Cyclocarya paliurus polysaccharides alleviate type 2 diabetic symptoms by modulating gut microbiota and short-chain fatty acids

Therapeutic potential of non-starch polysaccharides on type 2 diabetes: from hypoglycemic mechanism to clinical trials

Non-starch polysaccharides (NSPs) have been reported to exert therapeutic potential on managing type 2 diabetes mellitus (T2DM). Various mechanisms have been proposed; however, several studies have not considered the correlations between the anti-T2DM activity of NSPs and their molecular structure. Moreover, the current understanding of the role of NSPs in T2DM treatment is mainly based on in vitro and in vivo data, and more human clinical trials are required to verify the actual efficacy in treating T2DM. The related anti-T2DM mechanisms of NSPs, including regulating insulin action, promoting glucose metabolism and regulating postprandial blood glucose level, anti-inflammatory and regulating gut microbiota (GM), are reviewed. The structure-function relationships are summarized, and the relationships between NSPs structure and anti-T2DM activity from clinical trials are highlighted. The development of anti-T2DM medication or dietary supplements of NSPs could be promoted with an in-depth understanding of the multiple regulatory effects in the treatment/intervention of T2DM.

Combining fecal microbiome and metabolomics to reveal the disturbance of gut microbiota in liver injury and the therapeutic mechanism of shaoyao gancao decoction

Chemical liver injury is closely related to gut microbiota and its metabolites. In this study, we combined 16S rRNA gene sequencing, ¹H NMR-based fecal metabolomics and GC-MS to evaluate the changes in gut microbiota, fecal metabolites and Short-chain fatty acids (SCFAs) in CCl₄-induced liver injury in Sprague-Dawley rats, and the therapeutic effect of Shaoyao Gancao Decoction (SGD). The results showed that CCl₄-induced liver injury overexpressed CYP2E1, enhanced oxidative stress, decreased antioxidant enzymes (SOD, GSH), increased peroxidative products MDA and inflammatory responses (IL-6, TNF-α), which were ameliorated by SGD treatment. H&E staining showed that SGD could alleviate liver tissue lesions, which was confirmed by the recovered liver index, ALT and AST. Correlation network analysis indicated that liver injury led to a decrease in microbiota correlation, while SGD helped restore it. In addition, fecal metabolomic confirmed the PICRUSt results that liver injury caused disturbances in amino acid metabolism, which were modulated by SGD. Spearman’s analysis showed that liver injury disrupted ammonia transport, urea cycle, intestinal barrier and energy metabolism. Moreover, the levels of SCFAs were also decreased, and the abundance of Lachnoclostridium, Blautia, Lachnospiraceae_NK4A136_group, UCG-005 and Turicibacter associated with SCFAs were altered. However, all this can be alleviated by SGD. More importantly, pseudo germ-free rats demonstrated that the absence of gut microbiota aggravated liver injury and affected the efficacy of SGD. Taken together, we speculate that the gut microbiota has a protective role in the pathogenesis of liver injury, and has a positive significance for the efficacy of SGD. Moreover, SGD can treat liver injury by modulating gut microbiota and its metabolites and SCFAs. This provides useful evidence for the study of the pathogenesis of liver injury and the clinical application of SGD.

Progress in Research on the Alleviation of Glucose Metabolism Disorders in Type 2 Diabetes Using Cyclocarya paliurus

Globally, the incidence of diabetes is increasing annually, and China has the largest number of patients with diabetes. Patients with type 2 diabetes need lifelong medication, with severe cases requiring surgery. Diabetes treatment may cause complications, side-effects, and postoperative sequelae that could lead to adverse health problems and significant social and economic burdens; thus, more efficient hypoglycemic drugs have become a research hotspot. Glucose metabolism disorders can promote diabetes, a systemic metabolic disease that impairs the function of other organs, including the heart, liver, and kidneys. Cyclocarya paliurus leaves have gathered increasing interest among researchers because of their effectiveness in ameliorating glucose metabolism disorders. At present, various compounds have been isolated from C. paliurus, and the main active components include polysaccharides, triterpenes, flavonoids, and phenolic acids. C. paliurus mainly ameliorates glucose metabolism disorders by reducing glucose uptake, regulating blood lipid levels, regulating the insulin signaling pathway, reducing β-cell apoptosis, increasing insulin synthesis and secretion, regulating abundances of intestinal microorganisms, and exhibiting α-glucosidase inhibitor activity. In this paper, the mechanism of glucose metabolism regulation by C. paliurus was reviewed to provide a reference to prevent and treat diabetes, hyperlipidaemia, obesity, and other metabolic diseases.

A Polyclonal Aptamer Library for the Specific Binding of the Gut Bacterium Roseburia intestinalis in Mixtures with Other Gut Microbiome Bacteria and Human Stool Samples

Roseburia intestinalis has received attention as a potential probiotic bacterium. Recent studies have demonstrated that changes in its intestinal abundance can cause various diseases, such as obesity, enteritis and atherosclerosis. Probiotic administration or fecal transplantation alter the structure of the intestinal flora, offering possibilities for the prevention and treatment of these diseases. However, current monitoring methods, such as 16S rRNA sequencing, are complex and costly and require specialized personnel to perform the tests, making it difficult to continuously monitor patients during treatment. Hence, the rapid and cost-effective quantification of intestinal bacteria has become an urgent problem to be solved. Aptamers are of emerging interest because their stability, low immunogenicity and ease of modification are attractive properties for a variety of applications. We report a FluCell-SELEX polyclonal aptamer library specific for R. intestinalis isolated after seven evolution rounds, that can bind and label this organism for fluorescence microscopy and binding assays. Moreover, R. intestinalis can be distinguished from other major intestinal bacteria in complex defined mixtures and in human stool samples. We believe that this preliminary evidence opens new avenues towards aptamer-based electronic biosensors as new powerful and inexpensive diagnostic tools for the relative quantitative monitoring of R. intestinalis in gut microbiomes.

Advances on Cyclocarya paliurus polyphenols: Extraction, structures, bioactivities and future perspectives

Cyclocaryapaliurus (C. paliurus) is an edible and medicinal plant, distributed in southern China. As a kind of new food raw material, the leaves of C. paliurus are processed as tea products in daily life. C. paliurus is recognized as a good source to polyphenols, showing excellent bioactivities, which has attracted more and more attention. Polyphenols are important functional bioactive components in C. paliurus. C. paliurus polyphenols perform nutritional functions in anti-diabetes, anti-hyperlipidemic, anti-obesity, anti-oxidant, and other activities. In this review, we summarize the research progress of extraction technologies, structural characteristics, and bioactivities of C. paliurus polyphenols. Other potential functions of C. paliurus polyphenols are prospected. This review provides a reference for further research and applications of C. paliurus polyphenols in a field of functional food and medicines.

The Leaves of Cyclocarya paliurus: A Functional Tea with Preventive and Therapeutic Potential of Type 2 Diabetes

Type 2 diabetes mellitus (T2DM) has become a universal and chronic global public health concern and causes multiple complex complications. In order to meet the rapidly growing demand for T2DM treatment, increased research has been focused on hypoglycemic drugs. Cyclocarya paliurus (Batal.) Iljinsk is the only living species of the genus Cyclocarya Iljinskaja, whose leaves have been extensively used as a functional tea to treat obesity and diabetes in China. An enormous amount of very recent pharmacological research on the leaves of C. paliurus has demonstrated that they carry out numerous biological activities, such as hypoglycemic, anti-inflammatory, and intestinal microbiota regulation. Multiple in vitro and in vivo studies have also shown that the extracts of C. paliurus leaves are innocuous and safe. This study aims to provide an up-to-date review of the botany, traditional uses, phytochemistry, pharmacological effects against diabetes, toxicology, and clinical studies of C. paliurus leaves, in hopes of promoting a better understanding of their role in the prevention and treatment of T2DM.

