Gut Microbiota Differs in Composition and Functionality Between Children With Type 1 Diabetes and MODY2 and Healthy Control Subjects: A Case-Control Study

Dietary Ginsenoside T19 Supplementation Regulates Glucose and Lipid Metabolism via AMPK and PI3K Pathways and Its Effect on Intestinal Microbiota

Ginseng, as a functional food, is widely used worldwide because of its multifarious benefits. Studies have verified that 25-hydroxyl-protopanaxatriol (T19) is a new ginsenoside from ginseng, which had an important inhibitory effect on α-glucosidase and protein tyrosine phosphatase 1B in vitro. This study aims to assess the regulation of T19 against glycolipid metabolism by insulin-resistant HepG2 cells and diabetes mice induced with high-fat diet combined with streptozotocin (STZ). T19 effectively lowered the levels of blood glucose and lipid, alleviated insulin resistance, and improved histological pathology of liver and pancreas. Further study demonstrated that regulation of AMP-activated protein kinase- and phosphoinositide-3-kinase-signaling pathways was involved in the potential mechanism of T19 efficiency. Simultaneously, high-throughput sequencing of 16S rDNA revealed that T19 remarkably ameliorated the high-fat diet/STZ-induced disorders of intestinal microbiota by decreasing the value of Firmicutes/Bacteroidetes, and remarkably raised the relative abundance of the Lachnospiraceae family, which are the beneficial bacteria that can regulate glucose and lipid metabolism. The results may provide clues for further understanding the mechanism of T19 in regulating glycolipid metabolism, and may provide a scientific basis for ginseng as a potential dietary food to prevent metabolic diseases.

Update of Probiotics in Human World: A Nonstop Source of Benefactions till the End of Time

Lactic acid bacteria (LAB) are known for their biotechnological potential. Moreover, LAB are distinguished by amazing criteria: Adjusting the intestinal environment, inhibiting pathogenic microbes in the gastrointestinal tract, ability to reduce pathogen adhesion activity, improving the balance of the microbiota inside the intestine, capabilities of regulating intestinal mucosal immunity, and maintaining intestinal barrier function. The escalating number of research and studies about beneficial microorganisms and their impact on promoting health has attracted a big interest in the last decades. Since antiquity, various based fermented products of different kinds have been utilized as potential probiotic products. Nevertheless, the current upsurge in consumers' interest in bioalternatives has opened new horizons for the probiotic field in terms of research and development. The present review aims at shedding light on the world of probiotics, a continuous story of astonishing success in various fields, in particular, the biomedical sector and pharmaceutical industry, as well as to display the importance of probiotics and their therapeutic potential in purpose to compete for sturdy pathogens and to struggle against diseases and acute infections. Shadows and future trends of probiotics use are also discussed.

Effects of the Traditional Chinese Medicine Tang Luo Ning on Intestinal Flora and Oxidative Stress in Diabetic Rats

Objective

To determine the effects of TLN on glycolipid metabolism, oxidative stress, and intestinal flora in diabetic rat.

Materials and Methods

Thirty-five male Sprague-Dawley (SD) rats (180-200 g) were divided into two groups. The normal group was fed a standard-chow diet, whereas, in the model group, diabetes was induced by intraperitoneal administration of streptozotocin (STZ) combined with a high-fat sucrose diet. Then, the model group was randomly allocated to four groups: DM (diabetes model) and TLNH (TLN high dose), TLNL (TLN low dose), and NAC (N-acetylcysteine). Rats in the TLNH, TLNL, and NAC groups were intragastrically administered TLN and NAC for 12 weeks. Subsequently, their weights, fasting glucose levels, serum lipids, serum insulin, serum ROS, and intestinal flora were determined.

Results

The weight and intestinal flora abundance of the DM group were significantly lower than those of the normal group, whereas their total serum cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), serum reactive oxygen species (ROS), and serum insulin (INS) levels were significantly higher than those of the normal group. TC and LDL-C levels in the TLNL group and DM group were similar, whereas FBG, INS, and ROS levels in the TLNL group were obviously lower than those in the DM group. Compared with the DM group, there was a significant increase in intestinal flora abundance in the TLNL group. At the phylum level, the ratio of Firmicutes to Bacteroidetes (core microbiota) varied in all groups. However, in the DM group, Firmicutes abundance decreased, whereas that of Bacteroidetes increased. An opposite trend was observed in the TLN-treated groups.

Conclusions

TLN, which showed a dose-dependent therapeutic effect, can effectively decrease serum lipid, serum insulin, blood glucose, and serum ROS levels. It can also rebalance the ratio of Firmicutes to Bacteroidetes. Furthermore, the low-dose TLN treatment was most efficacious.

