Alpha-Glucosidase Inhibitors Alter Gut Microbiota and Ameliorate Collagen-Induced Arthritis

Preclinical RA: How to halt its progression

Rheumatoid arthritis (RA) is a chronic autoimmune disorder with a complex pathogenesis that evolves through various stages before clinical symptoms emerge. This review outlines the natural history of RA, starting from genetic predisposition and environmental triggers to preclinical autoimmunity and subsequent joint inflammation. Key genetic factors interact with environmental elements like smoking and infections, producing autoantibodies such as anti-citrullinated protein antibodies (ACPA) and rheumatoid factor, which precede clinical manifestations by several years. The preclinical phases offer critical opportunities for intervention aiming at halting disease progression. Preventive strategies including lifestyle modifications, dietary interventions, and targeted immune modulation may halt the progression to clinical RA in those at-risk individuals.

Acarbose impairs gut Bacteroides growth by targeting intracellular glucosidases

Acarbose is a type 2 diabetes medicine that prevents dietary starch breakdown into glucose by inhibiting host amylase and glucosidase enzymes. Numerous gut species in the Bacteroides genus enzymatically break down starch and change in relative abundance within the gut microbiome in acarbose-treated individuals. To mechanistically explain this observation, we used two model starch-degrading Bacteroides, Bacteroides ovatus (Bo), and Bacteroides thetaiotaomicron (Bt). Bt growth on starch polysaccharides is severely impaired by acarbose, whereas Bo growth is much less affected by the drug. The Bacteroides use a starch utilization system (Sus) to grow on starch. We hypothesized that Bo and Bt Sus enzymes are differentially inhibited by acarbose. Instead, we discovered that although acarbose primarily targets the Sus periplasmic GH97 enzymes in both organisms, the drug affects starch processing at multiple other points. Acarbose competes for transport through the TonB-dependent SusC proteins and binds to the Sus transcriptional regulators. Furthermore, Bo expresses a non-Sus GH97 (BoGH97D) when grown in starch with acarbose. The Bt homolog, BtGH97H, is not expressed in the same conditions, nor can overexpression of BoGH97D complement the Bt growth inhibition in the presence of acarbose. This work informs us about unexpected complexities of Sus function and regulation in Bacteroides, including variation between related species. Furthermore, this indicates that the gut microbiome may be a source of variable response to acarbose treatment for diabetes.

IMPORTANCE

Acarbose is a type 2 diabetes medication that works primarily by stopping starch breakdown into glucose in the small intestine. This is accomplished by the inhibition of host enzymes, leading to better blood sugar control via reduced ability to derive glucose from dietary starches. The drug and undigested starch travel to the large intestine where acarbose interferes with the ability of some bacteria to grow on starch. However, little is known about how gut bacteria interact with acarbose, including microbes that can use starch as a carbon source. Here, we show that two gut species, Bacteroides ovatus (Bo) and Bacteroides thetaiotaomicron (Bt), respond differently to acarbose: Bt growth is inhibited by acarbose, while Bo growth is less affected. We reveal a complex set of mechanisms involving differences in starch import and sensing behind the different Bo and Bt responses. This indicates the gut microbiome may be a source of variable response to acarbose treatment for diabetes via complex mechanisms in common gut microbes.

Butyrate: a bridge between intestinal flora and rheumatoid arthritis

In patients with rheumatoid arthritis (RA), intestinal flora imbalance and butyrate metabolism disorders precede clinical arthritis and are associated with the pathogenesis of RA. This imbalance can alter the immunology and intestinal permeability of the intestinal mucosa, leading to damage to the intestinal barrier. In this context, bacteria and their metabolites can enter the bloodstream and reach the distant target tissues of the host, resulting in local inflammation and aggravating arthritis. Additionally, arthritis is also exacerbated by bone destruction and immune tolerance due to disturbed differentiation of osteoclasts and adaptive immune cells. Of note, butyrate is a metabolite of intestinal flora, which not only locally inhibits intestinal immunity and targets zonulin and tight junction proteins to alleviate intestinal barrier-mediated arthritis but also inhibits osteoclasts and autoantibodies and balances the immune responses of T and B lymphocytes throughout the body to repress bone erosion and inflammation. Therefore, butyrate is a key intermediate linking intestinal flora to the host. As a result, restoring the butyrate-producing capacity of intestinal flora and using exogenous butyrate are potential therapeutic strategies for RA in the future.

Acupuncture influences multiple diseases by regulating gut microbiota

Acupuncture, an important green and side effect-free therapy in traditional Chinese medicine, is widely use both domestically and internationally. Acupuncture can interact with the gut microbiota and influence various diseases, including metabolic diseases, gastrointestinal diseases, mental disorders, nervous system diseases, and other diseases. This review presents a thorough analysis of these interactions and their impacts and examines the alterations in the gut microbiota and the potential clinical outcomes following acupuncture intervention to establish a basis for the future utilization of acupuncture in clinical treatments.

Two weeks of acarbose treatment shows no effect on gut microbiome composition in patients with type 2 diabetes: a randomised, placebo-controlled, double-blind, crossover study

Aim

The alpha-glucosidase inhibitor acarbose is approved for the treatment of type 2 diabetes (T2D). It acts in the lumen of the gut by reducing intestinal hydrolysis and absorption of ingested carbohydrates. This reduces postprandial blood glucose concentration and increases the content of carbohydrates in the distal parts of the intestine potentially influencing gut microbiome (GM) composition and possibly impacting the gut microbiome (GM) dysbiosis associated with T2D. Here, we investigated the effect of acarbose on GM composition in patients with T2D.

Methods

Faecal samples were collected in a previously conducted randomised, placebo-controlled, double-blind, crossover study in which 15 individuals with metformin-treated T2D (age 57-85 years, HbA1c 40-74 mmol/mol, BMI 23.6-34.6 kg/m2) were subjected to two 14-day treatment periods with acarbose and placebo, respectively, separated by a 6-week wash-out period. Faecal samples were collected before and by the end of each treatment period. The GM profiles were evaluated by 16S rRNA gene amplicon sequencing.