Hypoglycemic Effects of Lycium barbarum Polysaccharide in Type 2 Diabetes Mellitus Mice via Modulating Gut Microbiota

This study aims to explore the molecular mechanisms of Lycium barbarum polysaccharide (LBP) in alleviating type 2 diabetes through intestinal flora modulation. A high-fat diet (HFD) combined with streptozotocin (STZ) was applied to create a diabetic model. The results indicated that LBP effectively alleviated the symptoms of hyperglycemia, hyperlipidemia, and insulin resistance in diabetic mice. A high dosage of LBP exerted better hypoglycemic effects than low and medium dosages. In diabetic mice, LBP significantly boosted the activities of CAT, SOD, and GSH-Px and reduced inflammation. The analysis of 16S rDNA disclosed that LBP notably improved the composition of intestinal flora, increasing the relative abundance of Bacteroides, Ruminococcaceae_UCG-014, Intestinimonas, Mucispirillum, Ruminococcaceae_UCG-009 and decreasing the relative abundance of Allobaculum, Dubosiella, Romboutsia. LBP significantly improved the production of short-chain fatty acids (SCFAs) in diabetic mice, which corresponded to the increase in the beneficial genus. According to Spearman’s correlation analysis, Cetobacterium, Streptococcus, Ralstonia. Cetobacterium, Ruminiclostridium, and Bifidobacterium correlated positively with insulin, whereas Cetobacterium, Millionella, Clostridium_sensu_stricto_1, Streptococcus, and Ruminococcaceae_UCG_009 correlated negatively with HOMA-IR, HDL-C, ALT, AST, TC, and lipopolysaccharide (LPS). These findings suggested that the mentioned genus may be beneficial to diabetic mice’s hypoglycemia and hypolipidemia. The up-regulation of peptide YY (PYY), glucagon-like peptide-1 (GLP-1), and insulin were remarkably reversed by LBP in diabetic mice. The real-time PCR (RT-PCR) analysis illustrated that LBP distinctly regulated the glucose metabolism of diabetic mice by activating the IRS/PI3K/Akt signal pathway. These results indicated that LBP effectively alleviated the hyperglycemia and hyperlipidemia of diabetic mice by modulating intestinal flora.

Anti-diabetic effect of banana peel dietary fibers on type 2 diabetic mellitus mice induced by streptozotocin and high-sugar and high-fat diet

We used a high-fat diet (HFD) and streptozotocin (STZ) to induce type 2 diabetic mellitus (T2DM) mice and evaluated the effect of banana peel dietary fibers (BP-DFs) as potential hypoglycemic agents. After 5 weeks of intervention with banana peel dietary fibers (BP-DFs), food intake was reduced, body weight was increased, blood lipids and glucose were reduced, fasting insulin and GLP-1 levels were increased, and liver and pancreatic tissue damage was reduced. Banana peel soluble dietary fiber (BP-SDF) has the most significant effect. The results of fecal microbiota analysis showed that BP-DFs could ameliorates gut microbiome dysbiosis, and all three types of dietary fibers have obvious effects. The results of fecal short-chain fatty acids (SCFAs) showed that the content of fecal SCFAs was increased after BP-DFs dietary intervention, and BP-SDF had the most obvious effect. RT-PCR experiment results show that BP-DFs can up-regulate the mRNA expression levels of PI3K, AKT, IRS-1, and FOXO1 in the liver of diabetic mice, which indicates that BD-DFs may play a role in improving insulin resistance and insulin signal transduction via the IRS/PI3K/AKT pathway, improving insulin resistance and insulin signal transduction. Our research may be extended to BP-DFs, especially BP-SDF, as the basis for potential dietary intervention to prevent or treat type 2 diabetic mellitus. This work supports future research studies of the anti-diabetic properties of BP-SDF in humans. PRACTICAL APPLICATIONS: Diabetes can lead to a variety of complications that have a huge impact on health. Dietary fiber may help in lowering blood sugar. Our experimental results showed that banana peel dietary fibers have the effect of reducing food intake, blood sugar, improving liver and pancreas function, increasing the abundance of intestinal flora, and improving the IRS/PI3K/AKT pathway in T2DM mice. Therefore, this study could provide a theoretical basis for the development of functional foods with banana peel dietary fiber.

The Modulatory Effect of Cyclocarya paliurus Flavonoids on Intestinal Microbiota and Hypothalamus Clock Genes in a Circadian Rhythm Disorder Mouse Model

Circadian rhythm disruption is detrimental and results in adverse health consequences. We used a multi-omics profiling approach to investigate the effects of Cyclocarya paliurus flavonoid (CPF)-enriched diets on gut microbiota, metabolites, and hypothalamus clock genes in mice with induced circadian rhythm disruption. It was observed that CPF supplementation altered the specific composition and function of gut microbiota and metabolites induced by circadian rhythm disruption. Analysis showed that the abundance of Akkermansia increased, while the abundance of Clostridiales and Ruminiclostridium displayed a significant downward trend after the CPF intervention. Correlation analysis also revealed that these gut microbes had certain correlations with the metabolites, suggesting that CPFs help the intestinal microbiota to repair the intestinal environment and modulate the release of some beneficial metabolites. Notably, single-cell RNA-seq revealed that CPF supplementation significantly regulated the expression of genes associated with circadian rhythm, myelination, and neurodegenerative diseases. Altogether, these findings highlight that CPFs may represent a promising dietary therapeutic strategy for treating circadian rhythm disruption.

Developmental Profiling of Dietary Carbohydrate Digestion in Piglets

Carbohydrates are the main source of energy in the diet, accounting for the largest proportion in the diets of humans and monogastric animals. Although recent progress has been made in the study of intestinal carbohydrate digestion in piglets, there is a lack of comprehensive study on the dynamic changes in intestinal carbohydrate digestion with age in the early growth stage of piglets. To fill in this gap of knowledge, we collected samples of the small intestine, pancreatic tissues, and colonic digesta from 42 piglets during newborn [day (d) 0], lactation (d 7, 14), weaning (d 21), and nursery (d 28, 35, and 42) stages. Intestinal and pancreatic tissues and colonic digesta were collected at necropsy and analyzed for morphology, digestive enzyme activities, short-chain fatty acids (SCFA), and microbial abundance. Villus height reached a maximum at 1 week (d 7) in the duodenum and jejunum (P <0.01), and a higher ratio of villus height to crypt depth and lactase activity were observed on d 0 and 7 (P < 0.001) compared to other ages. However, the sucrase and maltase activities were increased with piglets' age. Similar activities of sucrase and maltase were found in the small intestine. In addition, amylase, lipase, and protease activities were assayed in the pancreas. The activity of amylase increased with age, while lipase and protease decreased gradually from birth to weaning (d 21, 28) and then increased after weaning (d 35, 42). Compared with d 0, d 42 increased the abundance of Firmicutes and Bacteroidetes with a higher concentration of total SCFA (P < 0.001) and decreased the abundance of Proteobacteria, but weaning (d 21, 28) increased the abundance of Proteobacteria in the colon. These results indicate that with the increase in piglet age, the carbohydrate digestive function gradually increased, but weaning hindered the development of intestinal function. These results provide us with new insights into the healthy development of piglets' intestines, which may help us to better regulate the physiological health of piglets in the future.

Changes in gut microbiota, metabolite SCFAs, and GPR43 expression in obese diabetic mice after sleeve gastrectomy

AIMS

To evaluate changes in short-chain fatty acid levels and G protein-coupled receptor 43 expression and distribution in gut microbiota and explore their relationships in obese diabetic mice after sleeve gastrectomy.