Differential Microbial Pattern Description in Subjects with Autoimmune-Based Thyroid Diseases: A Pilot Study

The interaction between genetic susceptibility, epigenetic, endogenous, and environmental factors play a key role in the initiation and progression of autoimmune thyroid diseases (AITDs). Studies have shown that gut microbiota alterations take part in the development of autoimmune diseases. We have investigated the possible relationship between gut microbiota composition and the most frequent AITDs. A total of nine Hashimoto's thyroiditis (HT), nine Graves-Basedow's disease (GD), and 11 otherwise healthy donors (HDs) were evaluated. 16S rRNA pyrosequencing and bioinformatics analysis by Quantitative Insights into Microbial Ecology and Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) were used to analyze the gut microbiota. Beta diversity analysis showed that gut microbiota from our groups was different. We observed an increase in bacterial richness in HT and a lower evenness in GD in comparison to the HDs. GD showed a significant increase of Fusobacteriaceae, Fusobacterium and Sutterella compared to HDs and the core microbiome features showed that Prevotellaceae and Prevotella characterized this group. Victivallaceae was increased in HT and was part of their core microbiome. Streptococcaceae, Streptococcus and Rikenellaceae were greater in HT compared to GD. Core microbiome features of HT were represented by Streptococcus, Alistipes, Anaerostipes, Dorea and Haemophilus. Faecalibacterium decreased in both AITDs compared to HDs. PICRUSt analysis demonstrated enrichment in the xenobiotics degradation, metabolism, and the metabolism of cofactors and vitamins in GD patients compared to HDs. Moreover, correlation studies showed that some bacteria were widely correlated with autoimmunity parameters. A prediction model evaluated a possible relationship between predominant concrete bacteria such as an unclassified genus of Ruminococcaceae, Sutterella and Faecalibacterium in AITDs. AITD patients present altered gut microbiota compared to HDs. These alterations could be related to the immune system development in AITD patients and the loss of tolerance to self-antigens.

Functional modulation of gut microbiota in diabetic rats following dietary intervention with pistachio nuts (Pistacia vera L.)

BACKGROUND

Gut microbiota holds a key-role in numerous biological functions and has emerged as a driving force for the development of diabetes. Diet contributes to gut microbiota diversity and functionality providing a tool for the prevention and management of the disease. The study aimed to investigate the effect of a dietary intervention with pistachio nuts, a rich source of monounsaturated fatty acids, dietary fibers and phytochemicals on gut microbiota composition in the rat model of Type 1 Diabetes.

METHODS

Male Wistar rats were randomly assigned into four groups: healthy animals which received control diet (CD) or pistachio diet (PD), and diabetic animals which received control diet (DCD) or pistachio diet (DPD) for 4 weeks. Plasma biochemical parameters were determined and histological examination of liver and pancreas was performed at the end of the dietary intervention. Adherent intestinal microbiota populations in jejunum, ileum, caecum and colon were analyzed. Fecal microbiota populations at the beginning and the end of the study were determined by microbiological analysis and 16S rRNA sequencing.

RESULTS

Diabetic animals of both groups exhibited high plasma glucose and low insulin concentrations, as well as characteristic pancreatic lesions. Pistachio supplementation significantly increased lactobacilli and bifidobacteria populations in jejunum, ileum and caecum (p < 0.05) and normalized microbial flora in all examined intestinal regions of diabetic animals. After 4 weeks of supplementation, populations of bifidobacteria and lactobacilli were increased in feces of both healthy and diabetic animals, while enterococci levels were decreased (p < 0.05). Next Generation Sequencing of fecal samples revealed increased and decreased counts of Firmicutes and Bacteroidetes, respectively, in healthy animals that received the pistachio diet. Actinobacteria OTUs were higher in diabetic animals and increased over time in the pistachio treated groups, along with increased abundance of Bifidobacterium. Lactobacillus, Turicibacter and Romboutsia populations were elevated in healthy animals administered the pistachio nuts. Of note, relative abundance of Bacteroides was higher in healthy than in diabetic rats (p < 0.05).

CONCLUSION

Dietary pistachio restored normal flora and enhanced the presence of beneficial microbes in the rat model of streptozotocin-induced diabetes.

Gut Microbiota Profile in Patients with Type 1 Diabetes Based on 16S rRNA Gene Sequencing: A Systematic Review

The gut microbiota has been presumed to have a role in the pathogenesis of type 1 diabetes (T1D). Significant changes in the microbial composition of T1D patients have been reported in several case-control studies. This study is aimed at systematically reviewing the existing literature, which has investigated the alterations of the intestinal microbiome in T1D patients compared with healthy controls (HCs) using 16S ribosomal RNA-targeted sequencing. The databases of MEDLINE, EMBASE, Web of Science, and the Cochrane Library were searched until April 2019 for case-control studies comparing the composition of the intestinal microbiome in T1D patients and HCs based on 16S rRNA gene sequencing techniques. The Newcastle-Ottawa Scale was used to assess the methodological quality. Ten articles involving 260 patients with T1D and 276 HCs were included in this systematic review. The quality scores of all included studies were 6-8 points. In summary, a decreased microbiota diversity and a significantly distinct pattern of clustering with regard to β-diversity were observed in T1D patients when compared with HCs. At the phylum level, T1D was characterised by a reduced ratio of Firmicutes/Bacteroidetes in the structure of the gut community, although no consistent conclusion was reached. At the genus or species level, T1D patients had a reduced abundance of Clostridium and Prevotella compared with HCs, whereas Bacteroides and Ruminococcus were found to be more enriched in T1D patients. This systematic review identified that there is a close association between the gut microbiota and development of T1D. Moreover, gut dysbiosis might be involved in the pathogenesis of T1D, although the causative role of gut microbiota remains to be established. Further well-controlled prospective studies are needed to better understand the role of the intestinal microbiome in the pathogenesis of T1D, which may help explore novel microbiota-based strategies to prevent and treat T1D.

