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

A predictive model based on the gut microbiota improves the diagnostic effect in patients with rheumatoid arthritis

OBJECTIVES

Rheumatoid arthritis (RA) is a chronic, destructive autoimmune disorder predominantly targeting the joints, with gut microbiota dysbiosis being intricately associated with its progression. The aim of the present study is to develop effective early diagnostic methods for early RA based on gut microbiota.

METHODS

A cohort comprising 262 RA patients and 475 healthy controls (HCs) was recruited. Faecal samples were collected from all participants, and microbial DNA was subsequently extracted. The V3-V4 region of the 16S rRNA gene was amplified via polymerase chain reaction (PCR) and subjected to high-throughput sequencing using the Illumina MiSeq platform. Additionally, a dataset with the accession number PRJNA450340 from the European Nucleotide Archive (ENA) was incorporated into the study. The sequencing data underwent processing and analysis utilizing QIIME2. To construct microbiome-based diagnostic models, Random Forest (RF), Support Vector Machine (SVM) and Generalized Linear Model (GLM) methodologies were employed, with the self-test data functioning as the training set and the PRJNA450340 dataset serving as the validation set.

RESULT

The results indicated that patients with RA exhibited a significantly reduced gut microbial α-diversity compared with the HCs group. The β-diversity analysis demonstrated notable distinctions in the gut microbiota structure between RA patients and HCs. Variations in the gut microbiome composition between RA patients and HCs were evident at both the phylum and genus levels. LEfSe analysis revealed a substantial number of significantly different microbiota between RA patients and HC, and seven key genera were obtained by intersection of the different flora in the two data sets: Ruminococcus_gnavus_group, Fusicatenibacter, Butyricicoccus, Subdoligranulum, Erysipelotrichaceae_UCG-003, Romboutsia and Dorea. Utilizing these seven core genera, RA diagnostic models were developed employing RF, SVM and GLM methodologies. The GLM model exhibited consistent performance, achieving an area under the curve (AUC) of 71.03% in the training set and 74.71% in the validation set.

CONCLUSION

Notable differences in gut microbiota exist between RA patients and healthy individuals. Diagnostic models based on key microbial genera hold potential for aiding in the early identification of individuals at risk for developing RA, thereby suggesting new avenues for its diagnosis.

Reduced abundance of Fusobacterium signifies cardiovascular benefits of sodium glucose cotransporter 2 inhibitor in type 2 diabetes: a single arm clinical trial

Background

The sodium glucose cotransporter 2 inhibitor (SGLT2i) dapagliflozin has been demonstrated cardiovascular benefits in patients with type 2 diabetes mellitus (T2DM). However, the underlying mechanism remains poorly understood.

Methods

We conducted an 8-week, single-arm clinical trial, which enrolled 12 patients with inadequate glycemic control on metformin monotherapy. These patients were treated with SGLT2i dapagliflozin (10 mg/day). We assessed changes in clinical parameters pertinent to glucose metabolism and risk factors of cardiovascular disease (CVD), as well as alterations in the gut microbiota using macrogene sequencing.

Results

Improvements were observed in anthropometric parameters, glucose metabolism, blood lipid-related indices, inflammatory markers, and endothelial cell function-related parameters. Concurrently, SGLT2i led to changes in composition and functional pathways of the gut microbiota, manifested as increased abundance of probiotics and decreased abundance of harmful bacteria. Importantly, reduced abundance of Fusobacterium was correlated with improvements in various clinical indicators.

Conclusion

SGLT2i represents a superior initial therapeutic option for T2DM patients at risk of CVD. The cardiovascular benefits of SGLT2i may be attributed to shifts in the gut microbiota, particularly the reduced abundance of Fusobacterium.

A Consensus Statement on establishing causality, therapeutic applications and the use of preclinical models in microbiome research

The gut microbiome comprises trillions of microorganisms and profoundly influences human health by modulating metabolism, immune responses and neuronal functions. Disruption in gut microbiome composition is implicated in various inflammatory conditions, metabolic disorders and neurodegenerative diseases. However, determining the underlying mechanisms and establishing cause and effect is extremely difficult. Preclinical models offer crucial insights into the role of the gut microbiome in diseases and help identify potential therapeutic interventions. The Human Microbiome Action Consortium initiated a Delphi survey to assess the utility of preclinical models, including animal and cell-based models, in elucidating the causal role of the gut microbiome in these diseases. The Delphi survey aimed to address the complexity of selecting appropriate preclinical models to investigate disease causality and to study host-microbiome interactions effectively. We adopted a structured approach encompassing a literature review, expert workshops and the Delphi questionnaire to gather insights from a diverse range of stakeholders. Experts were requested to evaluate the strengths, limitations, and suitability of these models in addressing the causal relationship between the gut microbiome and disease pathogenesis. The resulting consensus statements and recommendations provide valuable insights for selecting preclinical models in future studies of gut microbiome-related diseases.

Gut microbiome research: Revealing the pathological mechanisms and treatment strategies of type 2 diabetes

The high prevalence and disability rate of type 2 diabetes (T2D) caused a huge social burden to the world. Currently, new mechanisms and therapeutic approaches that may affect this disease are being sought. With in-depth research on the pathogenesis of T2D and growing advances in microbiome sequencing technology, the association between T2D and gut microbiota has been confirmed. The gut microbiota participates in the regulation of inflammation, intestinal permeability, short-chain fatty acid metabolism, branched-chain amino acid metabolism and bile acid metabolism, thereby affecting host glucose and lipid metabolism. Interventions focusing on the gut microbiota are gaining traction as a promising approach to T2D management. For example, dietary intervention, prebiotics and probiotics, faecal microbiota transplant and phage therapy. Meticulous experimental design and choice of analytical methods are crucial for obtaining accurate and meaningful results from microbiome studies. How to design gut microbiome research in T2D and choose different machine learning methods for data analysis are extremely critical to achieve personalized precision medicine.

