbiota in DCM mice. Specifically, ZGJTSXF treatment reverse the significant changes in the abundance of certain genera closely related to DCM phenotype, including Lactobacillus, Alloprevotella and Alistipes. Furthermore, ZGJTSXF alleviated DCM in mice by blunting TMAO/PERK/FoxO1 signaling pathway genes and proteins.

CONCLUSION

ZGJTSXF administration could ameliorate DCM mice by remodeling gut microbiota structure, reducing serum TMAO generation and suppressing TMAO/PERK/FoxO1 signaling pathway.

Potential Efficacy of Bacillus coagulans BACO-17 to Modulate Gut Microbiota in Rats Fed High-Fat Diet

This study aimed to evaluate the potential efficacy of Bacillus coagulans BACO-17 in ameliorating body fat accumulation as well as gut microbiota dysbiosis in animals, which were given a high-fat diet to mimic the adverse effect of an unhealthy dietary pattern. Compared with normal control, high-fat consumption resulted in significant (p < 0.05) elevations in weight gain (168%), feed efficiency (176%), visceral fat accumulation (228%), and a lesser total fecal short-chain fatty acids (SCFAs) (−27.5%). A significant shift of fecal Fimicutes:Bacteroidetes ratio from 1.13 to 3.14 was also observed. After 12 weeks of experiment, a supplementation of B. coagulans BACO-17 at high dose (9 log CFU/day) along with a high-fat diet could exert an apparent fat reduction ability by decreasing weight gain (by 23.7%) and visceral fat mass (by 24.0%). It was found that B. coagulans BACO-17 was able to increase fecal SCFA concentrations and revert Fimicutes:Bacteroidetes ratio back to the level comparable with the normal control. It could play a probiotic effect by increasing and decreasing the abundance of Muribaculaceae and Allobaculum, respectively. Therefore, a supplementation of adequate amount of B. coagulans BACO-17 might confer a concreted amelioration of deteriorated bacteria profiles and body fat accumulation due to high-fat consumption.

Gut microbiota mediated hypoglycemic effect of Astragalus membranaceus polysaccharides in db/db mice

Gut microbiota has been reported to be closely associated with Type-II diabetes. Restoration of disordered gut microbiota ecosystem has been developed into a therapeutic strategy and gradually applied on Type-II diabetes treatment with both western drugs and herbal polysaccharides. Although Astragalus membranaceus polysaccharides (AMP) have also been used to treat Type-II diabetes, no study investigated correlations between gut microbiota regulation and its hypoglycemic effect. In the present study, the role of gut microbiota on the hypoglycemic effect of AMP in db/db mice was investigated for the first time. Sixteen days treatment of AMP at the dosage of 600 mg/kg in db/db mice not only alleviated its diabetic symptoms significantly but also restored its gut microbiota community with increased production of fecal short chain fatty acids (SCFA). Our further Pearson correlation analyses revealed that the relative abundance of two intestinal bacteria, Akkermansia and Faecalibaculum, were significantly positively correlated with the hypoglycemic effect of AMP as well as fecal SCFA production. It was also noted that treatment of AMP resulted in increased secretion of glucagon-like peptide-1 (GLP-1) in serum and enhanced intestinal integrity. Further mechanistic study revealed that the increased SCFA after AMP treatment could stimulate GLP-1 secretion and improve intestinal integrity via enhancing the expression of G protein-coupled receptors 41/43 and tight junction proteins (Occudin and ZO-1), respectively, leading to the alleviation of diabetic symptoms in db/db mice.

Reduced gut microbiota diversity in patients with congenital generalized lipodystrophy

BACKGROUND

Previous studies suggest intestinal dysbiosis is associated with metabolic diseases. However, the causal relationship between them is not fully elucidated. Gut microbiota evaluation of patients with congenital generalized lipodystrophy (CGL), a disease characterized by the absence of subcutaneous adipose tissue, insulin resistance, and diabetes since the first years of life, could provide insights into these relationships.

METHODS

A cross-sectional study was conducted with patients with CGL (n = 17) and healthy individuals (n = 17). The gut microbiome study was performed by sequencing the 16S rRNA gene through High-Throughput Sequencing (BiomeHub Biotechnologies, Brazil).

RESULTS

The median age was 20.0 years old, and 64.7% were female. There was no difference between groups in pubertal stage, BMI, ethnicity, origin (rural or urban), delivery, breastfeeding, caloric intake, macronutrient, or fiber consumption. Lipodystrophic patients presented a lower alpha diversity (Richness index: 54.0 versus 67.5; p = 0.008). No differences were observed in the diversity parameters when analyzing the presence of diabetes, its complications, or the CGL subtype.