Results

The GM profiles after the treatment periods with acarbose or placebo remained unaffected (P > 0.7) when compared with the GM profiles before treatment. This applied to the analysis of within-sample diversity (α-diversity) and between-sample bacterial composition diversity (β-diversity). Additionally, no dominant bacterial species differentiated the treatment groups, and only minor increases in the relative abundances of Klebsiella spp. and Escherichia coli (P < 0.05) were observed after acarbose treatment.

Conclusion

In patients with metformin-treated T2D, 14 days of treatment with acarbose showed only minor effects on GM as seen in increased relative abundances of Klebsiella spp. and Escherichia coli.

Integrative analysis of systemic lupus erythematosus biomarkers: Role of fecal hsa-mir-223-3p and gut microbiota in transkingdom dynamics

Systemic lupus erythematosus (SLE) involves a florid set of clinical manifestations whose autoreactive origin is characterized by an overactivation of the immune system and the production of a large number of autoantibodies. Because it is a complex pathology with an inflammatory component, its pathogenesis is not yet fully understood, assuming both genetic and environmental predisposing factors. Currently, it is known that the role of the human microbiome is crucial in maintaining the transkingdom balance between commensal microorganisms and the immune system. In the present work we study the intestinal microbiota of Argentine patients with different stages of SLE receiving or not different treatments. Microbiota composition and fecal miRNAs were assessed by 16 S sequencing and qPCR. hsa-miR-223-3p, a miRNA involved in several inflammation regulation pathways, was found underexpressed in SLE patients without immunosuppressive treatment. In terms of microbiota there were clear differences in population structure (Weighted and Unweighted Unifrac distances, p-value <0.05) and core microbiome between cases and controls. In addition, Collinsella, Bifidobacterium, Streptococcus genera and aromatics degradation metabolisms were overrepresented in the SLE group. Medical treatment was also determinant as several microbial metabolic pathways were influenced by immunosuppressive therapy. Particularly, allantoin degradation metabolism was differentially expressed in the group of patients receiving immunosuppressants. Finally, we performed a logistic regression model (LASSO: least absolute shrinkage and selection operator) considering the expression levels of the fecal hsa-miR223-3p; the core microbiota; the differentially abundant bacterial taxa and the differentially abundant metabolic pathways (p<0.05). The model predicted that SLE patients could be associated with greater relative abundance of the formaldehyde oxidation pathway (RUMP_PWY). On the contrary, the preponderance of the ketodeoxyoctonate (Kdo) biosynthesis and activation route (PWY_1269) and the genera Lachnospiraceae_UCG_004, Lachnospira, Victivallis and UCG_003 (genus belonging to the family Oscillospiraceae of the class Clostridia) were associated with a control phenotype. Overall, the present work could contribute to the development of integral diagnostic tools for the comprehensive phenotyping of patients with SLE. In this sense, studying the commensal microbial profile and possible pathobionts associated with SLE in our population proposes more effective and precise strategies to explore possible treatments based on the microbiota of SLE patients.

Fufang Duzheng tablet attenuates adjuvant rheumatoid arthritis by inhibiting arthritis inflammation and gut microbiota disturbance in rats

Objective

To explore the treatment effect and potential mechanism on gut microbiota, nutrition, and metabolism of Fufang Duzheng Tablet (DZGP) on rheumatoid arthritis (RA).

Methods

Collagen-induced arthritis rats' models were established and divided into three groups: model control group (FK), DZGP group (FZ, 0.45 g/kg/d), and methotrexate group (FM, 1.35 mg/kg), which were treated by gavage for 28 days. The physiopathologic changes of joints and body weight in each group were recorded; the morphology of synovial and ankle tissues was observed by hematoxylin-eosin staining, and the level of serum TNF-α and IL-1β was tested by ELISA. UPLC/MS-MS and network pharmacological analysis were used to identify the serum components, and 16S rDNA sequencing analysis was applied to the intestinal contents of rats.

Results

DZGP treatment significantly alleviated arthritis symptoms, pathological manifestations, toe thickness, and TNF-α and IL-1β levels in RA rats. We identified 105 metabolites and 18 components in the serum of DZGP-group rats. The main therapeutic targets of DZGP for anti-RA were TP53, epidermal growth factor receptor, and AKT1. Molecular docking showed that there was good binding efficiency between core components and main targets. 16S rDNA sequencing showed that DZGP treatment regulated the structure of the gut microbiota.

Conclusion

DZGP showed a good anti-inflammatory effect on RA and played an important role in improving the structure of the gut microbiota in RA rats.

Human fecal alpha-glucosidase activity and its relationship with gut microbiota profiles and early stages of intestinal mucosa damage

OBJECTIVES

We investigated potential relationships among initial lesions of the intestinal mucosa, fecal enzymatic activities and microbiota profiles.

METHODS

Fecal samples from 54 volunteers were collected after recruitment among individuals participating in a colorectal cancer (CRC) screening program in our region (Northern Spain) or attending for consultation due to clinical symptoms; intestinal mucosa samples were resected during colonoscopy. Enzymatic activities were determined in fecal supernatants by a semi-quantitative method. The fecal microbiota composition was determined by 16S rRNA gene-based sequencing. The results were compared between samples from clinical diagnosis groups (controls and polyps), according with the type of polyp (hyperplastic polyps or conventional adenomas) and considering the grade of dysplasia for conventional adenomas (low and high grade dysplasia).

RESULTS

High levels of α-glucosidase activity were more frequent among samples from individuals diagnosed with intestinal polyps, reaching statistical significance for conventional adenomas and for low grade dysplasia adenomas when compared to controls. Regarding the microbiota profiles, higher abundance of Christensenellaceae_R-7 group and Oscillospiraceae_UCG-002 were found in fecal samples displaying low α-glucosidase activity as compared with those with higher activity as well as in controls with respect to conventional adenomas. A relationship was evidenced among intestinal mucosal lesions, gut glucosidase activities and intestinal microbiota profiles.