METHODS AND RESULTS

Diet-induced obese mice and obese diabetic ob/ob mice were established. Changes in glucose metabolism, lipid metabolism, gut microbiota, metabolite short-chain fatty acids, and G protein-coupled receptor 43 expression were assessed in both models 10 weeks postoperatively. Mice that underwent sleeve gastrectomy exhibited sustained weight loss and reduced glucose, insulin, leptin, and cholesterol levels. Metagenomic sequencing revealed significant characteristic alterations in gut microbiota after sleeve gastrectomy, which were correlated with changes in fecal short-chain fatty acid levels. Postoperatively, G protein-coupled receptor 43 expression in the colon tissue was upregulated in both models, whereas its expression in the adipose tissue was downregulated in the diet-induced obese mouse model.

CONCLUSIONS

Metabolic improvement in obese and diabetic mice after sleeve gastrectomy is associated with alterations in gut microbiota, short-chain fatty acid levels, and G protein-coupled receptor 43 expression.

SIGNIFICANCE AND IMPACT OF STUDY

Our findings reveal a possible mechanism through which sleeve gastrectomy improves obesity and diabetes via changes in bacteria producing short-chain fatty acids and G protein-coupled receptor 43.

Targeting Gut Microbiota With Natural Polysaccharides: Effective Interventions Against High-Fat Diet-Induced Metabolic Diseases

Unhealthy diet, in particular high-fat diet (HFD) intake, can cause the development of several metabolic disorders, including obesity, hyperlipidemia, type 2 diabetes mellitus (T2DM), non-alcoholic fatty liver disease (NAFLD), and metabolic syndrome (MetS). These popular metabolic diseases reduce the quality of life, and induce premature death worldwide. Evidence is accumulating that the gut microbiota is inextricably associated with HFD-induced metabolic disorders, and dietary intervention of gut microbiota is an effective therapeutic strategy for these metabolic dysfunctions. Polysaccharides are polymeric carbohydrate macromolecules and sources of fermentable dietary fiber that exhibit biological activities in the prevention and treatment of HFD-induced metabolic diseases. Of note, natural polysaccharides are among the most potent modulators of the gut microbiota composition. However, the prebiotics-like effects of polysaccharides in treating HFD-induced metabolic diseases remain elusive. In this review, we introduce the critical role of gut microbiota human health and HFD-induced metabolic disorders. Importantly, we review current knowledge about the role of natural polysaccharides in improving HFD-induced metabolic diseases by regulating gut microbiota.

Ginkgo biloba extract ameliorates atherosclerosis via rebalancing gut flora and microbial metabolism

The Ginkgo biloba leave extract (GbE) is widely applied in the prevention and treatment of atherosclerotic cardiovascular diseases in clinical practice. However, its mechanism of actions has not been totally elucidated. In this study, we confirmed the beneficial effects of GbE in alleviating hypercholesterolemia, inflammation and atherosclerosis in Ldlr^-/- mice, which were fed 12 weeks of Western diet (WD). Moreover, 16S rRNA sequencing revealed that GbE treatment reshaped the WD-perturbed intestinal microbiota, particularly decreased the Firmicutes/Bacteroidetes ratio and elevated the abundance of Akkermansia, Alloprevotella, Alistipes, and Parabacteroides. Furthermore, GbE treatment downregulated the intestinal transcriptional levels of proinflammatory cytokines and enhanced the expression of tight junction proteins, exerting the roles of attenuating the intestinal inflammation as well as repairing the gut barrier. Meanwhile, the targeted metabolomic analysis displayed that GbE treatment significantly reversed the dysfunction of the microbial metabolic phenotypes, including promoting the production of short chain fatty acids, indole-3-acetate and secondary bile acids, which were correlated with the atherosclerotic plaque areas. Finally, we confirmed GbE-altered gut microbiota was sufficient to alleviate atherosclerosis by fecal microbiota transplantation. In summary, our findings provide important insights into the pharmacological mechanism underlying the antiatherogenic efficacy of GbE.

Polysaccharide Regulation of Intestinal Flora: A Viable Approach to Maintaining Normal Cognitive Performance and Treating Depression

The intestinal tract of a healthy body is home to a large variety and number of microorganisms that will affect every aspect of the host’s life. In recent years, polysaccharides have been found to be an important factor affecting intestinal flora. Polysaccharides are widely found in nature and play a key role in the life activities of living organisms. In the intestinal tract of living organisms, polysaccharides have many important functions, such as preventing the imbalance of intestinal flora and maintaining the integrity of the intestinal barrier. Moreover, recent studies suggest that gut microbes can influence brain health through the brain-gut axis. Therefore, maintaining brain health through polysaccharide modulation of gut flora deserves further study. In this review, we outline the mechanisms by which polysaccharides maintain normal intestinal flora structure, as well as improving cognitive function in the brain via the brain-gut axis by virtue of the intestinal flora. We also highlight the important role that gut microbes play in the pathogenesis of depression and the potential for treating depression through the use of polysaccharides to modulate the intestinal flora.

Understanding the mechanism underlying the anti-diabetic effect of dietary component: a focus on gut microbiota

Diabetes has become one of the biggest non-communicable diseases and threatens human health worldwide. The management of diabetes is a complex and multifaceted process including drug therapy and lifestyle interventions. Dietary components are essential for both diabetes management and health and survival of trillions of the gut microbiota (GM). Herein, we will discuss the relationship between diets and GM, the mechanism linking diabetes and gut dysbiosis, and the effects of dietary components (nutrients, phytochemicals, probiotics, food additives, etc.) on diabetes from the perspective of modulating GM. The GM of diabetic patients differs from that of health individuals and GM disorder contributes to the onset and maintenance of diabetes. Studies in humans and animal models consolidate that dietary component is a key regulator of diabetes and increasing evidence suggests that the alteration of GM plays a salient role in dietary interventions for diabetes. Given that diabetes is a major public health issue, especially that diabetes is linked with a high risk of mortality from COVID-19, this review provides compelling evidence for that targeting GM by dietary components is a promising strategy, and offers new insights into potential preventive or therapeutic approaches (dietary and pharmacological intervention) for the clinical management of diabetes.

Cyclocarya paliurus (Batalin) Iljinskaja: Botany, Ethnopharmacology, phytochemistry and pharmacology

ETHNOPHARMACOLOGICAL RELEVANCE

Cyclocarya paliurus (Batalin) Iljinskaja (C. paliurus) also known as Sweet tea tree, Money tree, Money willow, green money plum, mountain willow and shanhua tree, is a native rare monocotyledonous plant in Southern China. It possesses numerous traditional benefits, including clearing heat, detoxification, producing saliva, slake thirst, anti-inflammatory, insecticidal, dispelling wind and relieving itching. It is also effective in preventing and treating diabetes, hypertension, hyperlipidemia, dizziness and swelling and pain, as well as reducing cholesterol, and modulating the functions of the immune system. The stem, leaves and bark of this plant are all medicinal parts, but the leaves have the highest research value.

AIM OF THE STUDY

This article summarized the plant's botanical description, distribution, ethnopharmacology, phytochemical profiles and pharmacological for the first time, to provide possible directions for future development and research in brief.

MATERIAL AND METHODS

The literature for this current manuscript was obtained from reports published from 1992 to May 2021 in diverse databases such as the China Knowledge Resource Integrated databases (CNKI), SciFinder, Google Scholar, Baidu Scholar, Elsevier and Pub-Med. The domestic and foreign references published about C. paliurus over recent years were collected, analyzed and summarized.

RESULTS

The botanical characteristics of the fruits of C. paliurus are unique in having a central nutlet surrounded by a circular wing to distinguish the living genera of Juglandaceae. In traditional medicine, C. paliurus leaves are used by the local people of Southern China to make tea to prevent diabetes. More than 210 compounds have been isolated from C. paliurus. Among them, the characteristic 3,4-seco-dammaranes accounted for the most. Other compounds include dammarane tetracyclic triterpenoids, various pentacyclic triterpenoids, flavonoids, isosclerones, phenolic derivatives and polysaccharides. The plant extracts and compounds have been reported to exert various pharmacological activities, such as anti-hyperglycemic, anti-hyperlipidemic, anti-cancer, cytotoxic, anti-oxidative, anti-inflammatory, hepatoprotective, and anti-microbial activities.

