Comparison of gut microbiota in adult patients with type 2 diabetes and healthy individuals

Differential intestinal and oral microbiota features associated with gestational diabetes and maternal inflammation

Maternal microbiota is involved in many metabolic diseases. However, its role in the pathophysiology of gestational diabetes mellitus (GDM) remains unclear. In this case-control study, we performed a 16S rRNA sequencing-based microbial survey to compare the intestinal and oral microflora at third trimester during pregnancy between 30 GDM and 31 normal controls. Sequentially, a correlation-based network analysis was further performed to explore the interactions among microbiota, maternal and infant blood sugar, and inflammatory markers. Our results show that, compared with controls, the GDM cases showed significant differences in β-diversity and increased Gammaproteobacteria and Hemophilus in intestinal microbiota. Furthermore, the GDM cases showed lower α-diversity, increased Selenomonas and Bifidobacterium, and decreased Fusobacteria and Leptotrichia in oral microbiota. The ROC curve showed the area under the curve to be equal to 0.70 and 0.66 when using oral Leptotrichia or gut Hemophilus, respectively, to predict GDM status. In addition, the components and topography of microbial cooccurrence and coexclusion network were quite distinct by GDM status. In summary, intestinal and oral microorganisms in pregnant women are closely related to the status of GDM in the third trimester of pregnancy. The changes of intestinal and oral microbial features may be noninvasive biomarkers for monitoring the health management of GDM pregnancy.

Intake of sucrose affects gut dysbiosis in patients with type 2 diabetes

Aims/Introduction

Gut dysbiosis is generally associated with type 2 diabetes mellitus. However, the effect of habitual dietary intake on gut dysbiosis in Japanese patients with type 2 diabetes mellitus has not yet been explicated. This study investigated whether alteration of the gut microbiota was influenced by dietary intake of sucrose in Japanese patients with type 2 diabetes mellitus.

Materials and Methods

In this cross‐sectional study, 97 patients with type 2 diabetes mellitus and 97 healthy individuals were matched by age and sex, and then, fecal samples were obtained. Next‐generation sequencing of the 16S ribosomal ribonucleic acid gene was carried out, and functional profiles for the gut microbiota were analyzed. We selected the top 30 gut microbial genera and top 20 functional profiles for the gut microbiota specified by the weighted average difference method. The association between gut microbial genera or functional profiles and habitual dietary intake was investigated by Spearman’s rank correlation coefficient, and then, clustering analysis was carried out to clarify the impact of habitual dietary intake.

Results

The Actinobacteria phylum was highly abundant in patients with type 2 diabetes mellitus, whereas the Bacteroidetes phylum was less abundant. Diabetic‐type gut microbes, specifically Bacteroides and Bifidobacterium, were altered by sucrose intake at the genus level. Furthermore, sucrose intake was associated with glycolysis/gluconeogenesis in the diabetic‐type functional profiles of the gut microbiota.

Conclusions

The gut microbiota and functional profiles for the gut microbiota in patients with type 2 diabetes mellitus were significantly different from those in healthy individuals. Furthermore, we showed that sucrose intake was closely associated with these differences.

Developmental Origins of Health and Disease: Impact of environmental dust exposure in modulating microbiome and its association with non-communicable diseases

Non-communicable diseases (NCDs) including obesity, diabetes, and allergy are chronic, multi-factorial conditions that are affected by both genetic and environmental factors. Over the last decade, the microbiome has emerged as a possible contributor to the pathogenesis of NCDs. Microbiome profiles were altered in patients with NCDs, and shift in microbial communities was associated with improvement in these health conditions. Since the genetic component of these diseases cannot be altered, the ability to manipulate the microbiome holds great promise for design of novel therapies in the prevention and treatment of NCDs. Together, the Developmental Origins of Health and Disease concept and the microbial hypothesis propose that early life exposure to environmental stimuli will alter the development and composition of the human microbiome, resulting in health consequences. Recent studies indicated that the environment we are exposed to in early life is instrumental in shaping robust immune development, possibly through modulation of the human microbiome (skin, airway, and gut). Despite much research into human microbiome, the origin of their constituent microbiota remains unclear. Dust (also known as particulate matter) is a key determinant of poor air quality in the modern urban environment. It is ubiquitous and serves as a major source and reservoir of microbial communities that modulates the human microbiome, contributing to health and disease. There are evidence that reported significant associations between environmental dust and NCDs. In this review, we will focus on the impact of dust exposure in shaping the human microbiome and its possible contribution to the development of NCDs.

The landscape of microbiota research in Iran; a bibliometric and network analysis

OBJECTIVES

To introduce bibliometric features of Iranian documents on microbiota and to provide descriptive information about retrieved documents related to the medical sciences and documents utilizing molecular techniques for microbiota detection.

METHODS

This is a descriptive bibliometric study of all Iranian documents on microbiota in any language that were indexed in Scopus before 7 September 2019. We assessed the research performance through statistical analysis of the bibliometric indicators, including number of publications, citations, institutions and journals activities, co-citations and bibliographic couplings, and network analysis of co-authorships, countries' collaborations, terms and keywords.