CONCLUSIONS

Our findings suggest a relationship among altered fecal α-glucosidase levels, the presence of intestinal mucosal lesions, which can be precursors of CRC, and shifts in defined microbial groups of the fecal microbiota.

Acarbose Impairs Gut Bacteroides Growth by Targeting Intracellular GH97 Enzymes

Acarbose is a type-2 diabetes medicine that inhibits dietary starch breakdown into glucose by inhibiting host amylase and glucosidase enzymes. Numerous gut species in the Bacteroides genus enzymatically break down starch and change in relative abundance within the gut microbiome in acarbose-treated individuals. To mechanistically explain this observation, we used two model starch-degrading Bacteroides, Bacteroides ovatus (Bo) and Bacteroides thetaiotaomicron (Bt). Bt growth is severely impaired by acarbose whereas Bo growth is not. The Bacteroides use a starch utilization system (Sus) to grow on starch. We hypothesized that Bo and Bt Sus enzymes are differentially inhibited by acarbose. Instead, we discovered that although acarbose primarily targets the Sus periplasmic GH97 enzymes in both organisms, the drug affects starch processing at multiple other points. Acarbose competes for transport through the Sus beta-barrel proteins and binds to the Sus transcriptional regulators. Further, Bo expresses a non-Sus GH97 (BoGH97D) when grown in starch with acarbose. The Bt homolog, BtGH97H, is not expressed in the same conditions, nor can overexpression of BoGH97D complement the Bt growth inhibition in the presence of acarbose. This work informs us about unexpected complexities of Sus function and regulation in Bacteroides, including variation between related species. Further, this indicates that the gut microbiome may be a source of variable response to acarbose treatment for diabetes.

Initial diet shapes resistance-gene composition and fecal microbiome dynamics in young ruminants during nursing

This study was conducted to examine how colostrum pasteurization affects resistance genes and microbial communities in calf feces. Forty female Holstein calves were randomly assigned to either the control (CON) group, which received unheated colostrum, or the pasteurized colostrum (PAT) group. The calves body weight was measured weekly before morning feeding. Calf starter intake were measured and recorded daily before morning feeding. Samples of colostrum were collected before feeding. Blood was collected on d 1 and 70 before morning feeding. Ten calves were randomly selected from each group (n = 20 calves total) for fecal sampling on d 3, 28, 56 and 70 for subsequent DNA extraction and metagenomic sequencing. Total bacterial counts in the colostrum were markedly higher in the CON group than in the PAT group. Pasteurized colostrum administration substantially reduced the ARO diversity and diminishes the abundance of Enterobacteriaceae, thereby decreasing their contribution to resistance genes. Pasteurization also reduced glucoside hydrolase-66 activity in 3-day-old calves which led to an increase in the activity of aminoglycoside antibiotics, resulting in 52.63 % of PAT-enriched bacteria acquiring aminoglycoside resistance genes. However, from the perspective of overall microbial community, the proportion of aminoglycoside, beta-lactam and tetracycline resistance genes carried by microbial community in PAT group was lower than CON group (P < 0.05). Fecal samples from the PAT group contained greater abundances of Subdoligranulum (P < 0.05) and Lachnospiraceae_NK4A136_group (P < 0.05) on days 28 and 70 compared to CON. Network analysis and abundance variations of the different bacteria obtained by linear discriminant analysis effect size analysis showed that pasteurized colostrum feeding reduced the interactions among related bacteria and maintained stability of the hind-gut microbiome. In conclusion, these findings underscore the intricate interactions between early diet, calf resistance-gene transmission and microbial dynamics, which should be carefully considered in calf-rearing practices.

Associations Between Thiazolidinediones Use and Incidence of Rheumatoid Arthritis: A Retrospective Population-Based Cohort Study

OBJECTIVE

Preclinical studies suggest that thiazolidinediones (TZDs) may have a protective effect on rheumatoid arthritis (RA), but evidence from population-based studies is scarce. This study aimed to assess the association between use of TZDs and incidence of RA in a retrospective cohort of patients with type 2 diabetes mellitus (T2DM).

METHODS

A retrospective cohort of patients with T2DM who were new users of TZDs or alpha glucosidase inhibitors (AGIs) was assembled. We applied the inverse probability of treatment weighted Cox model to estimate the hazard ratio (HR) of RA incidence associated with the use of TZDs compared with AGIs.

RESULTS

The final analysis included 56,796 new users of AGIs and 14,892 new users of TZDs. The incidence of RA was 187.4 and 135.2 per 100,000 person-years in AGI users and TZD users, respectively. Compared with use of AGIs, TZD use was associated with a reduction in RA incidence, with an HR of 0.72 (95% confidence interval [95% CI] 0.59-0.89). HRs for cumulative use of TZDs for 0.51 to 4.0 years and more than 4 years with incidence of RA were 0.55 (95% CI 0.35-0.88) and 0.74 (95% CI 0.57-0.98), respectively. Various subgroup analyses and sensitivity analyses were consistent with the primary analysis.

CONCLUSION

Use of TZDs is associated with a decreased risk of incident RA in patients with T2DM.

Dietary Macleaya cordata extract supplementation improves the growth performance and gut health of broiler chickens with necrotic enteritis

BACKGROUND

The poultry industry needs effective antibiotic alternatives to control outbreaks of necrotic enteritis (NE) caused by Clostridium perfringens.

METHODS

The aim of this study was to investigate the effects of dietary supplementation with Macleaya cordata extract (MCE) on the immune function and gut microbiota of broilers with NE. A total of 288 1-day-old broiler chicks were randomly assigned to a 2 × 2 factorial arrangement with two concentrations of dietary MCE supplementation (0 or 350 mg/kg of diet) and two disease challenge statuses (control or NE).