Unveiling the Antiobesity Mechanism of Sweet Potato Extract by Microbiome, Transcriptome, and Metabolome Analyses in Mice

This study aimed to elucidate the antiobesity mechanisms of sweet potato extract (SPE) through biochemical, gut microbiome, liver transcriptome, and metabolome analyses. Administration of SPE to high-fat-diet-fed mice significantly reduced body weight gain, serum low-density lipoprotein cholesterol, hepatic lipid accumulation, and adipocyte hypertrophy, which were closely linked to gut microbiome composition. SPE notably increased the abundance of Eubacterium_coprostanoligenes_group_unclassified and decreased that of Kineothrix, both of which were strongly associated with short-chain fatty acid (SCFA) production. LC-QTOF-MS analysis identified resin glycoside compounds from SPE with reduced levels in mouse feces, suggesting their utilization in vivo. SPE also promoted dietary fat excretion. Liver transcriptomic and metabolomic profiling revealed that SPE may exert antiobesity effects by modulating the bile-sphingolipid metabolism, which was closely correlated with the reshaped gut microbiomes and SCFAs. These findings provide new insights into the antiobesity effects and mechanisms of SPE.

Influence of menstrual cycle and oral contraception on taxonomic composition and gas production in the gut microbiome

Introduction. Oral contraceptives (OCs) are widely used for birth control and offer benefits such as menstrual cycle regulation and reduced menstrual pain. However, they have also been associated with an increased risk of cancer and reduced bone mass density.Gap Statement. While the gut microbiome is known to interact with endocrine factors, the impact of hormonal OCs on its composition and function remains underexplored. Additionally, we explore the relationship of OC use and the microbiome to gas production, which can cause symptoms and be indicative of poor health.Aim. This study investigates the effects of OCs on the diversity and composition of the gut microbiome and its association with breath hydrogen (H2) and methane (CH4) levels.Methodology. We utilized 16S rRNA gene sequencing to analyse faecal samples from 65 women, comparing OC users with non-users at two menstrual cycle time points. Breath tests measured hydrogen and CH4 production. Data were analysed for microbial diversity, community composition and correlation with gas production.Results. There were no differences in overall microbial diversity between OC users and non-users in samples collected on day 2 of the menstrual cycle. However, on day 21, we found a significant difference in microbial richness, suggesting a cycle-dependent effect of OCs on gut microbiota species richness but not composition. We found a strong correlation between H2 and CH4 concentrations and an interaction between OC use and the menstrual cycle on H2 and CH4 production. We also identified several taxa associated with both high levels of H2 and CH4 production and OC use.Conclusion. Our study highlights the intricate relationships among hormonal contraceptives, the gut microbiota and gas production and connects shifts in the microbiome composition to gastrointestinal symptoms (e.g. gas production) that can impact overall health. This underscores the need for further research on the long-term effects of OCs and for the development of precise therapeutic strategies to address potential adverse effects. Our findings offer new perspectives on the microbiome-hormone-gas production nexus, potentially broadening our understanding of the systemic implications of OCs.

Effects of maternal restraint stress on offspring intestinal microbiota and adipogenesis: insights from in vivo and in vitro studies

The maternal restraint stress animal model is based on a long-term stress paradigm administered to pregnant maternal animals, and these offspring have been shown to exhibit a variety of biochemical defects including obesity. This study aimed to investigate whether maternal restraint stress affects obesity-associated changes in offspring intestinal microbiota and the adipogenic differentiation of mesenchymal stem cells (MSCs).Pregnant mice were subjected to restraint stress three times daily from gestational Day12 to delivery. Changes in the composition of the intestinal microbiota of mothers (during pregnancy and lactation) and their lactating offspring exposed to maternal restraint stress were analyzed using next-generation sequencing. Maternal stress altered the maternal microbiota, with reduced Bacteroidetes and increased Firmicutes. While similar trends were observed in offspring, these changes were not statistically significant. However, maternal stress notably reduced microbial diversity in the offspring's intestinal microbiota. Bone marrow-derived MSCs from offspring at weaning were analyzed for adipogenic transcription factors and hormone receptor expression using quantitative PCR. Maternal stress enhanced the adipogenic phenotype of offspring MSCs, as evidenced by increased expression of adipogenic markers (PPARγ, leptin receptor) and a reduced osteogenic phenotype. In vitro induction further confirmed the higher adipocyte differentiation potential in stressed offspring MSCs compared to controls.Our results revealed that maternal restraint stress altered the maternal intestinal microbiota, leading to reduced microbial diversity in offspring, predisposing their MSCs toward an adipocyte phenotype. These finding suggest that modulating the intestinal microbiota of stressed pregnant women may improve the susceptibility to obesity in their children.

Gut Microbiota in T2DM Patients with Microvascular Complications: A 16S rRNA Sequencing Study

Objective

This study aims to investigate the characteristics of gut microbiota in patients with microvascular complications of Type 2 Diabetes Mellitus (T2DM) using 16S rRNA high-throughput sequencing technology.

Methods

Patients diagnosed with T2DM were enrolled as study subjects. Based on the presence of microvascular complications, subjects were divided into a study group, a control group. Clinical fecal samples from the two groups were subjected to diversity analysis using the Illumina MiSeq high-throughput sequencing technology, comparing the richness and diversity of the gut microbiota between the two groups. The Tax4Fun software was utilized for the functional prediction of differential microbiota.

Results

A total of 3727 operational taxonomic units (OTUs) were identified, with 1311 OTUs common to both groups, and 1363 and 1053 OTUs unique to the study group and the control group, respectively. The study group exhibited a significant increase in the relative abundance of Clostridia and Negativicutes, and a marked decrease in Gammaproteobacteria, Bacilli, and Verrucomicrobia compared to the control group. LefSe analysis revealed significant differences in the relative abundance at two phyla, two classes, two orders, three families, and two genera levels between the groups. KEGG pathway analysis of differential microbiota identified 10 pathways with statistically significant differences (P<0.05).

