Identification of therapeutic effect of glucagon-like peptide 1 in the treatment of STZ-induced diabetes mellitus in rats by restoring the balance of intestinal flora

Drug-microbiota interactions: an emerging priority for precision medicine

Individual variability in drug response (IVDR) can be a major cause of adverse drug reactions (ADRs) and prolonged therapy, resulting in a substantial health and economic burden. Despite extensive research in pharmacogenomics regarding the impact of individual genetic background on pharmacokinetics (PK) and pharmacodynamics (PD), genetic diversity explains only a limited proportion of IVDR. The role of gut microbiota, also known as the second genome, and its metabolites in modulating therapeutic outcomes in human diseases have been highlighted by recent studies. Consequently, the burgeoning field of pharmacomicrobiomics aims to explore the correlation between microbiota variation and IVDR or ADRs. This review presents an up-to-date overview of the intricate interactions between gut microbiota and classical therapeutic agents for human systemic diseases, including cancer, cardiovascular diseases (CVDs), endocrine diseases, and others. We summarise how microbiota, directly and indirectly, modify the absorption, distribution, metabolism, and excretion (ADME) of drugs. Conversely, drugs can also modulate the composition and function of gut microbiota, leading to changes in microbial metabolism and immune response. We also discuss the practical challenges, strategies, and opportunities in this field, emphasizing the critical need to develop an innovative approach to multi-omics, integrate various data types, including human and microbiota genomic data, as well as translate lab data into clinical practice. To sum up, pharmacomicrobiomics represents a promising avenue to address IVDR and improve patient outcomes, and further research in this field is imperative to unlock its full potential for precision medicine.

Relationship between Components, Intestinal Microbiota, and Mechanism of Hypoglycemic Effect of the Saggy Ink Cap Medicinal Mushroom (Coprinus Comatus, Agaricomycetes): A Review

Coprinus comatus is rich in a variety of nutrients, which has been reported to display a good hypoglycemic effect. However, there is no consensus on the hypoglycemic mechanism of this mushroom. Intestinal microbiota, a complex and intrinsic system, is closely related to metabolism. In this review, we discussed the potential relationship between certain components of C. comatus and intestinal microbiota to illustrate the possible hypoglycemic mechanism of C. comatus through intestinal microbiota. It will provide a new perspective for the study of hypoglycemic mechanism of C. comatus and promote the development and utilization of this mushroom.

Beneficial effects of curcumin in the diabetic rat ovary: a stereological and biochemical study

This study aimed to investigate the effects of curcumin treatment on ovaries at different periods of the diabetes disease. Fifty-six female Wistar albino rats (250-300 g) aged 12 weeks were divided into seven groups. No treatment was applied to the control group. The sham group was given 5 mL/kg of corn oil, and the curcumin group 30 mg/kg curcumin. In the diabetes mellitus (DM) groups, diabetes was induced by a single intraperitoneal dose of 50 mg/kg streptozotocin (STZ). The DM-treated groups received 30 mg/kg curcumin after either 7 days (DC1 group) or 21 days (DC2 group), or simultaneously with STZ injection (DC3 group). Number of follicles in the ovaries was estimated using stereological method. Follicle-stimulating hormone (FSH), luteinizing hormone (LH), and superoxide dismutase (SOD) levels and catalase (CAT) activity were measured in serum specimens. We found that follicle number and volume of corpus luteum, blood vessel, and cortex, gonadosomatic index, and FSH and SOD levels all decreased significantly in diabetic ovaries, while relative weight loss, connective tissue volume, and CAT activity increased (p < 0.01). Curcumin treatment had a protective effect on the number of primordial follicles in the DC2 group and on antral follicle numbers in the DC3 group. Curcumin also exhibited positive effects on CAT activity and SOD levels, blood glucose levels, and corpus luteum, connective tissue, and blood vessel volumes in the DC2 and DC3 groups. Curcumin also ameliorated FSH levels in the DC1 and DC3 groups (p < 0.01). These findings suggest that curcumin exhibits protective effects on ovarian structures and folliculogenesis, especially when used concurrently with the development of diabetes or in later stages of the disease.