CONCLUSION

In this study, we demonstrate for the first time a reduced gut microbiota diversity in individuals with CGL. Dysbiosis was present despite dietary treatment and was also observed in young patients. Our findings allow us to speculate that the loss of intestinal microbiota diversity may be due to metabolic abnormalities present since the first years of life in CGL. Longitudinal studies are needed to confirm these findings, clarifying the possible causal link between dysbiosis and insulin resistance in humans.

Quercetin positively affects gene expression profiles and metabolic pathway of antibiotic-treated mouse gut microbiota

Quercetin has a wide range of biological properties that can be used to prevent or decrease particular inflammatory diseases. In this study, we aimed to investigate the gene expression profile and metabolic pathway of the gut microbiota of an antibiotic-treated mouse model administered quercetin. Blood, feces, and intestinal tissue samples were collected and metagenomic sequencing, enzyme-linked immunosorbent assay, and western blot analysis were used to detect variations. The results showed that the quercetin-treated group exhibited increased levels of health beneficial bacterial species, including Faecalibaculum rodentium (103.13%), Enterorhabdus caecimuris (4.13%), Eggerthella lenta (4%), Roseburia hominis (1.33%), and Enterorhabdus mucosicola (1.79%), compared with the model group. These bacterial species were positively related to butyrate, propionate, and intestinal tight junction proteins (zonula occludens-1 and occludin) expression, but negatively related to serum lipopolysaccharide and tumor necrosis factor-α level. In addition, the metabolic pathway analysis showed that dietary quercetin significantly enhanced spliceosomes (111.11%), tight junctions (62.96%), the citrate cycle (10.41%), pyruvate metabolism (6.95%), and lysine biosynthesis (5.06%), but decreasing fatty acid biosynthesis (23.91%) and N-glycan (7.37%) biosynthesis. Furthermore, these metabolic pathway changes were related to relative changes in the abundance of 10 Kyoto Encyclopedia of Genes and Genomes genes (K00244, K00341, K02946, K03737, K01885, k10352, k11717, k10532, K02078, K01191). In conclusion, dietary quercetin increased butyrate-producing bacterial species, and the acetyl-CoA-mediated increased butyrate accelerated carbohydrate, energy metabolism, reduced cell motility and endotoxemia, and increased the gut barrier function, thereby leading to healthy colonic conditions for the host.

Effects of combination treatment with metformin and berberine on hypoglycemic activity and gut microbiota modulation in db/db mice

BACKGROUND

Gut microbiota alterations could influence the metabolism of administered drugs, leading to their altered pharmacokinetics and pharmacodynamics. Despite that metformin and berberine has individually demonstrated their impacts on hypoglycemic activities and gut microbiota alterations in diabetic mice, investigation regarding the impact of their combination treatment in diabetic treatment has never been conducted.

PURPOSE

Our current study was proposed aiming to investigate the effect of combination use of metformin with berberine on hypoglycemic activity and identify the possible intestinal bacteria involved in their microbiota-medicated drug-drug interactions in db/db mice.

STUDY DESIGN

Pharmacodynamics interactions between metformin and berberine were evaluated in six groups of db/db mice (db, M250, B250, B125, B250+M250, and B125+M250) with its wild type (WT) as control to receive 14 days treatment of vehicle, metformin at 250 mg/kg, berberine at 250/125 mg/kg, and metformin (250 mg/kg) 2 h after dosing berberine (250/125 mg/kg).

METHODS

On day 13, insulin tolerance test (ITT) was conducted. On day 15, fasting serum samples were obtained for insulin concentration determination followed by intraperitoneal glucose tolerance test (ipGTT), homeostatic model assessment for insulin resistance (HOMA-IR) calculation, and feces collection for microbial 16S rRNA sequencing analyses. In addition, metformin steady state plasma concentrations on day 15 were measured by validated LC-MS/MS method.

RESULTS

Combination treatment of metformin with berberine could further reduce in blood glucose in comparison to that of db/db diabetic control. Further microbial 16S rRNA sequencing analyses revealed that gut microbiota compositions were significantly changed with the abundance of Proteobacteria and Verrucomicrobia altered the most after metformin and berberine co-treatment compared to their monotherapy. In addition, steady state metformin concentrations in their combination treatment were significantly higher than that from metformin monotherapy.

CONCLUSION

Co-administration of metformin (250 mg/kg) with berberine (125 mg/kg) could not only further improve insulin sensitivity, but also demonstrate different alterations on gut microbial communities than that of their individual treatment in db/db mice.

