Metformin Exerts Anti-inflammatory and Mucus Barrier Protective Effects by Enriching Akkermansia muciniphila in Mice With Ulcerative Colitis

Metformin use in prediabetes: A review of evidence and a focus on metabolic features among peri-menopausal women

The prevalence of prediabetes has more than doubled over the past two decades. Although hormones associated with the menstrual cycle may offer some protection against diabetes by enhancing insulin sensitivity and suppressing gluconeogenesis, the prevalence of diabetes among women remains high at 10.5%. Notably, among the perimenopausal population, the prevalence catches up to-and even surpasses-that of men starting from the 70-74 age group, according to the 2021 International Diabetes Federation (IDF) report. This narrative review examines the benefits and potential risks of metformin across diverse populations, with a particular emphasis on women in the perimenopausal phase. Metformin's interaction with hormonal regulation significantly influences both its therapeutic efficacy and long-term side effect profile, contributing to sex-specific differences in treatment response. Consequently, its effectiveness varies among women at different stages of menopause, potentially due to differential impacts on inflammatory markers and modulation of the hypothalamic-pituitary-ovarian (HPO) and hypothalamic-pituitary-thyroid (HPT) axes. Emerging evidence also highlights metformin's potential in managing conditions such as polycystic ovary syndrome (PCOS), breast tissue inflammation and endometrial disorders within this demographic. Given these potential and multifaceted benefits, this review highlights the need for further randomized controlled trials (RCTs) to investigate metformin's role among perimenopausal and menopausal women and to better understand how menopausal status may influence its efficacy. PLAIN LANGUAGE SUMMARY: The number of people with prediabetes has more than doubled in the last 20 years. By 2021, about 720 million people worldwide were living with this condition, and that number is expected to reach 1 billion by 2045. While hormones that fluctuate with the menstrual cycle might help protect against diabetes, the overall rate of diabetes among women is still concerning, at 10.5%. For women going through menopause, the situation is even more serious. From the age of 70 to 74, the rates of diabetes in women surpass those in men. This may be because menopause reduces levels of protective hormones like estrogen and progesterone, which help guard against type 2 diabetes (T2D). Despite this growing issue, there hasn't been much research focused on prediabetes in women going through menopause and how the changes in hormones might affect treatment guidelines. To address this lack of information, our review focused on the use of metformin for women in the perimenopausal stage with prediabetes, aiming to help prevent them from developing T2D in the future. We gathered insights from recent clinical trials to summarize the benefits and risks of metformin for various groups, particularly perimenopausal women. Our findings indicate that metformin can be effective for managing prediabetes, although opinions vary. It's currently the only diabetes medication recommended for prediabetes by the American Diabetes Association (ADA), supported by significant studies like the Diabetes Prevention Program (DPP) and the Coronary Endothelial Dysfunction Multicentre Prospective Study (CODYCE study). Metformin's effectiveness seems to increase when combined with lifestyle changes, such as diet and exercise. Some challenges exist, though, like concerns that it might only work for those at a high risk of developing T2D, potential side effects, and the availability of other options, such as lifestyle adjustments or a new medication called tirzepatide. Still, many experts argue that metformin remains valuable because it allows for early intervention, particularly when lifestyle changes alone may not be enough. We also found that metformin might work differently for men and women due to variations in hormone interactions, differing gut bacteria, and weight-related factors that can influence its effectiveness. Interestingly, metformin seems to work better for women who have not yet gone through menopause. This might be because it helps with weight loss and reduces inflammation, which are important for postmenopausal health. Moreover, metformin has shown promise in addressing other health issues that postmenopausal women may face, such as inflammation in breast tissue, certain types of cancer, endometrial problems (as an alternative to hormone therapy), and polycystic ovarian syndrome (PCOS). In conclusion, our review stresses the importance of creating specific guidelines for managing prediabetes (e.g., metformin therapy) in the perimenopausal population. Understanding how sex hormones interact with blood sugar control is crucial for developing effective treatments tailored to women at different stages of menopause.

Metformin Is Associated With Improved Inflammatory Bowel Disease Outcomes in Patients With Type 2 Diabetes Mellitus: A Propensity-Matched Cohort Study

BACKGROUND

Metformin exerts anti-inflammatory properties through a positive effect on oxidative stress, gut barrier integrity, and the gut microbiota. Our aim was to evaluate the influence of metformin on inflammatory bowel disease (IBD) outcomes in patients with type 2 diabetes mellitus (T2DM).

METHODS

We conducted a retrospective cohort study using the TriNetX database in patients with IBD and T2DM who initiated metformin vs oral hypoglycemics or insulin (control cohort) between August 31, 2002, and August 31, 2022. One-to-one propensity score matching was performed. Primary outcomes were need for intravenous (IV) steroid use or IBD-related surgery within 1, 2, and 3 years after metformin initiation.

RESULTS

Our cohorts included 1323 patients with ulcerative colitis (UC) (mean age 58.7 ± 12.2 years, 50.1% female, 77.3% White) and 1278 patients with Crohn's disease (CD) (mean age 56.3 ± 12.6 years, 58.2% female, 76.5% White). At 1 year, patients with UC and CD were less likely to require IV steroids (UC: adjusted odds ratio [aOR], 0.45; 95% confidence interval [CI], 0.34-0.59; P < .01; CD: aOR, 0.67; 95% CI, 0.53-0.85; P < .01). The decreased need for IV steroids persisted in all metformin groups at 2 and 3 years. Patients with CD were at a lower risk for IBD-related surgery at year 1 (aOR, 0.5; 95% CI, 0.31-0.81; P < .01), and this finding persisted at 3 years (aOR, 0.62; 95% CI, 0.43-0.89; P < .01). Metformin did not affect risk for surgery in patients with UC.

CONCLUSIONS

Patients with IBD and T2DM on metformin had a decreased likelihood of worse IBD outcomes.

Xenobiotics mediated modulation of gut microbiota and its role in lifestyle diseases: a critical appraisal on exposomics

Gastrointestinal tract of humans provides a niche to thousands of microbes, referred as gut microbiota (GM). GM establishes an intricate relationship with other organs via gut-organ axis, and modulates host health. The structure and functioning of these gut microbes can be influenced by the type of external exposome an individual experiences. Depending upon GM perturbations and host genotype, this can result in variable health implications. On the other hand, the huge arsenal of enzymes possessed by GM can chemically alter the xenobiotic structure. Its consequences can be numerous, including formation of harmful metabolites that cause organ damage, reversal of host detoxification pathways, or favourable health effects. Additionally, GM-mediated bio-transformation of pharmaceuticals can alter their pharmacokinetics and pharmacodynamics, potentially yielding variable drug responses, resulting into prolonged or ineffective treatments. To address this bi-facial relationship and the pivotal role of GM, this review incorporates recent in vitro, in vivo, and multiomics studies. It also suggests the need of machine learning approaches to decode the complex host-microbiota-xenobiotics interactions. These knowledge will aid in comprehending recent rise in chronic lifestyle-diseases which poses a huge burden on the health sector, and can also be a learning curve in making formulations and therapies for personalized treatment.

[The Effect of Metformin on Short-Chain Fatty Acid Levels in Patients with Chronic Heart Failure, Prediabetes, and Sarcopenia]

Aim    To evaluate the effect of extended-release metformin (metformin long) on plasma concentrations of short-chain fatty acids (SCFA), physical performance and muscle strength in patients with chronic heart failure (CHF), sarcopenia and prediabetes.Material and methods    The study included 27 patients (mean age 68±9.8 years) with CHF, sarcopenia and prediabetes randomized into the groups of intervention (n=14) (metformin long + healthy lifestyle, HLS) and control (n=13) (HLS). Measurement of SCFA (C3, iC4, C4, αC5, βC5, C5, iC6, C6) concentrations, bioimpedancemetry, Short Physical Performance Battery (SPPB) test, and dynamometry were performed at the beginning of the study and after 6 months. R language and RStudio software were used for statistical analysis.Results    The study groups were comparable in clinical characteristics. The SCFA concentrations were significantly increased, except for iC6. After 6 months of treatment, the SCFA concentrations were decreased, except for C5, iC6, C3. Metformin long improved the physical performance and strength index. The median SPPB score in the control group was 4 [3.0; 9.5] and in the metformin group, 9 [7.25; 9.75], p = 0.0014. In the control group, the change in Δ strength index was -4.65 [-11.09; 17.66], in the metformin group, 18.75 [8.17; 33.03], p = 0.031.Conclusion    Metformin exerts a beneficial effect on plasma SCFA and physical performance in patients with prediabetes, CHF, and sarcopenia.

The adjunctive role of metformin in patients with mild to moderate ulcerative colitis: a randomized controlled study

Background

Metformin, hypoglycemic medication, is recognized for its diverse properties and its capacity to influence the inflammatory pathways. Medications with anti-inflammatory and anti-oxidative characteristics have been demonstrated to be able to elicit and sustain remission in ulcerative colitis (UC), chronic inflammatory disorder of the bowel. Studies in both preclinical and clinical settings have looked into the several metabolic pathways via which metformin protects against UC.