Genetically engineered bacterium: Principles, practices, and prospects

Advances in synthetic biology and the clinical application of bacteriotherapy enable the use of genetically engineered bacteria (GEB) to combat various diseases. GEB act as a small 'machine factory' in the intestine or other tissues to continuously produce heterologous proteins or molecular compounds and, thus, diagnose or cure disease or work as an adjuvant reagent for disease treatment by regulating the immune system. Although the achievements of GEBs in the treatment or adjuvant therapy of diseases are promising, the practical implementation of this new therapeutic modality remains a grand challenge, especially at the initial stage. In this review, we introduce the development of GEBs and their advantages in disease management, summarize the latest research advances in microbial genetic techniques, and discuss their administration routes, performance indicators and the limitations of GEBs used as platforms for disease management. We also present several examples of GEB applications in the treatment of cancers and metabolic diseases and further highlight their great potential for clinical application in the near future.

Reactive Oxygen Species/Reactive Nitrogen Species as Messengers in the Gut: Impact on Physiology and Metabolic Disorders

Significance: The role of reactive oxygen/nitrogen species as "friend" or "foe" messengers in the whole body is well characterized. Depending on the concentration in the tissue considered, these molecular actors exert beneficial or deleterious impacts leading to a pathological state, as observed in metabolic disorders such as type 2 diabetes and obesity. Recent Advances: Among the tissues impacted by oxidation and inflammation in this pathological state, the intestine is a site of dysfunction that can establish diabetic symptoms, such as alterations in the intestinal barrier, gut motility, microbiota composition, and gut/brain axis communication. In the intestine, reactive oxygen/nitrogen species (from the host and/or microbiota) are key factors that modulate the transition from physiological to pathological signaling. Critical Issues: Controlling the levels of intestinal reactive oxygen/nitrogen species is a complicated balance between positive and negative impacts that is in constant equilibrium. Here, we describe the synthesis and degradation of intestinal reactive oxygen/nitrogen species and their interactions with the host. The development of novel redox-based therapeutics that alter these processes could restore intestinal health in patients with metabolic disorders. Future Directions: Deciphering the mode of action of reactive oxygen/nitrogen species in the gut of obese/diabetic patients could result in a future therapeutic strategy that combines nutritional and pharmacological approaches. Consequently, preventive and curative treatments must take into account one of the first sites of oxidative and inflammatory dysfunctions in the body, that is, the intestine. Antioxid. Redox Signal. 37, 394-415.

Gut Microbiota and Antidiabetic Drugs: Perspectives of Personalized Treatment in Type 2 Diabetes Mellitus

Alterations in the composition and function of the gut microbiota have been reported in patients with type 2 diabetes mellitus (T2DM). Emerging studies show that prescribed antidiabetic drugs distort the gut microbiota signature associated with T2DM. Even more importantly, accumulated evidence provides support for the notion that gut microbiota, in turn, mediates the efficacy and safety of antidiabetic drugs. In this review, we highlight the current state-of-the-art knowledge on the crosstalk and interactions between gut microbiota and antidiabetic drugs, including metformin, α-glucosidase inhibitors, glucagon-like peptide-1 receptor agonists, dipeptidyl peptidase-4 inhibitors, sodium-glucose cotransporter 2 inhibitors, traditional Chinese medicines and other antidiabetic drugs, as well as address corresponding microbial-based therapeutics, aiming to provide novel preventative strategies and personalized therapeutic targets in T2DM.

LncRNA-AK137033 inhibits the osteogenic potential of adipose-derived stem cells in diabetic osteoporosis by regulating Wnt signaling pathway via DNA methylation

OBJECTIVES

Bone tissue engineering based on adipose-derived stem cells (ASCs) is expected to become a new treatment for diabetic osteoporosis (DOP) patients with bone defects. However, compared with control ASCs (CON-ASCs), osteogenic potential of DOP-ASCs is decreased, which increased the difficulty of bone reconstruction in DOP patients. Moreover, the cause of the poor osteogenesis of ASCs in a hyperglycemic microenvironment has not been elucidated. Therefore, this study explored the molecular mechanism of the decline in the osteogenic potential of DOP-ASCs from the perspective of epigenetics to provide a possible therapeutic target for bone repair in DOP patients with bone defects.