RESULTS

We extracted 425 relevant documents, 260 of which pertain to the medical sciences. The most focused microbiota modulating interventions and diseases in 33 clinical trials are 'synbiotics' (n = 8) and 'probiotics' (n = 8), and 'Obesity' (n = 3) and 'non-alcoholic fatty liver disease' (n = 3), respectively. During the last decade, Iranian microbiota publications have increasingly grown with a constant upward slope, particularly in the area of medical sciences after 2016. Citation counting reveals that originals and reviews have been cited 4221 times, with an average 10.76 citations and H-index of 34. The most significant performance in publishing Iranian microbiota documents belongs to 'Tehran University of Medical Sciences' as the active institution (n = 89 publications) and the supporting sponsor (n = 19), 'Microbial Pathogenesis' as the productive journal (n = 12), 'Seidavi A' as the most authorships (n = 19), and 'the United States' as the collaborative country (n = 46).

CONCLUSIONS

The qualitative and quantitative information of this study will be a practical guidance for future study planning and policy-decision making.

gutMDisorder: a comprehensive database for dysbiosis of the gut microbiota in disorders and interventions

gutMDisorder (http://bio-annotation.cn/gutMDisorder), a manually curated database, aims at providing a comprehensive resource of dysbiosis of the gut microbiota in disorders and interventions. Alterations in the composition of the gut microbial community play crucial roles in the development of chronic disorders. And the beneficial effects of drugs, foods and other intervention measures on disorders could be microbially mediated. The current version of gutMDisorder documents 2263 curated associations between 579 gut microbes and 123 disorders or 77 intervention measures in Human, and 930 curated associations between 273 gut microbes and 33 disorders or 151 intervention measures in Mouse. Each entry in the gutMDisorder contains detailed information on an association, including an intestinal microbe, a disorder name, intervention measures, experimental technology and platform, characteristic of samples, web sites for downloading the sequencing data, a brief description of the association, a literature reference, and so on. gutMDisorder provides a user-friendly interface to browse, retrieve each entry using gut microbes, disorders, and intervention measures. It also offers pages for downloading all the entries and submitting new experimentally validated associations.

Insights into the gut microbiota of Nigerian elderly with type 2 diabetes and non-diabetic elderly persons

Type 2 diabetes (T2D) is a prevalent non-communicable disease among the world's growing elderly population. The contribution of the gut microbiota to T2D in several Westernized countries has been established. However, there is little information on the role of the gut microbiota in T2D from the African continent where lifestyle and life expectancy are different.

AIMS

This study sought to investigate gut microbiota variation in relation to elderly people living with T2D. in Nigeria.

METHODS

Whole microbial community DNA were derived from the stool samples of healthy urban-dwelling elderly individuals and urban-dwelling elderly individuals with T2D. The V4 region of the 16S rRNA gene was Illumina-sequenced and analyzed using QIIME2.

RESULTS

Beta taxonomic diversity was significantly different between healthy elderly individuals and elderly individuals with T2D. However, no difference in the alpha taxonomic diversity and predicted functional alpha diversity of the gut microbiota was observed. The genus Ruminococcus (T2D versus Healthy: 2.89% vs 2.21%), families Coriobacteriaceae (Collinsella, T2D versus Healthy: 2.62 % vs 1.25%) and Bifidobacteriaceae were enriched in elderly individuals with T2D, while members of Clostridiaceae (Clostridium, Healthy versus T2D: 5.6% vs 3.2%) and Peptostreptococcaceae (Healthy versus T2D: 3.45% vs 1.99%) were enriched in healthy volunteers. Pathways involved in amino acid biosynthesis were enriched in elderly individuals with T2D, while pathways involved in respiration and the biosynthesis of vital building blocks were enriched in healthy volunteers.

CONCLUSIONS

The study demonstrated for the first time in an African elderly population that the abundance of Bifidobacteriaceae, Collinsella, and Ruminococcus within the gut varies in relation to T2D. Findings from this study suggest that the restoration of features associated with healthiness via the way of gut microbiota modification could be one step needed to improve elderly patient care.

From role of gut microbiota to microbial-based therapies in type 2-diabetes

The incidence of type 2 diabetes mellitus (T2DM) has increased dramatically at an alarming level around the world.T2DM is associated with changeable risk factors in lifestyle as well as genetic and family associated risk factors. More importantly, imbalanced or impaired gut microbial distribution (dysbiosis) has been reported as a contributing risk factor in insulin resistance progression in T2DM. Dysbiosis may restructure the metabolic and functional pathways in the intestine which are involved in the development of T2DM. However, several studies have indicated the constructive and helpful effect of prebiotics, probiotics, and fecal microbiota transplantation (FMT) on the improvement of gut microbiota (GM) and accordingly host metabolism. In this review, the association between GM and T2DM have been evaluated and the role of prebiotics, probiotics and FMT, as potential therapeutic approaches have been discussed. Relevant studies were obtained randomly from online databases such as PubMed/Medline and ISI Web of Science.