Aim

To assess efficacy of metformin as adjunctive therapy in patients with mild to moderate UC.

Methods

This clinical research was double-blinded, randomized, controlled, and involved 60 patients with mild to moderate UC. The participants were randomly assigned to one of two groups (n = 30). The control group was given 1 g of mesalamine three times a day (t.i.d.) for a period of 6 months (mesalamine group). The metformin group was given 500 mg of metformin twice daily and 1 g of mesalamine t. i.d. For a period of 6 months. Patients with UC were assessed by a gastroenterologist using the disease activity index (DAI) both at the beginning of treatment and 6 months thereafter. To evaluate the drug's biological efficacy, measurements of fecal calprotectin, serum C-reactive protein (CRP), interleukin 10 (IL-10), and nitric oxide (NO) were taken both before and after treatment.

Study outcomes

Decrease in DAI and change in the level of measured serum and fecal markers.

Results

The metformin group displayed a statistical reduction in DAI (p = 0.0001), serum CRP (p = 0.019), NO (p = 0.04), and fecal calprotectin (p = 0.027), as well as a significant increase in IL-10 (p = 0.04) when compared to the mesalamine group. There was a significant direct correlation between DAI and calprotectin (p < 0.0001, r = 0.551), and between DAI and CRP (p < 0.0001, r = 0.794). There was a significant negative correlation between DAI and IL-10 (p = 0.0003, r = 0.371).

Conclusion

Metformin may be an effective adjunct drug in management of patients with mild to moderate UC by decreasing DAI and other inflammatory markers that were involved in the pathogenesis of UC.

Clinical Trial Registration

identifier NCT05553704.

Akkermansia muciniphila: promises and pitfallsfor next-generation beneficial microorganisms

Akkermansia muciniphila, a microorganism ubiquitously colonizing the mucosal layer of the human gut, has garnered significant scientific interest as a promising candidate for probiotic therapeutics. Its persistent identification in both laboratory and living organism studies underscores its potential physiological benefits, positioning it as a bacterium of paramount importance in promoting host health. This review examines the diversity and abundance of gut microbiota members, emphasizing the identification of microbial species engaged in cross-feeding networks with A. muciniphila. Insightful exploration into the mechanisms of cross-feeding, including mucin-derived nutrient exchange and metabolite production, unveils the intricate dynamics shaping microbial community stability. Such interactions contribute not only to the availability of essential nutrients within the gut environment but also to the production of metabolites influencing microbial community dynamics and host health. In conclusion, the cumulative evidence from in vitro and in vivo perspectives substantiates the notion that A. muciniphila holds tremendous promise as a next-generation probiotic. By leveraging its unique physiological benefits, particularly in mucosal health and metabolic regulation, A. muciniphila stands poised to revolutionize the landscape of probiotic interventions for enhanced host well-being.

Orlistat ameliorates lipid dysmetabolism in high-fat diet-induced mice via gut microbiota modulation

Orlistat reduces obesity by inhibiting gastrointestinal lipases, thereby blocking the absorption and accumulation of triglycerides in the intestine. It has been shown to improve lipid metabolism and alter intestinal microbial communities in animals and humans. However, the impact of Orlistat-induced changes in gut microbiota on obesity requires further investigation. In this study, we found that Orlistat significantly improved metabolic disorders, inhibited fat accumulation, and reshaped the structure of intestinal microbiota. Specifically, it reduced α diversity and increased the relative abundance of Verrucomicrobia and Akkermansia. Notably, antibiotic-induced gut microbiota depletion significantly weakened Orlistat's effect on improving metabolic disorders. Furthermore, microbiota transplanted from Orlistat-treated mice effectively alleviated lipid metabolic disorders caused by a high-fat diet. We also observed that Orlistat increased food intake in mice and inhibited the synthesis of appetite-regulating hormones glucose-dependent insulinotropic polypeptide (GIP) and glucagon (Gcg). However, antibiotic-depleted microbiota mitigated this inhibitory effect. Interestingly, although Orlistat altered the gut microbiota of mice, transplanting these microbiota did not inhibit the synthesis of appetite-regulating hormones. In summary, our results suggest that Orlistat can reshape the gut microbiota, and the altered gut microbiota works synergistically with Orlistat to improve metabolic disorders. This improvement is related to the increased abundance of Verrucomicrobia and Akkermansia.

Health Effects and Therapeutic Potential of the Gut Microbe Akkermansia muciniphila

Akkermansia muciniphila is a bacterium commonly found in the human gastrointestinal tract that has received considerable interest as a potential probiotic for the improvement of gut health and overall metabolic function. A. muciniphila is enriched in the mucus layer of the intestinal lining, where it degrades mucin and plays a significant role in gut barrier maintenance and immune regulation. A higher abundance of A. muciniphila has been observed in the gut of healthy individuals relative to those with metabolic disorders, and multiple metabolic benefits, including improved glucose management, reduced body fat, and reduced inflammation have been linked to A. muciniphila. Current research on A. muciniphila primarily relies on mouse models, with limited human interventional studies available. While these animal studies offer valuable insights into the potential roles of A. muciniphila in health and disease, further clinical investigations in humans are needed to fully understand its impact. Here, we explore the current scope of A. muciniphila research and its potential as a therapeutic agent to improve gut and metabolic health while also emphasizing the need to optimize techniques to further improve studies of this organism.

Saussurea costus alleviates ulcerative colitis by regulating the gut microbiota and improving intestinal barrier integrity

Introduction

The global health challenge of ulcerative colitis (UC) has been classified by the WHO as a modern refractory disease, commonly referred to as green cancer, with limited treatment options still available, highlighting the urgent need for the development of new therapeutic strategies. Recent pharmacological research has shown that traditional Chinese medicine saussurea costus (SC) possesses beneficial antibacterial and anti-inflammatory properties. Nevertheless, its underlying mechanism remains elusive.

Methods

Firstly, we identified the main active components of SC through UHPLC-QTOF-MS analysis. Subsequently, UC mice were induced using DSS and administered different doses of SC to evaluate its efficacy. Additionally, the impact of SC on the repair of the intestinal mucosal barrier was evaluated through immunofluorescence and western blot. Furthermore, 16s rRNA gene sequencing was conducted to elucidate the contribution of gut microbiota to UC pathogenesis.

Results

The primary components of SC include Proline, Phenylalanine, Isoleucine, Lucidenic acid M, and Pyroglutamic acid. The efficacy of SC was concurrently assessed, revealing its potential to ameliorate histological injury in colitis mice. Furthermore, SC was found to decrease levels of TNF-α, IL-1β, IL-8, and IL-18 while promoting the expression of IL-10 and IL-22. Similarly, we also found that the expression of ZO-1 and Occludin was reversed by SC in colitis mice. In addition, analysis of 16S rRNA gene sequencing indicated that SC reduced harmful bacterial populations, such as Proteobacteria, while simultaneously enhancing the levels of beneficial bacteria like Lactobacillus, thereby contributing to the improvement of UC pathology.

Conclusion

This study highlights the therapeutic potential of SC in managing UC through its ability to attenuate inflammatory responses, restore intestinal barrier functionality, and modulate gut microbiota composition, which findings offer insights into potential strategies for advancing UC treatment.

Akkermansia muciniphila: A Potential Target for the Prevention of Diabetes

Akkermansia muciniphila, a Gram-negative anaerobic bacterium colonizing the intestinal mucus layer, is regarded as a promising "next-generation probiotic". There is mounting evidence that diabetes and its complications are associated with disorders of A. muciniphila abundance. Thus, A. muciniphil and its components, including the outer membrane protein Amuc_1100, A. muciniphila-derived extracellular vesicles (AmEVs), and the secreted proteins P9 and Amuc_1409, are systematically summarized with respect to mechanisms of action in diabetes mellitus. Diabetes treatments that rely on altering changes in A. muciniphila abundance are also reviewed, including the identification of A. muciniphila active ingredients, and dietary and pharmacological interventions for A. mucinihila abundance. The potential and challenges of using A. muciniphila are also highlighted, and it is anticipated that this work will serve as a reference for more in-depth studies on A. muciniphila and diabetes development, as well as the creation of new therapeutic targets by colleagues domestically and internationally.

Akkermansia muciniphila: A promising probiotic against inflammation and metabolic disorders

Metabolic disease is a worldwide epidemic that has become a public health problem. Gut microbiota is considered to be one of the important factors that maintain human health by regulating host metabolism. As an abundant bacterium in the host gut, A. muciniphila regulates metabolic and immune functions, and protects gut health. Multiple studies have indicated that alterations in the abundance of A. muciniphila are associated with various diseases, including intestinal inflammatory diseases, obesity, type 2 diabetes mellitus, and even parasitic diseases. Beneficial effects were observed not only in live A. muciniphila, but also in pasteurized A. muciniphila, A. muciniphila-derived extracellular vesicles, outer membrane, and secreted proteins. Although numerous studies have only proven the simple correlation between multiple diseases and A. muciniphila, an increasing number of studies in animal models and preclinical models have demonstrated that the beneficial impacts shifted from correlations to in-depth mechanisms. In this review, we provide a comprehensive view of the beneficial effects of A. muciniphila on different diseases and summarize the potential mechanisms of action of A. muciniphila in the treatment of diseases. We provide a comprehensive understanding of A. muciniphila for improving host health and discuss the perspectives of A. muciniphila in the future studies.