CONCLUSIONS

Comprehensive literature analysis shows that C. paliurus extract and its compounds have a variety of biological activities for the treatment of various diseases. The current modern pharmacology research is mostly related to the records of ethnic pharmacology, mainly in vitro research, relatively few in vivo research. Therefore, future studies should focus on this aspect. In addition, we also would like to recommend further research should concentrate on toxicity studies and quality control of C. paliurus to fill the study gap, as well as to provide theoretical support for the further development of the potential functions and clinical applications of the plant.

Alterations in Intestinal Antioxidant and Immune Function and Cecal Microbiota of Laying Hens Fed on Coated Sodium Butyrate Supplemented Diets

This study was designed to evaluate the effects of dietary coated sodium butyrate (CSB) on the intestinal antioxidant, immune function, and cecal microbiota of laying hens. A total of 720 52-week-old Huafeng laying hens were randomly allocated into five groups and fed a basal diet supplemented with CSB at levels of 0 (control), 250 (S250), 500 (S500), 750 (S750), and 1000 (S1000) mg/kg for eight weeks. The results revealed that CSB supplementation quadratically decreased the malondialdehyde content and increased the superoxide dismutase activity of the jejunum as well as the total antioxidative capacity activity of the ileum (p < 0.05). Dietary CSB supplementation linearly decreased the diamine oxidase and D-lactic acid content of the serum (p < 0.05). Compared with the control group, the addition of CSB resulted in linear and/or quadratic effects on the mRNA expression of inflammatory cytokines TNF-α, IL-6, and IL-10 in the jejunum and ileum (p < 0.05). The short-chain fatty acid concentrations increased quadratically as supplemental CSB improved (p < 0.05). Additionally, dietary CSB levels had no effect on microbial richness estimators, but ameliorated cecal microbiota by raising the abundance of probiotics and lowering pathogenic bacteria enrichment. In conclusion, our results suggest that dietary supplementation with CSB could improve the intestinal health of laying hens via positively influencing the antioxidant capacity, inflammatory cytokines, short-chain fatty acids, and gut microbiota. In this study, 500 mg/kg CSB is the optimal supplement concentration in the hens’ diet.

Review of the correlation between Chinese medicine and intestinal microbiota on the efficacy of diabetes mellitus

Diabetes mellitus is a serious metabolic disorder that can lead to a number of life-threatening complications. Studies have shown that intestinal microbiota is closely related to the development of diabetes, making it a potential target for the treatment of diabetes. In recent years, research on the active ingredients of traditional Chinese medicine (TCM), TCM compounds, and prepared Chinese medicines to regulate intestinal microbiota and improve the symptoms of diabetes mellitus is very extensive. We focus on the research progress of TCM active ingredients, herbal compounds, and prepared Chinese medicines in the treatment of diabetes mellitus in this paper. When diabetes occurs, changes in the abundance and function of the intestinal microbiota disrupt the intestinal environment by disrupting the intestinal barrier and fermentation. TCM and its components can increase the abundance of beneficial bacteria while decreasing the abundance of harmful bacteria, regulate the concentration of microbial metabolites, improve insulin sensitivity, regulate lipid metabolism and blood glucose, and reduce inflammation. TCM can be converted into active substances with pharmacological effects by intestinal microbiota, and these active substances can reverse intestinal microecological disorders and improve diabetes symptoms. This can be used as a reference for diabetes prevention and treatment.

Multiomics signatures of type 1 diabetes with and without albuminuria

AIMS/HYPOTHESIS

To identify novel pathophysiological signatures of longstanding type 1 diabetes (T1D) with and without albuminuria we investigated the gut microbiome and blood metabolome in individuals with T1D and healthy controls (HC). We also mapped the functional underpinnings of the microbiome in relation to its metabolic role.

METHODS

One hundred and sixty-one individuals with T1D and 50 HC were recruited at the Steno Diabetes Center Copenhagen, Denmark. T1D cases were stratified based on levels of albuminuria into normoalbuminuria, moderate and severely increased albuminuria. Shotgun sequencing of bacterial and viral microbiome in stool samples and circulating metabolites and lipids profiling using mass spectroscopy in plasma of all participants were performed. Functional mapping of microbiome into Gut Metabolic Modules (GMMs) was done using EggNog and KEGG databases. Multiomics integration was performed using MOFA tool.

RESULTS

Measures of the gut bacterial beta diversity differed significantly between T1D and HC, either with moderately or severely increased albuminuria. Taxonomic analyses of the bacterial microbiota identified 51 species that differed in absolute abundance between T1D and HC (17 higher, 34 lower). Stratified on levels of albuminuria, 10 species were differentially abundant for the moderately increased albuminuria group, 63 for the severely increased albuminuria group while 25 were common and differentially abundant both for moderately and severely increased albuminuria groups, when compared to HC. Functional characterization of the bacteriome identified 23 differentially enriched GMMs between T1D and HC, mostly involved in sugar and amino acid metabolism. No differences in relation to albuminuria stratification was observed. Twenty-five phages were differentially abundant between T1D and HC groups. Six of these varied with albuminuria status. Plasma metabolomics indicated differences in the steroidogenesis and sugar metabolism and circulating sphingolipids in T1D individuals. We identified association between sphingolipid levels and Bacteroides sp. abundances. MOFA revealed reduced interactions between gut microbiome and plasma metabolome profiles albeit polar metabolite, lipids and bacteriome compositions contributed to the variance in albuminuria levels among T1D individuals.

CONCLUSIONS

Individuals with T1D and progressive kidney disease stratified on levels of albuminuria show distinct signatures in their gut microbiome and blood metabolome.

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.

Semen microbiota in normal and leukocytospermic males

Large numbers of microbes can be present in seminal fluid, and there are differences in the semen microbiota between normal and abnormal semen samples. To evaluate the semen microbiota in patients with leukocytospermia, 87 seminal fluid samples, including 33 samples with a normal seminal leukocyte count and 54 samples with leukocytospermia, were obtained for a cross-sectional analysis. Twenty samples with a normal seminal leukocyte count had normal sperm parameters (Control group), and 13 samples with a normal seminal leukocyte count were from asthenozoospermia patients (Ast group). However, 32 samples with leukocytospermia were from asthenozoospermia patients (LA group), and only 22 samples with leukocytospermia had normal sperm parameters (Leu group). The 16S ribosomal RNA (rRNA) gene sequencing method was used to sequence the microbiota in the seminal fluid, and multiple bioinformatics methods were utilized to analyze the data. Finally, the results showed that the worse sperm parameters were observed in the leukocytospermia-related groups. Semen microbiota analysis found that there was increased alpha diversity in the leukocytospermia-related groups. Firmicutes, Proteobacteria, Actinobacteria, and Bacteroidetes were the primary phyla in the seminal fluid. Two microbiota profiles, namely, Lactobacillus-enriched and Streptococcus-enriched groups, were identified in this study. The majority of the samples in the groups with a normal seminal leukocyte count could be categorized as Lactobacillus-enriched, whereas the majority of the leukocytospermia samples could be categorized as Streptococcus-enriched. Our study indicated that males with leukocytospermia have worse sperm parameters and a different semen microbiota composition compared to males with a normal seminal leukocyte count.