MATERIALS AND METHODS

An animal model of DOP was established in mice. CON-ASCs and DOP-ASCs were isolated from CON and DOP mice, respectively. AK137033 small interfering RNA (SiRNA) and an AK137033 overexpression plasmid were used to regulate the expression of AK137033 in CON-ASCs and DOP-ASCs in vitro. Lentiviruses that carried shRNA-AK137033 or AK137033 cDNA were used to knockdown or overexpress AK137033, respectively, in CON-ASCs and DOP-ASCs in vivo. Hematoxylin and eosin (H&E), Masson's, alizarin red, and alkaline phosphatase (ALP) staining, micro-computed tomography (Micro-CT), flow cytometry, qPCR, western blotting, immunofluorescence, and bisulfite-specific PCR (BSP) were used to analyze the functional changes of ASCs.

RESULTS

The DOP mouse model was established successfully. Compared with CON-ASCs, AK137033 expression, the DNA methylation level of the sFrp2 promoter region, Wnt signaling pathway markers, and the osteogenic differentiation potential were decreased in DOP-ASCs. In vitro experiments showed that AK137033 silencing inhibited the Wnt signaling pathway and osteogenic ability of CON-ASCs by reducing the DNA methylation level in the sFrp2 promoter region. Additionally, overexpression of AK137033 in DOP-ASCs rescued these changes caused by DOP. Moreover, the same results were obtained in vivo.

CONCLUSIONS

LncRNA-AK137033 inhibits the osteogenic potential of DOP-ASCs by regulating the Wnt signaling pathway via modulating the DNA methylation level in the sFrp2 promoter region. This study provides an important reference to find new targets for the treatment of bone defects in DOP patients.

Loss of renal olfactory receptor 1393 leads to improved glucose homeostasis in a type 1 diabetic mouse model

Renal olfactory receptor 1393 (Olfr1393) is an understudied sensory receptor that contributes to glucose handling in the proximal tubule. Our previous studies have indicated that this receptor may serve as a regulator of the sodium glucose co-transporters (SGLTs) and contributes to the development of glucose intolerance and hyperfiltration in the setting of diet-induced obesity. We hypothesized that Olfr1393 may have a similar function in Type 1 Diabetes. Using Olfr1393 wildtype (WT) and knockout (KO) mice along with streptozotocin (STZ) to induce pancreatic β-cell depletion, we tracked the development and progression of diabetes over 12 weeks. Here we report that diabetic male Olfr1393 KO mice have a significant improvement in hyperglycemia and glucose tolerance, despite remaining susceptible to STZ. We also confirm that Olfr1393 localizes to the renal proximal tubule, and have uncovered additional expression within the glomerulus. Collectively, these data indicate that loss of renal Olfr1393 affords protection from STZ-induced type 1 diabetes and may be a general regulator of glucose handling in both health and disease.

Tocopheryl quinone improves non-alcoholic steatohepatitis (NASH) associated dysmetabolism of glucose and lipids by upregulating the expression of glucagon-like peptide 1 (GLP-1) via restoring the balance of intestinal flora in rats

CONTEXT

Glucagon-like peptide 1 (GLP-1) and α-tocopheryl quinone can promote the growth of intestinal flora and affect the pathogenesis of non-alcoholic steatohepatitis (NASH).

OBJECTIVE

This study determines the molecular mechanism of the effect of tocopheryl quinone in the treatment of high cholesterol and cholate diet (HFCC)-induced NASH.

MATERIALS AND METHODS

Thirty-two male Sprague Dawley (SD) rats grouped as lean control (LC), LC + tocopheryl quinone (1 mL of 3 × 10⁶ dpm tocopheryl quinone via i.p. injection), HFCC (5.1 kcal/g of fat diet), and HFCC + tocopheryl quinone. Profiles of intestinal flora were assessed by 16S ribosomal ribonucleic acid-based analysis. Levels and activity of GLP-1, interleukin 6 (IL-6) and tumour necrosis factor alpha (TNF-α) in intestinal tissues were detected by immunohistochemistry (IHC), Western blot and enzyme-linked immunosorbent assay (ELISA).