RESULTS

The results revealed that NE significantly increased the feed conversion rate (FCR), mortality, intestinal lesion score, the levels of IL-1β, IL-17 and IFN-γ/IL-4 in serum and IL-17/IL-10 in the jejunal mucosa, mRNA levels of TLR2, IFN-γ and pIgR in the jejunum, and Clostridium perfringens concentrations in the cecum. NE significantly decreased the body weight (BW), body weight gain (BWG), jejunal villus height, V/C, mRNA level of AMPK-α1 in jejunum, IL-4 level in the jejunal mucosa and lactic acid bacteria abundance in the cecum. MCE significantly increased BW, BWG, jejunal villus height, V/C, mRNA levels of occludin, ZO-1 and AMPK-α1 in the jejunum, the levels of IgA and IgG in serum and IL-10 in the jejunal mucosa and mRNA levels of NF-κB, IL-10 and MHC-II in the jejunum. Additionally, MCE significantly decreased the FCR, mortality, intestinal lesion score, jejunal crypt depth, the levels of IFN-γ and IL-17 in serum and IL-17/IL-10 in the jejunal mucosa, Clostridium perfringens concentrations in the cecum, and mRNA levels of IL-17/IL-10 in the jejunum. Moreover, NE significantly increased the abundance of bacteria that are associated with inflammation, obesity and depression (Alistipes, Barnesiella, Intestinimonas, RF39 and UCG-005) and significantly decreased the abundance of short-chain fatty acid (SCFA)-producing bacteria (Anaerotruncus, Butyricicoccus and Bacteroides) in the cecum. MCE significantly increased the abundance of SCFA-producing bacteria (Streptococcus, Ruminococcus_torques_group and Lachnospiraceae_NK4A136_group) and significantly reduced the abundance of bacteria that are associated with inflammation and obesity (Alistipes, Barnesiella and UCG-010) in the cecum. In the cecum of broilers with NE, the relative abundance of Barnesiella and Alistipes was higher and that of Lachnoclostridium and Shuttleworthia was lower. Interestingly, these trends were reversed by the addition of MCE to the diet. Spearman correlation analysis showed that Barnesiella and Alistipes were associated with enhanced intestinal inflammation and inhibited growth performance, whereas Lachnoclostridium and Shuttleworthia were associated with anti-inflammatory effects.

CONCLUSIONS

MCE ameliorated the loss of growth performance in broiler chickens with NE, probably by regulating the intestinal barrier, immune function, and gut microbiota.

Gut Microbiome and Microbiome-Derived Metabolites in Patients with End-Stage Kidney Disease

The composition of the gut microbiome is altered in patients with chronic kidney disease (CKD). Dysbiosis leads to decreased levels of stool organic acids (OAs) and systemic inflammation, followed by accumulation of uremic toxins (UTs) and the development of end-stage kidney disease (ESKD). We assessed the relationship between the microbiome and UT levels or the development of ESKD by comparing patients undergoing hemodialysis (HD) and those with normal renal function (NRF). This cross-sectional study recruited 41 patients undergoing HD and 38 sex- and age-matched patients with NRF, and gut microbiome, levels of plasma UTs, inflammatory markers, and stool OAs were compared. The indices of beta-diversity differed significantly between patients with NRF and those undergoing HD, and between patients undergoing HD with and without type 2 diabetes. The levels of stool total OA, inflammatory markers, and UTs differed significantly between the patients with NRF and those undergoing HD. The combined main effects of type 2 diabetes and kidney function status were accumulation of indoxyl sulfate and p-cresyl sulfate. The relative abundances of Negativicutes and Megamonas were associated with development of ESKD and with the levels of UTs, even after adjustment for factors associated with the progression of ESKD. The present study indicates that the gut environment differs between patients with NRF and those undergoing HD and between patients undergoing HD with and without type 2 diabetes. Moreover, ESKD patients with diabetes accumulate more UTs derived from the gut microbiome, which might be associated with cardio-renal diseases and poor prognosis.

Inactivation of the antidiabetic drug acarbose by human intestinal microbial-mediated degradation

Drugs can be modified or degraded by the gut microbiota, which needs to be considered in personalized therapy. The clinical efficacy of the antidiabetic drug acarbose, an inhibitor of α-glucosidase, varies greatly among individuals for reasons that are largely unknown. Here we identify in the human gut acarbose-degrading bacteria, termed Klebsiella grimontii TD1, whose presence is associated with acarbose resistance in patients. Metagenomic analyses reveal that the abundance of K. grimontii TD1 is higher in patients with a weak response to acarbose and increases over time with acarbose treatment. In male diabetic mice, co-administration of K. grimontii TD1 reduces the hypoglycaemic effect of acarbose. Using induced transcriptome and protein profiling, we further identify an acarbose preferred glucosidase, Apg, in K. grimontii TD1, which can degrade acarbose into small molecules with loss of inhibitor function and is widely distributed in human intestinal microorganisms, especially in Klebsiella. Our results suggest that a comparatively large group of individuals could be at risk of acarbose resistance due to its degradation by intestinal bacteria, which may represent a clinically relevant example of non-antibiotic drug resistance.

Targeting the human gut microbiome with small-molecule inhibitors

The human gut microbiome is a complex microbial community that is strongly linked to both host health and disease. However, the detailed molecular mechanisms underlying the effects of these microorganisms on host biology remain largely uncharacterized. The development of non-lethal, small-molecule inhibitors that target specific gut microbial activities enables a powerful but underutilized approach to studying the gut microbiome and a promising therapeutic strategy. In this Review, we will discuss the challenges of studying this microbial community, the historic use of small-molecule inhibitors in microbial ecology, and recent applications of this strategy. We also discuss the evidence suggesting that host-targeted drugs can affect the growth and metabolism of gut microbes. Finally, we address the issues of developing and implementing microbiome-targeted small-molecule inhibitors and define important future directions for this research.