Coix seed polysaccharides alleviate type 2 diabetes mellitus via gut microbiota-derived short-chain fatty acids activation of IGF1/PI3K/AKT signaling

Type 2 diabetes mellitus (T2DM) has become a worldwide concern in recent years. Coix seed (CS) as a homologous substance of traditional Chinese medicine and food, its polysaccharides can improve the symptoms of patients with metabolic disorders. Since most plant polysaccharides are difficult to digest and absorb, we hypothesized that Coix seed polysaccharides (CSP) exert hypoglycemic effects through the gut. In this study, the underlying mechanisms regulating hypoglycemic effects of CSP on a T2DM mouse model were investigated. After treatment with CSP, serum insulin and high-density lipoprotein cholesterol levels were increased, while total cholesterol, triglycerides and low-density lipoprotein cholesterol levels were decreased in T2DM mice. In addition, CSP treatment helped repair the intestinal barrier and modulated the gut microbial composition in T2DM mice, mainly facilitating the growth of short-chain fatty acid (SCFA)-producing bacteria, Spearman's analysis revealed these bacteria were positively related with the hypoglycemic efficacy of CSP. Colonic transcriptome analysis indicated the hypoglycemic effect of CSP was associated with the activation of the IGF1/PI3K/AKT signaling pathway. Correlative analysis revealed that this activation may result from the increase of SCFAs-producing bacteria by CSP. GC-MS detection verified that CSP treatment increased fecal SCFAs levels. Molecular docking revealed that SCFAs could bind with IGF1, PI3K, and AKT. Our findings demonstrated that CSP treatment modulates gut microbial composition, especially of the SCFAs-producing bacteria, activates the IGF1/PI3K/AKT signaling pathways, and exhibits hypoglycemic efficacy.

Curcumin β-D-Glucuronide Modulates an Autoimmune Model of Multiple Sclerosis with Altered Gut Microbiota in the Ileum and Feces

We developed a prodrug type of curcumin, curcumin monoglucuronide (CMG), whose intravenous/intraperitoneal injection achieves a high serum concentration of free-form curcumin. Although curcumin has been reported to alter the gut microbiota and immune responses, it is unclear whether the altered microbiota could be associated with inflammation in immune-mediated diseases, such as multiple sclerosis (MS). We aimed to determine whether CMG administration could affect the gut microbiota at three anatomical sites (feces, ileal contents, and the ileal mucosa), leading to suppression of inflammation in the central nervous system (CNS) in an autoimmune model for MS, experimental autoimmune encephalomyelitis (EAE). We injected EAE mice with CMG, harvested the brains and spinal cords for histological analyses, and conducted microbiome analyses using 16S rRNA sequencing. CMG administration modulated EAE clinically and histologically, and altered overall microbiota compositions in feces and ileal contents, but not the ileal mucosa. Principal component analysis (PCA) of the microbiome showed that principal component (PC) 1 values in ileal contents, but not in feces, correlated with the clinical and histological EAE scores. On the other hand, when we analyzed the individual bacteria of the microbiota, the EAE scores correlated with significant increases in the relative abundance of two bacterial species at each anatomical site: Ruminococcus bromii and Blautia (Ruminococcus) gnavus in feces, Turicibacter sp. and Alistipes finegoldii in ileal contents, and Burkholderia spp. and Azoarcus spp. in the ileal mucosa. Therefore, CMG administration could alter the gut microbiota at the three different sites differentially in not only the overall gut microbiome compositions but also the abundance of individual bacteria, each of which was associated with modulation of neuroinflammation.

Anti-Hyperglycemic Effects of Refined Fractions from Cyclocarya paliurus Leaves on Streptozotocin-Induced Diabetic Mice

To identify the chemical components responsible for the anti-hyperglycemic effect of Cyclocarya paliurus (Batal.) Iljinsk (Juglandaceae) leaves, an ethanol extract (CPE) and a water extract (CPW) of C. paliurus leaves, as well as their total flavonoids (CPF), triterpenoids (CPT) and crude polysaccharides (CPP), were prepared and assessed on streptozotocin (STZ)-induced diabetic mice. After being orally administrated once a day for 24 days, CPF (300 mg/kg), CPP (180 mg/kg), or CPF+CPP (300 mg/kg CPF + 180 mg/kg CPP) treatment reversed STZ-induced body weight and muscle mass losses. The glucose tolerance tests and insulin tolerance tests suggested that CPF, CPP, and CPF+CPP showed anti-hyperglycemic effect in STZ-induced diabetic mice. Furthermore, CPF enhances glucose-stimulated insulin secretion in MIN6 cells and insulin-stimulated glucose uptake in C2C12 myotubes. CPF and CPP suppressed inflammatory cytokine levels in STZ-induced diabetic mice. Additionally, CPF and CPP improved STZ-induced diabetic nephropathy assessed by H&E staining, blood urea nitrogen content, and urine creatinine level. The molecular networking and Emperor analysis results indicated that CPF showed potential anti-hyperglycemic effects, and HPLC–MS/MS analysis indicated that CPF contains 3 phenolic acids and 9 flavonoids. In contrast, CPT (650 mg/kg) and CPC (300 mg/kg CPF + 180 mg/kg CPP + 650 mg/kg CPT) did not show anti-hyperglycemic effect. Taken together, polysaccharides and flavonoids are responsible for the anti-hyperglycemic effect of C. paliurus leaves, and the clinical application of C. paliurus need to be refined.

Characterization of gut microbiota, metabolism and cytokines in benzene-induced hematopoietic damage

Benzene exposure leads to hematopoietic dysfunction and is characterized clinically by a decrease in blood cells, but the underlying mechanisms remain elusive. Disturbed gut microbiota may induce host metabolic, immune disorders and the onset of disease. However, the characterization of gut microbiota, metabolism, cytokines and their association with benzene-induced hematopoietic toxicity lacks systematic evidence. Here, the microbiomics, metabolomics and cytokine network were applied to find out the critical characteristics of gut microbiota, metabolism and cytokines in mice involved in the benzene-induced hematopoietic toxicity. We found that the decline in hematopoietic stem cells was earlier than the hematological changes in the 5 mg/kg and 25 mg/kg benzene exposure groups. While 125 mg/kg benzene exposure resulted in a significant decline in whole blood cells. High-throughput sequencing results showed that benzene exposure disrupted homeostasis of gut microbiota, metabolism and cytokine in mice. 6 bacteria, 12 plasma metabolites and 6 cytokines were associated with benzene-induced hematopoietic damage. Notably, IL-5 was significantly increased in benzene exposure group in a dose-dependent manner, and a significant negative correlation was found between IL-5 and hematopoietic damage. We further found that increased Family_XIII_AD3011_group at the genus level and decreased Anaerotruncus_sp at the species level in benzene-exposed group were strongly associated with hematopoietic toxicity and IL-5. Furthermore, the abundance of Family_XIII_AD3011_group and Anaerotruncus_sp were negatively correlated with Adipic acid and 4-Hydroxyproline, respectively. Our findings indicated that altered flora structure of gut microbiota affects the metabolic phenotype which acts as messengers for the gut microbes, affecting host inflammation. This preliminary study provides new insight into the potential mechanisms of benzene-induced hematopoietic toxicity, further exploration by functional studies is required in the future.