RESULTS

HFCC rats presented higher levels of cholesterol, low-density lipoprotein (LDL) and high-density lipoprotein (HDL), while tocopheryl quinone reversed the effects of HFCC. HFCC dysregulated malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD), Vitamin E, 12-hydroxyeicosatetraenoic acid (12-HETE), 13-hydroxyoctadecadienoic acid (13-HODE) and nuclear factor kappa B (NF-κB), and the effects of HFCC were reversed by the treatment of tocopheryl quinone. Also, GLP-1 in the HFCC group was down-regulated while the IL-6 and TNF-α activity and endotoxins were all up-regulated. HFCC significantly decreased the number and diversity of bacteria, whereas tocopheryl quinone substantially restored the balance of intestinal flora and promoted the growth of both Bacteroides and Lactobacilli in vitro.

DISCUSSION AND CONCLUSIONS

α-Tocopheryl quinone relieves HFCC-induced NASH via regulating oxidative stress, GLP-1 expression, intestinal flora imbalance, and the metabolism of glucose and lipids.

Effect of intestinal microbiota imbalance associated with chronic hepatitis B virus infection on the expression of microRNA‑192 and GLP‑1

It has been reported that hepatitis B virus (HBV) infection has an impact on intestinal microbiota imbalance to induce diabetes mellitus (DM), but the underlying mechanisms still remain to be explored. The present study aimed to investigate the regulatory role of microRNA‑192 (miR‑192‑5p) and glucagon‑like peptide‑1 (GLP‑1) in intestinal microbiota imbalance by recruiting patients with DM infected with HBV. In the present study, patients with HBV infection and different levels of alanine transaminase (ALT) were recruited and divided into three groups. Intestinal microbiota analysis was performed to evaluate the fecal bacterial composition of patients in various groups. Quantitative PCR was performed to explore the differential expression of miR‑192‑5p and GLP‑1 in the feces, peripheral blood and intestinal mucosal tissue samples of each patient. Immunohistochemistry was used to assess the expression of GLP‑1 protein in the intestinal mucosal tissue samples. Luciferase assays were performed by cell transfection of miR‑192‑5p mimics/precursors/inhibitors to study the inhibitory effect of miR‑192‑5p on GLP‑1 expression. Intestinal microbiota imbalance was observed in hepatitis B surface antigen (HBsAg)‑positive patients with high ALT. The expression of miR‑192‑5p was significantly elevated in the feces, peripheral blood and intestinal mucosal tissue samples of HBsAg‑positive patients with high ALT along with decreased GLP‑1 mRNA and protein expression. Luciferase activity of GLP‑1 vector was inhibited by miR‑192‑5p mimics and promoted by miR‑192‑5p inhibitors. Transfection of miR‑192‑5p precursors resulted in upregulation of miR‑192‑5p and downregulation of GLP‑1, while miR‑192‑5p inhibitors remarkably suppressed the expression of miR‑192‑5p and notably induced the expression of GLP‑1. These results showed a regulatory network involving HBV infection, intestinal microbiota imbalance, and miR‑192‑5p and GLP‑1 expression.

A case-control study on the association of intestinal flora with ulcerative colitis

The association between intestinal flora and ulcerative colitis (UC) was studied in order to provide a basis and method for clinical treatment. Fresh fecal samples were collected from 30 active UC patients and 10 healthy controls. The intestinal flora DNA from each sample was extracted and 16S rRNA gene sequencing was carried out using HiSeq platform to identify the intestinal flora in fecal samples. The richness and diversity of intestinal flora in UC patients were significantly lower than those in healthy control group (P < 0.05). Significant differences were observed between the intestinal flora-species of UC patients and healthy controls. Synergistetes (P < 0.01) and Firmicutes (P < 0.05), along with probiotics Veillonella (P < 0.01), Ruminococcus and Coprococcus (P < 0.05) in the UC patients were lower than that in the healthy controls significantly. Furthermore, compared with the control group, Tenericutes (P < 0.01) and intestinal pathogenic bacteria, including Bacteroides (P < 0.01), Escherichia and Sutterella (P < 0.05) were significantly increased. The incidence of UC is significantly associated with the changes in intestinal flora. Changes in intestinal flora may lead to a decrease in the diversity of intestinal flora or to the enrichment of a particular intestinal flora.

Characteristics of the intestinal flora in patients with peripheral neuropathy associated with type 2 diabetes

OBJECTIVE

To study the characteristics of the intestinal flora in patients with diabetic peripheral neuropathy (DPN) and analyze the association between the intestinal flora and clinical indicators.