Comparison of the Activity of Fecal Enzymes and Concentration of SCFA in Healthy and Overweight Children

In modern societies obesity has become a serious issue which must be urgently addressed. The health implications of neglected obesity are substantial, as not only does it affect individuals' everyday lives, but it also leads to significantly increased mortality due to the development of several disorders such as type-2 diabetes, cardiovascular diseases, cancers, and depression. The objective of this research was to investigate the alterations in selected health markers caused by overweight and obesity in children. The measured parameters were the activity of the fecal enzymes, the concentration of short-chain fatty acids (SCFAs), and the concentration of branched-chain fatty acids (BCFAs). The activity of the fecal enzymes, specifically α-glucosidase, α-galactosidase, β-glucosidase, β-galactosidase, and β-glucuronidase, was determined using spectrophotometry at a wavelength of 400 nm. Furthermore, concentrations of lactic acid, SCFAs (formic, acetic, propionic, butyric, and valeric acids), and BCFAs (isobutyric and isovaleric acids) were determined using the HPLC method. The obtained results reveal that obese children have different fecal enzyme activity and a different profile of fatty acids from children of normal weight. The group of obese children, when compared to children of normal weight, had increased concentrations of BCFAs (p < 0.05) and higher activity of potentially harmful enzymes such as β-glucosidase and β-glucuronidase (p < 0.05). In comparison, children of normal weight exhibited significantly increased concentrations of lactic acid and SCFAs (especially formic and butyric acids) (p < 0.05). Furthermore, their α-glucosidase and α-galactosidase activity were higher when compared to the group of obese children (p < 0.05). These results suggest that the prevalence of obesity has a significant impact on metabolites produced in the gastrointestinal tract, which might result in a higher chance of developing serious diseases.

Gut-joint axis: Gut dysbiosis can contribute to the onset of rheumatoid arthritis via multiple pathways

Rheumatoid Arthritis (RA) is an autoimmune disease characterized by loss of immune tolerance and chronic inflammation. It is pathogenesis complex and includes interaction between genetic and environmental factors. Current evidence supports the hypothesis that gut dysbiosis may play the role of environmental triggers of arthritis in animals and humans. Progress in the understanding of the gut microbiome and RA. has been remarkable in the last decade. In vitro and in vivo experiments revealed that gut dysbiosis could shape the immune system and cause persistent immune inflammatory responses. Furthermore, gut dysbiosis could induce alterations in intestinal permeability, which have been found to predate arthritis onset. In contrast, metabolites derived from the intestinal microbiota have an immunomodulatory and anti-inflammatory effect. However, the precise underlying mechanisms by which gut dysbiosis induces the development of arthritis remain elusive. This review aimed to highlight the mechanisms by which gut dysbiosis could contribute to the pathogenesis of RA. The overall data showed that gut dysbiosis could contribute to RA pathogenesis by multiple pathways, including alterations in gut barrier function, molecular mimicry, gut dysbiosis influences the activation and the differentiation of innate and acquired immune cells, cross-talk between gut microbiota-derived metabolites and immune cells, and alterations in the microenvironment. The relative weight of each of these mechanisms in RA pathogenesis remains uncertain. Recent studies showed a substantial role for gut microbiota-derived metabolites pathway, especially butyrate, in the RA pathogenesis.

Polysaccharides from natural Cordyceps sinensis attenuated dextran sodium sulfate-induced colitis in C57BL/6J mice

As potential candidates for treating ulcerative colitis (UC), polysaccharides have been attracting extensive interest in recent years. Cordyceps sinensis (C. sinensis) is a kind of traditional Chinese edible food, and its polysaccharide fractions have been found to be effective in regulating immunity and protecting the kidneys. To determine the potential function of polysaccharides from natural C. sinensis on UC, their effects in terms of histological, serological, biochemical, and immunological aspects on dextran sulphate sodium (DSS)-induced colitis mice model were investigated. Results showed that the polysaccharides significantly alleviated colitis by increasing the colon length, alleviating colon tissue damage, and inhibiting the activation of the NF-κB pathway. In addition, polysaccharides reduced the contents of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) in the serum, increased the number of goblet cells, and improved the expression of intestinal tight junction proteins (Occludin and Claudin-1). They also evidently enhanced the formation of IgA-secretory cells and sIgA contents. Furthermore, the polysaccharides modulated the gut microbiota by decreasing the relative abundance of Bilophila and increasing the relative abundance of Dehalobacterium, Coprococcus, Oscillospira, and Desulfovibrio, which is accompanied by an increase in the short chain fatty acids' (SCFAs) concentrations in cecal contents. These results suggested that C. sinensis polysaccharides possessed promising intervening effects on experimental acute UC in mice.

Type 2 Diabetes and the Microbiome

Diabetes represents one of the most significant, and rapidly escalating, global healthcare crises we face today. Diabetes already affects one-tenth of the world's adults-more than 537 million people, numbers that have tripled since 2000 and are estimated to reach 643 million by 2030. Type 2 diabetes (T2D), the most prevalent form, is a complex disease with numerous contributing factors, including genetics, epigenetics, diet, lifestyle, medication use, and socioeconomic factors. In addition, the gut microbiome has emerged as a significant potential contributing factor in T2D development and progression. Gut microbes and their metabolites strongly influence host metabolism and immune function, and are now known to contribute to vitamin biosynthesis, gut hormone production, satiety, maintenance of gut barrier integrity, and protection against pathogens, as well as digestion and nutrient absorption. In turn, gut microbes are influenced by diet and lifestyle factors such as alcohol and medication use, including antibiotic use and the consumption of probiotics and prebiotics. Here we review current evidence regarding changes in microbial populations in T2D and the mechanisms by which gut microbes influence glucose metabolism and insulin resistance, including inflammation, gut permeability, and bile acid production. We also explore the interrelationships between gut microbes and different T2D medications and other interventions, including prebiotics, probiotics, and bariatric surgery. Lastly, we explore the particular role of the small bowel in digestion and metabolism and the importance of studying small bowel microbes directly in our search to find metabolically relevant biomarkers and therapeutic targets for T2D.