Time-course alterations of gut microbiota and short-chain fatty acids after short-term lincomycin exposure in young swine

Increasing evidence suggests that antibiotic administration causes gut injury, negatively affecting nutrient digestion, immune regulation, and colonization resistance against pathogens due to the disruption of gut microbiota. However, the time-course effects of therapeutic antibiotics on alterations of gut microbes and short-chain fatty acids (SCFAs) in young swine are still unknown. In this study, twenty piglets were assigned into two groups and fed commercial diets with or without lincomycin in the first week for a 28-day trial period. Results showed that 1-week lincomycin exposure (LE) did reduce the body weight on day 14 (p = 0.0450) and 28 (p = 0.0362). The alpha-diversity notably reduced after 1-week LE, and then gradually raised and reached the control group level in the second week on cessation of LE, indicated by the variation of Sobs, Chao, Shannon, and ACE index (p < 0.05). Beta-diversity analysis revealed that the distinct microbial cluster existed persistently for the whole trial period between two groups (p < 0.001). The relative abundance of most microbes including fiber-degrading (e.g., Agathobacter and Coprococcus), beneficial (e.g., Lactobacillus and Mitsuokella), or pathogenic bacteria (e.g., Terrisporobacter and Lachnoclostridium) decreased (LDA score > 3), and the concentration of SCFAs also diminished in the feces of 1-week lincomycin-administrated young swine, indicating that therapeutic LE killed most bacteria and reduced SCFA production with gut dysbiosis occurring. After the LE stopped, the state of gut dysbiosis gradually attenuated and formed new gut-microbe homeostasis distinct from microbial homeostasis of young pigs unexposed to lincomycin. The increased presence of potential pathogens, such as Terrisporobacter, Negativibacillus, and Escherichia-Shigella, and decreased beneficial bacteria, such as Lactobacillus and Agathobacter, were observed in new homeostasis reshaped by short-lincomycin administration (LDA score > 3 or p < 0.05), adversely affecting gut development and health of young pigs. Collectively, these results suggested that severe disruption of the commensal microbiota occurred after short-term LE or termination of LE in young swine. KEY POINTS: • Therapeutic lincomycin exposure induced gut dysbiosis, killing most bacteria and reducing short-chain fatty acid production. • Gut dysbiosis gradually attenuated and formed new homeostasis after lincomycin exposure stopped. • The new homeostasis, increased Escherichia-Shigella etc. and decreased Lactobacillus etc., was potentially harmful to gut health.

The Role of Short-Chain Fatty Acids of Gut Microbiota Origin in Hypertension

Hypertension is a significant risk factor for cardiovascular and cerebrovascular diseases, and its development involves multiple mechanisms. Gut microbiota has been reported to be closely linked to hypertension. Short-chain fatty acids (SCFAs)-the metabolites of gut microbiota-participate in hypertension development through various pathways, including specific receptors, immune system, autonomic nervous system, metabolic regulation and gene transcription. This article reviews the possible mechanisms of SCFAs in regulating blood pressure and the prospects of SCFAs as a target to prevent and treat hypertension.

Four new dammarane triterpenoid glycosides from the leaves of Cyclocarya paliurus and their SIRT1 activation activities

Four new C-11 monosaccharide attached dammarane triterpenoid glycosides cypaliurusides SV (1-4), along with nine known dammarane triterpenoid glycosides (5-13) were isolated from a CHCl3-soluble extract of the leaves of Cyclocarya paliurus. All characterized compounds were assayed for their cytotoxicities against HepG2 cells and 10 compounds were evaluated for the agonistic effects on sirtuin1 (SIRT1). The results showed that compounds 1, 5 and 6 were strongly cytotoxic in HepG2 cell line. Two dammarane triterpenoid glycosides 3 and 10 exhibited agonistic activities on SIRT1 with IC50 of 10 μM and 20 μM, respectively.

Sargassum fusiforme Alginate Relieves Hyperglycemia and Modulates Intestinal Microbiota and Metabolites in Type 2 Diabetic Mice

Sargassum fusiforme alginate (SF-Alg) possess many pharmacological activities, including hypoglycemic and hypolipidemic. However, the hypoglycemic mechanisms of SF-Alg remain unclear due to its low bioavailability. In this study, we evaluated the therapeutic effect of SF-Alg on high-fat diet (HFD)/streptozotocin (STZ)-induced type 2 diabetes (T2D) mice. SF-Alg intervention was found to significantly reduce fasting blood glucose (FBG), triglycerides (TG), and total cholesterol (TC), while increasing high-density lipoprotein cholesterol (HDL-c) and improving glucose tolerance. In addition, administrating SF-Alg to diabetic mice moderately attenuated pathological changes in adipose, hepatic, and heart tissues as well as skeletal muscle, and diminished oxidative stress. To probe the underlying mechanisms, we further analyzed the gut microbiota using 16S rRNA amplicon sequencing, as well as metabolites by non-targeted metabolomics. Here, SF-Alg significantly increased some benign bacteria (Lactobacillus, Bacteroides, Akkermansia Alloprevotella, Weissella and Enterorhabdus), and significantly decreased harmful bacteria (Turicibacter and Helicobacter). Meanwhile, SF-Alg dramatically decreased branched-chain amino acids (BCAAs) and aromatic amino acids (AAAs) in the colon of T2D mice, suggesting a positive benefit of SF-Alg as an adjvant agent for T2D.

A Metagenome-Wide Association Study of the Gut Microbiome and Metabolic Syndrome

Metabolic syndrome (MetS) is a wide-ranging disorder, which includes insulin resistance, altered glucose and lipid metabolism, and increased blood pressure and visceral obesity. MetS symptoms combine to result in a significant increase in cardiovascular risk. It is therefore critical to treat MetS in the early stages of the disorder. In this study, 123 MetS patients and 304 controls were recruited to determine whether the gut microbiome plays a role in MetS development and progression. By using whole-genome shotgun sequencing, we found that the gut microbiomes of MetS patients were different from those of controls, with MetS patients possessing significantly lower gut microbiome diversity. In addition, 28 bacterial species were negatively correlated with waist circumstance, with Alistipes onderdonkii showing the strongest correlation, followed by Bacteroides thetaiotaomicron, Clostridium asparagiforme, Clostridium citroniae, Clostridium scindens, and Roseburia intestinalis. These species were also enriched in controls relative to MetS patients. In addition, pathways involved in the biosynthesis of carbohydrates, fatty acids, and lipids were enriched in the MetS group, indicating that microbial functions related to fermentation may play a role in MetS. We also found that microbiome changes in MetS patients may aggravate inflammation and contribute to MetS diseases by inhibiting the production of short-chain fatty acids (SCFAs). Taken together, these results indicate the potential utility of beneficial gut microbiota as a potential therapeutic to alleviate MetS.

Exposure to High Aerial Ammonia Causes Hindgut Dysbiotic Microbiota and Alterations of Microbiota-Derived Metabolites in Growing Pigs

Ammonia, an atmospheric pollutant in the air, jeopardizes immune function, and perturbs metabolism, especially lipid metabolism, in human and animals. The roles of intestinal microbiota and its metabolites in maintaining or regulating immune function and metabolism are irreplaceable. Therefore, this study aimed to investigate how aerial ammonia exposure influences hindgut microbiota and its metabolites in a pig model. Twelve growing pigs were treated with or without aerial ammonia (35 mg/m³) for 25 days, and then microbial diversity and microbiota-derived metabolites were measured. The results demonstrated a decreasing trend in leptin (p = 0.0898) and reduced high-density lipoprotein cholesterol (HDL-C, p = 0.0006) in serum after ammonia exposure. Besides, an upward trend in hyocholic acid (HCA), lithocholic acid (LCA), hyodeoxycholic acid (HDCA) (p < 0.1); a downward trend in tauro-deoxycholic acid (TDCA, p < 0.1); and a reduced tauro-HDCA (THDCA, p < 0.05) level were found in the serum bile acid (BA) profiles after ammonia exposure. Ammonia exposure notably raised microbial alpha-diversity with higher Sobs, Shannon, or ACE index in the cecum or colon and the Chao index in the cecum (p < 0.05) and clearly exhibited a distinct microbial cluster in hindgut indicated by principal coordinate analysis (p < 0.01), indicating that ammonia exposure induced alterations of microbial community structure and composition in the hindgut. Further analysis displayed that ammonia exposure increased the number of potentially harmful bacteria, such as Negativibacillus, Alloprevotella, or Lachnospira, and decreased the number of beneficial bacteria, such as Akkermansia or Clostridium_sensu_stricto_1, in the hindgut (FDR < 0.05). Analysis of microbiota-derived metabolites in the hindgut showed that ammonia exposure increased acetate and decreased isobutyrate or isovalerate in the cecum or colon, respectively (p < 0.05). Unlike the alteration of serum BA profiles, cecal BA data showed that high ammonia exposure had a downward trend in cholic acid (CA), HCA, and LCA (p < 0.1); a downward trend in deoxycholic acid (DCA) and HDCA (p < 0.05); and an upward trend in glycol-chenodeoxycholic acid (GCDCA, p < 0.05). Mantel test and correlation analysis revealed associations between microbiota-derived metabolites and ammonia exposure-responsive cecal bacteria. Collectively, the findings illustrated that high ammonia exposure induced the dysbiotic microbiota in the hindgut, thereby affecting the production of microbiota-derived short-chain fatty acids and BAs, which play a pivotal role in the modulation of host systematic metabolism.