METHODS

We classified 80 subjects into three groups: patients with DPN (n = 45), patients type 2 diabetes without DPN (n = 21), and healthy controls (n = 14). The intestinal flora composition was compared among the three groups, and the correlation between the intestinal flora and clinical indicators was analyzed.

RESULTS

At the phylum level, the richness of Firmicutes and Actinobacteria was elevated in the DN group, and that of Bacteroidetes was decreased. At the genus level, the richness of Bacteroides and Faecalibacterium was significantly decreased in the DPN group, whereas that of Escherichia-Shigella, Lachnoclostridium, Blautia, Megasphaera, and Ruminococcus torques group was increased. The homeostasis model assessment insulin resistance index was positively correlated with Megasphaera richness. Glycine ursodeoxycholic acid was positively correlated with Ruminococcus gnavus group and Phascolarctobacterium richness. Tauroursodeoxycholic acid was positively correlated with Ruminococcus gnavus group and Parabacteroides richness.

CONCLUSION

There was obvious intestinal microbiota disorder in patients with DPN, which may be related to insulin resistance. These changes may have important roles in the development of DPN.

Tangshen formula modulates gut Microbiota and reduces gut-derived toxins in diabetic nephropathy rats

Growing evidence shows that diabetic kidney disease (DKD) is linked with intestinal dysbiosis from gut-derived toxins. Tangshen Formula (TSF) is a traditional Chinese herbal medicine that has been used to treat DKD. In this study, streptozotocin injection and uninephrectomy-induced diabetic nephropathy (DN) rat model was established to explore the impact of TSF on gut microbiota composition, gut-derived toxins, and the downstream inflammatory pathway of urotoxins in the kidney. TSF treatment for 12 weeks showed significant attenuation of both renal histologic injuries and urinary excretion of albumin compared with DN rats without treatment. TSF treatment also reconstructed gut dysbiosis and reduced levels of indoxyl sulfate and metabolic endotoxemia/lipopolysaccharide. MCP-1 and TNF-α were decreased by TSF both in the serum and kidney. In addition, we revealed that the inhibitory effect of TSF on renal inflammation was associated with the inhibition of aryl hydrocarbon, a receptor of indoxyl sulfate, and TLR4, thereby inhibiting JNK and NF-κB signaling in the kidney. Spearman correlation analysis found that a cluster of gut bacterial phyla and genera were significantly correlated with renal pathology, renal function, and systemic inflammation. In conclusion, orally administered TSF significantly inhibited diabetic renal injury, and modulated gut microbiota, which decreased levels of lipopolysaccharide and indoxyl sulfate, and attenuated renal inflammation. Our results indicate that TSF may be used as an agent in the prevention of gut dysbiosis and elimination of intestinal toxins in DN individuals.

Liraglutide Attenuates Nonalcoholic Fatty Liver Disease by Modulating Gut Microbiota in Rats Administered a High-Fat Diet

This study aimed to determine whether modulation of the gut microbiota structure by liraglutide helps improve nonalcoholic fatty liver disease (NAFLD) in rats on a high-fat diet (HFD). Rats were administered an HFD for 12 weeks to induce NAFLD and then administered liraglutide for 4 additional weeks. Next-generation sequencing and multivariate analysis were performed to assess structural changes in the gut microbiota. Liraglutide attenuated excessive hepatic ectopic fat deposition, maintained intestinal barrier integrity, and alleviated metabolic endotoxemia in HFD rats. Liraglutide significantly altered the overall structure of the HFD-disrupted gut microbiota and gut microbial composition in HFD rats in comparison to those on a normal diet. An abundance of 100 operational taxonomic units (OTUs) were altered upon liraglutide administration, with 78 OTUs associated with weight gain or inflammation. Twenty-three OTUs positively correlated with hepatic steatosis-related parameters were decreased upon liraglutide intervention, while 5 OTUs negatively correlated with hepatic steatosis-related parameters were increased. These results suggest that liraglutide-mediated attenuation of NAFLD partly results from structural changes in gut microbiota associated with hepatic steatosis.