Conclusion

This study reveals significant disparities in gut microbiota abundance between T2DM patients and those with microvascular complications of T2DM, suggesting potential microbial markers for diagnosing and treating microvascular complications of T2DM.

A systematic review on gut microbiota in type 2 diabetes mellitus

Aims/hypothesis

The gut microbiota play crucial roles in the digestion and degradation of nutrients, synthesis of biological agents, development of the immune system, and maintenance of gastrointestinal integrity. Gut dysbiosis is thought to be associated with type 2 diabetes mellitus (T2DM), one of the world's fastest growing diseases. The aim of this systematic review is to identify differences in the composition and diversity of the gut microbiota in individuals with T2DM.

Methods

A systematic search was conducted to identify studies reporting on the difference in gut microbiota composition between individuals with T2DM and healthy controls. Relevant studies were evaluated, and their characteristics and results were extracted using a standardized data extraction form. The studies were assessed for risk of bias and their findings were reported narratively.

Results

58 observational studies published between 2010 and 2024 were included. Beta diversity was commonly reported to be different between individuals with T2DM and healthy individuals. Genera Lactobacillus, Escherichia-Shigella, Enterococcus, Subdoligranulum and Fusobacteria were found to be positively associated; while Akkermansia, Bifidobacterium, Bacteroides, Roseburia, Faecalibacteirum and Prevotella were found to be negatively associated with T2DM.

Conclusions

This systematic review demonstrates a strong association between T2DM and gut dysbiosis, as evidenced by differential microbial abundances and altered diversity indices. Among these taxa, Escherichia-Shigella is consistently associated with T2DM, whereas Faecalibacterium prausnitzii appears to offer a protective effect against T2DM. However, the heterogeneity and observational nature of these studies preclude the establishment of causative relationships. Future research should incorporate age, diet and medication-matched controls, and include functional analysis of these gut microbes.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42023459937.

Understanding Patterns of the Gut Microbiome May Contribute to the Early Detection and Prevention of Type 2 Diabetes Mellitus: A Systematic Review

The rising burden of type 2 diabetes mellitus (T2DM) is a growing global public health problem, particularly prominent in developing countries. The early detection of T2DM and prediabetes is vital for reversing the outcome of disease, allowing early intervention. In the past decade, various microbiome-metabolome studies have attempted to address the question of whether there are any common microbial patterns that indicate either prediabetic or diabetic gut microbial signatures. Because current studies have a high methodological heterogeneity and risk of bias, we have selected studies that adhered to similar design and methodology. We performed a systematic review to assess if there were any common changes in microbiome belonging to diabetic, prediabetic and healthy individuals. The cross-sectional studies presented here collectively covered a population of 65,754 people, with 1800 in the 2TD group, 2770 in the prediabetic group and 61,184 in the control group. The overall microbial diversity scores were lower in the T2D and prediabetes cohorts in 86% of the analyzed studies. Re-programming of the microbiome is potentially one of the safest and long-lasting ways to eliminate diabetes in its early stages. The differences in the abundance of certain microbial species could serve as an early warning for a dysbiotic gut environment and could be easily modified before the onset of disease by changes in lifestyle, taking probiotics, introducing diet modifications or stimulating the vagal nerve. This review shows how metagenomic studies have and will continue to identify novel therapeutic targets (probiotics, prebiotics or targets for elimination from flora). This work clearly shows that gut microbiome intervention studies, if performed according to standard operating protocols using a predefined analytic framework (e.g., STORMS), could be combined with other similar studies, allowing broader conclusions from collating all global cohort studies efforts and eliminating the effect-size statistical insufficiency of a single study.

Impact of Ketogenic and Mediterranean Diets on Gut Microbiota Profile and Clinical Outcomes in Drug-Naïve Patients with Diabesity: A 12-Month Pilot Study

Background/Objectives: Managing type 2 diabetes mellitus (T2DM) and obesity requires a multidimensional, patient-centered approach including nutritional interventions (NIs) and physical activity. Changes in the gut microbiota (GM) have been linked to obesity and the metabolic alterations typical of T2DM and obesity, and they are strongly influenced by diet. However, few studies have evaluated the effects on the GM of a very-low-calorie ketogenic diet (VLCKD) in patients with T2DM, especially in the mid-term and long-term. This longitudinal study is aimed at evaluating the mid-term and long-term impact of the VLCKD and Mediterranean diet (MD) on the GM and on the anthropometric, metabolic, and lifestyle parameters of 11 patients with T2DM and obesity (diabesity). This study extends previously published results evaluating the short-term (three months) impact of these NIs on the same patients. Methods: At baseline, patients were randomly assigned to either a VLCKD (KETO group) or a Mediterranean diet (MEDI group). After two months, the KETO group gradually shifted to a Mediterranean diet (VLCKD-MD), according to current VLCKD guidelines. From the fourth month until the end of the study both groups followed a similar MD. Previous published results showed that VLCKD had a more beneficial impact than MD on several variables for 3 months of NI. In this study, the analyses were extended until six (T6) and twelve months (T12) of NI by comparing data prospectively and against baseline (T0). The GM analysis was performed through next-generation sequencing. Results: Improvements in anthropometric and metabolic parameters were more pronounced in the KETO group at T6, particularly for body mass index (-5.8 vs. -1.7 kg/m2; p = 0.006) and waist circumference (-15.9 vs. -5.2 cm; p = 0.011). At T6, a significant improvement in HbA1c (6.7% vs. 5.5% p = 0.02) and triglyceride (158 vs. 95 mg/dL p = 0.04) values compared to T0 was observed only in the KETO group, which maintained the results achieved at T3. The VLCKD-MD had a more beneficial impact than the MD on the GM phenotype. A substantial positive modulatory effect was observed especially up to the sixth month of the NI in KETO due to the progressive increase in bacterial markers of human health. After the sixth month, most markers of human health decreased, though they were still increased compared with baseline. Among them, the Verrucomicrobiota phylum was identified as the main biomarker in the KETO group, together with its members Verrucomicrobiae, Akkermansiaceae, Verrucomicrobiales, and Akkermansia at T6 compared with baseline. Conclusions: Both dietary approaches ameliorated health status, but VLCKD, in support of the MD, has shown greater improvements on anthropometric and metabolic parameters, as well as on GM profile, especially up to T6 of NI.