Polysaccharides catabolism by the human gut bacterium -Bacteroides thetaiotaomicron: advances and perspectives

In recent years, the degradation processes of polysaccharides by human gut microbiota are receiving considerable attention due to the discoveries of the powerful function of gut microbiota. Gut microbiota has developed a sensitive, accurate, and complex system for sensing, capturing, and degrading different polysaccharides. Among the gut microbiota, Bacteroides thetaiotaomicron, a representative species of Bacteroides, is considered as the best degrader of polysaccharides and a potential probiotic in pharmaceutical and food industries. Here, we summarize the degradation system of B. thetaiotaomicron and the degradation pathways of different polysaccharides by B. thetaiotaomicron. We also describe a technical route for investigating a specific polysaccharide degradation pathway by human gut bacteria. In addition, we also provide the future perspectives in the development of novel polysaccharides or oligosaccharides drugs, precision microbiology medicine, and personalized nutrition.

Microbial Signature in Adipose Tissue of Crohn's Disease Patients

Crohn’s disease (CD) is characterized by compromised immune tolerance to the intestinal commensal microbiota, intestinal barrier inflammation, and hyperplasia of creeping fat (CF) and mesenteric adipose tissue (AT), which seems to be directly related to disease activity. Gut microbiota dysbiosis might be a determining factor in CD etiology, manifesting as a low microbial diversity and a high abundance of potentially pathogenic bacteria. We tested the hypothesis that CF is a reservoir of bacteria through 16S-rRNA sequencing of several AT depots of patients with active and inactive disease and controls. We found a microbiome signature within CF and mesenteric AT from patients, but not in subcutaneous fat. We failed to detect bacterial DNA in any fat depot of controls. Proteobacteria was the most abundant phylum in both CF and mesenteric AT, and positively correlated with fecal calprotectin/C-reactive protein. Notably, the clinical status of patients seemed to be related to the microbiome signature, as those with the inactive disease showed a reduction in the abundance of pathogenic bacteria. Predictive functional profiling revealed many metabolic pathways including lipopolysaccharide biosynthesis and sulfur metabolism overrepresented in active CD relative to that in inactive CD. Our findings demonstrate that microbiota dysbiosis associated with CD pathophysiology is reflected in AT and might contribute to disease severity.

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.

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.

Gut microbiota and metabolites in the pathogenesis of endocrine disease

Type 1 diabetes (T1D) and Hashimoto's thyroiditis (HT) are the two most common autoimmune endocrine diseases that have rising global incidence. These diseases are caused by the immune-mediated destruction of hormone-producing endocrine cells, pancreatic beta cells and thyroid follicular cells, respectively. Both genetic predisposition and environmental factors govern the onset of T1D and HT. Recent evidence strongly suggests that the intestinal microbiota plays a role in accelerating or preventing disease progression depending on the compositional and functional profile of the gut bacterial communities. Accumulating evidence points towards the interplay between the disruption of gut microbial homeostasis (dysbiosis) and the breakdown of host immune tolerance at the onset of both diseases. In this review, we will summarize the major recent findings about the microbiome alterations associated with T1D and HT, and the connection of these changes to disease states. Furthermore, we will discuss the potential mechanisms by which gut microbial dysbiosis modulates the course of the disease, including disruption of intestinal barrier integrity and microbial production of immunomodulatory metabolites. The aim of this review is to provide broad insight into the role of gut microbiome in the pathophysiology of these diseases.

Lactobacillus plantarum FRT10 alleviated high-fat diet-induced obesity in mice through regulating the PPARα signal pathway and gut microbiota

Previous studies showed that probiotics supplementation contributed to alleviate obesity. This work was to assess the efficacy of Lactobacillus plantarum FRT10 from sour dough in alleviating obesity in mice fed with a high-fat diet (HFD), and the underlying mechanisms focusing on modulation of the gut microbiota profile. Kunming mice were fed with a regular diet (CT), a high-fat diet (HFD), and two HFDs containing low and high doses of L. plantarum FRT10 for 8 weeks. The physiological and biochemical modulations in liver were analyzed. Cecal contents were analyzed by high-throughput 16S ribosomal RNA sequencing. FRT10 supplementation significantly reduced body weight gain, fat weight, and liver triacylglycerols (TGs) and alanine aminotransferase (ALT) concentrations (P < 0.05). FRT10 significantly ameliorated the HFD-induced gut dysbiosis, as evidenced by increased abundance of microbes, including Butyricicoccus, Butyricimonas, Intestinimonas, Odoribacter, and Alistipes, and decreased abundance of Desulfovibrionaceae, Roseburia, and Lachnoclostridium. Lactobacillus, Bifidobacterium, and Akkermansia were markedly increased after FRT10 intervention. In addition, real-time quantitative PCR revealed that FRT10 upregulated the mRNA expression levels of peroxisome proliferator-activated receptor-α (PPARα) and carnitine palmitoyltransferase-1α (CPT1α), and downregulated the mRNA expression levels of sterol regulatory element-binding protein 1 (SREBP-1) and TG-synthesizing enzyme diacylglycerol acyltransferase 1 (DGAT1) in liver. These findings suggested that FRT10 had anti-obesity effects in obese mice partly related to the activation of PPARα/CPT1α pathway. FRT10 can be considered a single probiotic agent for preventing HFD-induced obesity in humans and animals.