Main gut bacterial composition differs between patients with type 1 and type 2 diabetes and non-diabetic adults

Background

Regarding the role of gut microbial dysbiosis in hyperglycemia, we aimed to compare the main gut bacterial composition among type 1 and type 2 diabetic patients and healthy non-diabetic adults.

Methods

A total of 110 adult subjects (49 patients diagnosed with type 2 diabetes, 21 patients diagnosed with type 1 diabetes and 40 healthy persons) were included in this case-control study. The intestinal microbiota composition was investigated by quantitative real-time polymerase chain reaction (qPCR) method targeting bacterial 16S rRNA gene. Comparison between three groups was done using one-way analysis of variance.

Results

The participants' mean age in the type 1 diabetes, type 2 diabetes and control groups was 35.4, 57.2 and 38.0 years, respectively. Higher level of Escherichia, Prevotella and Lactobacillus was observed in both type 1 and type 2 diabetic patients compared with the healthy group (P ˂0.001). In contrast, bacterial load of Bifidobacterium, Roseburia and Bacteroides was higher in healthy control group (P < 0.05). Faecalibacterium was significantly lower in type 1 diabetic patients compared with the other two groups (P ˂0.001). No significant difference was found in Akkermansia level among three groups.

Conclusions

Gut microbial alterations have been observed among patients suffering from type 1 and type 2 diabetes mellitus and healthy control adults. Butyrate producing genera including Roseburia and Faecalibacterium decreased while Escherichia, Prevotella and Lactobacillus increased in diabetic patients compared to healthy subjects. Modulating approaches of gut microbiota composition could be helpful in diabetes management.

Composite probiotics alleviate type 2 diabetes by regulating intestinal microbiota and inducing GLP-1 secretion in db/db mice

BACKGROUD/AIM

Previous studies have found that probiotic fermented camel milk has anti-diabetic effect by inducing (glucagon-like peptide-1) GLP-1 secretion. Probiotics are valuable in prevention and treatment of diabetes. As a result, our team islolated 14 probiotics from fermented camel milk. These probiotics have beneficial characteristics, but the possible anti-diabetic mechanisms remains unclear. The present study aimed to explore the possoble anti-diabetic mechanisms of 14 probiotics.

METHODS

C57BL/Ks mice were normal group. The db/db mice were randomized into five groups: model group, metformin group, liraglutide group, low-dose and high-dose probiotic group. Biochemical parameters were determined by the respective assay kits. The levels of the short-chain fatty acids (SCFAs) and microbiota were respectively determined by gas chromatography and qRT-PCR. HE staining and immunofluorescence were used for histomorphological observation. Quantitative PCR and western-blot were determined the gene and protein expression of Bax, Bcl-2, Caspase-3 and PI3K/AKT.

RESULTS

Probiotics significantly improved blood glucose and blood lipid parameters, as well as the morphological changes of pancreas, liver and kidney. Probiotics improved the gut barrier function through increasing the levels of SCFA-producing bacteria and SCFAs as well as the expression of claudin-1 and mucin-2, and decreasing Escherichia coli and LPS level. In additon, probiotics enhanced insulin secretion through glucose-triggered GLP-1 secretion by upregulating G protein-coupled receptor 43/41 (GPR43/41), proglucagon and proconvertase 1/3 activity. Forthermore, probiotics protected pancreas against apoptosis, which may be dependent on the upregulation of PI3K/AKT pathway.

CONCLUSIONS

The anti-diabetic effect of 14 probiotics in db/db mice seem to be related to an increase of SCFA-producing bacteria, the improvement of intestinal barrier function and the upregulation of GLP-1 production, and indicate these probiotics might be a good candidate to prevent and treat diabetes.

Arsenic disturbs the gut microbiome of individuals in a disadvantaged community in Nepal

Arsenic is ubiquitous in nature, highly toxic, and is particularly abundant in Southern Asia. While many studies have focused on areas like Bangladesh and West Bengal, India, disadvantaged regions within Nepal have also suffered from arsenic contamination levels, with wells and other water sources possessing arsenic contamination over the recommended WHO and EPA limit of 10 μg/L, some wells reporting levels as high as 500 μg/L. Despite the region's pronounced arsenic concentrations within community water sources, few investigations have been conducted to understand the impact of arsenic contamination on host gut microbiota health. This study aims to examine differential arsenic exposure on the gut microbiome structure within two disadvantaged communities in southern Nepal. Fecal samples (n = 42) were collected from members of the Mahuawa (n = 20) and Ghanashyampur (n = 22) communities in southern Nepal. The 16S rRNA gene was amplified from fecal samples using Illumina-tag PCR and subject to high-throughput sequencing to generate the bacterial community structure of each sample. Bioinformatics analysis and multivariate statistics were conducted to identify if specific fecal bacterial assemblages and predicted functions were correlated with urine arsenic concentration. Our results revealed unique assemblages of arsenic volatilizing and pathogenic bacteria positively correlated with increased arsenic concentration in individuals within the two respective communities. Additionally, we observed that commensal gut bacteria negatively correlated with increased arsenic concentration in the two respective communities. Our study has revealed that arsenic poses a broader human health risk than was previously known. It is influential in shaping the gut microbiome through its enrichment of arsenic volatilizing and pathogenic bacteria and subsequent depletion of gut commensals. This aspect of arsenic has the potential to debilitate healthy humans by contributing to disorders like heart and liver cancers and diabetes, and it has already been shown to contribute to serious diseases and disorders, including skin lesions, gangrene and several types of skin, renal, lung, and liver cancers in disadvantaged areas of the world like Nepal.