Changes in Intestinal Microbiota and Their Relationship With Patient Characteristics in Colorectal Cancer

BACKGROUND

Gut microbiota are associated with the pathological features and development of colorectal cancer (CRC); however, how gut microbiota changes in patients with CRC is unknown. This study investigated the role of gut microbiota in the development and progression of CRC by retrospectively comparing the structural differences between the gut microbiota of patients with CRC and healthy individuals.

METHODS

Together with clinical data, we collected fecal samples from patients with CRC (n = 18) and healthy controls (n = 18) and performed 16S rRNA gene sequencing and alpha and beta diversity analysis to compare microbiota richness and diversity. Based on the differences in microbiota between the CRC and control groups, we identified disease-specific microbial communities after relevant factors. PICRUSt2 software was used to predict the differential microbial functions.

RESULTS

The CRC and control groups differed in both composition and abundance of intestinal microbiota. Firmicutes and Bacteroidetes were the most abundant phyla in both groups, while Verrucomicrobi was significantly more abundant in the CRC group. Megamonas, Lachnospira, and Romboutsia were more abundant in the control group; 18 genera differed significantly in abundance between the groups, which were found to involve 21 metabolic pathways. The distribution and abundance of gut microbiota differed significantly between patients with CRC with and without lymph node metastasis; at the genus level, the abundance of Rothia and Streptococcus was significantly higher and that of Bacteroides, Parabacteroides, and Oscillibacter was significantly lower in patients with lymph node metastasis.

CONCLUSIONS

The gut microbiota is altered in CRC patients compared with healthy individuals, with specific changes in the microbiota associated with clinical and pathological features such as tumor stage, lymph node involvement, and tumor differentiation. Our findings elaborate to some extent on the link between the gut microbiota and CRC.

Racial-Ethnic Disparities of Obesity Require Community Context-Specific Biomedical Research for Native Hawaiians and Other Pacific Islanders

Compared to the general population of Hawai'i, Native Hawaiians and Other Pacific Islanders (NHPI) shoulder a disproportionately high risk for obesity-related cardiometabolic disorders, such as type 2 diabetes and cardiovascular disease. The gut microbiome is an area of rapid research interest for its role in regulating adjacent metabolic pathways, offering novel opportunities to better understand the etiology of these health disparities. Obesity and the gut microbiome are influenced by regional, racial-ethnic, and community-specific factors, limiting the generalizability of current literature for understudied populations. Additionally, anthropometric and directly measured obesity indices are variably predictive of adiposity and metabolic health risk in this diverse population. Thus, further NHPI-inclusive research is required to adequately characterize community-specific factors in the context of obesity-related disease etiology. Culturally responsible research ethics and scientific communication are crucial to conducting such research, especially among indigenous and understudied populations. In this review, we explore these limitations in current literature, emphasizing the urgent need for NHPI-inclusive research to assess community-specific factors accurately. Such accuracy in Indigenous health research may ensure that findings relevant to individual or public health recommendations and/or policies are meaningful to the communities such research aims to serve.

The Role of the Gut Microbiome in the Development and Progression of Type 2 Diabetes and Liver Disease

Type 2 diabetes mellitus (T2DM) and progressive liver disease are 2 of the most significant global health concerns, and they have alarming and ever-increasing prevalence. A growing body of literature has demonstrated a potential multilateral link between gut microbiome dysbiosis and the development and progression of the above-mentioned conditions. Modulation of gut microbial composition from the norm is due to changes in diet allied with external factors such as age, genetics, and environmental changes. In this comprehensive review, we recapitulate the research to date investigating the links between gut microbiome dysbiosis and T2DM or liver disease, with special attention to the importance of diet. Additionally, we review the most commonly used tools and methodologies of investigating changes in the gut microbiome, highlighting the advantages and limitations of each strategy, before introducing a novel in vitro approach to the problem. Finally, the review offers recommendations for future research in this field that will allow better understanding of how the gut microbiota affects disease progression and of the prospects for intestinal microbiota-based therapeutic options.

Changes in the Composition and Diversity of the Intestinal Microbiota Associated with Carbohydrate Consumption in Type 2 Diabetes Mellitus Patients

Type 2 diabetes mellitus (T2DM) is a multifactorial disease, influenced by dietary and environmental factors that can modify the intestinal microbiota. The aim of this study was to evaluate changes in the composition and diversity of the intestinal microbiota associated with carbohydrate (CHO) consumption in T2DM patients. Forty patients participated, with and without T2DM. Fecal samples were collected for the characterization of microbial diversity from the massive sequencing of the 16S rRNA gene. Carbohydrate consumption was quantified using the Frequency Consumption Foods questionnaire (FCF), the groups were categorized according to Body Mass Index (BMI) and BMI + CHO consumption. The group without T2DM showed normal biochemical and anthropometric parameters, although they had a high carbohydrate consumption compared to the group with T2DM. At the phylum level, there were differences in relative abundance; the control overweight group (CL-OW > CHO) and T2DM-Normal Weight > CHO patients had increased Bacteroides and decreased Firmicutes. In contrast, the CL-OW > CHO and T2DM-OW < CHO patients, showed reduced Bacteroidetes and an elevated amount of Firmicutes. At the genus level, the differences were in the relative abundance of Roseburia, Clostridium_IV, Prevotella, and Sporobacter, associated with the consumption of carbohydrates. The groups that consumed high amounts of carbohydrates, regardless of whether they had diabetes mellitus or were overweight, had a significantly reduced proportion of Faecalibacterium, an altered proportion of Bacteroides. The high consumption of carbohydrates showed considerable modifications in the composition and diversity of the bacterial communities.