The impact of Rhodiola rosea on biomarkers of diabetes, inflammation, and microbiota in a leptin receptor-knockout mouse model

Type 2 diabetes is the most prevalent endocrine disease in the world, and recently the gut microbiota have become a potential target for its management. Recent studies have illustrated that this disease may predispose individuals to certain microbiome compositions, and treatments like metformin have been shown to change gut microbiota and their associated metabolic pathways. However, given the limitations and side effects associated with pharmaceuticals currently being used for therapy of diabetes, there is a significant need for alternative treatments. In this study, we investigated the effects of a root extract from Rhodiola rosea in a Leptin receptor knockout (db/db) mouse model of type 2 diabetes. Our previous work showed that Rhodiola rosea had anti-inflammatory and gut microbiome-modulating properties, while extending lifespan in several animal models. In this study, treatment with Rhodiola rosea improved fasting blood glucose levels, altered the response to exogenous insulin, and decreased circulating lipopolysaccharide and hepatic C-reactive protein transcript levels. We hypothesize that these changes may in part reflect the modulation of the microbiota, resulting in improved gut barrier integrity and decreasing the translocation of inflammatory biomolecules into the bloodstream. These findings indicate that Rhodiola rosea is an attractive candidate for further research in the management of type 2 diabetes.

Acromegaly is associated with a distinct oral and gut microbiota

PURPOSE

Our aim was to investigate the changes in the composition of oral and gut microbiota in patients with newly diagnosed acromegaly and their relationship with IGF-1 levels.

METHODS

Oral and fecal samples were collected from patients with newly diagnosed acromegaly without comorbidities and from healthy controls. The composition of the microbiota was analyzed. The general characteristics, oral and stool samples of the patients and healthy control subjects were compared. The changes in microbiota composition in both habitats, their correlations and associations with IGF-1 were statistically observed using machine learning models.

RESULTS

Fifteen patients with newly diagnosed acromegaly without comorbidities and 15 healthy controls were included in the study. There was good agreement between fecal and oral microbiota in patients with acromegaly (p = 0.03). Oral microbiota diversity was significantly increased in patients with acromegaly (p < 0.01). In the fecal microbiota, the Firmicutes/Bacteroidetes ratio was lower in patients with acromegaly than in healthy controls (p = 0.011). Application of the transfer learned model to the pattern of microbiota allowed us to identify the patients with acromegaly with perfect accuracy.

CONCLUSIONS

Patients with acromegaly have their own oral and gut microbiota even if they do not have acromegaly-related complications. Moreover, the excess IGF-1 levels could be correctly predicted based on the pattern of the microbiome.

The Microbiome and Gut Endocannabinoid System in the Regulation of Stress Responses and Metabolism

The endocannabinoid system, with its receptors and ligands, is present in the gut epithelium and enteroendocrine cells, and is able to modulate brain functions, both indirectly through circulating gut-derived factors and directly through the vagus nerve, finally acting on the brain’s mechanisms regarding metabolism and behavior. The gut endocannabinoid system also regulates gut motility, permeability, and inflammatory responses. Furthermore, microbiota composition has been shown to influence the activity of the endocannabinoid system. This review examines the interaction between microbiota, intestinal endocannabinoid system, metabolism, and stress responses. We hypothesize that the crosstalk between microbiota and intestinal endocannabinoid system has a prominent role in stress-induced changes in the gut-brain axis affecting metabolic and mental health. Inter-individual differences are commonly observed in stress responses, but mechanisms underlying resilience and vulnerability to stress are far from understood. Both gut microbiota and the endocannabinoid system have been implicated in stress resilience. We also discuss interventions targeting the microbiota and the endocannabinoid system to mitigate metabolic and stress-related disorders.