Role of gut microbiota in type 2 diabetes pathophysiology

A substantial body of literature has provided evidence for the role of gut microbiota in metabolic diseases including type 2 diabetes. However, reports vary regarding the association of particular taxonomic groups with disease. In this systematic review, we focused on the potential role of different bacterial taxa affecting diabetes. We have summarized evidence from 42 human studies reporting microbial associations with disease, and have identified supporting preclinical studies or clinical trials using treatments with probiotics. Among the commonly reported findings, the genera of Bifidobacterium, Bacteroides, Faecalibacterium, Akkermansia and Roseburia were negatively associated with T2D, while the genera of Ruminococcus, Fusobacterium, and Blautia were positively associated with T2D. We also discussed potential molecular mechanisms of microbiota effects in the onset and progression of T2D.

Alterations of Gut Microbiota in Type 2 Diabetes Individuals and the Confounding Effect of Antidiabetic Agents

Type 2 diabetes is a leading cause of morbidity and a common risk of several disorders. Identifying the microbial ecology changes is essential for disease prediction, therapy, and prevention. Thus, our study is aimed at investigating the intestinal microbiota among healthy and type 2 diabetes individuals and exploring the effect of antidiabetic agents on gut bacterial flora. 24 type 2 diabetes (metformin, glimepiride, and nontherapeutic subgroups; N = 8) and 24 healthy control subjects were enrolled in this study, and intestinal bacterial microbiota was investigated by analyzing V3-V4 regions of 16S rRNA gene sequence. Numerous alterations were observed in the gut microbial community of diabetic individuals. These changes were characterized by a significant lowered abundance of Faecalibacterium, Fusobacterium, Dialister, and Elusimicrobium in the nontherapeutic subgroup compared to the healthy control group. Likewise, correlation analysis showed a substantial decline in gut microbiota richness and diversity with the duration of illness. Furthermore, antidiabetic agents restored to some extent the richness and diversity of gut microbiota and improved the abundance of many beneficial bacteria with a significant increase of Methanobrevibacter in the metformin subcategory compared to the nontherapeutic subgroup. In return, they decreased the abundance of some opportunistic pathogens. The findings of this study have added a novel understanding about the pathogenesis of the disease and the mechanisms underlying antidiabetic therapy, which are of potential interest for therapeutic lines and further studies.

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.

Effects of Metformin on the Gut Microbiota in Obesity and Type 2 Diabetes Mellitus

Metformin is a first-line treatment for type 2 diabetes mellitus (T2DM); however, its underlying mechanism is not fully understood. Gut microbiota affect the development and progression of T2DM. In recent years, an increasing number of studies has focused on the relationship between metformin and gut microbiota, suggesting that metformin might exert part of its hypoglycemic effect through these microbes. However, most of these results were not consistent due to the complex composition of the microbiota, the differences between species, the large variation between individuals, and the differences in experimental design, bringing great obstacle for our better understanding of the effects of metformin on the gut microbiota. Here, we reviewed the published papers concerning about the impacts of metformin on the gut microbiota of mice, rats, and humans with obesity or T2DM, and summarized the changes of gut microbiota composition caused by metformin and the possible underlying hypoglycemic mechanism which is related to gut microbiota. It was found that the proportions of some microbiota, such as phyla Bacteroidetes and Verrucomicrobia and genera Akkermansia, Bacteroides and Escherichia, were significantly affected by metformin in several studies. Metformin may exert part of hypoglycemic effects by altering the gut microbiota in ways that maintain the integrity of the intestinal barrier, promote the production of short-chain fatty acids (SCFAs), regulate bile acid metabolism, and improve glucose homeostasis.

Enterotype Bacteroides Is Associated with a High Risk in Patients with Diabetes: A Pilot Study

BACKGROUND

More and more studies focus on the relationship between the gastrointestinal microbiome and type 2 diabetes, but few of them have actually explored the relationship between enterotypes and type 2 diabetes. Materials and Methods. We enrolled 134 patients with type 2 diabetes and 37 nondiabetic controls. The anthropometric and clinical indices of each subject were measured. Fecal samples of each subject were also collected and were processed for 16S rDNA sequencing. Multiple logistic regression analysis was used to determine the associations of enterotypes with type 2 diabetes. Multiple linear regression analysis was used to explore the relationship between lipopolysaccharide levels and insulin sensitivity after adjusting for age, BMI, TG, HDL-C, DAO, and TNF-α. The correlation analysis between factors and microbiota was identified using Spearman correlation analysis. The correlation analysis between factors was identified using partial correlation analysis.