Effects of Non-insulin Anti-hyperglycemic Agents on Gut Microbiota: A Systematic Review on Human and Animal Studies

Background: As growing evidence links gut microbiota with the therapeutic efficacy and side effects of anti-hyperglycemic drugs, this article aims to provide a systematic review of the reciprocal interactions between anti-hyperglycemic drugs and gut microbiota taxa, which underlie the effect of the gut microbiome on diabetic control via bug-host interactions. Method: We followed the PRISMA requirements to perform a systematic review on human vs. animal gut microbiota data in PubMed, SCOPUS, and EMBASE databases, and used Cochrane, ROBIN-I, and SYRCLE tools to assess potential bias risks. The outcomes of assessment were trends on gut microbiota taxa, diversity, and associations with metabolic control (e.g., glucose, lipid) following anti-hyperglycemic treatment. Results: Of 2,804 citations, 64 studies (17/humans; 47/mice) were included. In human studies, seven were randomized trials using metformin or acarbose in obese, pre-diabetes, and type 2 diabetes (T2D) patients. Treatment of pre-diabetes and newly diagnosed T2D patients with metformin or acarbose was associated with decreases in genus of Bacteroides, accompanied by increases in both Bifidobacterium and Lactobacillus. Additionally, T2D patients receiving metformin showed increases in various taxa of the order Enterobacteriales and the species Akkermansia muciniphila. Of seven studies with significant differences in beta-diversity, the incremental specific taxa were associated with the improvement of glucose and lipid profiles. In mice, the effects of metformin on A. muciniphila were similar, but an inverse association with Bacteroides was reported. Animal studies on other anti-hyperglycemic drugs, however, showed substantial variations in results. Conclusions: The changes in specific taxa and β-diversity of gut microbiota were associated with metformin and acarbose in humans while pertinent information for other anti-hyperglycemic drugs could only be obtained in rodent studies. Further human studies on anti-hyperglycemic drugs other than metformin and acarbose are needed to explore gut microbiota's role in their therapeutic efficacies and side effects.

TGR5 Activation Modulates an Inhibitory Effect on Liver Fibrosis Development Mediated by Anagliptin in Diabetic Rats

Hyperglycemia and hyperinsulinemia activate the proliferative potential of hepatic stellate cells (HSCs) and promote hepatic fibrosis. Dipeptidyl peptidase-4 (DPP-4) inhibitors, antidiabetic agents, reportedly inhibit the HSC proliferation. Additionally, Takeda G protein-coupled receptor 5 (TGR5) agonists induce the systemic release of glucagon-like peptides from intestinal L cells, which maintains glycemic homeostasis. This study assessed the combined effect of TGR5 agonist and DPP-4 inhibitor on diabetes-based liver fibrosis development. Male diabetic rats received intraperitoneal injection of porcine serum (PS) to induce liver fibrosis, and they were orally administered the following agents: oleanolic acid (OA) as a TGR5 agonist, anagliptin (ANA) as a DPP-4 inhibitor, and a combination of both agents. Treatment with OA or ANA significantly improved glycemic status and attenuated intrahepatic steatosis and lipid peroxidation in diabetic rats. PS-induced liver fibrosis development was also drastically suppressed by treatment with either agent, and the combination of both reciprocally enhanced the antifibrotic effect. Fecal microbiome demonstrated that both agents inhibited the increase in the Firmicutes/Bacteroidetes ratio, an indicator of dysbiosis related to metabolic syndromes. Furthermore, ANA directly inhibited in vitro HSC proliferative and profibrogenic activities. Collectively, TGR5 agonist and DPP-4 inhibitor appears to be a novel strategy against liver fibrosis under diabetic conditions.

Dissecting the Physiology and Pathophysiology of Glucagon-Like Peptide-1

An aging world population exposed to a sedentary life style is currently plagued by chronic metabolic diseases, such as type-2 diabetes, that are spreading worldwide at an unprecedented rate. One of the most promising pharmacological approaches for the management of type 2 diabetes takes advantage of the peptide hormone glucagon-like peptide-1 (GLP-1) under the form of protease resistant mimetics, and DPP-IV inhibitors. Despite the improved quality of life, long-term treatments with these new classes of drugs are riddled with serious and life-threatening side-effects, with no overall cure of the disease. New evidence is shedding more light over the complex physiology of GLP-1 in health and metabolic diseases. Herein, we discuss the most recent advancements in the biology of gut receptors known to induce the secretion of GLP-1, to bridge the multiple gaps into our understanding of its physiology and pathology.