Early Childhood Antibiotic Treatment for Otitis Media and Other Respiratory Tract Infections Is Associated With Risk of Type 1 Diabetes: A Nationwide Register-Based Study With Sibling Analysis

OBJECTIVE

The effect of early-life antibiotic treatment on the risk of type 1 diabetes is debated. This study assessed this question, applying a register-based design in children up to age 10 years including a large sibling-control analysis.

RESEARCH DESIGN AND METHODS

All singleton children (n = 797,318) born in Sweden between 1 July 2005 and 30 September 2013 were included and monitored to 31 December 2014. Cox proportional hazards models, adjusted for parental and perinatal characteristics, were applied, and stratified models were used to account for unmeasured confounders shared by siblings.

RESULTS

Type 1 diabetes developed in 1,297 children during the follow-up (median 4.0 years [range 0-8.3]). Prescribed antibiotics in the 1st year of life (23.8%) were associated with an increased risk of type 1 diabetes (adjusted hazard ratio [HR] 1.19 [95% CI 1.05-1.36]), with larger effect estimates among children delivered by cesarean section (P for interaction = 0.016). The association was driven by exposure to antibiotics primarily used for acute otitis media and respiratory tract infections. Further, we found an association of antibiotic prescriptions in pregnancy (22.5%) with type 1 diabetes (adjusted HR 1.15 [95% CI 1.00-1.32]). In general, sibling analysis supported these results, albeit often with statistically nonsignificant associations.

CONCLUSIONS

Dispensed prescription of antibiotics, mainly for acute otitis media and respiratory tract infections, in the 1st year of life is associated with an increased risk of type 1 diabetes before age 10 years, most prominently in children delivered by cesarean section.

The responses of the gut microbiota to MBL deficiency

Mannose-binding lectin (MBL) deficiency is a common innate immune system deficiency, and is associated with exacerbations and increased colonization of some pathogens. However, the response of the gut microbiota, a pivotal factor in host health, to MBL deficiency is not clear. In this study, MBL-/- and wild-type (WT) mice were generated by backcrossing from MBL-A and MBL-C knockout (KO) mice, and fecal samples were collected at different ages (4th, 8th, 12th, 19th and 27th weeks). The gut microbiota was analyzed by high-throughput sequencing with universal 16S rDNA primers (V3-V5 region). The results showed that structural segregation of the gut microbiota occurred at the 8th, 12th, 19th and 27th weeks of age, although there were no significant differences in alpha diversities between MBL-/- and WT mice at different ages. Impressively, in MBL-/- mice, Akkermansia (from the family Verrucomicrobiaceae) were decreased significantly, Lactobacillus (from the family Lactobacillaceae) abundances, Alistipes and Rikenella (both from the family of Rikenellaceae) were always enriched. Network analysis showed that more interactions existed in the gut microbiota from WT mice (33 nodes and 70 edges) than in the gut microbiota from MBL-/- mice (23 nodes and 40 edges). The 16S rDNA function prediction results indicated that the abundances of predicted genes in the "immune system disease", "metabolic disease" and "nucleotide metabolism" pathways were significantly increased in the MBL-/- mice. In conclusion, this study revealed that the gut microbiota changed in MBL deficient mice, especially at ages older than 4 weeks.

Bacteroidetes and Firmicutes levels in gut microbiota and effects of hosts TLR2/TLR4 gene expression levels in adult type 1 diabetes patients in Istanbul, Turkey

AIM

The aim of this study was to determine and compare the levels of both Bacteroidetes and Firmicutes in the gut microbiota and TLR2/TLR4 gene expression in the blood of patients with type 1 diabetes mellitus (T1DM) and healthy individuals. These results may serve as a preliminary assessment to guide future research.

METHOD

Between January and October 2014, stool and blood samples were collected from 53 adult T1DM patients and 53 age- and gender-matched healthy individuals. Bacteroidetes and Firmicutes levels were assessed from stool sample DNA and TLR2 and TLR4 expression levels were analyzed via qPCR using RNA from EDTA blood samples from both patients and healthy controls.

RESULTS

The amounts of Bacteroidetes and Firmicutes were statistically significantly higher and lower, respectively, in the T1DM group than in the healthy control group (p < 0.001 and p < 0.001, respectively). In addition, the Firmicutes/Bacteroidetes ratios in patients with T1DM were significantly lower than in healthy controls. The TLR4 and TLR2 gene expression levels in T1DM patients were significantly upregulated and downregulated, respectively, compared to those in the control group.

CONCLUSION

Our data are the first to show a relationship between T1DM and gut microbiota in our country. In addition, our results provide information about the connections between T1DM, gut microbiota, and TLR2 and TLR4 expression. We believe that Bacteroidetes and Firmicutes in the gut microbiota may play a role in the autoimmune process of T1DM and that these findings should be further investigated in the future.

Improvement on metabolic syndrome in high fat diet-induced obese mice through modulation of gut microbiota by sangguayin decoction

ETHNOPHARMACOLOGICAL RELEVANCE

Our previous research found that Sangguayin (SGY) deccoction made by four dietary and medicinal plant components (Leaf of Morus alba L., Root of Pueraria lobata (Willd.) Ohwi., Root of Dioscorea opposita Thunb. and Fruit of Momordica charantia L.) showed significant anti-diabetic effects on db/db mice and high fat diet induced obese mice. Nevertheless, it remained unclear what the role of gut microbiota in the hypoglycaemia effects of SGY.