Gut microbiome and health: mechanistic insights

The gut microbiota is now considered as one of the key elements contributing to the regulation of host health. Virtually all our body sites are colonised by microbes suggesting different types of crosstalk with our organs. Because of the development of molecular tools and techniques (ie, metagenomic, metabolomic, lipidomic, metatranscriptomic), the complex interactions occurring between the host and the different microorganisms are progressively being deciphered. Nowadays, gut microbiota deviations are linked with many diseases including obesity, type 2 diabetes, hepatic steatosis, intestinal bowel diseases (IBDs) and several types of cancer. Thus, suggesting that various pathways involved in immunity, energy, lipid and glucose metabolism are affected.In this review, specific attention is given to provide a critical evaluation of the current understanding in this field. Numerous molecular mechanisms explaining how gut bacteria might be causally linked with the protection or the onset of diseases are discussed. We examine well-established metabolites (ie, short-chain fatty acids, bile acids, trimethylamine N-oxide) and extend this to more recently identified molecular actors (ie, endocannabinoids, bioactive lipids, phenolic-derived compounds, advanced glycation end products and enterosynes) and their specific receptors such as peroxisome proliferator-activated receptor alpha (PPARα) and gamma (PPARγ), aryl hydrocarbon receptor (AhR), and G protein-coupled receptors (ie, GPR41, GPR43, GPR119, Takeda G protein-coupled receptor 5).Altogether, understanding the complexity and the molecular aspects linking gut microbes to health will help to set the basis for novel therapies that are already being developed.

Gut microbiome and health: mechanistic insights

The gut microbiota is now considered as one of the key elements contributing to the regulation of host health. Virtually all our body sites are colonised by microbes suggesting different types of crosstalk with our organs. Because of the development of molecular tools and techniques (ie, metagenomic, metabolomic, lipidomic, metatranscriptomic), the complex interactions occurring between the host and the different microorganisms are progressively being deciphered. Nowadays, gut microbiota deviations are linked with many diseases including obesity, type 2 diabetes, hepatic steatosis, intestinal bowel diseases (IBDs) and several types of cancer. Thus, suggesting that various pathways involved in immunity, energy, lipid and glucose metabolism are affected.In this review, specific attention is given to provide a critical evaluation of the current understanding in this field. Numerous molecular mechanisms explaining how gut bacteria might be causally linked with the protection or the onset of diseases are discussed. We examine well-established metabolites (ie, short-chain fatty acids, bile acids, trimethylamine N-oxide) and extend this to more recently identified molecular actors (ie, endocannabinoids, bioactive lipids, phenolic-derived compounds, advanced glycation end products and enterosynes) and their specific receptors such as peroxisome proliferator-activated receptor alpha (PPARα) and gamma (PPARγ), aryl hydrocarbon receptor (AhR), and G protein-coupled receptors (ie, GPR41, GPR43, GPR119, Takeda G protein-coupled receptor 5).Altogether, understanding the complexity and the molecular aspects linking gut microbes to health will help to set the basis for novel therapies that are already being developed.

Leptin Signaling in Obesity and Colorectal Cancer

Obesity and colorectal cancer (CRC) are among the leading diseases causing deaths in the world, showing a complex multifactorial pathology. Obesity is considered a risk factor in CRC development through inflammation, metabolic, and signaling processes. Leptin is one of the most important adipokines related to obesity and an important proinflammatory marker, mainly expressed in adipose tissue, with many genetic variation profiles, many related influencing factors, and various functions that have been ascribed but not yet fully understood and elucidated, the most important ones being related to energy metabolism, as well as endocrine and immune systems. Aberrant signaling and genetic variations of leptin are correlated with obesity and CRC, with the genetic causality showing both inherited and acquired events, in addition to lifestyle and environmental risk factors; these might also be related to specific pathogenic pathways at different time points. Moreover, mutation gain is a crucial factor enabling the genetic process of CRC. Currently, the inconsistent and insufficient data related to leptin's relationship with obesity and CRC indicate the necessity of further related studies. This review summarizes the current knowledge on leptin genetics and its potential relationship with the main pathogenic pathways of obesity and CRC, in an attempt to understand the molecular mechanisms of these associations, in the context of inconsistent and contradictory data. The understanding of these mechanisms linking obesity and CRC could help to develop novel therapeutic targets and prevention strategies, resulting in a better prognosis and management of these diseases.

Dietary Blueberry Ameliorates Vascular Complications in Diabetic Mice Possibly through NOX4 and Modulates Composition and Functional Diversity of Gut Microbes

SCOPE

In diabetes, endothelial inflammation and dysfunction play a pivotal role in the development of vascular disease. This study investigates the effect of dietary blueberries on vascular complications and gut microbiome in diabetic mice.

METHODS AND RESULTS

Seven-week-old diabetic db/db mice consume a standard diet (db/db) or a diet supplemented with 3.8% freeze-dried blueberry (db/db+BB) for 10 weeks. Control db/+ mice are fed a standard diet (db/+). Vascular inflammation is assessed by measuring monocyte binding to vasculature and inflammatory markers. Isometric tension procedures are used to assess mesenteric artery function. db/db mice exhibit enhanced vascular inflammation and reduced endothelial-dependent vasorelaxation as compared to db/+ mice, but these are improved in db/db+BB mice. Blueberry supplementation reduces the expression of NOX4 and IκKβ in the aortic vessel and vascular endothelial cells (ECs) isolated from db/db+BB compared to db/db mice. The blueberry metabolites serum reduces glucose and palmitate induced endothelial inflammation in mouse aortic ECs. Further, blueberry supplementation increases commensal microbes and modulates the functional potential of gut microbes in diabetic mice.