Modulatory Effects of Lactobacillus paracasei-Fermented Turmeric on Metabolic Dysregulation and Gut Microbiota in High-Fat Diet-Induced Obesity in Mice

Turmeric, derived from Curcuma longa, and Lactobacillus paracasei, a lactic acid bacteria, have been studied for their potential antiobesity effects. To date, the antiobesity effects of turmeric fermented with L. paracasei have not been sufficiently investigated. This study was conducted via oral administration of 5% L. paracasei-fermented (FT) and unfermented turmeric (UT) in diet over 16 weeks using high-fat diet (HFD)-induced obese C57BL/6J mice. Results showed that the curcuminoid content of turmeric decreased following fermentation. Furthermore, FT significantly suppressed weight gain and liver and visceral adipose tissue weight and reduced plasma metabolic parameters in both the UT and FT experimental groups. The effects of FT were more noticeable than those of the unfermented form. Moreover, FT downregulated the expression of adipogenesis, lipogenesis, and inflammatory-related protein, but upregulated liver β-oxidation protein SIRT 1, PPARα, and PGC-1α in perigonadal adipose tissue. Additionally, FT ameliorated insulin resistance by activating insulin receptor pathway protein expressions in visceral adipose tissues. FT also modulated gut microbiota composition, particularly in two beneficial bacteria, Akkermansia muciniphila and Desulfovibrio, as well as two short-chain fatty acid-producing bacteria: Muribaculum intestinale and Deltaproteobacteria. Our findings indicate that the modulation effect of FT may be an important pathway for its antiobesity mechanisms.

The central role of the gut microbiota in the pathophysiology and management of type 2 diabetes

The inhabitants of our intestines, collectively called the gut microbiome, comprise fungi, viruses, and bacterial strains. These microorganisms are involved in the fermentation of dietary compounds and the regulation of our adaptive and innate immune systems. Less known is the reciprocal interaction between the gut microbiota and type 2 diabetes mellitus (T2DM), as well as their role in modifying therapies to reduce associated morbidity and mortality. In this review, we aim to discuss the existing literature on gut microbial strains and their diet-derived metabolites involved in T2DM. We also explore the potential diagnostics and therapeutic avenues the gut microbiota presents for targeted T2DM management. Personalized treatment plans, driven by diet and medication based on the patient's microbiome and clinical markers, could optimize therapy.

Quantification and Correlation Analysis of Bacteroides Species with Diabetes-Related Amino Acids in Individuals with Prediabetes and Type 2 Diabetes Mellitus

Background: The relationship between gut microbiota and diabetes-related amino acids significantly impacts insulin resistance and obesity. We aimed to quantify two Bacteroidetes species and their correlation with branched-chain amino acids, aromatic amino acids, and glutamate in prediabetes (preDM) and type 2 diabetes mellitus (T2DM). Methods: Fecal samples were collected from 68 participants, including 21 with T2DM, 23 with preDM, and 24 with normal glycemic tolerance (NGT). The abundance of Bacteroides vulgatus and Bacteroides thetaiotaomicron was determined by quantitative real-time polymerase chain reaction. Plasma amino acid measurements were performed using liquid chromatography coupled with tandem mass spectrometry. Results: The quantities of B. vulgatus and B. thetaiotaomicron were reduced in preDM and T2DM than in NGT subjects, but it was not statistically significant. The concentrations of leucine, valine, and tyrosine were significantly higher in preDM and T2DM than in NGT subjects (P < 0.05). A negative correlation was observed between B. thetaiotaomicron abundance and two aromatic amino acids (tyrosine, r = -0.28, P = 0.04; phenylalanine, r = -0.26, P = 0.05). Conclusions: These findings imply that, since gut microbiota varies throughout ethnic groups, further research with many participants will be required to determine the abundance of B. vulgatus and B. thetaiotaomicron in preDM and T2DM and their association with diabetes-related amino acids.

CYP8B1 downregulation mediates the metabolic effects of vertical sleeve gastrectomy in mice

BACKGROUND AND AIMS

Although the benefits of vertical sleeve gastrectomy (VSG) surgery are well known, the molecular mechanisms by which VSG alleviates obesity and its complications remain unclear. We aim to determine the role of CYP8B1 (cytochrome P450, family 8, subfamily B, polypeptide 1) in mediating the metabolic benefits of VSG.

APPROACH AND RESULTS

We found that expression of CYP8B1, a key enzyme in controlling the 12α-hydroxylated (12α-OH) bile acid (BA) to non-12α-OH BA ratio, was strongly downregulated after VSG. Using genetic mouse models of CYP8B1 overexpression, knockdown, and knockout, we demonstrated that overexpression of CYP8B1 dampened the metabolic improvements associated with VSG. In contrast, short hairpin RNA-mediated CYP8B1 knockdown improved metabolism similar to those observed after VSG. Cyp8b1 deficiency diminished the metabolic effects of VSG. Further, VSG-induced alterations to the 12α-OH/non-12α-OH BA ratio in the BA pool depended on CYP8B1 expression level. Consequently, intestinal lipid absorption was restricted, and the gut microbiota (GM) profile was altered. Fecal microbiota transplantation from wild type-VSG mice (vs. fecal microbiota transplantation from wild-type-sham mice) improved metabolism in recipient mice, while there were no differences between mice that received fecal microbiota transplantation from knockout-sham and knockout-VSG mice.

CONCLUSIONS

CYP8B1 is a critical downstream target of VSG. Modulation of BA composition and gut microbiota profile by targeting CYP8B1 may provide novel insight into the development of therapies that noninvasively mimic bariatric surgery to treat obesity and its complications.