AIMS OF THE STUDY

This study aimed to examine the beneficial effects of Sangguayin Deccoction against metabolic syndrome and and its regulating role in gut microbiota and hepatic metabolome.

MATERIALS AND METHODS

C57BL/6J mice were divided to a normal chow diet (NCD), high-fat diet (HFD), and high-fat diet with Sangguayin Decoction (HFD-SGY, oral dose of 250 mg/kg/d) for 16 weeks. Next generation sequencing was applied for analyzing the gut microbial community of colonic contents. Further, untargeted metabolomic analysis based on LC-MS was used for determining the changes of hepatic metabolites. Hepatic genes expression were measured by quantitative PCR.

RESULTS

SGY supplement decreased blood glucose level and glucose intolerance. Illumina MiSeq sequencing revealed that SGY increased Verrucomicrobia phylum, resulting in a bloom of Akkermansia, and eventually upregulated the contents of Lachoclostridium and Roseburia. Additionally, dietary SGY decreased bacteria including Faecalibaculum, and Blautia. Moreover, the hepatic lipid metabolism was notably altered by SGY treatment. The oxidation of glutamione metabolism idecreasees, production of poly-unsaturated fatty acid (PUFA) got significant increase in liver tissue. The reversion of PUFA metabolism by SGY may act through PPARα mediated Fads1 and Fads2 gene expression. The altered metabolites in liver showed intimate correlatship with modified genera.

CONCLUSION

Data indicated that SGY reshaped gut microbial structure and improved PUFA metabolism. These functions of SGY may alter hepatic lipid metabolism, conferring preventative effects against high-fat diet induced metabolic syndrome.

The Alteration in Composition and Function of Gut Microbiome in Patients with Type 2 Diabetes

BACKGROUND

Diabetes mellitus (DM) has become one of the most common chronic metabolic diseases worldwide. Due to the increasing prevalence and various complications, diabetes brings about a huge financial burden to DM patients. Nowadays, more and more studies reveal the relationship between diseases and gut microbial community. We aimed to explore the alteration in composition and function of the gut microbiome in T2DM patients.

METHODS

A total of 137 patients with diabetes and 179 age- and gender-matched healthy controls selected from the healthy people sample center in the First Affiliated Hospital of Zhengzhou University were divided into the DM group and the Con group, respectively. We collected their venous blood for laboratory tests and stool samples for 16S rRNA sequencing. The comparison between the two groups including both composition and function of the gut microbiome is presented.

RESULTS

We found that the α-diversity of bacterial taxa in the DM group had an evident decrease compared to that in the Con group. At the phylum level, the DM group had an obvious decrease of Bacteroidetes and a marked increase of Proteobacteria, Actinobacteria, and Verrucomicrobia. At the genus level, Bacteroides and Prevotella decreased the most while Escherichia-Shigella, Lachnospiraceae_incertae_sedis, Subdoligranulum, Enterococcus, and Klebsiella had different degrees of expansion in the DM group. The ROC based on 246 optimum OTUs had very high test efficiency with an AUC of 92.25% in the training set and 90.48% in the test set. As for prediction of metabolic function, the gut microbiome of DM patients was predicted to be more active in environmental information processing and human diseases but less in metabolism.

CONCLUSION

We observed alteration of composition and function of the gut microbiome in the DM group. These changes may provide a new treatment strategy for DM patients and new research targets.

Evaluating the Causal Role of Gut Microbiota in Type 1 Diabetes and Its Possible Pathogenic Mechanisms

Type 1 diabetes (T1D) is a multifactorial autoimmune disease mediated by genetic, epigenetic, and environmental factors. In recent years, the emergence of high-throughput sequencing has allowed us to investigate the role of gut microbiota in the development of T1D. Significant changes in the composition of gut microbiome, also termed dysbiosis, have been found in subjects with clinical or preclinical T1D. However, whether the dysbiosis is a cause or an effect of the disease remains unclear. Currently, increasing evidence has supported a causal link between intestine microflora and T1D development. The current review will focus on recent research regarding the associations between intestine microbiome and T1D progression with an intention to evaluate the causality. We will also discuss the possible mechanisms by which imbalanced gut microbiota leads to the development of T1D.

Association of suboptimal health status with intestinal microbiota in Chinese youths

Suboptimal health status (SHS), a physical state between health and disease, is a subclinical and reversible stage of chronic disease. Previous studies have shown alterations in the intestinal microbiota in patients with some chronic diseases. This study aimed to investigate the association between SHS and intestinal microbiota in a case-control study with 50 SHS individuals and 50 matched healthy controls. Intestinal microbiota was analysed by MiSeq 250PE. Alpha diversity of intestinal microbiota in SHS individuals was higher compared with that of healthy controls (Simpson index, W = 2238, P = .048). Beta diversity was different between SHS and healthy controls (P = .018). At the phylum level, the relative abundance of Verrucomicrobia was higher in the SHS group than that in the controls (W = 2201, P = .049). Compared with that of the control group, nine genera were significantly higher and five genera were lower in abundance in the SHS group (all P < .05). The intestinal microbiota, analysed by a random forest model, was able to distinguish individuals with SHS from the controls, with an area under the curve of 0.79 (95% confidence interval: 0.77-0.81). We demonstrated that the alteration of intestinal microbiota occurs with SHS, an early stage of disease, which might shed light on the importance of intestinal microbiota in the primary prevention of noncommunicable chronic diseases.