CONCLUSION

Dietary blueberry suppresses vascular inflammation, attenuates arterial endothelial dysfunction, and supports the growth of commensal microbes in diabetic mice. The endothelial-specific vascular benefits of blueberries are mediated through NOX4 signaling.

Effects of Exogenous Hydrogen Sulfide on Diabetic Metabolic Disorders in db/db Mice Are Associated With Gut Bacterial and Fungal Microbiota

The effects of hydrogen sulfide (H2S) on diabetic metabolic disorders are still controversial, and the mechanisms underlying these effects remain largely unknown. This study was conducted to investigate the potential relationship between the gut microbiota and the improvement of diabetic metabolic disorders by exogenous H2S in obese db/db mice. The db/db mice were treated with sodium hydrosulfide (NaHS) (80 μmol/kg), or vehicle for 16 weeks, respectively. We measured the serum H2S, obesity parameters, glucose homeostasis, and triglyceride. The sequencing of bacterial 16S rRNA gene and fungal internal transcribed spacer (ITS) in the cecal contents of NaHS-treated mice was performed to evaluate the gut microbial communities. We found that supplying exogenous H2S for 16 weeks significantly inhibited the increase of serum triglyceride, blood glucose, and insulin levels and altered specifically the gut bacterial microbiota structure in db/db mice. The relative abundance of some bacterial genera was correlated with the H2S or blood glucose level. Indeed, exogenous H2S increased Firmicutes and decreased Bacteroidetes at the phylum level along with changes of abundance of multifarious genera. Among them, Unclassified_Enterobacteriaceae, Prevotella, and Lactobacillus decreased and Unclassified_Ruminococcaceae, Oscillospira, Ruminococcus, Sutterella, and Desulfovibrio increased. For fungi, exogenous H2S decreased the abundance of Candida and Aspergillus. Here we demonstrated that, in diabetes, microbial dysbiosis may not be just limited to bacteria due to the inter-linked metabolic interactions among bacteria and fungi in the gut. The beneficial effects of exogenous H2S on diabetic metabolic disorders are likely associated with the alterations of specific microbiota.

Curcumin Alleviates DSS-Induced Anxiety-Like Behaviors via the Microbial-Brain-Gut Axis

The anxiety and depression caused by inflammatory bowel diseases (IBD) are known to greatly affect the mental health of patients. The mechanism of psychiatric disorders caused by IBD is not fully understood. Previous research has suggested that the gut microbiome plays a key role in IBD. Curcumin is a yellow polyphenol extracted from the rhizome of the ginger plant, which has been shown to have effects against both depression and anxiety. Research has indicated that curcumin affects the gut microbiome and exerts antianxiety and neuroprotective effects through the microbiota-gut-brain axis (MGB). However, whether curcumin can alleviate the psychiatric disorders caused by IBD and how curcumin affects the MGB axis through the gut microbiota have not been fully understood. Therefore, this study was aimed at determining the metabolic parameters and microbiological environment in the peripheral and central nervous system to determine the effects of curcumin against anxiety induced by dextran sulfate sodium salt (DSS) in mice. To elaborate on the link between the gut microbiota and how curcumin alleviates anxiety-like behaviors, we performed a fecal microbiota transplantation (FMT) experiment. The results suggested that curcumin can effectively relieve anxiety-like behaviors caused by DSS in mice. Further, curcumin treatment can alleviate disturbances in the gut microbiota and systemic disorders of lipid metabolism caused by DSS. Finally, through FMT, we verified that curcumin increased phosphatidylcholine in the prefrontal cortex of the mice and alleviated DSS-induced anxiety-like behaviors by modulating specific gut microbiota. We also revealed that Muribaculaceae may be a key part of the gut microbiota for curcumin to alleviate DSS-induced anxiety-like behaviors through the MGB axis.

The anti-obesity and gut microbiota modulating effects of taxifolin in C57BL/6J mice fed with a high-fat diet

BACKGROUND

Taxifolin is a natural dihydroflavonol found in many plants and health products. In the present study, its anti-obesity and gut microbiota modulating effects were studied. C57BL/6J mice were fed with a high-fat diet (HFD) supplemented with taxifolin (0, 0.5 and 1 mg mL^-1 , respectively) in drinking water for 15 weeks.