Metformin: Diverse molecular mechanisms, gastrointestinal effects and overcoming intolerance in type 2 Diabetes Mellitus: A review

Metformin, the first line treatment for patients with type 2 diabetes mellitus, has alternative novel roles, including cancer and diabetes prevention. This narrative review aims to explore its diverse mechanisms, effects and intolerance, using sources obtained by searching Scopus, PubMed and Web of Science databases, and following Scale for the Assessment of Narrative Review Articles reporting guidelines. Metformin exerts it actions through duration influenced, and organ specific, diverse mechanisms. Its use is associated with inhibition of hepatic gluconeogenesis targeted by mitochondria and lysosomes, reduction of cholesterol levels involving brown adipose tissue, weight reduction influenced by growth differentiation factor 15 and novel commensal bacteria, in addition to counteraction of meta-inflammation alongside immuno-modulation. Interactions with the gastrointestinal tract include alteration of gut microbiota, enhancement of glucose uptake and glucagon like peptide 1 and reduction of bile acid absorption. Though beneficial, they may be linked to intolerance. Metformin related gastrointestinal adverse effects are associated with dose escalation, immediate release formulations, gut microbiota alteration, epigenetic predisposition, inhibition of organic cation transporters in addition to interactions with serotonin, histamine and the enterohepatic circulation. Potentially effective measures to overcome intolerance encompasses carefully objective targeted dose escalation, prescription of fixed dose combination, microbiome modulators and prebiotics, in addition to use of extended release formulations.

Rethinking about Metformin: Promising Potentials

Metformin is widely used drugs in the treatment of type 2 diabetes mellitus. However, the mechanisms of action are complex and are still not fully understood yet. Metformin has a dose-dependent blood sugar-lowering effect. The most common adverse reactions of metformin are gastrointestinal symptoms, and women tend to be more experienced than men. A positive correlation between the administration of duration and the daily dose of metformin and the risk of vitamin B12 deficiency is confirmed. Novel glucose-lowering mechanism through the activation of AMP-activated protein kinase and alteration of gut microbiota composition is identified. In addition, metformin has immunomodulatory properties in various mechanisms, including anti-inflammatory actions, and so forth. Metformin improves insulin sensitivity, which may reduce the risk of tumor growth in certain cancers. The antiviral effects of metformin may occur through several mechanisms, including blocking angiotensin converting enzyme 2 receptor, and so forth. These potential mechanisms of metformin are promising in various clinical settings, such as inflammatory diseases, autoimmune diseases, cancer, and coronavirus disease 2019.

NLRP3 Inflammasome and Gut Dysbiosis Linking Diabetes Mellitus and Inflammatory Bowel Disease

Diabetes mellitus and inflammatory bowel disease are chronic conditions with significant overlap in their pathophysiology, primarily driven by chronic inflammation. Both diseases are characterized by an aberrant immune response and disrupted homeostasis in various tissues. However, it remains unclear which disease develops first, and which one contributes to the other. Diabetes mellitus increases the risk of inflammatory bowel disease and inflammatory bowel disease may increase the risk of developing diabetes. This review focuses on comprehensively discussing the factors commonly contributing to the pathogenesis of diabetes mellitus and inflammatory bowel disease to draw a relationship between them and the possibility of targeting common factors to attenuate the incidence of one if the other is present. A key player in the intersection of diabetes mellitus and inflammatory bowel disease is the NLRP3 inflammasome, which regulates the production of pro-inflammatory cytokines leading to prolonged inflammation and tissue damage. Additionally, toll-like receptors via sensing microbial components contribute to diabetes mellitus and inflammatory bowel disease by initiating inflammatory responses. Gut dysbiosis, a common link in both diseases, further intensifies inflammation and metabolic dysfunction. Alterations in gut microbiota composition affect intestinal permeability and immune modulation, perpetuating a vicious cycle of inflammation and disease progression by changing protein expression. The overlap in the underlying inflammatory mechanisms has led to the potential of targeting mediators of chronic inflammation using anti-inflammatory drugs and biologics that benefit both conditions or attenuate the incidence of one in the presence of the other.

METFORMIN: FROM DIABETES TO CANCER TO PROLONGATION OF LIFE

The metformin molecule dates back to over a century, but its clinical use started in the '50s. Since then, its use in diabetics has grown constantly, with over 150 million users today. The therapeutic profile also expanded, with improved understanding of novel mechanisms. Metformin has a major activity on insulin resistance, by acting on the insulin receptors and mitochondria, most likely by activation of the adenosine monophosphate-activated kinase. These and associated mechanisms lead to significant lipid lowering and body weight loss. An anti-cancer action has come up in recent years, with mechanisms partly dependent on the mitochondrial activity and also on phosphatidylinositol 3-kinase resistance occurring in some malignant tumors. The potential of metformin to raise life-length is the object of large ongoing studies and of several basic and clinical investigations. The present review article will attempt to investigate the basic mechanisms behind these diverse activities and the potential clinical benefits. Metformin may act on transcriptional activity by histone modification, DNA methylation and miRNAs. An activity on age-associated inflammation (inflammaging) may occur via activation of the nuclear factor erythroid 2 related factor and changes in gut microbiota. A senolytic activity, leading to reduction of cells with the senescent associated secretory phenotype, may be crucial in lifespan prolongation as well as in ancillary properties in age-associated diseases, such as Parkinson's disease. Telomere prolongation may be related to the activity on mitochondrial respiratory factor 1 and on peroxisome gamma proliferator coactivator 1-alpha. Very recent observations on the potential to act on the most severe neurological disorders, such as amyotrophic lateral sclerosis and frontotemporal dementia, have raised considerable hope.

The central role of the gut microbiota in the pathophysiology and management of type 2 diabetes

The inhabitants of our intestines, collectively called the gut microbiome, comprise fungi, viruses, and bacterial strains. These microorganisms are involved in the fermentation of dietary compounds and the regulation of our adaptive and innate immune systems. Less known is the reciprocal interaction between the gut microbiota and type 2 diabetes mellitus (T2DM), as well as their role in modifying therapies to reduce associated morbidity and mortality. In this review, we aim to discuss the existing literature on gut microbial strains and their diet-derived metabolites involved in T2DM. We also explore the potential diagnostics and therapeutic avenues the gut microbiota presents for targeted T2DM management. Personalized treatment plans, driven by diet and medication based on the patient's microbiome and clinical markers, could optimize therapy.

Region-Specific Effects of Metformin on Gut Microbiome and Metabolome in High-Fat Diet-Induced Type 2 Diabetes Mouse Model

The glucose-lowering drug metformin alters the composition of the gut microbiome in patients with type 2 diabetes mellitus (T2DM) and other diseases. Nevertheless, most studies on the effects of this drug have relied on fecal samples, which provide limited insights into its local effects on different regions of the gut. Using a high-fat diet (HFD)-induced mouse model of T2DM, we characterize the spatial variability of the gut microbiome and associated metabolome in response to metformin treatment. Four parts of the gut as well as the feces were analyzed using full-length sequencing of 16S rRNA genes and targeted metabolomic analyses, thus providing insights into the composition of the microbiome and associated metabolome. We found significant differences in the gut microbiome and metabolome in each gut region, with the most pronounced effects on the microbiomes of the cecum, colon, and feces, with a significant increase in a variety of species belonging to Akkermansiaceae, Lactobacillaceae, Tannerellaceae, and Erysipelotrichaceae. Metabolomics analysis showed that metformin had the most pronounced effect on microbiome-derived metabolites in the cecum and colon, with several metabolites, such as carbohydrates, fatty acids, and benzenoids, having elevated levels in the colon; however, most of the metabolites were reduced in the cecum. Thus, a wide range of beneficial metabolites derived from the microbiome after metformin treatment were produced mainly in the colon. Our study highlights the importance of considering gut regions when understanding the effects of metformin on the gut microbiome and metabolome.

Wheat peptide alleviates DSS-induced colitis by activating the Keap1-Nrf2 signaling pathway and maintaining the integrity of the gut barrier

Inflammatory bowel disease (IBD) is difficult to cure, and formulating a dietary plan is an effective means to prevent and treat this disease. Wheat peptide contains a variety of bioactive peptides with anti-inflammatory and antioxidant functions. The results of this study showed that preventive supplementation with wheat peptide (WP) can significantly alleviate the symptoms of dextran sulfate sodium (DSS)-induced colitis in mice. WP can increase body weight, alleviate colon shortening, and reduce disease activity index (DAI) scores. In addition, WP improved intestinal microbial disorders in mice with colitis. Based on LC-MS, a total of 313 peptides were identified in WP, 4 of which were predicted to be bioactive peptides. The regulatory effects of WP and four bioactive peptides on the Keap1-Nrf2 signaling pathway were verified in Caco-2 cells. In conclusion, this study demonstrated that WP alleviates DSS-induced colitis by helping maintain gut barrier integrity and targeting the Keap1-Nrf2 axis; these results provided a rationale for adding WP to dietary strategies to prevent IBD.