Genome-wide DNA methylation profiling of high-fat emulsion-induced hyperlipidemia mice intervened by a polysaccharide from Cyclocarya paliurus (Batal) Iljinskaja

Genome-wide DNA methylation was used to study the lipid-lowering effect of Cyclocarya paliurus (Batal) Iljinskaja polysaccharide (CPP). The objective of this study was to investigate the hypolipidemic effects and the potential underlying mechanisms of action of CPP-2 in high-fat emulsion (HFE)-induced mice. The results showed that CPP-2 reduced the level of genome-wide DNA methylation in the liver of HFE-induced mice, which had a lipid-lowering effect by regulating the AMP-activated protein kinase (AMPK) signaling-, fatty acid metabolism-, fatty acid biosynthesis- and adipocytokine signaling pathways. A series of lipid metabolism genes were screened out by conjoint analysis of the Gene Ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. Hereafter, fatty acid synthase (FAS) and peroxisome proliferators-activated receptor α (PPARα) as target genes were selected to validate the accuracy of the results. The findings demonstrated that CPP-2 might be effective in lowering the lipid content, thereby protecting against HFE-induced hyperlipidemia.

Ge-Gen-Jiao-Tai-Wan Affects Type 2 Diabetic Rats by Regulating Gut Microbiota and Primary Bile Acids

The Ge-Gen-Jiao-Tai-Wan (GGJTW) formula has been used to treat type 2 diabetes mellitus (T2DM) in China for a long time. Our previous study has proved that GGJTW could alleviate the type 2 diabetic symptoms, but the underlying mechanisms are still unclear. This study aimed to investigate the changes in gut microbiota and primary bile acids (PBAs) to determine the potential mechanisms of GGJTW in treating T2DM.The fecal transplant method and pseudogerm-free rats were used in our study.The16S rRNA gene sequencing method was used to analyze the changes in the intestinal flora, and PBAs in the colon contents were detected. Finally, the expression of farnesoid X receptor (FXR), G protein-coupled membrane receptor 5 (TGR5), and glucagon-like peptide-1 (GLP-1) was assessed. Following GGJTW treatment, we observed a decrease in blood glucose levels and improvements in glucose tolerance and serum lipid levels. Furthermore, we found that GGJTW could regulate the composition of the gut microbiota and upregulate the diabetic beneficial phylum Firmicutes and bile-acid-related genus Lactobacillus. PBAs in the colon contents were increased in the GGJTW-treated group, accompanied by upregulated expression of the bile acid receptors FXR and TGR5 and increased concentrations of GLP-1. These results indicated that GGJTW could alleviate symptoms of type 2 diabetic rats by regulating the gut microbiota, promoting the production of PBAs, and upregulating the PBA-FXR/TGR5-GLP-1 pathway.

[Research progress in the role and mechanism of polysaccharides in regulating glucose and lipid metabolism]

Polysaccharides are a group of compounds composed of multiple monosaccharides of the same or different structures combined by glycosidic bonds, and are widely found in animals and plants and in the cell walls of microorganisms. Polysaccharides possess the advantages of high safety and low toxicity. Recent studies revealed that polysaccharides have a wide range of biological activities including immunoregulation, anti-tumor, antiviral, antioxidant activities, and blood glucose-and lipid- lowering effects. The effects of polysaccharides in improving insulin sensitivity and regulating glucose and lipid metabolism have drawn much attention from researchers. Many polysaccharides can reduce blood glucose and blood lipid by repairing pancreatic islet cells, improving insulin resistance, regulating intestinal flora, enhancing antioxidant capacity, and regulating the activities of key enzymes in glucose and lipid metabolism. This reviews examines the role and mechanism of polysaccharides in regulating glucose and lipid metabolism. The mechanisms of polysaccharide in regulating glucose metabolism include repairing islet cells and increasing insulin content, increasing insulin sensitivity and improving insulin resistance, regulating the activity of key enzymes in glucose metabolism, increasing synthesis of liver glycogen, and regulating intestinal flora. Polysaccharides can also regulate glucose metabolism by improving immune regulation and antagonizing glucagon. Polysaccharide also regulate lipid metabolism by regulating lipid absorption, expression of the related genes such as PPAR-α, enzyme activities in lipid metabolism, improving antioxidant capacity, and modulating intestinal flora and signaling pathways.

Bifidobacterium adolescentis Isolated from Different Hosts Modifies the Intestinal Microbiota and Displays Differential Metabolic and Immunomodulatory Properties in Mice Fed a High-Fat Diet

The incidence of obesity, which is closely associated with the gut microbiota and chronic inflammation, has rapidly increased in the past 40 years. Therefore, the probiotic-based modification of the intestinal microbiota composition has been developed as a strategy for the treatment of obesity. In this study, we selected four Bifidobacterium adolescentis strains isolated from the feces of newborn and elderly humans to investigate whether supplementation with B. adolescentis of various origins could alleviate obesity in mice. Male C57BL/6J mice fed a high-fat diet (HFD, 60% energy as fat) received one of the following 14-week interventions: (i) B. adolescentis N4_N3, (ii) B. adolescentis Z25, (iii) B. adolescentis 17_3, (iv) B. adolescentis 2016_7_2, and (v) phosphate-buffered saline. The metabolic parameters, thermogenesis, and immunity of all treated mice were measured. Cecal and colonic microbial profiles were determined by 16S rRNA gene sequencing. Intestinal concentrations of short-chain fatty acids (SCFAs) were measured by gas chromatography-mass spectrometry (GC-MS). The B. adolescentis strains isolated from the feces of elderly humans (B. adolescentis Z25, 17_3, and 2016_7_2) decreased the body weight or weight gain of mice, whilst the strain isolated from the newborn (B. adolescentis N4_N3) increased the body weight of mice. The B. adolescentis strains isolated from the elderly also increased serum leptin concentrations and induced the expression of thermogenesis- and lipid metabolism-related genes in brown adipose tissue. All the B. adolescentis strains alleviated inflammations in the spleen and brain and modified the cecal and colonic microbiota. Particularly, all strains reversed the HFD-induced depletion of Bifidobacterium and reduced the development of beta-lactam resistance. In addition, the B. adolescentis strains isolated from the elderly increased the relative abundances of potentially beneficial genera, such as Bacteroides, Parabacteroides, and Faecalibaculum. We speculate that such increased abundance of commensal bacteria may have mediated the alleviation of obesity, as B. adolescentis supplementation decreased the intestinal production of SCFAs, thereby reducing energy delivery to the host mice. Our results revealed that certain strains of B. adolescentis can alleviate obesity and modify the gut microbiota of mice. The tested strains of B. adolescentis showed different effects on lipid metabolism and immunity regulation, with these effects related to whether they had been isolated from the feces of newborn or elderly humans. This indicates that B. adolescentis from different sources may have disparate effects on host health possibly due to the transmission of origin-specific functions to the host.