Efficacy of high-intensity interval and continuous endurance trainings on cecal microbiota metabolites and inflammatory factors in diabetic rats induced by high-fat diet

Physical exercise is known to modulate the intestinal microbiota composition and control the symptoms of metabolic syndrome. In this research, we intend to investigate and compare the effect of high-intensity interval and continuous endurance trainings (HIIT and CET) on cecal microbiota metabolites and inflammatory factors in diabetic rats. A number of Wistar rats were made diabetic by a high-fat diet and trained under two types of exercise protocols, HIIT and CET. After taking samples from the cecal tissue and serum of rats to reveal the effect of exercise, three microbial species from the Firmicute and Bacteroid phyla, which are the main types of intestinal microbes, and their metabolites include two short-chain fatty acids (SCFAs), butyrate and propionate and also, the inflammatory factors TLR4 and IL6 were analyzed through quantitative polymerase chain reaction (qPCR), high-performance liquid chromatography (HPLC), and Enzyme-linked immunosorbent assay (ELISA) methods. In general, exercise while increasing the representative of Firmicute has caused a relative reduction of Bacteroides and improved the concentration of SCFAs. In this regard, HIIT outperforms CET in up-regulating Akkermansia and Butyrivibrio expression, and butyrate and propionate metabolites concentration. Also, both exercises significantly reduced cecal expression of TLR4 and sera concentration of IL6 compared to the diabetic group, although the reduction rate was higher in the CET group than in HIIT. Our findings suggest that some symptoms of metabolic syndrome such as intestinal dysbiosis and the resulting metabolic disorders are better controlled by HIIT and inflammation by CET. Certainly, more extensive research on other contributing factors could help clarify the results.

17β-Estradiol protects female rats from bilateral oophorectomy-induced nonalcoholic fatty liver disease induced by improving linoleic acid metabolism alteration and gut microbiota disturbance

After surgical or natural menopause, women face a high risk of nonalcoholic fatty liver disease (NAFLD), which can be diminished by hormone replacement therapy (HRT). The gut microbiota is subject to modulation by various physiological changes and the progression of diseases. This microbial ecosystem coexists symbiotically with the host, playing pivotal roles in immune maturation, microbial defense mechanisms, and metabolic functions essential for nutritional and hormone homeostasis. E2 supplementation effectively prevented the development of NAFLD after bilateral oophorectomy (OVX) in female rats. The changes in the gut microbiota such as abnormal biosynthetic metabolism of fatty acids caused by OVX were partially restored by E2 supplementation. The combination of liver transcriptomics and metabolomics analysis revealed that linoleic acid (LA) metabolism, a pivotal pathway in fatty acids metabolism was mainly manipulated during the induction and treatment of NAFLD. Further correlation analysis indicated that the gut microbes were associated with abnormal serum indicators and different LA metabolites. These metabolites are also closely related to serum indicators of NAFLD. An in vitro study verified that LA is an inducer of hepatic steatosis. The changes in transcription in the LA metabolism pathway could be normalized by E2 treatment. The metabolic perturbations of LA may directly and secondhand impact the development of NAFLD in postmenopausal individuals. This research focused on the sex-specific pathophysiology and treatment of NAFLD, providing more evidence for HRT and calling for the multitiered management of NAFLD.

Discovery of Bacterial Key Genes from 16S rRNA-Seq Profiles That Are Associated with the Complications of SARS-CoV-2 Infections and Provide Therapeutic Indications

SARS-CoV-2 infections, commonly referred to as COVID-19, remain a critical risk to both human life and global economies. Particularly, COVID-19 patients with weak immunity may suffer from different complications due to the bacterial co-infections/super-infections/secondary infections. Therefore, different variants of alternative antibacterial therapeutic agents are required to inhibit those infection-causing drug-resistant pathogenic bacteria. This study attempted to explore these bacterial pathogens and their inhibitors by using integrated statistical and bioinformatics approaches. By analyzing bacterial 16S rRNA sequence profiles, at first, we detected five bacterial genera and taxa (Bacteroides, Parabacteroides, Prevotella Clostridium, Atopobium, and Peptostreptococcus) based on differentially abundant bacteria between SARS-CoV-2 infection and control samples that are significantly enriched in 23 metabolic pathways. A total of 183 bacterial genes were found in the enriched pathways. Then, the top-ranked 10 bacterial genes (accB, ftsB, glyQ, hldD, lpxC, lptD, mlaA, ppsA, ppc, and tamB) were selected as the pathogenic bacterial key genes (bKGs) by their protein-protein interaction (PPI) network analysis. Then, we detected bKG-guided top-ranked eight drug molecules (Bemcentinib, Ledipasvir, Velpatasvir, Tirilazad, Acetyldigitoxin, Entreatinib, Digitoxin, and Elbasvir) by molecular docking. Finally, the binding stability of the top-ranked three drug molecules (Bemcentinib, Ledipasvir, and Velpatasvir) against three receptors (hldD, mlaA, and lptD) was investigated by computing their binding free energies with molecular dynamic (MD) simulation-based MM-PBSA techniques, respectively, and was found to be stable. Therefore, the findings of this study could be useful resources for developing a proper treatment plan against bacterial co-/super-/secondary-infection in SARS-CoV-2 infections.

PuRenDan alleviates type 2 diabetes mellitus symptoms by modulating the gut microbiota and its metabolites

ETHNOPHARMACOLOGICAL RELEVANCE

PuRenDan (PRD) is a traditional Chinese medicine formula comprising five herbs that have been traditionally used to treat type 2 diabetes mellitus (T2DM). While PRD has been shown to be effective in treating T2DM in clinical and animal studies, the mechanisms by which it works on the gut microbiome and metabolites related to T2DM are not well understood.

AIM OF THE STUDY

The objective of this study was to partially elucidate the mechanism of PRD in treating T2DM through analyses of the gut microbiota metagenome and metabolome.