Akkermansia muciniphila and Parabacteroides distasonis synergistically protect from colitis by promoting ILC3 in the gut

Inflammatory bowel disease (IBD) is a group of inflammatory conditions of the gastrointestinal tract. The etiology of IBD remains elusive, but the disease is suggested to arise from the interaction of environmental and genetic factors that trigger inadequate immune responses and inflammation in the intestine. The gut microbiome majorly contributes to disease as an environmental variable, and although some causative bacteria are identified, little is known about which specific members of the microbiome aid in the intestinal epithelial barrier function to protect from disease. While chemically inducing colitis in mice from two distinct animal facilities, we serendipitously found that mice in one facility showed remarkable resistance to disease development, which was associated with increased markers of epithelial barrier integrity. Importantly, we show that Akkermansia muciniphila and Parabacteroides distasonis were significantly increased in the microbiota of resistant mice. To causally connect these microbes to protection against disease, we colonized susceptible mice with the two bacterial species. Our results demonstrate that A. muciniphila and P. distasonis synergistically drive a protective effect in both acute and chronic models of colitis by boosting the frequency of type 3 innate lymphoid cells in the colon and by improving gut epithelial integrity. Altogether, our work reveals a combined effort of commensal microbes in offering protection against severe intestinal inflammation by shaping gut immunity and by enhancing intestinal epithelial barrier stability. Our study highlights the beneficial role of gut bacteria in dictating intestinal homeostasis, which is an important step toward employing microbiome-driven therapeutic approaches for IBD clinical management.

IMPORTANCE

The contribution of the gut microbiome to the balance between homeostasis and inflammation is widely known. Nevertheless, the etiology of inflammatory bowel disease, which is known to be influenced by genetics, immune response, and environmental cues, remains unclear. Unlocking novel players involved in the dictation of a protective gut, namely, in the microbiota component, is therefore crucial to develop novel strategies to tackle IBD. Herein, we revealed a synergistic interaction between two commensal bacterial strains, Akkermansia muciniphila and Parabacteroides distasonis, which induce protection against both acute and chronic models of colitis induction, by enhancing epithelial barrier integrity and promoting group 3 innate lymphoid cells in the colonic mucosa. This study provides a novel insight on how commensal bacteria can beneficially act to promote intestinal homeostasis, which may open new avenues toward the use of microbiome-derived strategies to tackle IBD.

Understanding the action mechanisms of metformin in the gastrointestinal tract

Metformin is the initial medication recommended for the treatment of type 2 diabetes mellitus (T2DM). In addition to diabetes treatment, the function of metformin also can be anti-aging, antiviral, and anti-inflammatory. Nevertheless, further exploration is required to fully understand its mode of operation. Historically, the liver has been acknowledged as the main location where metformin reduces glucose levels, however, there is increasing evidence suggesting that the gastrointestinal tract also plays a significant role in its action. In the gastrointestinal tract, metformin effects glucose uptake and absorption, increases glucagon-like peptide-1 (GLP-1) secretion, alters the composition and structure of the gut microbiota, and modulates the immune response. However, the side effects of it cannot be ignored such as gastrointestinal distress in patients. This review outlines the impact of metformin on the digestive system and explores potential explanations for variations in metformin effectiveness and adverse effects like gastrointestinal discomfort.

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.

Metformin facilitates anti-PD-L1 efficacy through the regulation of intestinal microbiota

Metformin is a synthetic biguanide proven to have beneficial effects against various human diseases. Research has confirmed that metformin exerts its effects by regulating the composition of intestinal microbiota. The composition of intestinal microbiota influences the efficacy of anti-PD-L1 immunotherapy. We assume that the regulation of metformin on intestinal microbiota could enhance the therapeutic efficiency of anti-PD-L1 antibodies. In Lewis lung cancer-bearing C57BL/6J mice, we find that metformin enhances PD-L1 antibody efficacy mainly depending on the existence of gut microbiota, and metformin increases the anti-tumor immunity through modulation of intestinal microbiota and affects the integrity of the intestinal mucosa. Antibiotic depletion of gut microbiota abolished the combination efficacy of PD-L1 antibody and metformin, implying the significance of intestinal microbiota in metformin's antitumor action. Combining anti-PD-L1 antibody with metformin provoked tumor necrosis by causing increased CD8 T-cell infiltration and IFN-γ expression. In conclusion, metformin could be employed as a microecological controller to prompt antitumor immunity and increase the efficacy of anti-PD-L1 antibodies. Our study provided reliable evidence that metformin could be synergistically used with anti-PD-L1 antibody to enhance the anti-cancer effect.

Correlations between genetically predicted lipid-lowering drug targets and inflammatory bowel disease

BACKGROUND

Millions of individuals globally suffer from Inflammatory bowel diseases (IBDs). There is a dearth of large population-based investigations on lipid metabolism and IBDs, and it is unclear whether lipid-lowering drugs target IBDs causally. Consequently, the aim of this study was to investigate the effects of lipid-lowering medication targets on the occurrence and progression of IBDs.

METHODS

Among the more than 400,000 participants in the UK Biobank cohort and the more than 170,000 participants in the Global Lipids Genetics Consortium, a total of nine genes linked to lipid-lowering drug targets were obtained (ABCG5/ABCG8, APOB, APOC3, LDLR, LPL, HMGCR, NPC1L1, PCSK9, and PPARA). IBD data were acquired from de Lange et al. (patients/sample size of IBDs: 25042/59957; ulcerative colitis (UC): 12366/45,975; Crohn's disease (CD): 12194/40,266) and the FinnGen cohort (patients/total sample size of IBDs: 4420/176,899; CD: 1520/171,906; UC: 3325/173,711). All four datasets were cross-combined for validation via Mendelian randomization analysis, and potential mediating factors were explored via mediation analysis.

RESULTS

Genetically proxied APOC3 inhibition was related to increased IBD risk (odds ratio (95% confidence interval): 0.87 (0.80-0.95); P < 0.01) and UC risk (0.83 (0.73-0.94); P < 0.01). IBD and CD risk were reduced by genetic mimicry of LDLR and LPL enhancements, respectively (odds ratioLDLR: 1.18 (1.03-1.36); P = 0.018; odds ratioCD: 1.26 (1.11-1.43); P = 2.60E-04). Genetically proxied HMGCR inhibition was associated with increased CD risk (0.68 (0.50-0.94); P = 0.018). These findings were confirmed through Mendelian analysis of the cross-combination of four separate datasets. APOC3-mediated triglyceride levels may contribute to IBDs partly through mediated triglycerides, Clostridium sensu stricto 1, Clostridiaceae 1, or the Lachnospiraceae FCS020 group. LDLR enhancement may contribute to IBDs partly through increasing Lactobacillaceae.

CONCLUSION

Vigilance is required to prevent adverse effects on IBDs (UC) for patients receiving volanesorsen (an antisense oligonucleotide targeting ApoC3 mRNA) and adverse effects on CD for statin users. LPL and LDLR show promise as candidate drug targets for CD and IBD, respectively, with mechanisms that are potentially independent of their lipid-lowering effects.

Bear Bile Powder Improves Ulcerative Colitis by Protecting the Intestinal Mechanical Barrier and Regulating Intestinal Flora

BACKGROUND

Bear Bile Powder (BBP) is a traditional Chinese medicine. It has been widely used in clinical practices and has shown a good anti-inflammatory effect. However, its effectiveness in treating Ulcerative Colitis (UC) has not yet been studied.

OBJECTIVE

To explore the therapeutic effect of BBP on ulcerative colitis and its potential mechanism by combining acute ulcerative colitis mouse models and comprehensively observing various physiological and biochemical indexes of mice.

METHODS

The acute ulcerative colitis model was induced by drinking water containing dextran sulfate sodium salt (DSS) for 7 days. Studies were divided into Control, DSS, DSS+ Sulfasalazine (SASP, 450 mg/kg), and DSS + bear bile powder group (BBP, 320 mg/kg). The Disease Activity Index (DAI) and colonic tissue damage of mice were evaluated. Tissue immunofluorescence and western blot were used to determine related tight Junction Proteins (TJs), and 16S V34 amplicon was used to analyze intestinal microorganisms. The therapeutic effect of BBP on ulcerative colitis model mice was studied comprehensively.

RESULTS

After treatment, BBP can significantly improve the physiological condition of acute UC mice and reduce DAI fraction. Compared with the DSS group, the BBP group significantly increased the colon length and significantly decreased the injury fraction of acute UC mice. Regarding the intestinal mechanical barrier, BBP significantly increased the expression of ZO-1, Occludin, and Claudin 1 protein in colon tissue. In terms of microbial community, the intestinal microbial diversity of mice decreased after the administration of BBP, but there was no significant difference in structural composition between the BBP group and the Control group. By comparing the four groups of species with significant differences, it was found that the BBP group significantly reduced the abundance of specific harmful microorganisms at the order, family, genus, and species levels.