Potential Role of Natural Plant Medicine Cyclocarya paliurus in the Treatment of Type 2 Diabetes Mellitus

Type 2 diabetes mellitus (T2DM) is a common chronic metabolic disease that has become increasingly prevalent worldwide. It poses a serious threat to human health and places a considerable burden on global social medical work. To meet the increasing demand for T2DM treatment, research on hypoglycemic drugs is rapidly developing. Cyclocarya paliurus (Batal.) Iljinskaja is a medicinal plant that grows in China. The leaves of C. paliurus contain polysaccharides, triterpenoids, and other chemical components, which have numerous health benefits. Therefore, the use of this plant has attracted extensive attention in the medical community. Over the past few decades, contemporary pharmacological studies on C. paliurus extracts have revealed that it has abundant biological activities. Multiple in vitro and in vivo experiments have shown that C. paliurus extracts are safe and can play a therapeutic role in T2DM through anti-inflammatory and antioxidation activities, and intestinal flora regulation. Its efficacy is closely related to many factors, such as extraction, separation, purification, and modification. Based on summarizing the existing extraction methods, this article further reviews the potential mechanism of C. paliurus extracts in T2DM treatment, and we aimed to provide a reference for future research on natural plant medicine for the prevention and treatment of T2DM and its related complications.

Short-Term Lincomycin Exposure Depletion of Murine Microbiota Affects Short-Chain Fatty Acids and Intestinal Morphology and Immunity

Lincomycin, as one of the most commonly used antibiotics, may cause intestinal injury, enteritis and other side effects, but it remains unknown whether these effects are associated with microbial changes and the effects of different doses of lincomycin on infants. Here, 21-day old mice were exposed to 1 and 5 g/L lincomycin to explore the effects of lincomycin on the gut microbiota, metabolites and inflammation. Compared to the control mice, 1 g/L lincomycin exposure decreased the body weight gain of mice (p < 0.05). Both 1 and 5 g/L lincomycin exposure reduced the diversity and microbial composition of mice (p < 0.05). Furthermore, 1 and 5 g/L lincomycin reduced the relative concentrations of acetate, propionate, butyrate, valerate, isobutyric acid and isovaleric acid in the colon chyme of mice (p < 0.05). In addition, 5 g/L lincomycin exposure reduced the villus height, crypt depth, and relative expression of TLR2, TLR3, TLR4, IL-18, TNF-α, and p65 in the jejunum of mice (p < 0.05), while 1 g/L lincomycin exposure reduced the relative expression of TLR2, TLR3, TNF-α, and p65 (p < 0.05). Collectively, these results highlight the depletion effect of short-term lincomycin exposure on microbiota and the further regulatory effect on intestinal morphology and immunosuppression in infant mice.

Short-Chain Fatty Acids: A Soldier Fighting Against Inflammation and Protecting From Tumorigenesis in People With Diabetes

Converging evidences showed that people with diabetes mellitus (DM) have significantly higher risk for different cancers, of which the exact mechanism underlying the association has not been fully realized. Short-chain fatty acids (SCFAs), the fermentation products of the intestinal microbiota, are an essential source for energy supply in gut epithelial cells. They have been reported to improve intestinal barrier integrity, prevent microbial translocation, and further dampen inflammation. Gut dysbiosis and reduction in SCFA-producing bacteria as well as SCFAs production in the intestine are commonly seen in metabolic disorders including DM and obesity. Moreover, inflammation can contribute to tumor initiation and progression through multiple pathways, such as enhancing DNA damage, accumulating mutations in tumor suppressor genes Tp53, and activating nuclear factor-kappa B (NF-κB) signaling pathways. Based on these facts, we hypothesize that lower levels of microbial SCFAs resulted from gut dysbiosis in diabetic individuals, enhance microbial translocation, and increase the inflammatory responses, inducing tumorigenesis ulteriorly. To this end, we will discuss protective properties of microbial SCFAs and explore the pivotal roles SCFAs played in the link of DM with cancer, so as to take early precautions to reduce the risk of cancer in patients with DM.

The effect of traditional Chinese medicine on gut microbiota in adults with type 2 diabetes: A protocol for systematic review and meta-analysis

BACKGROUND

Type 2 diabetes (T2DM), which is the major type of diabetes, accounts for more than 90% of all case of diabetes, and its pathogenesis remains inconclusive. Recent studies have revealed a significant role of gut microbiota in the onset and development of T2DM. Traditional Chinese medicine (TCM) has accumulated rich clinical experience in the treatment of T2DM for thousands of years and a large amount of studies have shown that TCM has the capacity of lowering blood glucose and modulating gut microbiota. The aim of this systematic review is to evaluate all randomized controlled trials on TCM for gut microbiota to assess the effectiveness and safety of TCM in T2DM patients.

METHODS

Seven electronic databases (Web of Science, PubMed, EMBASE, Cochrane Library, China National Knowledge Infrastructure, Wanfang Database, and VIP Information-Chinese Scientific Journal Database) will be searched from inception to present in the English and Chinese languages. Eligible randomized controlled trials evaluating the effect of TCM in T2DM patients, compared with western medicine, placebo or no intervention will be included in the study. The primary outcomes are the glucose metabolism and gut microbiota as well as its metabolites. The second outcomes are changes in weight, and changes in inflammatory markers. Two authors will independently select studies, extract data, and assess the quality of the studies by scanning the titles, abstracts, and full texts. The meta-analysis will be conducted using Review Manager version 5.3. The results will be presented as risk ratios for dichotomous data and adverse events, and as mean differences for continuous data.

RESULT

The study will provide a summary of current evidence for the treatment of T2DM from the perspective of gut microbiota by using TCM based on the outcome measures.

CONCLUSION

The systematic review will evaluate the efficacy of TCM in treating T2DM from the perspective of gut microbiota, providing current evidence and laying a foundation for further work in the field.

PROSPERO REGISTRATION NUMBER

CRD42020188043.

Berberine alleviates type 2 diabetic symptoms by altering gut microbiota and reducing aromatic amino acids

OBJECTIVE

Berberine (BBR), which is extracted from traditional Chinese herb, is abundant in Coptis chinensis and Berberis vulgaris, with a treatment on type 2 diabetes mellitus (T2DM). However, its oral bioavailability is poor. Therefore, the ability of BBR to regulate gut microbiota and intestinal metabolites might exist. This study aimed to investigate changes in gut microbiota and intestinal metabolites, and to reveal the potential mechanism of BBR.

METHODS

To observe the role of gut microbiota in the treatment of T2DM by BBR, antibiotics intervened gut microbiota was used in this study, and the therapeutic effects of BBR were evaluated. A 16S rRNA gene sequencing approach was utilized to analyze gut microbiota alterations, and UHPLC-QTOF/MS-based untargeted metabolomics analysis of colon contents was used to identity differential intestinal metabolites. Finally, serum aromatic amino acids (AAAs) were absolutely quantified using LC/MS.

RESULTS

Inhibition of the blood glucose levels, and improvements in glucose tolerance and serum lipid parameters were observed in the BBR treated group. Type 2 diabetic symptoms in rats in the BA group (treated with antibotics and BBR) were alleviated. However, the therapeutical effects are weaker in the BA group compared with the BBR group, indicating that BBR can be used to treat type 2 diabetic rats immediately, and modulation of gut microbiota is related to the mechanism of BBR in the treatment of T2DM. The community richness and diversity of the gut microbiota were significantly increased by BBR, and the relative abundance of Bacteroidetes was increased in the BBR group, which was accompanied by a decreased relative abundance of Proteobacteria and Verrucomicrobia at the phylum level. At the family level, a probiotic Lactobacillaceae was significantly upregulated not only in the BBR group but also in the BA group and was negatively associated with the risk of T2DM. Metabolomic analysis of colon contents identified 55 differential intestinal metabolites between the BBR group and the model group. AAAs, including tyrosine, tryptophan and phenylalanine, were obviously decreased in the BBR group not only in the colon contents but also in the serum.

CONCLUSIONS

These results demonstrated that BBR could alleviate symptoms in type 2 diabetic rats by affecting gut microbiota composition and reducing the concentration of AAAs.