Modulatory Mechanisms of the NLRP3 Inflammasomes in Diabetes

The inflammasome is a multiprotein complex that acts to enhance inflammatory responses by promoting the production and secretion of key cytokines. The best-known inflammasome is the NLRP3 (nucleotide-binding oligomerization domain-like receptor [NLR] family pyrin domain-containing 3) inflammasome. The evidence has shown that the NLRP3 inflammasome, IL-1β, thioredoxin-interacting protein (TXNIP), and pyroptosis play vital roles in the development of diabetes. This review summarizes the regulation of type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM) by NLRP3 via modulation of glucose tolerance, insulin resistance, inflammation, and apoptosis mediated by endoplasmic reticulum stress in adipose tissue. Moreover, NLRP3 participates in intestinal homeostasis and inflammatory conditions, and NLRP3-deficient mice experience intestinal lesions. The diversity of an individual's gut microbiome and the resultant microbial metabolites determines the extent of their involvement in the physiological and pathological mechanisms within the gut. As such, further study of the interaction between the NLRP3 inflammasome and the complex intestinal environment in disease development is warranted to discover novel therapies for the treatment of diabetes.

Personalized Nutrition: Are We There Yet?

The human genome has been proposed to contribute to interpersonal variability in the way we respond to nutritional intake. However, personalized diets solely based on gene-nutrient interactions have not lived up to their expectations to date. Advances in microbiome research have indicated that a science-based generation of a personalized diet based on a combination of clinical and microbial features may constitute a promising new approach enabling accurate prediction of dietary responses. In addition, scientific advances in our understanding of defined dietary components and their effects on human physiology led to the incorporation and testing of defined diets as preventive and treatment approaches for diseases, such as epilepsy, ulcerative colitis, Crohn disease, and type 1 diabetes mellitus. Additionally, exciting new studies show that tailored diet regiments have the potential to modulate pharmaceutical treatment efficacy in cancer treatment. Overall, the true therapeutic potential of nutritional interventions is coming to light but is also facing substantial challenges in understanding mechanisms of activity, optimization of dietary interventions for specific human subpopulations, and elucidation of adverse effects potentially stemming from some dietary components in a number of individuals.

Lactobacillus reuteri DSM 17938 feeding of healthy newborn mice regulates immune responses while modulating gut microbiota and boosting beneficial metabolites

Early administration of Lactobacillus reuteri DSM 17938 (LR) prevents necrotizing enterocolitis and inhibits regulatory T-cell (Treg)-deficiency-associated autoimmunity in mice. In humans, LR reduces crying time in breastfed infants with colic, modifies severity in infants with acute diarrheal illnesses, and improves pain in children with functional bowel disorders. In healthy breastfed newborns with evolving microbial colonization, it is unclear if early administration of LR can modulate gut microbiota and their metabolites in such a way as to promote homeostasis. We gavaged LR (107 colony-forming units/day, daily) to C57BL/6J mice at age of day 8 for 2 wk. Both male and female mice were investigated in these experiments. We found that feeding LR did not affect clinical phenotype or inflammatory biomarkers in plasma and stool, but LR increased the proportion of Foxp3+ regulatory T cells (Tregs) in the intestine. LR also increased bacterial diversity and the relative abundance of p_Firmicutes, f_Lachnospiraceae, f_Ruminococcaceae, and genera Clostridium and Candidatus arthromitus, while decreasing the relative abundance of p_Bacteriodetes, f_Bacteroidaceae, f_Verrucomicrobiaceae, and genera Bacteroides, Ruminococcus, Akkermansia, and Sutterella. Finally, LR exerted a major impact on the plasma metabolome, upregulating amino acid metabolites formed via the urea, tricarboxylic acid, and methionine cycles and increasing tryptophan metabolism. In conclusion, early oral administration of LR to healthy breastfed mice led to microbial and metabolic changes which could be beneficial to general health.NEW & NOTEWORTHY Oral administration of Lactobacillus reuteri DSM 17938 (LR) to healthy breastfed mice promotes intestinal immune tolerance and is linked to proliferation of beneficial gut microbiota. LR upregulates plasma metabolites that are involved in the urea cycle, the TCA cycle, methionine methylation, and the polyamine pathway. Herein, we show that LR given to newborn mice specifically increases levels of tryptophan metabolites and the purine nucleoside adenosine that are known to enhance tolerance to inflammatory stimuli.

Sick Individuals and Sick (Microbial) Populations: Challenges in Epidemiology and the Microbiome

The human microbiome represents a new frontier in understanding the biology of human health. While epidemiology in this area is still in its infancy, its scope will likely expand dramatically over the coming years. To rise to the challenge, we argue that epidemiology should capitalize on its population perspective as a critical complement to molecular microbiome research, allowing for the illumination of contextual mechanisms that may vary more across populations rather than among individuals. We first briefly review current research on social context and the gut microbiome, focusing specifically on socioeconomic status (SES) and race/ethnicity. Next, we reflect on the current state of microbiome epidemiology through the lens of one specific area, the association of the gut microbiome and metabolic disorders. We identify key methodological shortcomings of current epidemiological research in this area, including extensive selection bias, the use of noncompositionally robust measures, and a lack of attention to social factors as confounders or effect modifiers.