CONCLUSION

Oral administration of a certain dose of BBP can significantly improve the symptoms of ulcerative colitis in mice. Part of the reason may be that it increases the expression of tight junction proteins, regulates specific flora in the intestine of mice, and maintains intestinal barrier homeostasis. In the future, the clinical application value of BBP will be explored, and BBP will be developed as a drug with the potential to treat UC and alleviate the pain of UC patients.

Triggerable Prodrug Nanocoating Enables On-Demand Activation of Microbial and Small-Molecular Therapeutics for Combination Treatment

The synergy of living microbial and small-molecular therapeutics has been widely explored for treating a variety of diseases, while current combination strategies often suffer from low bioavailability, heterogeneous spatiotemporal distribution, and premature drug release. Here, the use of a triggerable prodrug nanocoating is reported to enable the on-demand activation of microbial and small-molecular therapeutics for combination treatment. As a proof-of-concept study, a reactive oxygen species-responsive aromatic thioacetal linker is employed to prepare cationic chitosan-drug conjugates, which can form a nanocoating on the surface of living bacteria via electrostatic interaction. Following administration, the wrapped bacteria can be prevented from in vivo insults by the shielding effect of the nanocoating and be co-delivered with the conjugated drug in a spatiotemporally synchronous manner. Upon reaching the lesion site, the upgraded reactive oxygen species trigger in situ cleavage of the thioacetal linker, resulting in the release of the conjugated drug and a linker-derived therapeutic cinnamaldehyde. Meanwhile, a charge reversal achieved by the generation of negatively charged thiolated chitosan induces the dissociation of the nanocoating, leading to synchronous release of the living bacteria. The adequate activation of the combined therapeutics at the lesion site exhibits superior synergistic treatment efficacy, as demonstrated by an in vivo assessment using a mouse model of colitis. This work presents an appealing approach to combine living microbial and small-molecular therapeutics for advanced therapy of diseases.

The Beneficial Effects of Dietary Interventions on Gut Microbiota-An Up-to-Date Critical Review and Future Perspectives

Different dietary interventions, especially intermittent fasting, are widely used and promoted by physicians; these regimens have been studied lately for their impact on the gut microbiota composition/function and, consequently, on the general physiopathological processes of the host. Studies are showing that dietary components modulate the microbiota, and, at the same time, the host metabolism is deeply influenced by the different products resulting from nutrient transformation in the microbiota compartment. This reciprocal relationship can potentially influence even drug metabolism for chronic drug regimens, significantly impacting human health/disease. Recently, the influence of various dietary restrictions on the gut microbiota and the differences between the effects were investigated. In this review, we explored the current knowledge of different dietary restrictions on animal and human gut microbiota and the impact of these changes on human health.

Microbiome differences related to metformin intolerance among Black individuals with diabetes, a pilot cross-sectional study

Aims

Metformin is the broadly accepted the first-line medication for diabetes. Its use, however, is limited by gastrointestinal side effects present in approximately 25% of patients. This study aimed to better understand the interplay between metformin intolerance and gut microbiota among Black individuals with diabetes.

Methods

We performed a cross-sectional study among 29 Black individuals living with diabetes with or without metformin intolerance. Participants with mean age 59±11, 58% female, were stratified into three groups: 1)intolerant: metformin intolerance in the past, not on metformin; 2)partially intolerant: mild to moderate gastrointestinal symptoms, currently taking metformin 3)tolerant: using metformin without symptoms. We collected and analyzed rectal swabs and analyzed microbiota composition using V3-V4 regions of the 16s rRNA.

Results

Metformin intolerant subjects trended towards having greatest alpha diversity, followed by tolerant and partially tolerant (Intolerant:4.9; Tolerant:4.2; Partially tolerant:3.9). Mean difference in alpha diversity for intolerant versus partially tolerant was 1.0 (95% CI-0.1,2.1) and intolerant versus tolerant were 0.7 (95% CI -0.4,1.8).

Conclusion

This was the first study to evaluate the role of microbiota and metformin intolerance among Black individuals. We report on differences in alpha diversity as well as microbiota composition.

Integrated Network Pharmacology, Molecular Docking and Animal Experiment to Explore the Efficacy and Potential Mechanism of Baiyu Decoction Against Ulcerative Colitis by Enema

Background

Baiyu Decoction (BYD), a clinical prescription of traditional Chinese medicine, has been proven to be valuable for treating ulcerative colitis (UC) by enema. However, the mechanism of BYD against UC remains unclear.

Purpose

A combination of bioinformatics methods including network pharmacology and molecular docking and animal experiments were utilized to investigate the potential mechanism of BYD in the treatment of UC.

Materials and Methods

Firstly, the representative compounds of each herb in BYD were detected by liquid chromatography-mass spectrometry. Subsequently, we predicted the core targets and potential pathways of BYD for treating UC through network pharmacology. And rat colitis model was established with dextran sodium sulfate. UC rats were subjected to BYD enema administration, during which we recorded body weight changes, disease activity index, and colon length to assess the effectiveness of BYD. Besides, quantitative real-time PCR, western blotting, ELISA and immunofluorescence were used to detect intestinal inflammatory factors, intestinal barrier biomarkers and TOLL-like receptor pathway in rats. Finally, the core components and targets of BYD were subjected to molecular docking so as to further validate the results of network pharmacology.

Results

A total of 41 active compositions and 203 targets related to BYD-UC were subjected to screening. The results of bioinformatics analysis showed that quercetin and kaempferol may be the main compounds. Additionally, AKT1, IL-6, TP53, TNF and IL-1β were regarded as potential therapeutic targets. KEGG results explained that TOLL-like receptor pathway might play a pivotal role in BYD protecting against UC. In addition, animal experiments and molecular docking validated the network pharmacology results. BYD enema treatment can reduce body weight loss, lower disease activity index score, reverse colon shortening, relieve intestinal inflammation, protect intestinal barrier, and inhibit TOLL-like receptor pathway in UC rats. Besides, molecular docking suggested that quercetin and kaempferol docked well with TLR4, AKT1, IL-6, TP53.

Conclusion

Utilizing network pharmacology, animal studies, and molecular docking, enema therapy with BYD was confirmed to have anti-UC efficacy by alleviating intestinal inflammation, protecting the intestinal barrier, and inhibiting the TOLL-like receptor pathway. Researchers should focus not only on oral medications but also on the rectal administration of medications in furtherance of the cure of ulcerative colitis.

Targeting the Gut Microbiota in Kidney Disease: The Future in Renal Nutrition and Metabolism

There is increasing interest in the therapeutic potential of manipulating the gut microbiome of patients with chronic kidney disease (CKD). This is because there is a substantial deviation from a balanced gut microbiota profile in CKD, with many deleterious downstream effects. Nutritional interventions such as plant-based diets with reduced animal protein intake and the use of probiotics, prebiotics, and synbiotics may alter the microbiome. This article aims to briefly describe what is known about the gut microbiome in patients with CKD, factors contributing to gut dysbiosis, and outline important evidence gaps. Future potential therapies, including restoring the microbiota with food and microbiota-based and metabolomic-based therapies, are also discussed.

Unveiling the potential pleiotropic effects of metformin in treating COVID-19: a comprehensive review

This review article explores the potential of metformin, a medication commonly used for type 2 diabetes, as an antiviral and anti-inflammatory agent in the context of coronavirus disease 2019 (COVID-19). Metformin has demonstrated inhibitory effects on the growth of SARS-CoV-2 in cell culture models and has shown promising results in reducing viral load and achieving undetectable viral levels in clinical trials. Additionally, metformin exhibits anti-inflammatory properties by reducing the production of pro-inflammatory cytokines and modulating immune cell function, which may help prevent cytokine storms associated with severe COVID-19. The drug's ability to regulate the balance between pro-inflammatory Th17 cells and anti-inflammatory Treg cells suggests its potential in mitigating inflammation and restoring T cell functionality. Furthermore, metformin's modulation of the gut microbiota, particularly changes in bacterial taxa and the production of short-chain fatty acids, may contribute to its therapeutic effects. The interplay between metformin, bile acids, the gut microbiome, glucagon-like peptide-1 secretion, and glycemic control has implications for the management of diabetes and potential interventions in COVID-19. By refreshing the current evidence, this review highlights the potential of metformin as a therapeutic option in the management of COVID-19, while also exploring its effects on the gut microbiome and immunometabolism.