Gut Microbiome Analysis Can Be Used as a Noninvasive Diagnostic Tool and Plays an Essential Role in the Onset of Membranous Nephropathy

Membranous nephropathy (MN) is a common cause of nephrotic syndrome. The aim is to establish a non-invasive diagnostic model of MN using differential gut microbiome analysis, and to explore the relationship between the gut microbiome and MN pathogenesis in vivo. 825 fecal samples from MN patients and healthy participants are collected from multiple medical centers across China. Key operational taxonomic units (OTUs) obtained through 16S rRNA sequencing are used to establish a diagnostic model. A rat model of MN is developed to explore the relationship between the gut microbiome and the pathogenesis of MN. The diversity and richness of the gut microbiome are significantly lower in patients with MN than in healthy individuals. The diagnostic model based on seven OTUs achieves an excellent efficiency of 98.36% in the training group and also achieves high efficiency in cross-regional cohorts. In MN rat model, gut microbiome elimination prevents model establishment, but fecal microbiome transplantation restores the phenotype of protein urine. Gut microbiome analysis can be used as a non-invasive tool for MN diagnosis. The onset of MN depends on the presence of naturally colonized microbiome. Early intervention in the gut microbiome may help reduce urinary protein level in MN.

Sulfonylureas or biguanides is associated with a lower risk of rheumatoid arthritis in patients with diabetes: A nationwide cohort study

Objective

Diabetes mellitus (DM) is associated with immune dysregulation, while sulfonylureas or biguanides have been linked to anti-inflammatory mechanisms. In this study, we aimed to examine the occurrence rate of rheumatoid arthritis (RA) among DM patients and its incidence rate between different treatments.

Methods

This cohort study used the Taiwan National Health Insurance Research Database between 1997 and 2013 to evaluate the primary outcomes of the preventive role of sulfonylureas or biguanides in the development of RA. We used the Chi-square test for categorical variables and Cox proportional hazard regression and log-rank test to explore the time for development of RA in DM patients. Logistic regression was adopted to estimate the odds ratio of RA in different dosages of medication exposure.

Results

Our cohort study included 94,141 DM cases. The risk of RA development of non-sulfonylureas/biguanides users among the DM group in each analysis was set as the reference, and the adjusted hazard ratio of RA in DM patients who were using sulfonylureas or biguanides was 0.73 (95% confidence interval 0.60–0.90). Within 1 year before the index date, compared with no-biguanides users, patients with more than 180 days of prescription of biguanides had a significantly lower RA risk. Similarly, the significantly lower risk of RA was still observed in DM patients who had more than 365 days of prescription of sulfonylurea within 2 or 3 years before the index date of first RA visit (all p &lt; 0.05).

Conclusion

Our data suggest that sulfonylureas or biguanides are associated with a lower rate of RA development in patients with DM; the effect of biguanides appeared more rapid than that of sulfonylureas, but the sulfonylureas might have a longer effect on lowering RA development incidence.

Anti-Inflammatory and Anti-asthmatic Effects of TMDCT Decoction in Eosinophilic Asthma Through Treg/Th17 Balance

Tuo-Min-Ding-Chuan decoction (TMDCT) is a Traditional Chinese Medicine (TCM) formula consisting of twelve herbs that can relieve the symptoms and treat allergic asthma. Yet, the underlying mechanism of action is still unclear. In this study, we investigated the effect of TMDCT in regulating Treg/Th17 cells immune balance and explored potential metabolic and gut biomarkers associated with Treg and Th17 cells in eosinophilic asthma mice treated by TMDCT. We found that TMDCT increases Treg cells percentage and decreases Th17 cells percentage in the ovalbumin (OVA) -induced eosinophilic asthma mice model. Furthermore, Imidazoleacetic acid, dL-glutamine, L-pyroglutamic acid, 2-deoxy-d-glucose were preliminary identified as biomarkers in plasma metabolites treated by TMDCT, meanwhile genus Desulfovibrio, genus Butyricimonas and genus Prevotella 9 were preliminary identified as gut microbiota biomarkers after TMDCT treatment. These results provide an experimental foundation for the treatment of allergic asthma with Chinese herbal compounds.

Low-Dose Interleukin-2 Altered Gut Microbiota and Ameliorated Collagen-Induced Arthritis

Purpose

Low-dose interleukin-2 (ld-IL-2) has been shown to regulate the balance between effector T and regulatory T (Treg) cells and has been used in several clinical trials to treat autoimmune diseases including rheumatoid arthritis (RA). In this study, we investigated the effects of ld-IL-2 on collagen-induced arthritis (CIA) in mice.

Methods

Arthritis severity in CIA mice was measured using the arthritis index (AI), radiographs, and hematoxylin and eosin staining. Cytokines were detected using enzyme-linked immunosorbent assay. Gut microbiota alterations and short-chain fatty acid production were analyzed through 16S rRNA sequencing and gas chromatography.

Results

The AI scores of CIA mice treated with ld-IL-2 were significantly lower compared to the model group, which significantly reduced the severity of arthritis. Ld-IL-2 also altered the gut microbiota in CIA mice. The diversity, composition, and dominant species of gut microbiota were altered by ld-IL-2 treatment. Ld-IL-2 also increased short-chain fatty acid levels. There was a strong correlation between ld-IL-2 treatment and improved gut microbiota.

Conclusion

Ld-IL-2 significantly ameliorated joint inflammation and bone damage and improved gut microbial dysbiosis in CIA, indicating that it may be a promising therapy for RA patients.