RESULTS

Taxifolin supplementation showed no influence on food and water intake. However, it decreased body weight gain, inhibited fat accumulation, and decreased total cholesterol and triacylglycerol level in mice liver. Taxifolin enhanced superoxide dismutase (SOD) activity in mice liver, which in turn protected the liver from lipid peroxidation damage. It also improved insulin resistance in obese mice. Metagenomic analysis of bacterial 16S rRNA demonstrated that HFD decreased gut microbiota diversity and caused dysbiosis. However, taxifolin improved the gut microbiota diversity and decreased the Firmicutes/Bacteroidetes ratio. In particular, it inhibited Proteobacteria from blooming, this being a signature of dysbiosis in gut microbiota.

CONCLUSION

Taxifolin ameliorated the symptoms of obesity, hepatic steatosis, lipid peroxidation, insulin resistance, and gut microbiota dysbiosis in HFD fed C57BL/6J mice. © 2021 Society of Chemical Industry.

Akkermansia muciniphila Ameliorates Acetaminophen-Induced Liver Injury by Regulating Gut Microbial Composition and Metabolism

The gut microbiota drives individual sensitivity to excess acetaminophen (APAP)-mediated hepatotoxicity. It has been reported that the bacterium Akkermansia muciniphila protects hosts against liver disease via the liver-gut axis, but its therapeutic potential for drug-induced liver injury remains unclear. In this study, we aimed to investigate the effect of A. muciniphila on APAP-induced liver injury and the underlying mechanism. Administration of A. muciniphila efficiently alleviated APAP-induced hepatotoxicity and reduced the levels of serum alanine aminotransferase (ALT) and aspartate transaminase (AST). A. muciniphila significantly attenuated APAP-induced oxidative stress and the inflammatory response, as evidenced by restoration of the reduced glutathione/oxidized glutathione (GSH/GSSG) balance, enhanced superoxide dismutase (SOD) activity, reduced proinflammatory cytokine production, and alleviation of macrophage and neutrophil infiltration. Moreover, A. muciniphila maintained gut barrier function, reshaped the perturbed microbial community and promoted short-chain fatty acid (SCFA) secretion. The beneficial effects of A. muciniphila were accompanied by alterations in hepatic gene expression at the transcriptional level and activation of the phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway. Our results suggested that A. muciniphila could be a potential pretreatment for APAP-induced liver injury.

IMPORTANCE Our work revealed that A. muciniphila attenuated APAP-induced liver injury by alleviating oxidative stress and inflammation in the liver, and its hepatoprotective effect was accompanied by activation of the PI3K/Akt pathway and mediated by regulation of the composition and metabolic function of the intestinal microbiota. This finding suggested that the microbial community is a non-negligible impact on drug metabolism and probiotic administration could be a potential therapy for drug-induced liver injury.

Mutual Links between the Endocannabinoidome and the Gut Microbiome, with Special Reference to Companion Animals: A Nutritional Viewpoint

There is growing evidence that perturbation of the gut microbiome, known as “dysbiosis”, is associated with the pathogenesis of human and veterinary diseases that are not restricted to the gastrointestinal tract. In this regard, recent studies have demonstrated that dysbiosis is linked to the pathogenesis of central neuroinflammatory disorders, supporting the existence of the so-called microbiome-gut-brain axis. The endocannabinoid system is a recently recognized lipid signaling system and termed endocannabinoidome monitoring a variety of body responses. Accumulating evidence demonstrates that a profound link exists between the gut microbiome and the endocannabinoidome, with mutual interactions controlling intestinal homeostasis, energy metabolism and neuroinflammatory responses during physiological conditions. In the present review, we summarize the latest data on the microbiome-endocannabinoidome mutual link in health and disease, focalizing the attention on gut dysbiosis and/or altered endocannabinoidome tone that may distort the bidirectional crosstalk between these two complex systems, thus leading to gastrointestinal and metabolic diseases (e.g., idiopathic inflammation, chronic enteropathies and obesity) as well as neuroinflammatory disorders (e.g., neuropathic pain and depression). We also briefly discuss the novel possible dietary interventions based not only on probiotics and/or prebiotics, but also, and most importantly, on endocannabinoid-like modulators (e.g., palmitoylethanolamide) for intestinal health and beyond.