MATERIALS AND METHODS

Sprague-Dawley rats were fed high-fat diets (HFDs) and injected with low-dose streptozotocin (STZ) to replicate T2DM models. Then the therapeutic effects of PRD were evaluated by measuring clinical markers such as blood glucose, insulin resistance (IR), lipid metabolism biomarkers (total cholesterol, low-density lipoprotein, non-esterified fatty acids, and triglycerides), and inflammatory factors (tumor necrosis factor alpha, interleukin-6 [IL-6], interferon gamma, and IL-1β). Colon contents were collected, and metagenomics, combined with ultra-high-performance liquid chromatography quadrupole time-of-flight mass spectrometry metabolic profiling, was performed to evaluate the effects of T2DM and PRD on gut microbiota and its metabolites in rats. Spearman analysis was used to calculate the correlation coefficient among different microbiota, clinical indices, and metabolites.

RESULTS

PRD exhibited significant improvement in blood glucose and IR, and reduced serum levels of lipid metabolism biomarkers and inflammatory factors. Moreover, the diversity and abundance of gut microbiota undergo significant changes in rats with T2DM that PRD was able to reverse. The gut microbiota associated with T2DM including Rickettsiaceae bacterium 4572_127, Psychrobacter pasteurii, Parabacteroides sp. CAG409, and Paludibacter propionicigenes were identified. The gut microbiota most closely related to PRD were Prevotella sp. 10(H), Parabacteroides sp. SN4, Flavobacteriales bacterium, Bacteroides massiliensis, Alistipes indistinctus, and Ruminococcus flavefaciens. Additionally, PRD regulated the levels of gut microbiota metabolites including pantothenic acid, 1-Methylhistamine, and 1-Methylhistidine; these affected metabolites were involved in pantothenate and coenzyme A biosynthesis, histidine metabolism, and secondary bile acid biosynthesis. Correlation analysis illustrated a close relationship among gut microbiota, its metabolites, and T2DM-related indexes.

CONCLUSION

Our study provides insights into the gut microbiota and its metabolites of PRD therapy for T2DM. It clarifies the role of gut microbiota and the metabolites in the pathogenesis of T2DM, highlighting the potential of PRD for the treatment of this disease.

Metformin, Cognitive Function, and Changes in the Gut Microbiome

The decline in cognitive function and the prevalence of neurodegenerative disorders are among the most serious threats to health in old age. The prevalence of dementia has reached 50 million people worldwide and has become a major public health problem. The causes of age-related cognitive impairment are multiple, complex, and difficult to determine. However, type 2 diabetes (T2D) is linked to an enhanced risk of cognitive impairment and dementia. Human studies have shown that patients with T2D exhibit dysbiosis of the gut microbiota. This dysbiosis may contribute to the development of insulin resistance and increased plasma lipopolysaccharide concentrations. Metformin medication mimics some of the benefits of calorie restriction and physical activity, such as greater insulin sensitivity and decreased cholesterol levels, and hence may also have a positive impact on aging in humans. According to recent human investigations, metformin might partially restore gut dysbiosis related to T2D. Likewise, some studies showed that metformin reduced the risk of dementia and improved cognition, although not all studies are concordant. Therefore, this review focused on those human studies describing the effects of metformin on the gut microbiome (specifically the changes in taxonomy, function, and circulating metabolomics), the changes in cognitive function, and their possible bidirectional implications.

Intestinal Dysbiosis in Subjects with Obesity from Western Mexico and Its Association with a Proinflammatory Profile and Disturbances of Folate (B9) and Carbohydrate Metabolism

Obesity is a public health problem with a growing prevalence worldwide. In Mexico, it is estimated that one out of three adults suffer from obesity. In these patients, the intestinal microbiota (IM) undergoes pathological changes that are associated with a dysbiotic state; however, the microbiota profile of adult subjects with obesity from western Mexico has not been described. To assess this, fecal samples were obtained from 65 participants (Obese = 38; Control = 27). The microbial composition was characterized by 16S rRNA amplicon sequencing. The IM of the group with obesity revealed a clear decrease in richness and diversity (p < 0.001), as well as a significant increase in proinflammatory bacterial groups, mainly genera belonging to the Negativicutes class, Escherichia/Shigella, and Prevotella. Likewise, an increase in short-chain fatty acid-producing bacteria was found, especially the genus Lachnoclostridium. Additionally, PICRUSt2 analysis showed a depletion of vitamin B9 metabolism and an increase in saccharolytic pathways. The IM of patients with obesity possesses a dysbiotic, proinflammatory environment, possibly contributing to lipogenesis and adiposity. Thus, assessing the IM will allow for a better understanding of the pathophysiology of metabolic diseases of high prevalence, such as obesity. These findings are described for the first time in the adult population of western Mexico.

Gut microbial ecology and exposome of a healthy Pakistani cohort

BACKGROUND

Pakistan is a multi-ethnic society where there is a disparity between dietary habits, genetic composition, and environmental exposures. The microbial ecology of healthy Pakistani gut in the context of anthropometric, sociodemographic, and dietary patterns holds interest by virtue of it being one of the most populous countries, and also being a Lower Middle Income Country (LMIC).

METHODS

16S rRNA profiling of healthy gut microbiome of normo-weight healthy Pakistani individuals from different regions of residence is performed with additional meta-data collected through filled questionnaires. The current health status is then linked to dietary patterns through [Formula: see text] test of independence and Generalized Linear Latent Variable Model (GLLVM) where distribution of individual microbes is regressed against all recorded sources of variability. To identify the core microbiome signature, a dynamic approach is used that considers into account species occupancy as well as consistency across assumed grouping of samples including organization by gender and province of residence. Fitting neutral modeling then revealed core microbiome that is selected by the environment.

RESULTS

A strong determinant of disparity is by province of residence. It is also established that the male microbiome is better adapted to the local niche than the female microbiome, and that there is microbial taxonomic and functional diversity in different ethnicities, dietary patterns and lifestyle habits. Some microbial genera, such as, Megamonas, Porphyromonas, Haemophilus, Klebsiella and Finegoldia showed significant associations with consumption of pickle, fresh fruits, rice, and cheese. Our analyses suggest current health status being associated with the diet, sleeping patterns, employment status, and the medical history.