Effects of Oral Glucose-Lowering Agents on Gut Microbiota and Microbial Metabolites

The current research and existing facts indicate that type 2 diabetes mellitus (T2DM) is characterized by gut microbiota dysbiosis and disturbed microbial metabolites. Oral glucose-lowering drugs are reported with pleiotropic beneficial effects, including not only a decrease in glucose level but also weight loss, antihypertension, anti-inflammation, and cardiovascular protection, but the underlying mechanisms are still not clear. Evidence can be found showing that oral glucose-lowering drugs might modify the gut microbiome and thereby alter gastrointestinal metabolites to improve host health. Although the connections among gut microbial communities, microbial metabolites, and T2DM are complex, figuring out how antidiabetic agents shape the gut microbiome is vital for optimizing the treatment, meaningful for the instruction for probiotic therapy and gut microbiota transplantation in T2DM. In this review, we focused on the literatures in gut microbiota and its metabolite profile alterations beneficial from oral antidiabetic drugs, trying to provide implications for future study in the developing field of these drugs, such as combination therapies, pre- and probiotics intervention in T2DM, and subjects with pregestational diabetes and gestational diabetes mellitus.

Gut Microbiota-Medication Interaction in Rheumatic Diseases

Besides its contribution to the development of rheumatic diseases, the gut microbiota interact with anti-rheumatic drugs. The intestinal microbiota can directly metabolize many drugs and indirectly change drug metabolism through a complex multi-dimensional interaction with the host, thus affecting individual response to drug therapy and adverse effects. The focus of the current review is to address recent advances and important progress in our understanding of how the gut microbiota interact with anti-rheumatic drugs and provide perspectives on promoting precision treatment, drug discovery, and better therapy for rheumatic diseases.

The Association of Altered Gut Microbiota and Intestinal Mucosal Barrier Integrity in Mice With Heroin Dependence

The gut microbiota is believed to play a significant role in psychological and gastrointestinal symptoms in heroin addicts. However, the underlying mechanism remains largely unknown. We show here that heroin addicts had a decrease in body mass index (BMI) and abnormal serum D-lactic acid (DLA), endotoxin (ET) and diamine oxidase (DAO) levels during their withdrawal stage, suggesting a potential intestinal injury. The gut microbial profiles in the mouse model with heroin dependence showed slightly decreased alpha diversity, as well as higher levels of Bifidobacterium and Sutterella and a decrease in Akkermansia at genus level compared to the control group. Fecal microbiota transplantation (FMT) further confirmed that the microbiota altered by heroin dependence was sufficient to impair body weight and intestinal mucosal barrier integrity in recipient mice. Moreover, short-chain fatty acids (SCFAs) profiling revealed that microbiota-derived propionic acid significantly decreased in heroin dependent mice compared to controls. Overall, our study shows that heroin dependence significantly altered gut microbiota and impaired intestinal mucosal barrier integrity in mice, highlighting the role of the gut microbiota in substance use disorders and the pathophysiology of withdrawal symptoms.

Electroacupuncture interventions alleviates myocardial ischemia reperfusion injury through regulating gut microbiota in rats

Electroacupuncture (EA) intervention has a remarkable cardioprotection against myocardial ischemia reperfusion injury (MIRI). Recently, it has been suggested that the gut microbiota plays an important role in regulating the progression and prognosis of MIRI. The purpose of this study was to illustrate the relationship between gut microbiota and cardioprotection of EA on MIRI. We conducted a MIRI model by ligating the left anterior descending coronary artery for 30 min followed by reperfusion in male Sprague Dawley rats, which then received 7 days of EA intervention. Echocardiography was employed to evaluate left ventricular function. Fecal samples were collected for microbial analysis by 16S rDNA high-throughput sequencing. Blood samples and myocardium were collected for inflammatory cytokine detection by enzyme linked immunosorbent assay (ELISA) and Western blot. Hematoxylin & eosin (HE) staining and immunofluorescence of ileum tissue were performed for intestinal damage evaluation. After 7 days of EA intervention, the left ventricular function was improved with significantly increased ejection fraction and fractional shortening. Furthermore, we found that EA intervention reversed the changed gut microbiota induced by MIRI, including Clostridiales, RF39, S24-7, Desulfovibrio, and Allobaculum, improved the impaired gut barrier, reduced the production and circulation of lipopolysaccharide (LPS), inhibited the level of interleukin 6 (IL-6) and interleukin 12 (IL-12) in periphery and decreased the expression of Toll like receptor 4 (TLR4) and IL-6 in myocardium. EA intervention could improve the impaired gut mucosal barrier and reduce the production and circulation of LPS after MIRI through regulating gut microbiota, thus inhibiting the circulation and myocardium inflammation and finally exerted the cardioprotective effect.

Gut Microbiome and Metabolites in Systemic Lupus Erythematosus: Link, Mechanisms and Intervention

Systemic lupus erythematosus (SLE), often considered the prototype of autoimmune diseases, is characterized by over-activation of the autoimmune system with abnormal functions of innate and adaptive immune cells and the production of a large number of autoantibodies against nuclear components. Given the highly complex and heterogeneous nature of SLE, the pathogenesis of this disease remains incompletely understood and is presumed to involve both genetic and environmental factors. Currently, disturbance of the gut microbiota has emerged as a novel player involved in the pathogenesis of SLE. With in-depth research, the understanding of the intestinal bacteria-host interaction in SLE is much more comprehensive. Recent years have also seen an increase in metabolomics studies in SLE with the attempt to identify potential biomarkers for diagnosis or disease activity monitoring. An intricate relationship between gut microbiome changes and metabolic alterations could help explain the mechanisms by which gut bacteria play roles in the pathogenesis of SLE. Here, we review the role of microbiota dysbiosis in the aetiology of SLE and how intestinal microbiota interact with the host metabolism axis. A proposed treatment strategy for SLE based on gut microbiome (GM) regulation is also discussed in this review. Increasing our understanding of gut microbiota and their function in lupus will provide us with novel opportunities to develop effective and precise diagnostic strategies and to explore potential microbiota-based treatments for patients with lupus.

Modification of Gut Microbiota in Inflammatory Arthritis: Highlights and Future Challenges

PURPOSE OF REVIEW

This Review evaluates the available information on the modification of the microbiota by diet, prebiotics, probiotics, or drugs and its association with the severity of arthritis in animals and humans and highlights how this modulation could have therapeutic applications in RA.