Is there any association between gut microbiota and type 1 diabetes? A systematic review

Introduction

Type 1 diabetes (T1D) is the second most common autoimmune disease among children. There is evidence suggesting that dysbiosis of some gut colonizing bacteria are associated with the pathogenesis of T1D. However, these studies are still controversial and a systematic review was conducted to evaluate the association between gut microbiota and T1D.

Methods

A systematic search was carried out in Medline (Via Pubmed) and Embase from January 2000 to January 2019 for all original cross-sectional, cohort, case–control or nested case–control studies investigating the association between gut microbiota and T1D.

Results

Of 568 articles identified, 26 studies met the inclusion criteria. The total population study of these articles consists of 2600 children (under 18 years old) and 189 adults. Among the included studies, 24 articles confirmed the association between gut microbiota dysbiosis and T1D. The most common bacterial alterations in T1D patients included Bacteroides spp., Streptococcus spp., Clostridium spp., Bifidobacterium spp., Prevotella spp., Staphylococcus spp., Blautia spp., Faecalibacterium spp., Roseburia spp., and Lactobacillus spp.

Conclusion

Our study showed a significant association between alterations in intestinal microbial composition and T1D; however, in some articles, it is not clear which one happens first. Investigation of altered gut microbiota can help in the early detection of T1D before seropositivity. Targeted microbiome modulation can be a novel potential therapeutic strategy.

Effect of Prebiotic on Microbiota, Intestinal Permeability, and Glycemic Control in Children With Type 1 Diabetes

CONTEXT

Patients with type 1 diabetes (T1D) have lower microbiota diversity and distinct gut microbial profiles that have been linked to changes in intestinal permeability. Prebiotics are nondigestible carbohydrates that alter gut microbiota and could potentially improve glycemic control and reduce intestinal permeability and thereby insulin sensitivity.

OBJECTIVE

To determine the effect of prebiotics on glycemic control, gut microbiota, and intestinal permeability in children with T1D.

DESIGN

A randomized, placebo-controlled trial in children 8 to 17 years of age with T1D using placebo or prebiotic oligofructose-enriched inulin for 12 weeks. Baseline, 3-month, and 6-month assessments included HbA1c, C-peptide, gut microbiota, intestinal permeability, frequency of diabetic ketoacidosis (DKA), and severe hypoglycemia.

RESULTS

Forty-three subjects were randomized and 38 completed the study. The groups were similar at baseline: prebiotic (N = 17), age 12.5 years (SD of 2.8), HbA1c 8.02% (SD of 0.82); placebo (N = 21), age 12.0 years (SD of 2.6), HbA1c 8.08% (SD of 0.91). No significant differences were found in the frequency of DKA or severe hypoglycemia. At 3-months, C-peptide was significantly higher (P = 0.029) in the group who received prebiotics, which was accompanied by a modest improvement in intestinal permeability (P = 0.076). There was a significant increase in the relative abundance of Bifidobacterium within the prebiotic group at 3 months that was no longer present after the 3-month washout. The placebo group had significantly higher relative abundance of Streptococcus, Roseburia inulinivorans, Terrisporobacter, and Faecalitalea compared with the prebiotic group at 3 months.

CONCLUSION

Prebiotics are a potentially novel, inexpensive, low-risk treatment addition for T1D that may improve glycemic control. Further larger-scale trials are needed.

Exploiting the Zonulin Mouse Model to Establish the Role of Primary Impaired Gut Barrier Function on Microbiota Composition and Immune Profiles

The balanced interplay between epithelial barrier, immune system, and microbiota maintains gut homeostasis, while disruption of this interplay may lead to inflammation. Paracellular permeability is governed by intercellular tight-junctions (TJs). Zonulin is, to date, the only known physiological regulator of intestinal TJs. We used a zonulin transgenic mouse (Ztm) model characterized by increased small intestinal permeability to elucidate the role of a primary impaired gut barrier on microbiome composition and/or immune profile. Ztm exhibit an altered gene expression profile of TJs in the gut compared to wild-type mice (WT): Claudin-15, Claudin-5, Jam-3, and Myosin-1C are decreased in the male duodenum whereas Claudin-15, Claudin-7, and ZO-2 are reduced in the female colon. These results are compatible with loss of gut barrier function and are paralleled by an altered microbiota composition with reduced abundance of the genus Akkermansia, known to have positive effects on gut barrier integrity and strengthening, and an increased abundance of the Rikenella genus, associated to low-grade inflammatory conditions. Immune profile analysis shows a subtly skewed distribution of immune cell subsets toward a pro-inflammatory phenotype with more IL-17 producing adaptive and innate-like T cells in Ztm. Interestingly, microbiota “normalization” involving the transfer of WT microbiota into Ztm, did not rescue the altered immune profile. Our data suggest that a primary impaired gut barrier causing an uncontrolled trafficking of microbial products leads to a latent pro-inflammatory status, with a skewed microbiota composition and immune profile that, in the presence of an environmental trigger, as we have previously described (1), might promote the onset of overt inflammation and an increased risk of chronic disease.