RESULTS

Gut microbiota in type 2 diabetes group exhibited lower bacterial diversity compared with nondiabetic controls. The fecal communities from all subjects clustered into two enterotypes distinguished by the levels of Bacteroides and Prevotella. Logistic regression analysis showed that the Bacteroides and Bacteroides and Prevotella enterotype. Partial correlation analysis showed that lipopolysaccharide was closely associated with diamine oxidase, tumor necrosis factor-alpha, and Gutt insulin sensitivity index after adjusting for multiple covariates. Furthermore, the level of lipopolysaccharide was found to be an independent risk factor for insulin sensitivity.

CONCLUSIONS

We identified two enterotypes, Bacteroides and Prevotella, among all subjects. Our results showed that the Bacteroides enterotype was an independent risk factor for type 2 diabetes, which was due to increased levels of lipopolysaccharide causing decreased insulin sensitivity.Bacteroides and Prevotella enterotype. Partial correlation analysis showed that lipopolysaccharide was closely associated with diamine oxidase, tumor necrosis factor-alpha, and Gutt insulin sensitivity index after adjusting for multiple covariates. Furthermore, the level of lipopolysaccharide was found to be an independent risk factor for insulin sensitivity. Bacteroides and.

Analysis of gut microbiota of obese individuals with type 2 diabetes and healthy individuals

Type 2 diabetes mellitus (T2DM) accounts for 90% of diabetes cases worldwide. The majority of T2DM patients are obese. Dysbiosis in the gut microflora is strongly associated with the pathogenesis of obesity and T2DM; however, the microbiome of obese-T2DM individuals in the Pakistani population remains unexplored. The gut microbiota signature of 60 Pakistani adults was studied using 16S rRNA sequencing targeting V₃–V₄ hypervariable regions. The sequence analysis revealed that bacteria from Firmicutes were predominant along with those from Clostridia and Negativicutes, whereas bacteria from Verrucomicrobia, Bacteroidetes, Proteobacteria, and Elusimicrobia were less abundant among the obese T2DM patients. These data distinctively vary from those in reports on the Indian population. The difference in gut microbiota could presumably be related to the distinct lifestyle and eastern dietary habits (high carbohydrate and fat intake, low fiber intake) and unregulated antibiotic consumption. This is the first study carried out to understand the gut microbiome and its correlation with individual life style of obese T2DM patients in the Pakistani population.

Abnormal gut microbiota composition contributes to the development of type 2 diabetes mellitus in db/db mice

It is well recognized that type 2 diabetes mellitus (T2DM) is an age-related metabolic disease, emerging gradually as a major global health burden that has gained public attention. Meanwhile, increasing attention is paid to the crucial role of gut microbiota in the pathogenesis and therapeutic mechanisms of metabolic disorders, especially T2DM. In this study, we used C57 BL/KS db/db male mice as a T2DM murine model. We found that the β-diversity and relative abundances of gut bacteria were obviously altered in db/db mice, associated with a significant increase in Verrucomicrobia at six levels (phylum, class, order, etc.) and family S24-7 and a significant decrease in Bacteroidaceae at family, genus, and species levels, as well as Prevotellaceae at family and genus levels. Furthermore, fecal bacteria from db/db and m/m mice transplanted into pseudo-germ-free mice showed a significant change in the metabolic parameters, including the body weight, fasting blood glucose, fluid and food intake, and alterations in the composition of the gut microbiota. Taken together, these findings suggest that abnormalities in the composition of the gut microbiota might contribute to the development of T2DM and that potential therapeutic strategies improving gut microbiota might provide beneficial effects for individuals with T2DM and age-related glucose intolerance.

[Potential application of human microbiomes in the diagnosis and treatment of type 2 diabetes mellitus]

Human microbiome refers to the total microorganism genetic information of human body surface and internal, which is closely related to human health and disease. Oral and gut microbiomes are the most diverse microbial communities, which can interact and play a role in the development of the disease, and can reflect the health and disease state in real time. Type 2 diabetes mellitus is a metabolic disorder caused by both genetic and environmental factors. Recent research has shown a link between microbes and diabetes. This article reviewed the latest research on the changes of oral and gut microbiomes in type 2 diabetes mellitus patients, which expects to provide a reference for exploring the development of the disease model for prediction, diagnosis and prognosis of type 2 diabetes mellitus based on human microbiome characteristics.

Edgeworthia gardneri (Wall.) Meisn. water extract improves diabetes and modulates gut microbiota

ETHNOPHARMACOLOGICAL RELEVANCE

In Chinese folk medicine, the flower of Edgeworthia gardneri (Wall.) Meisn. is used to treat various metabolic diseases, such as hyperglycemia, hypertension, and hyperlipidemia.

AIM OF THE STUDY

This study aimed to explore the antidiabetes potential of the flower of E. gardneri and investigate whether it can benefit the entire gut bacteria community.