RECENT FINDINGS

The gut microbiota and microbiota-derived metabolites play a role in developing rheumatoid arthritis (RA) in animals and humans, making the intestinal microbiota an exciting novel approach to suppress autoimmunity. Studies in animal models of RA show that it is possible to modify the intestinal microbiota with drugs, natural products, diet, probiotics, and prebiotics. Furthermore, these changes showed beneficial effects on symptom relief in animal models of RA and that these effects were associated with modulation of the immune response. Therapies that modify the gut microbiota would significantly impact the preclinical stage of arthritis, based on the fact that dysbiosis occurs before clinical arthritis. The effects of interventions to modulate the microbiota could not reverse arthritis. Furthermore, the therapies modulating therapies in controlling symptoms were limited once arthritis developed. The results obtained in the study of acarbose, probiotics, and prebiotics suggest that these interventions may decrease the disease's incidence rather than treat or cure it.

Diabetes medications as potential calorie restriction mimetics-a focus on the alpha-glucosidase inhibitor acarbose

The field of aging research has grown rapidly over the last half-century, with advancement of scientific technologies to interrogate mechanisms underlying the benefit of life-extending interventions like calorie restriction (CR). Coincident with this increase in knowledge has been the rise of obesity and type 2 diabetes (T2D), both associated with increased morbidity and mortality. Given the difficulty in practicing long-term CR, a search for compounds (CR mimetics) which could recapitulate the health and longevity benefits without requiring food intake reductions was proposed. Alpha-glucosidase inhibitors (AGIs) are compounds that function predominantly within the gastrointestinal tract to inhibit α-glucosidase and α-amylase enzymatic digestion of complex carbohydrates, delaying and decreasing monosaccharide uptake from the gut in the treatment of T2D. Acarbose, an AGI, has been shown in pre-clinical models to increase lifespan (greater longevity benefits in males), with decreased body weight gain independent of calorie intake reduction. The CR mimetic benefits of acarbose are further supported by clinical findings beyond T2D including the risk for other age-related diseases (e.g., cancer, cardiovascular). Open questions remain regarding the exclusivity of acarbose relative to other AGIs, potential off-target effects, and combination with other therapies for healthy aging and longevity extension. Given the promising results in pre-clinical models (even in the absence of T2D), a unique mechanism of action and multiple age-related reduced disease risks that have been reported with acarbose, support for clinical trials with acarbose focusing on aging-related outcomes and incorporating biological sex, age at treatment initiation, and T2D-dependence within the design is warranted.

Diabetes medications as potential calorie restriction mimetics-a focus on the alpha-glucosidase inhibitor acarbose

The field of aging research has grown rapidly over the last half-century, with advancement of scientific technologies to interrogate mechanisms underlying the benefit of life-extending interventions like calorie restriction (CR). Coincident with this increase in knowledge has been the rise of obesity and type 2 diabetes (T2D), both associated with increased morbidity and mortality. Given the difficulty in practicing long-term CR, a search for compounds (CR mimetics) which could recapitulate the health and longevity benefits without requiring food intake reductions was proposed. Alpha-glucosidase inhibitors (AGIs) are compounds that function predominantly within the gastrointestinal tract to inhibit α-glucosidase and α-amylase enzymatic digestion of complex carbohydrates, delaying and decreasing monosaccharide uptake from the gut in the treatment of T2D. Acarbose, an AGI, has been shown in pre-clinical models to increase lifespan (greater longevity benefits in males), with decreased body weight gain independent of calorie intake reduction. The CR mimetic benefits of acarbose are further supported by clinical findings beyond T2D including the risk for other age-related diseases (e.g., cancer, cardiovascular). Open questions remain regarding the exclusivity of acarbose relative to other AGIs, potential off-target effects, and combination with other therapies for healthy aging and longevity extension. Given the promising results in pre-clinical models (even in the absence of T2D), a unique mechanism of action and multiple age-related reduced disease risks that have been reported with acarbose, support for clinical trials with acarbose focusing on aging-related outcomes and incorporating biological sex, age at treatment initiation, and T2D-dependence within the design is warranted.

Polyherbal formula SC-E3 inhibits rheumatoid arthritis activity in a mouse model of type-II collagen-induced arthritis

OBJECTIVE

SC-E3 is a polyherbal formula that contains five medicinal herbs used frequently in traditional herbal medicine. In our previous study, we demonstrated the antioxidant and anti-inflammatory effects of SC-E3. The present study examined the effects of SC-E3 in a mouse model of type-II collagen-induced arthritis (CIA).

METHODS

In vivo, male DBA/1J mice were immunized by intradermal injection of bovine type-II collagen and complete or incomplete Freund's adjuvant, to induce arthritis. SC-E3 was orally administered daily for 23 days. In vitro, bone marrow-derived macrophages (BMMs) were treated with macrophage colony-stimulating factor (M-CSF) and receptor activator of nuclear factor-κB ligand (RANKL) in the absence or presence of SC-E3.

RESULTS

Administrations of SC-E3 were found to have anti-arthritic effects in the joints of CIA mice, as evidenced by reduced paw swelling, bone erosion and deformation, inflammatory cell infiltration, and inflammation in synovial membrane. SC-E3 also reduced serum levels of tumor necrosis factor-α, interleukin-1β, aspartate aminotransferase and alanine aminotransferase. Furthermore, tartrate-resistant acid phosphatase-positive osteoclast numbers in the joints were significantly lower in SC-E3-treated CIA mice than in CIA mice. In addition, the differentiations of BMMs to multinucleated osteoclasts induced by M-CSF and RANKL stimulation were dose-dependently reduced by SC-E3.

CONCLUSION

These results suggest that SC-E3 possesses substantial anti-arthritic activity because it inhibits pro-inflammatory cytokines and osteoclastogenesis, and that SC-E3 has potential therapeutic use for the treatment of rheumatoid arthritis.