Non-lethal growth inhibition by arresting the starch utilization system of clinically relevant human isolates of Bacteroides dorei

We describe the inhibition of the starch utilization system (Sus) belonging to various strains of Bacteroides dorei in a non-lethal manner using the small molecule probe, acarbose. Concentrations of acarbose as low as 5 μM significantly impede the growth of B. dorei and increase the doubling time of cultures. The successful inhibition of this species of Bacteroides is relevant to several disease states including type I diabetes mellitus. This method continues to explore a new, potential route to intervene in illnesses associated with aberrant changes in the composition of the human gut microbiota through the strategic manipulation of its constituents.

Microbiome and type 1 diabetes

The steep increase in the incidence of type 1 diabetes (T1D), in the Western world after World War II, cannot be explained solely by genetic factors but implies that this rise must be due to crucial interactions between predisposing genes and environmental changes. Three parallel phenomena in early childhood – the dynamic development of the immune system, maturation of the gut microbiome, and the appearance of the first T1D-associated autoantibodies – raise the question whether these phenomena might reflect causative relationships. Plenty of novel data on the role of the microbiome in the development of T1D has been published over recent years and this review summarizes recent findings regarding the associations between islet autoimmunity, T1D, and the intestinal microbiota.

H. pylori eradication with antibiotic treatment causes changes in glucose homeostasis related to modifications in the gut microbiota

Background

H. pylori infection and eradication cause perturbations of the gut microbiome. The gut microbiota has been identified as a potential contributor to metabolic diseases. We evaluate whether these alterations in intestinal microbiota composition produced by H. pylori infection and its posterior eradication with antibiotic treatment could be associated with glucose homeostasis in metabolically healthy subjects.

Methods

Forty adult patients infected with H. pylori and 20 control subjects were recruited. The infected subjects were evaluated before and two months after eradication treatment (omeprazole, clarithromycin, amoxicillin). The microbiota composition in fecal samples was determined by 16S rRNA gene (V3-V4) sequencing using Illumina Miseq.

Results

Patients (pre- and post-H. pylori eradication) showed a decreased bacterial richness and diversity with respect to controls. There was an improvement in glucose homeostasis in subjects two months after H. pylori eradication treatment. Changes in the amount of Rikenellaceae, Butyricimonas, E. biforme, B. fragilis, and Megamonas were inversely associated with changes in the glucose level or related parameters (Hb1ac) in H. pylori eradication subjects.

Conclusions

H. pylori infection and eradication with antibiotic treatment causes alteration of the human gut microbiome. The increase in SCFA-producing bacteria and glucose-removing bacteria, specifically members of Megamonas, Rikenellaceae and Butyricimonas, has been related with an improvement in glucose homeostasis after H. pylori eradication with antibiotic treatment.

Dietary fibers as emerging nutritional factors against diabetes: focus on the involvement of gut microbiota

Diabetes mellitus (DM) increases the risk of cardiovascular diseases and other secondary complications, such as nephropathy, neuropathy, retinopathy, etc. The important risk factors for the pathogenesis of DM are aging, family history, sedentary lifestyle, unhealthy dietary habits, and obesity. Evidence from epidemiological studies also indicates that DM is characterized by specific alterations in the human gut microbiota (GM). GM transplantation in rodents and humans revealed that a specific GM constituent can be the cause and not just the consequence of the DM condition and complications. These findings suggest a potential role of GM in human health, disease prevention, and treatment. Dietary intervention studies using dietary fibers (DFs) suggested that modulation of the GM can suppress the metabolic risk markers in humans. However, a causal role of GM in such studies remains unexplored. Long-term follow-up studies disclosed that the diet rich in insoluble and non-viscous fibers are responsible for DF-mediated antidiabetic activities, while soluble and viscous fibers have little influence on DM despite having a profound impact on glycemia. However, general conclusions cannot be drawn simply based on these findings. Long-term follow-up studies are urgently required in this area to explore the therapeutic potential of different DFs in treating DM and to delineate the exact role of GM involvement. Here we review and discuss the signature of GM during DM, antidiabetic activity of metformin via GM modulation, DFs from different sources and their antidiabetic activity, and the possible role of GM involvement.

Beneficial effects of Saccharomyces boulardii CNCM I-745 on clinical disorders associated with intestinal barrier disruption

Intestinal barrier defects lead to "leaky gut syndrome", defined as an increase in intestinal permeability that allows the passage of luminal content into intestinal tissue and the bloodstream. Such a compromised intestinal barrier is the main factor underlying the pathogenesis of inflammatory bowel disease, but also commonly occurs in various systemic diseases such as viral infections and metabolic syndrome. The non-pathogenic yeast Saccharomyces boulardii CNCM I-745 has demonstrated its effectiveness as a probiotic in the prevention and treatment of antibiotic-associated, infectious and functional diarrhea. Via multiple mechanisms of action implicated in intestinal barrier function, S. boulardii has beneficial effects on altered intestinal microbiota and epithelial barrier defects in different pathologies. The well-studied probiotic yeast S. boulardii plays a crucial role in the preservation and/or restoration of intestinal barrier function in multiple disorders. This could be of major interest in diseases characterized by alterations in intestinal barrier function.