Metformin: update on mechanisms of action and repurposing potential

Currently, metformin is the first-line medication to treat type 2 diabetes mellitus (T2DM) in most guidelines and is used daily by >200 million patients. Surprisingly, the mechanisms underlying its therapeutic action are complex and are still not fully understood. Early evidence highlighted the liver as the major organ involved in the effect of metformin on reducing blood levels of glucose. However, increasing evidence points towards other sites of action that might also have an important role, including the gastrointestinal tract, the gut microbial communities and the tissue-resident immune cells. At the molecular level, it seems that the mechanisms of action vary depending on the dose of metformin used and duration of treatment. Initial studies have shown that metformin targets hepatic mitochondria; however, the identification of a novel target at low concentrations of metformin at the lysosome surface might reveal a new mechanism of action. Based on the efficacy and safety records in T2DM, attention has been given to the repurposing of metformin as part of adjunct therapy for the treatment of cancer, age-related diseases, inflammatory diseases and COVID-19. In this Review, we highlight the latest advances in our understanding of the mechanisms of action of metformin and discuss potential emerging novel therapeutic uses.

The Role of Activating Transcription Factor 3 in Metformin's Alleviation of Gastrointestinal Injury Induced by Restraint Stress in Mice

Metformin is one of the most commonly used drugs for type 2 diabetes mellitus. In addition to its anti-diabetic property, evidence suggests more potential applications for metformin, such as antiaging, cellular protection, and anti-inflammation. Studies have reported that metformin activates pathways with anti-inflammatory effects, enhances the integrity of gut epithelial tight junctions, and promotes a healthy gut microbiome. These actions contribute to the protective effect of metformin against gastrointestinal (GI) tract injury. However, whether metformin plays a protective role in psychological-stress-associated GI tract injury remains elusive. We aim to elucidate the potential protective effect of metformin on the GI system and develop an effective intervention strategy to counteract GI injury induced by acute psychological stress. By monitoring the levels of GI-nonabsorbable Evans blue dye in the bloodstream, we assessed the progression of GI injury in live mice. Our findings demonstrate that the administration of metformin effectively mitigated GI leakage caused by psychological stress. The GI protective effect of metformin is more potent when used on wild-type mice than on activating-transcription-factor 3 (ATF3)-deficient (ATF3^-/-) mice. As such, metformin-mediated rescue was conducted in an ATF3-dependent manner. In addition, metformin-mediated protection is associated with the induction of stress-induced GI mRNA expressions of the stress-induced genes ATF3 and AMP-activated protein kinase. Furthermore, metformin treatment-mediated protection of CD326⁺ GI epithelial cells against stress-induced apoptotic cell death was observed in wild-type but not in ATF3^-/- mice. These results suggest that metformin plays a protective role in stress-induced GI injury and that ATF3 is an essential regulator for metformin-mediated rescue of stress-induced GI tract injury.

Targeting the gut microbiome to control drug pharmacomicrobiomics: the next frontier in oral drug delivery

INTRODUCTION

The trillions of microorganisms that comprise the gut microbiome form dynamic bidirectional interactions with orally administered drugs and host health. These relationships can alter all aspects of drug pharmacokinetics and pharmacodynamics (PK/PD); thus, there is a desire to control these interactions to maximize therapeutic efficacy. Attempts to modulate drug-gut microbiome interactions have spurred advancements within the field of 'pharmacomicrobiomics' and are poised to become the next frontier of oral drug delivery.

AREAS COVERED

This review details the bidirectional interactions that exist between oral drugs and the gut microbiome, with clinically relevant case examples outlining a clear motive for controlling pharmacomicrobiomic interactions. Specific focus is attributed to novel and advanced strategies that have demonstrated success in mediating drug-gut microbiome interactions.

EXPERT OPINION

Co-administration of gut-active supplements (e.g. pro- and pre-biotics), innovative drug delivery vehicles, and strategic polypharmacy serve as the most promising and clinically viable approaches for controlling pharmacomicrobiomic interactions. Targeting the gut microbiome through these strategies presents new opportunities for improving therapeutic efficacy by precisely mediating PK/PD, while mitigating metabolic disturbances caused by drug-induced gut dysbiosis. However, successfully translating preclinical potential into clinical outcomes relies on overcoming key challenges related to interindividual variability in microbiome composition and study design parameters.

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.

Bacteroides dorei BDX-01 alleviates DSS-induced experimental colitis in mice by regulating intestinal bile salt hydrolase activity and the FXR-NLRP3 signaling pathway

Background: The relationships among intestinal dysbiosis, bile acid (BA) metabolism disorders, and ulcerative colitis pathogenesis are now recognized. However, how specific strains regulate BA metabolism to alleviate colitis is still unclear. This study investigated the effects of Bacteroides dorei on the development of acute colitis and elucidated the underlying mechanisms. Methods: The safety of BDX-01 was evaluated in vitro and in vivo. 2.5% dextran sulfate sodium (DSS) induced colitis in C57BL/6 mice, Caco-2, and J774A.1 cells were used to evaluate the anti-inflammatory effect of BDX-01. qPCR and Western blotting were used to detect the expression of inflammatory pathways. Microbiota composition was analyzed by 16S rRNA gene sequencing. Enzyme activity analysis and targeted metabolomics were used to analyze fecal bile salt hydrolase (BSH) and BA levels. Antibiotic-induced pseudo-germ-free mice were used to investigate the role of gut microbiota in the alleviation of colitis by BDX-01. Results: We confirmed the safety of novel strain Bacteroides dorei BDX-01 in vitro and in vivo. Oral BDX-01 administration significantly ameliorated the symptoms and pathological damage of DSS-induced acute colitis. Moreoever, 16S rRNA sequencing and enzyme activity analysis showed that BDX-01 treatment increased intestinal BSH activity and the abundance of bacteria harboring this enzyme. Targeted metabolomics revealed that BDX-01 significantly increased intestinal BA excretion and deconjugation. Certain BAs act as FXR agonists. The β-muricholic acid (βMCA): taurine β-muricholic acid (T-βMCA) and cholic acid (CA): taurocholic acid (TCA) ratios and the deoxycholic acid (DCA) level decreased markedly in the colitis models but increased substantially in BDX-01-treated mice. The colonic farnesoid X receptor (FXR) and fibroblast growth factor 15 (FGF15) were upregulated in mice treated with BDX-01. BDX-01 downregulated the expression of colonic proinflammatory cytokines pyrin domain-containing 3 (NLRP3), ASC, cleaved caspase-1, and IL-1β. Antibiotic treatment didn't abolish the protective effect of BDX-01 on colitis. In vitro studies showed TβMCA abolished the effects of BDX-01 on FXR activation and inhibition of the NLRP3 inflammasome activation. Conclusion: BDX-01 improved DSS-induced acute colitis by regulating intestinal BSH activity and the FXR-NLRP3 signaling pathway. Our findings indicate that BDX-01 is a promising probiotic to improve the management of ulcerative colitis.

Pediococcus acidilactici pA1c® Improves the Beneficial Effects of Metformin Treatment in Type 2 Diabetes by Controlling Glycaemia and Modulating Intestinal Microbiota

Type 2 diabetes (T2D) is a complex metabolic disease, which involves maintained hyperglycemia, mainly due to the development of an insulin resistance process. Metformin administration is the most prescribed treatment for diabetic patients. In a previously published study, we demonstrated that Pediococcus acidilactici pA1c^® (pA1c) protects from insulin resistance and body weight gain in HFD-induced diabetic mice. The present work aimed to evaluate the possible beneficial impact of a 16-week administration of pA1c, metformin, or the combination of pA1c and metformin in a T2D HFD-induced mice model. We found that the simultaneous administration of both products attenuated hyperglycemia, increased high-intensity insulin-positive areas in the pancreas and HOMA-β, decreased HOMA-IR and also provided more beneficial effects than metformin treatment (regarding HOMA-IR, serum C-peptide level, liver steatosis or hepatic Fasn expression), and pA1c treatment (regarding body weight or hepatic G6pase expression). The three treatments had a significant impact on fecal microbiota and led to differential composition of commensal bacterial populations. In conclusion, our findings suggest that P. acidilactici pA1c^® administration improved metformin beneficial effects as a T2D treatment, and it would be a valuable therapeutic strategy to treat T2D.

Health and Disease: Akkermansia muciniphila, the Shining Star of the Gut Flora

Akkermansia muciniphila (A. muciniphila) has drawn much attention as an important gut microbe strain in recent years. A. muciniphila can influence the occurrence and development of diseases of the endocrine, nervous, digestive, musculoskeletal, and respiratory systems and other diseases. It can also improve immunotherapy for some cancers. A. muciniphila is expected to become a new probiotic in addition to Lactobacillus and Bifidobacterium. An increase in A. muciniphila abundance through direct or indirect A. muciniphila supplementation may inhibit or even reverse disease progression. However, some contrary findings are found in type 2 diabetes mellitus and neurodegenerative diseases, where increased A. muciniphila abundance may aggravate the diseases. To enable a more comprehensive understanding of the role of A. muciniphila in diseases, we summarize the relevant information on A. muciniphila in different systemic diseases and introduce regulators of A. muciniphila abundance to promote the clinical transformation of A. muciniphila research.