MATERIALS AND METHODS

Chemical constituents of the extract were analyzed by UHPLC-Q Exactive Mass Spectrometer (UHPLC-QE-MS). The antidiabetes effect of the water extract (WAE) of the flower of E. gardneri was evaluated in diabetic mice induced by high-fat diet (HFD) and streptozotocin (STZ) (six groups, n = 8) daily at doses of 1, 2, and 3 g/kg for 4 weeks. The gut microbiota was analyzed using high-throughput 16S rRNA gene sequencing. Short-chain fatty acids (SCFAs) in the fecal were also investigated.

RESULTS

UHPLC-QE-MS analysis identified 29 compounds, including five alkaloids, six coumarins, four flavonoids, 11 organic acids, and three additional compounds, in the WAE. Results showed that the high dose of WAE considerably decreased the blood glucose level by 30.0%. Furthermore, E. gardneri significantly ameliorated insulin resistance and lipid metabolism dysfunction and repaired islet, hepatic, and white fat and colon histology in diabetic mice. Diabetic mice treated with WAE showed apparent changes in the structure and composition of the gut microbiota. WAE reversed the changes in Clostridiales, Lachnospiraceae, S24-7, Rikenellaceae, and Dorea in diabetic mice. The correlation analysis indicated that key OTUs were related to diabetes indices. The amounts of SCFAs, including acetic, propionic, and valeric acids, were significantly high in WAE-treated diabetic groups.

CONCLUSIONS

E. gardneri treatment improved the glucose metabolism and reshaped the unbalanced gut microbiota of diabetic mice. Our study provides evidence for application of E. gardneri to treatment of diabetes mellitus.

Gut microbiota: An underestimated and unintended recipient for pesticide-induced toxicity

Pesticide pollution residues have become increasingly common health hazards over the last several decades because of the wide use of pesticides. The gastrointestinal tract is the first physical and biological barrier to contaminated food and is therefore the first exposure site. Interestingly, a number of studies have shown that the gut microbiota plays a key role in the toxicity of pesticides and has a profound relationship with environmental animal and human health. For instance, intake of the pesticide of chlorpyrifos can promote obesity and insulin resistance through influencing gut and gut microbiota of mice. In this review, we discussed the possible effects of different kinds of widely used pesticides on the gut microbiota in different experimental models and analyzed their possible subsequent effects on the health of the host. More and more studies indicated that the gut microbiota of animals played a very important role in pesticides-induced toxicity, suggesting that gut micriobita was also the unintended recipient of pesticides. We hope that more attention can focus on the relationship between pesticides, gut microbiota and environmental health risk assessment in near future.

Aged garlic extract ameliorates fatty liver and insulin resistance and improves the gut microbiota profile in a mouse model of insulin resistance

Aged garlic extract (AGE) produced by the aging process has various beneficial pharmacological effects. In this study, the effects of AGE on fatty liver, insulin resistance and intestinal microbiota were compared between ddY-H mice, an insulin resistance mouse, and ddY-L mice, normal mice. Mice were fed an AGE-supplemented diet (4% w/w) for 7 weeks. The administration of AGE had no effect on the body weight and dietary intake of both types of mice. In the ddY-H mice, the serum levels of glucose and insulin were increased and glucose tolerance was impaired; however, the administration of AGE ameliorated these abnormal conditions. AGE did not have these effects in ddY-L mice. Triglyceride (TG) accumulation in the liver and fat absorption from the digestive tract were increased in the ddY-H mice; however, the administration of AGE reduced this increase. On the other hand, AGE exerted no such effects in the ddY-L mice. In addition, the gut microbiota has been shown to be closely associated with obesity, diabetes, dyslipidemia and non-alcoholic fatty liver disease in human and animal models. The bacterial composition of the gut microbiota in the feces of the ddY-H mice did not differ from that of the ddY-L mice at 5 weeks of age; however, it was altered in the mice at 9 and 12 weeks of age even when the mice were fed a standard diet. In the ddY-H mice, the relative presence of Lactobacillales was increased, while that of Bifidobacterium, Clostridium cluster XVIII and Prevotella was decreased. The alteration of the bacterial composition in the ddY-H mice was reversed by the administration of AGE; however, this effect of AGE was not observed in the ddY-L mice. On the whole, the findings of this study indicate that AGE improves abnormal fat accumulation and insulin resistance, and also alters the intestinal flora in ddY-H mice, suggesting the possibility that these effects of AGE may be related.