(Wh)olistic (E)ndocannabinoidome-Microbiome-Axis Modulation through (N)utrition (WHEN) to Curb Obesity and Related Disorders

The discovery of the endocannabinoidome (eCBome) is evolving gradually with yet to be elucidated functional lipid mediators and receptors. The diet modulates these bioactive lipids and the gut microbiome, both working in an entwined alliance. Mounting evidence suggests that, in different ways and with a certain specialisation, lipid signalling mediators such as N-acylethanolamines (NAEs), 2-monoacylglycerols (2-MAGs), and N-acyl-amino acids (NAAs), along with endocannabinoids (eCBs), can modulate physiological mechanisms underpinning appetite, food intake, macronutrient metabolism, pain sensation, blood pressure, mood, cognition, and immunity. This knowledge has been primarily utilised in pharmacology and medicine to develop many drugs targeting the fine and specific molecular pathways orchestrating eCB and eCBome activity. Conversely, the contribution of dietary NAEs, 2-MAGs and eCBs to the biological functions of these molecules has been little studied. In this review, we discuss the importance of (Wh) olistic (E)ndocannabinoidome-Microbiome-Axis Modulation through (N) utrition (WHEN), in the management of obesity and related disorders.

Owens J, Barbian ME, Jones RM, R. Naudin C. At the heart of microbial conversations: endocannabinoids and the microbiome in cardiometabolic risk

Cardiometabolic syndrome encompasses intertwined risk factors such as hypertension, dyslipidemia, elevated triglycerides, abdominal obesity, and other maladaptive metabolic and inflammatory aberrations. As the molecular mechanisms linking cardiovascular disease and metabolic disorders are investigated, endocannabinoids have emerged as molecules of interest. The endocannabinoid system (ECS) of biologically active lipids has been implicated in several conditions, including chronic liver disease, osteoporosis, and more recently in cardiovascular diseases. The gut microbiome is a major regulator of inflammatory and metabolic signaling in the host, and if disrupted, has the potential to drive metabolic and cardiovascular diseases. Extensive studies have unraveled the impact of the gut microbiome on host physiology, with recent reports showing that gut microbes exquisitely control the ECS, with significant influences on host metabolic and cardiac health. In this review, we outline how modulation of the gut microbiome affects host metabolism and cardiovascular health via the ECS, and how these findings could be exploited as novel therapeutic targets for various metabolic and cardiac diseases.

Curcumin and Weight Loss: Does It Work?

Obesity is a global health problem needing urgent research. Synthetic anti-obesity drugs show side effects and variable effectiveness. Thus, there is a tendency to use natural compounds for the management of obesity. There is a considerable body of knowledge, supported by rigorous experimental data, that natural polyphenols, including curcumin, can be an effective and safer alternative for managing obesity. Curcumin is a is an important compound present in Curcuma longa L. rhizome. It is a lipophilic molecule that rapidly permeates cell membrane. Curcumin has been used as a pharmacological traditional medicinal agent in Ayurvedic medicine for ∼6000 years. This plant metabolite doubtless effectiveness has been reported through increasingly detailed in vitro, in vivo and clinical trials. Regarding its biological effects, multiple health-promoting, disease-preventing and even treatment attributes have been remarkably highlighted. This review documents the status of research on anti-obesity mechanisms and evaluates the effectiveness of curcumin for management of obesity. It summarizes different mechanisms of anti-obesity action, associated with the enzymes, energy expenditure, adipocyte differentiation, lipid metabolism, gut microbiota and anti-inflammatory potential of curcumin. However, there is still a need for systematic and targeted clinical studies before curcumin can be used as the mainstream therapy for managing obesity.

The crosstalk between gut microbiota, intestinal immunological niche and visceral adipose tissue as a new model for the pathogenesis of metabolic and inflammatory diseases: the paradigm of type 2 diabetes mellitus

Gut microbiota (GM) comprises more than one thousand microorganisms between bacterial species, viruses, fungi, and protozoa, and represents the main actor of a wide net of molecular interactions, involving, among others, the endocrine system, immune responses, and metabolism. GM influences many endocrine functions such as adrenal steroidogenesis, thyroid function, sexual hormones, IGF-1 pathway and peptides produced in gastrointestinal system. It is fundamental in glycaemic control and obesity, while also exerting an important function in modulating the immune system and associated inflammatory disease. The result of this crosstalk in gut mucosa is the formation of the intestinal immunological niche. Visceral adipose tissue (VAT) produces about 600 different peptides, it is involved in lipid and glucose metabolism and in some immune reactions through several adipokines. GM and VAT interact in a bidirectional fashion: while gut dysbiosis can modify VAT adipokines and hormone secretion, VAT hyperplasia modifies GM composition. Acquired or genetic factors leading to gut dysbiosis or increasing VAT (i.e., Western diet) induce a proinflammatory condition, which plays a pivotal role in the development of dysmetabolic and immunologic conditions, such as diabetes mellitus. Diabetes is clearly associated with specific patterns of GM alterations, with an abundance or reduction of GM species involved in controlling mucosal barrier status, glycaemic levels and exerting a pro- or anti-inflammatory activity. All these factors could explain the higher incidence of several inflammatory conditions in Western countries; furthermore, besides the specific alterations observed in diabetes, this paradigm could represent a common pathway acting in many metabolic conditions and could pave the way to a new, interesting therapeutic approach.