AMPK activation alleviated dextran sulfate sodium-induced colitis by inhibiting ferroptosis

OBJECTIVES

Ferroptosis is a newly discovered cell death mode that has been confirmed to occur in the intestinal epithelial cells in ulcerative colitis (UC). In this study we aimed to elucidate the mechanism of ferroptosis and its association with adenosine monophosphate-activated protein kinase (AMPK) in UC.

METHODS

Gene expression profiles of colonic mucosa (GSE87473) were downloaded. Both human colonic samples and dextran sodium sulfate (DSS)-induced colitis murine model were used. The molecular markers of ferroptosis were detected using western blot and immunohistochemistry. Symptoms, iron abundance, and lipid peroxidation level of the mouse model were measured to evaluate the role of AMPK activation in ferroptosis.

RESULTS

Both gene and protein expressions of GPX4 and FTH1 were decreased in UC patients compared with the healthy controls. An increased iron abundance and lipid peroxidation level in colon tissues and damaged mitochondria were found in DSS-induced colitis. AMPK expression was decreased in UC patients and correlated with FTH1 and GPX4. Activation of AMPK with metformin inhibited ferroptosis in the colon, improved symptoms, and prolonged the lifespan in DSS-induced colitis mice.

CONCLUSIONS

Ferroptosis can be observed in colonic tissues in UC. AMPK activation inhibits ferroptosis in murine colitis model, which may act as a potential target for the treatment of colitis.

Gut microbiota remodeling improves natural aging-related disorders through Akkermansia muciniphila and its derived acetic acid

Accumulating evidence indicates gut microbiota contributes to aging-related disorders. However, the exact mechanism underlying gut dysbiosis-related pathophysiological changes during aging remains largely unclear. In the current study, we first performed gut microbiota remodeling on old mice by fecal microbiota transplantation (FMT) from young mice, and then characterized the bacteria signature that was specifically altered by FMT. Our results revealed that FMT significantly improved natural aging-related systemic disorders, particularly exerted hepatoprotective effects, and improved glucose sensitivity, hepatosplenomegaly, inflammaging, antioxidative capacity and intestinal barrier. Moreover, FMT particularly increased the abundance of fecal A.muciniphila, which was almost nondetectable in old mice. Interestingly, A.muciniphila supplementation also exerted similar benefits with FMT on old mice. Notably, targeted metabolomics on short chain fatty acids (SCFAs) revealed that only acetic acid was consistently reversed by FMT. Then, acetic acid intervention exerted beneficial actions on both Caenorhabditis elegans and natural aging mice. In conclusion, our current study demonstrated that gut microbiota remodeling improved natural aging-related disorders through A.muciniphila and its derived acetic acid, suggesting that interventions with potent stimulative capacity on A. muciniphila growth and production of acetic acid was alternative and effective way to maintain healthy aging. DATA AVAILABILITY STATEMENT: The data of RNAseq and 16 S rRNA gene sequencing can be accessed in NCBI with the accession number PRJNA848996 and PRJNA849355.

Ameliorating Effects of Vitamin K2 on Dextran Sulfate Sodium-Induced Ulcerative Colitis in Mice

Ulcerative colitis (UC) is a chronic recurrent inflammatory illness of the gastrointestinal system. The purpose of this study was to explore the alleviating effect of vitamin K2 (VK2) on UC, as well as its mechanism. C57BL/6J mice were given 3% DSS for seven days to establish UC, and they then received VK2 (15, 30, or 60 mg/kg·bw) and 5-aminosalicylic acid (100 mg/kg·bw) for two weeks. We recorded the clinical signs, body weights, colon lengths, and histological changes during the experiment. We detected the inflammatory factor expressions using enzyme-linked immunosorbent assay (ELISA) kits, and we detected the tight junction proteins using Western blotting. We analyzed the intestinal microbiota alterations and short-chain fatty acids (SCFAs) using 16S rRNA sequencing and targeted metabolomics. According to the results, VK2 restored the colon lengths, improved the colonic histopathology, reduced the levels of proinflammatory cytokines (such as IL-1β, TNF-α, and IL-6), and boosted the level of the immunosuppressive cytokine IL-10 in the colon tissues of the colitis mice. Moreover, VK2 promoted the expression of mucin and tight junction proteins (such as occludin and zonula occludens-1) in order to preserve the intestinal mucosal barrier function and prevent UC in mice. Additionally, after the VK2 intervention, the SCFAs and SCFA-producing genera, such as Eubacterium_ruminantium_group and Faecalibaculum, were elevated in the colon. In conclusion, VK2 alleviated the DSS-induced colitis in the mice, perhaps by boosting the dominant intestinal microflora, such as Faecalibaculum, by reducing intestinal microflora dysbiosis, and by modulating the expression of SCFAs, inflammatory factors, and intestinal barrier proteins.

ROS-triggered self-disintegrating and pH-responsive astaxanthin nanoparticles for regulating the intestinal barrier and colitis

Smart delivery systems with stimuli-responsive capability are able to improve the bioaccessibility through increasing the solubility, physicochemical stability and biocompatibility of bioactive compounds. In this study, the astaxanthin nanoparticles with reactive oxygen species (ROS) and pH dual-response function were design and constructed using poly (propylene sulfide) covalently modified sodium alginate as carriers based on ultrasonic assisted self-assembly strategy. Atomic force microscope and scanning electron microscope analysis showed that the nanoparticles were spherical in shape with a size of around 260 nm. Meanwhile, the astaxanthin nanoparticles showed both pH and ROS stimuli-responsive release characteristics. In vitro cell experiments showed that astaxanthin nanoparticles significantly inhibited the production of ROS and mitochondrial depolarization induced by oxidative stress. In vivo colitis experiment of mice revealed that astaxanthin nanoparticles could significantly relieve colitis, protect the integrity of colon tissue and restore the expression of tight junction proteins ZO-1 and occludin. The abundance of Lactobacillus and Lachnospiraceae, and the ratio of Firmicutes/Bacteroidota of gut microbiota were significantly improved after intervention of the stimuli-responsive astaxanthin nanoparticles. This work provided a simple strategy for constructing ROS/pH dual response delivery system, which provided an experimental basis for improving the oral bioavailability of hydrophobic active compounds.

Leaky Gut Plays a Critical Role in the Pathophysiology of Autism in Mice by Activating the Lipopolysaccharide-Mediated Toll-Like Receptor 4–Myeloid Differentiation Factor 88–Nuclear Factor Kappa B Signaling Pathway

Increased intestinal barrier permeability, leaky gut, has been reported in patients with autism. However, its contribution to the development of autism has not been determined. We selected dextran sulfate sodium (DSS) to disrupt and metformin to repair the intestinal barrier in BTBR T+tf/J autistic mice to test this hypothesis. DSS treatment resulted in a decreased affinity for social proximity; however, autistic behaviors in mice were improved after the administration of metformin. We found an increased affinity for social proximity/social memory and decreased repetitive and anxiety-related behaviors. The concentration of lipopolysaccharides in blood decreased after the administration of metformin. The expression levels of the key molecules in the toll-like receptor 4 (TLR4)–myeloid differentiation factor 88 (MyD88)–nuclear factor kappa B (NF-κB) pathway and their downstream inflammatory cytokines in the cerebral cortex were both repressed. Thus, “leaky gut” could be a trigger for the development of autism via activation of the lipopolysaccharide-mediated TLR4–MyD88–NF-κB pathway.

Global trends in Akkermansia muciniphila research: A bibliometric visualization

BACKGROUND

Akkermansia muciniphila is a member of the gut microbiome, using mucin as sources of carbon, nitrogen, and energy. Since the first discovery of this unique bacterium in 2004, A. muciniphila has been extensively studied. It is considered a promising "next-generation beneficial microbe." The purpose of this paper is to sort out the research status and summarize the hotspots through bibliometric analysis of the publications of A. muciniphila.

METHODS

The publications about A. muciniphila from January 2004 to February 2022 were obtained from the Web of Science Core Collection. Visualization analyses were performed using three bibliometric tools and GraphPad Prism.

RESULTS

A total of 1,478 published documents were analyzed. Annual publication number grew from 1 in 2004 to 336 in 2021, with China being the leading producer (33.36%). De Vos, Willem M was the most productive author with the highest H-index (documents = 56, H-index = 37), followed by Cani, Patrice D (documents = 35, H-index = 25). And Scientific Reports published the most papers. PNAS was the keystone taxa in this field, with high betweenness centrality (0.11) and high frequency. The keywords with high frequency in recent years include: oxidative stress, diet, metformin, fecal microbiota transplantation, short-chain fatty acids, polyphenols, microbiota metabolites and so on. The keyword "oxidative stress" was observed to be increasing in frequency recently.

CONCLUSION

Over time, the scope of the research on the clinical uses of A. muciniphila has gradually increased, and was gradually deepened and developed toward a more precise level. A. muciniphila is likely to remain a research hotspot in the foreseeable future and may contribute to human health.