Identification of an intestinal microbiota signature associated with hospitalized patients with diarrhea

As an important global health challenge, diarrhea kills nearly two million people each year. Postinfectious irritable bowel syndrome (IBS) usually manifests itself as the diarrhea-predominant subtype. Small intestinal bacterial overgrowth has been observed more frequently in patients with IBS compared to healthy controls. However, the pathophysiology of IBS is not fully understood, and based on recent evidences, altered gut microbiota is involved in the pathogenesis of IBS. Therefore, we aimed to compare the microbiome in hospitalized patients with diarrhea and healthy individuals. Thirty patients and 10 healthy controls were included into this case-control study. Microbial count was performed using quantitative real-time polymerase chain reaction method using bacterial 16S rRNA gene. Clostridium cluster IV and Bacteroides were significantly more frequent in the patients compared with the healthy individuals (p = 0.02 and 0.023, respectively). However, the quantity of Enterococcus and Bifidobacterium groups were significantly higher in healthy controls than in diarrheal group (p = 0.000076 and 0.001, respectively). The results showed that the number of bacteria in all bacterial groups was significantly different between healthy individuals and diabetic group, whereas the difference between the healthy group and IBS was not significant for Bifidobacterium group. The findings of this study outlined the relationship between diarrhea, IBS, and diabetes disease and bacterial composition. It could be concluded that modifying the bacterial composition by probiotics can be helpful in the control and management of the mentioned disease.

Age-stratified comparative analysis of the differences of gut microbiota associated with blood glucose level

Background

Gut bacteria are an important component of the microbiota ecosystem in humans and other animals, and they play important roles in human health. The aim of this study was to investigate the relationship between gut microbiota and multiple demographical-, behavioral-, or biochemical-related factors in subjects with chronic disease. Subjects with a very wide age range who participated in community-based chronic disease prevention and screening programs in China were enrolled. We analyzed the intestinal microbiota composition using 16S rRNA-based high-throughput sequencing of fecal samples, analyzed the association between gut microbiota structure and multiple demographical, behavioral, and biochemical factors, and compared the differences in microbiota composition in age-stratified groups with different blood glucose levels.

Results

Our results showed that both age and blood glucose levels had a significant impact on the gut microbiota structure. We also identified several taxa showed distinct abundance in groups with different glucose levels. Lactobacillus and Bifidobacterium at genus level and their related taxa were more abundant in the GLU high group comparing with GLU normal group and in NGR group comparing with DM group. Further analysis using the age-stratified data showed that blood glucose levels had a more significant impact on the gut microbiota in the ≥76 y age group than in the ≤75 y age group, which indicated that it is necessary to take age into account when conducting such studies. Moreover, we identified several taxa that were highly associated with blood glucose levels in the ≥76 y age group but not in the ≤75 y age group. Within the ≥76 y age group, Lachnospiraceae incertae sedis and Bacteroides were more abundant in the GLU normal group, whereas Lactobacillus and Bifidobacterium at genus level were more abundant in the GLU high group.

Conclusions

This result suggested that taxa that are capable of differentiating blood glucose levels might differ significantly in different age groups.

Gut microbiota disorders cause type 2 diabetes mellitus and homeostatic disturbances in gut-related metabolism in Japanese subjects

Few studies have investigated the host-microbe metabolic axis in people with type 2 diabetes mellitus (T2DM). This study aimed to determine and compare the nutrient intakes and metabolic markers and to elucidate the relationships among these factors in Japanese T2DM patients and control individuals. Fifty-nine Japanese T2DM patients and 59 matched healthy control individuals participated in this study. We examined the differences regarding the participants’ dietary habits, microbiota, and fecal short-chain fatty acids, and analyzed the relationships between the gut microbiota and blood metabolic markers in the T2DM patients and the control subjects. The T2DM patients consumed more carbohydrates, and had lower fecal propionate and butyrate concentrations, larger fecal populations of Bifidobacterium spp. and bacteria of the order Lactobacillales, and smaller fecal Bacteroides spp. populations than the control individuals. In the T2DM patients, the level of Bifidobacterium spp. correlated negatively with the carbohydrate intake and the level of bacteria of the order Lactobacillales correlated negatively with the protein intake. T2DM patients have gut dysbiosis that may contribute to disease onset and influence its prognosis. Furthermore, homeostatic disturbances in the gut-related metabolism may underlie the pathogenesis of T2DM.

Revisit gut microbiota and its impact on human health and disease

Trillions of microbes have evolved with and continue to live on human beings. With the rapid advances in tools and technology in recent years, new knowledge and insight in cross-talk between the microbes and their hosts have gained. It is the aim of this work to critically review and summarize recent literature reports on the role of microbiota and mechanisms involved in the progress and development of major human diseases, which include obesity, hypertension, cardiovascular disease, diabetes, cancer, Inflammatory Bowel Disease (IBD), gout, depression and arthritis, as well as infant health and longevity.

Probiotic Lactobacillus gasseri SBT2055 improves insulin secretion in a diabetic rat model

The probiotic Lactobacillus gasseri SBT2055 (LG2055) has a protective effect against metabolic syndrome in rats and humans. Metabolic syndrome increases the risk of type 2 diabetes mellitus. In this study, Goto-Kakizaki rats were used as a diabetic model and fed diets containing LG2055-fermented or nonfermented skim milk for 4 wk. Indices of diabetes such as blood glucose levels, serum glucagon levels, plasma levels of insulin, C-peptide, and glucagon-like peptide-1, tissue glycogen contents, and pancreatic mRNA levels were measured. The plasma C-peptide levels and pancreatic mRNA levels of insulin genes (Ins1 and Ins2) and Pdx1 (a transcriptional factor of insulin genes) were increased in LG2055 diet-fed rats. The increase in insulin secretion corresponded to an improvement in serum and pancreatic inflammatory status, associated with decreases in serum levels of serum amyloid P and pancreatic levels of granulocyte colony-stimulating factor. Insulin resistance in Goto-Kakizaki rats was ameliorated by increased glycogen storage in the liver and quadriceps femoris muscles and decreased serum free fatty acid levels. This improvement may be related to the increased cecal production of short-chain fatty acids. In conclusion, dietary LG2055 improved insulin secretion in diabetic rats by improving the inflammatory status in the pancreas and serum.