Lactobacillus casei Zhang exerts anti-obesity effect to obese glut1 and gut-specific-glut1 knockout mice via gut microbiota modulation mediated different metagenomic pathways

PURPOSE

Obesity is a major risk factor for various metabolic diseases, including metabolic syndrome and type-2 diabetes. Glucose transporter 1 (GLUT1) impairment has been proposed as a mechanism of fat accumulation and glucose tolerance. Our aims were to determine the role of intestinal epithelial glut1 activity in obesity and the mechanism of anti-obesity effect of Lactobacillus casei Zhang (LCZ) intervention in the absence of gut villi-specific glut1 expression.

METHODS

This study compared the body weight, intestinal microbiota perturbations, fat mass accumulation, and glucose tolerance (by oral glucose tolerance test) between high-fat diet fed villi-specific glut1 knockout (KO) mice and control mice (glut1 flox/flox) with/without LCZ intervention. The intestinal microbiota was evaluated by metagenomic sequencing.

RESULTS

Our results showed that villi-specific glut1 KO mice had more fat deposition at the premetaphase stage, impaired glucose tolerance, and obvious alterations in gut microbiota compared to control mice. Probiotic administration significantly lowered the body weight, the weights of mesenteric and perirenal white adipose tissues (WAT), and mediated gut microbiota modulation in both types of KO and control mice. The species Barnesiella intestinihominis and Faecalibaculum rodentium might contribute to fasting fat mass accumulation associated with gut-specific glut1 inactivation, while the probiotic-mediated anti-obesity effect was linked to members of the Bacteroides genera, Odoribacter genera and Alistipes finegoldii.

CONCLUSION

Our study demonstrated that abrogating gut epithelial GLUT1 activity affected the gut microbiota, fat mass accumulation, and glucose tolerance; and LCZ administration reduced fat mass accumulation and central obesity.

Cross-Talk Between Gut Microbiota and Adipose Tissues in Obesity and Related Metabolic Diseases

The rapid increase of obesity and associated diseases has become a major global health problem. Adipose tissues are critical for whole-body homeostasis. The gut microbiota has been recognized as a significant environmental factor in the maintenance of energy homeostasis and host immunity. A growing body of evidence suggests that the gut microbiota regulates host metabolism through a close cross-talk with adipose tissues. It modulates energy expenditure and alleviates obesity by promoting energy expenditure, but it also produces specific metabolites and structural components that may act as the central factors in the pathogenesis of inflammation, insulin resistance, and obesity. Understanding the relationship between gut microbiota and adipose tissues may provide potential intervention strategies to treat obesity and associated diseases. In this review, we focus on recent advances in the gut microbiota and its actions on adipose tissues and highlight the joint actions of the gut microbiota and adipose tissue with each other in the regulation of energy metabolism.

Progenitor with cardiometabolic disorders increases food intake, systemic inflammation and gut microbiota alterations in the second generation offspring

This work presents the effects of the high-fat diet (H) consumed by the progenitor (G0) on cardiometabolic disorders and on intestinal microbiota in the second generation ofspring (F2). Rats submitted...

Inflammaging and Cannabinoids

Aging is a complex phenomenon associated with a wide spectrum of physical and physiological changes affecting every part of all metazoans, if they escape death prior to reaching maturity. Critical to survival, the immune system evolved as the principal component of response to injury and defense against pathogen invasions. Because how significantly immune system affects and is affected by aging, several neologisms now appear to encapsulate these reciprocal relationships, such as Immunosenescence. The central part of Immunosenescence is Inflammaging -a sustained, low-grade, sterile inflammation occurring after reaching reproductive prime. Once initiated, the impact of Inflammaging and its adverse effects determine the direction and magnitudes of further Inflammaging. In this article, we review the nature of this vicious cycle, we will propose that phytocannabinoids as immune regulators may possess the potential as effective adjunctive therapies to slow and, in certain cases, reverse the pathologic senescence to permit a more healthy aging.