Tauroursodeoxycholic acid functions as a critical effector mediating insulin sensitization of metformin in obese mice

Metformin is widely used to surmount insulin resistance (IR) and type 2 diabetes. Accumulating evidence suggests that metformin may improve IR through regulating gut microbiota and bile acids. However, the underlying mechanisms remain unclear. Our metabolomic analysis showed that metformin significantly increased the accumulation of tauroursodeoxycholic acid (TUDCA) in intestine and liver from high-fat diet (HFD)-induced IR mice. TUDCA also alleviated IR, and reduced oxidative stress and intestinal inflammation in ob/ob mice. TUDCA blocked KEAP1 to bind with Nrf2, resulting in Nrf2 translocation into nuclear and initiating the transcription of antioxidant genes, which eventually reduced intracellular ROS accumulation and improved insulin signaling. Analysis of gut microbiota further revealed that metformin reduced the relative abundance of Bifidobacterium, which produces bile salt hydrolase (BSH). The reduction in BSH was probably crucial for the accumulation of TUDCA. Metformin also increased the proportion of Akkermanisia muciniphlia in gut microbiota of ob/ob mice via TUDCA. These beneficial effects of metformin in remodeling gut microbiota, reducing oxidative stress and improving insulin sensitivity were partly due to the accumulation of TUDCA, suggesting that TUDCA may be a potential therapy for metabolic syndrome.

Potential benefits of metformin and pioglitazone combination therapy via gut microbiota and metabolites in high-fat diet-fed mice

Metformin and pioglitazone monotherapy have been proven to alter gut microbiota in diabetes and obesity. The present study aimed to investigated whether the combined administration of pioglitazone and metformin achieved superior protective effects on high-fat diet (HFD)-fed obese mice and elucidated its molecular mechanism via the gut microbiota and its metabolites. C57BL/6 males were randomly divided into five groups: the control group, fed a normal control diet; the HFD group, fed an HFD; the metformin monotherapy group, fed an HFD and treated with metformin; the pioglitazone monotherapy group, fed an HFD and treated with pioglitazone; and the combination therapy group, fed an HFD and treated with metformin and pioglitazone combination therapy. The cecal contents were collected for 16S rDNA amplicon sequencing and untargeted metabolomics analysis. The results showed that the combination therapy of metformin and pioglitazone significantly improved insulin sensitivity and glucolipid metabolism in HFD-fed mice. Combination therapy markedly altered gut microbiota by increasing beneficial bacteria, such as Bifidobacterium, Christensenellaceae_R-7_group, Faecalibacterium and Roseburia, and decreasing harmful bacteria, such as Oscillibacter and Eubacterium_xylanophilum_group. Fecal metabolites were significantly changed in the combination therapy group, including a reduction in amino acid metabolism and augmentation of lipid metabolism, such as citrulline, sarcosine, D-glutamine, lipoxin A4, prostaglandin E2, stearidonic acid and lucidenic acid A. These results revealed that combined metformin and pioglitazone therapy had synergistic effects or at least have an additive effect on modifying gut microbiota and metabolites, closely associated with improved glucolipid metabolic parameters in HFD-fed mice, which provides novel evidence and promising targets for metformin and pioglitazone combination therapy in type 2 diabetes.

Repurposing metformin as a potential treatment for inflammatory bowel disease: Evidence from cell to the clinic

Inflammatory bowel disease (IBD) comprises a group of intestinal disorders, including ulcerative colitis and Crohn's disease. Currently, the incidence and prevalence of IBD are increasing globally. Although both biologic agents and small molecule drugs have been available for treatment of IBD patients, approximately one third of treated patients do not respond to these treatments. Therefore, novel therapy or repurposing of drugs have been extensively studied to obtain an effective therapy for IBD patients. Among these drugs, metformin has been reported to exert beneficial effects in many organs via its anti-inflammatory effect. Additionally, evidence from cellular to clinical models of IBD demonstrated significant positive effects of metformin on inflammatory pathways, oxidative stress, gut barrier integrity, and gut microbiota. In this review, the beneficial effects of metformin on IBD are comprehensively summarized and discussed using the results of in vitro, in vivo, and clinical studies. Increased understanding of these protective effects and the underlying mechanisms may pave the way for effective use of metformin in IBD patients.

Pretreatment with IPA ameliorates colitis in mice: Colon transcriptome and fecal 16S amplicon profiling

3-Indolepropionic acid (IPA) is a tryptophan metabolite that has anti-inflammatory properties. The present study try to investigate the phylactic effects of IPA on dextran sodium sulfate (DSS)-induced colitis mice. The results showed that IPA pretreatment ameliorated the DSS-induced decrease in growth performance, and intestinal damage and enhanced immunity in mice. RNA-seq analysis of mouse colon samples revealed that the differentially expressed genes (DEGs) were mainly enriched in immune-related pathways. 16S rRNA sequencing showed that IPA pretreatment ameliorated DSS-induced colonic microbiota dysbiosis. Moreover, the expression levels of gut immune genes were positively correlated with the relative abundance of several probiotics, such as Alloprevotella and Catenibacterium. In conclusion, IPA alleviates DSS-induced acute colitis in mice by regulating inflammatory cytokines, balancing the colonic microbiota and modulating the expression of genes related to inflammation, which would also provide a theoretical basis for IPA as a strategy to improve intestinal health.

Anti-Hyperglycemic Agents in the Adjuvant Treatment of Sepsis: Improving Intestinal Barrier Function

Intestinal barrier injury and hyperglycemia are common in patients with sepsis. Bacteria translocation and systemic inflammatory response caused by intestinal barrier injury play a significant role in sepsis occurrence and deterioration, while hyperglycemia is linked to adverse outcomes in sepsis. Previous studies have shown that hyperglycemia is an independent risk factor for intestinal barrier injury. Concurrently, increasing evidence has indicated that some anti-hyperglycemic agents not only improve intestinal barrier function but are also beneficial in managing sepsis-induced organ dysfunction. Therefore, we assume that these agents can block or reduce the severity of sepsis by improving intestinal barrier function. Accordingly, we explicated the connection between sepsis, intestinal barrier, and hyperglycemia, overviewed the evidence on improving intestinal barrier function and alleviating sepsis-induced organ dysfunction by anti-hyperglycemic agents (eg, metformin, peroxisome proliferators activated receptor-γ agonists, berberine, and curcumin), and summarized some common characteristics of these agents to provide a new perspective in the adjuvant treatment of sepsis.

Diet Supplementation with NUTRIOSE, a Resistant Dextrin, Increases the Abundance of Parabacteroides distasonis in the Human Gut

SCOPE

An imbalance of the gut microbiota ("dysbiosis") is associated with numerous chronic diseases, and its modulation is a promising novel therapeutic approach. Dietary supplementation with soluble fiber is one of several proposed modulation strategies. This study aims at confirming the impact of the resistant dextrin NUTRIOSE (RD), a soluble fiber with demonstrated beneficial health effects, on the gut microbiota of healthy individuals.

METHODS AND RESULTS

Fifty healthy women are enrolled and supplemented daily with either RD (n = 24) or a control product (n = 26) during 6 weeks. Characterization of the fecal metagenome with shotgun sequencing reveals that RD intake dramatically increases the abundance of the commensal bacterium Parabacteroides distasonis. Furthermore, presence in metagenomes of accessory genes from P. distasonis, coding for susCD (a starch-binding membrane protein complex) is associated with a greater increase of the species. This suggests that response to RD might be strain-dependent.

CONCLUSION

Supplementation with RD can be used to specifically increase P. distasonis in gut microbiota of healthy women. The magnitude of the response may be associated with fiber-metabolizing capabilities of strains carried by subjects. Further research will seek to confirm that P. distasonis directly modulates the clinical effects observed in other studies.

Metformin Protects the Intestinal Barrier by Activating Goblet Cell Maturation and Epithelial Proliferation in Radiation-Induced Enteropathy

Radiotherapy or accidental exposure to high-dose radiation can cause severe damage to healthy organs. The gastrointestinal (GI) tract is a radiation-sensitive organ of the body. The intestinal barrier is the first line of defense in the GI tract, and consists of mucus secreted by goblet cells and a monolayer of epithelium. Intestinal stem cells (ISCs) help in barrier maintenance and intestinal function after injury by regulating efficient regeneration of the epithelium. The Wnt/β-catenin pathway plays a critical role in maintaining the intestinal epithelium and regulates ISC self-renewal. Metformin is the most widely used antidiabetic drug in clinical practice, and its anti-inflammatory, antioxidative, and antiapoptotic effects have also been widely studied. In this study, we investigated whether metformin alleviated radiation-induced enteropathy by focusing on its role in protecting the epithelial barrier. We found that metformin alleviated radiation-induced enteropathy, with increased villi length and crypt numbers, and restored the intestinal barrier function in the irradiated intestine. In a radiation-induced enteropathy mouse model, metformin treatment increased tight-junction expression in the epithelium and inhibited bacterial translocation to mesenteric lymph nodes. Metformin increased the number of ISCs from radiation toxicity and enhanced epithelial repair by activating Wnt/β-catenin signaling. These data suggested that metformin may be a potential therapeutic agent for radiation-induced enteropathy.