Oil tea improves glucose and lipid levels and alters gut microbiota in type 2 diabetic mice

Oil tea has traditionally been used in minority populations in China for treating various ailments in traditional Chinese medicine. Individually, green tea and ginger, which are the main ingredients of oil tea, have demonstrated antidiabetic effects; however, whether oil tea exerts antidiabetic effects remains unknown. In addition, aberrant gut microbiota structure is associated with diabetic status, and research indicates that there may be beneficial effects of tea on gut microbiota. Therefore, we hypothesized that oil tea exerts antidiabetic effects and induces alteration in gut microbiota. To test our hypothesis, we first examined the nutrition composition of oil tea. Then, db/db mice were randomly divided into 3 groups and orally gavaged with saline, metformin, and oil tea for 8 weeks. Fasting blood glucose (FBG), oral glucose tolerance test (OGTT), and lipid levels were tested during the experiment. 16S rRNA genes were sequenced and changes in gut microbiota in response pre/post treatment were examined. Our experiments showed that oil tea contains high concentrations of tea polyphenols (246.35 mg/100 g) and [6]-gingerol (2.98 mg/100 g). It appeared that oil tea treatment significantly suppressed the postprandial blood glucose elevation and lowered the levels of FBG, total cholesterol, triglycerides, and LDL-cholesterol (P < .05). The composition of gut microbiota changed significantly in response to oil tea treatment, Lachnospiraceae were significantly enriched (q < 0.05, LDA score> 3.5). Redundancy analysis identified 155 oil tea-modulating family level phylotypes, where Lachnospiraceae significantly correlated with FBG, total cholesterol, and LDL-cholesterol (P < .05). Our findings demonstrate that oil tea improved glucose and lipid levels and modulated gut microbiota in db/db mice.

Structure of intestinal microflora in hepatitis B cirrhosis patients and hepatitis B cirrhosis patients with diabetes mellitus

AIM

To analyze the changes of intestinal microflora in hepatitis B cirrhosis patients and hepatitis B cirrhosis patients with diabetes mellitus.

METHODS

Fecal samples were collected from nine patients with hepatitis B cirrhosis and six hepatitis B cirrhosis patients with diabetes mellitus, and DNA was extracted from the fecal samples. The extracted DNA was purified and amplified by PCR, and the V3-V6 regions of the 16S rDNA of the fecal flora of the two groups were sequenced using the Roche454 high-throughput sequencing platform. The sequencing results were finally analyzed.

RESULTS

There were no significant differences in diversity parameters (OTUs, Chao1 index, Simpson index, and Shannon index) between the two groups. At the phylum level, the proportion of Proteobacteria in intestinal microflora of hepatitis B cirrhosis patients with diabetes increased significantly (P < 0.05). There was no significant difference in the proportions of Bacteroidetes and Firmicutes. At the class level, the proportion of Gammaproteobacteria in the intestinal flora of hepatitis B cirrhosis patients with diabetes mellitus was significantly higher than that in the hepatitis B cirrhosis group (P < 0.05), although the rest classes were not statistically different. At the order level, Desulfovibrionales in the intestinal microflora had obvious advantage in hepatitis B cirrhosis patients over hepatitis B cirrhosis patients with diabetes mellitus (P < 0.05), but the percentage of Burkholderiales in the intestinal flora of patients with cirrhosis and diabetes mellitus increased obviously (P < 0.05). At the family level, the proportions of Veillonellaceae and Alcaligenaceae in the intestinal flora increased significantly in hepatitis B cirrhosis patients with diabetes mellitus compared with patients with cirrhosis alone (P < 0.05), and the percentages of Streptococcaceae and Clostridiaceaein in the intestinal flora of patients with hepatitis B cirrhosis had obvious advantages (P < 0.05). At the genus level, the proportions of Parabacteroides, Roseburia, Veillonellaceae, and Sutterella in hepatitis B cirrhosis patients with diabetes mellitus were significantly higher than those in patients with cirrhosis alone (P < 0.05), and the populations of Faecalibacterium and Streptococcus had advantages in hepatitis B cirrhosis patients (P < 0.05).

CONCLUSION

Although hepatitis B cirrhosis and hepatitis B cirrhosis patients with diabetes have similar intestinal flora structures, there are differences between them. The differences in certain bacterial populations may be a new target for the treatment of hepatitis B cirrhosis with diabetes.