CONCLUSIONS

This study provides a snapshot of the healthy core Pakistani gut microbiome by focusing on the most populous provinces and ethnic groups residing in predominantly urban areas. The study serves a reference dataset for exploring variations in disease status and designing personalized dietary and lifestyle interventions to promote gut health, particularly in LMICs settings.

Broccoli Improves Lipid Metabolism and Intestinal Flora in Mice with Type 2 Diabetes Induced by HFD and STZ Diet

Globally, type 2 diabetes (T2DM) is on the rise. Maintaining a healthy diet is crucial for both treating and preventing T2DM.As a common vegetable in daily diet, broccoli has antioxidant, anti-inflammatory and anticarcoma physiological activities. We developed a mouse model of type 2 diabetes and carried out a systematic investigation to clarify the function of broccoli in reducing T2DM symptoms and controlling intestinal flora. The findings demonstrated that broccoli could successfully lower fasting blood glucose (FBG), lessen insulin resistance, regulate lipid metabolism, lower the levels of TC, TG, LDL-C, and MDA, stop the expression of IL-1β and IL-6, and decrease the harm that diabetes causes to the pancreas, liver, fat, and other organs and tissues. Furthermore, broccoli altered the intestinal flora's makeup in mice with T2DM. At the genus level, the relative abundance of Allobaculum decreased, and that of Odoribacter and Oscillospira increased; At the family level, the relative abundances of Odoribacteraceae, Rikenellaceae and S24-7 decreased, while the relative abundances of Erysipelotrichaceae and Rikenellaceae increased.

Methodology for biomarker discovery with reproducibility in microbiome data using machine learning

BACKGROUND

In recent years, human microbiome studies have received increasing attention as this field is considered a potential source for clinical applications. With the advancements in omics technologies and AI, research focused on the discovery for potential biomarkers in the human microbiome using machine learning tools has produced positive outcomes. Despite the promising results, several issues can still be found in these studies such as datasets with small number of samples, inconsistent results, lack of uniform processing and methodologies, and other additional factors lead to lack of reproducibility in biomedical research. In this work, we propose a methodology that combines the DADA2 pipeline for 16s rRNA sequences processing and the Recursive Ensemble Feature Selection (REFS) in multiple datasets to increase reproducibility and obtain robust and reliable results in biomedical research.

RESULTS

Three experiments were performed analyzing microbiome data from patients/cases in Inflammatory Bowel Disease (IBD), Autism Spectrum Disorder (ASD), and Type 2 Diabetes (T2D). In each experiment, we found a biomarker signature in one dataset and applied to 2 other as further validation. The effectiveness of the proposed methodology was compared with other feature selection methods such as K-Best with F-score and random selection as a base line. The Area Under the Curve (AUC) was employed as a measure of diagnostic accuracy and used as a metric for comparing the results of the proposed methodology with other feature selection methods. Additionally, we use the Matthews Correlation Coefficient (MCC) as a metric to evaluate the performance of the methodology as well as for comparison with other feature selection methods.

CONCLUSIONS

We developed a methodology for reproducible biomarker discovery for 16s rRNA microbiome sequence analysis, addressing the issues related with data dimensionality, inconsistent results and validation across independent datasets. The findings from the three experiments, across 9 different datasets, show that the proposed methodology achieved higher accuracy compared to other feature selection methods. This methodology is a first approach to increase reproducibility, to provide robust and reliable results.

The therapeutic potential of dietary intervention: based on the mechanism of a tryptophan derivative-indole propionic acid on metabolic disorders

Tryptophan (TRP) contributes to individual immune homeostasis and good condition via three complex metabolism pathways (5-hydroxytryptamine (5-HT), kynurenine (KP), and gut microbiota pathway). Indole propionic acid (IPA), one of the TRP derivatives of the microbiota pathway, has raised more attention because of its impact on metabolic disorders. Here, we retrospect increasing evidence that TRP metabolites/IPA derived from its proteolysis impact host health and disease. IPA can activate the immune system through aryl hydrocarbon receptor (AHR) and/or Pregnane X receptor (PXR) as a vital mediator among diet-caused host and microbe cross-talk. Different levels of IPA in systemic circulation can predict the risk of NAFLD, T2DM, and CVD. IPA is suggested to alleviate cognitive impairment from oxidative damage, reduce gut inflammation, inhibit lipid accumulation and attenuate the symptoms of NAFLD, putatively enhance the intestinal epithelial barrier, and maintain intestinal homeostasis. Now, we provide a general description of the relationships between IPA and various physiological and pathological processes, which support an opportunity for diet intervention for metabolic diseases.

Evaluation of gut microbiota predictive potential associated with phenotypic characteristics to identify multifactorial diseases

Gut microbiota has been implicated in various clinical conditions, yet the substantial heterogeneity in gut microbiota research results necessitates a more sophisticated approach than merely identifying statistically different microbial taxa between healthy and unhealthy individuals. Our study seeks to not only select microbial taxa but also explore their synergy with phenotypic host variables to develop novel predictive models for specific clinical conditions.

DESIGN

We assessed 50 healthy and 152 unhealthy individuals for phenotypic variables (PV) and gut microbiota (GM) composition by 16S rRNA gene sequencing. The entire modeling process was conducted in the R environment using the Random Forest algorithm. Model performance was assessed through ROC curve construction.

RESULTS

We evaluated 52 bacterial taxa and pre-selected PV (p < 0.05) for their contribution to the final models. Across all diseases, the models achieved their best performance when GM and PV data were integrated. Notably, the integrated predictive models demonstrated exceptional performance for rheumatoid arthritis (AUC = 88.03%), type 2 diabetes (AUC = 96.96%), systemic lupus erythematosus (AUC = 98.4%), and type 1 diabetes (AUC = 86.19%).

CONCLUSION

Our findings underscore that the selection of bacterial taxa based solely on differences in relative abundance between groups is insufficient to serve as clinical markers. Machine learning techniques are essential for mitigating the considerable variability observed within gut microbiota. In our study, the use of microbial taxa alone exhibited limited predictive power for health outcomes, while the integration of phenotypic variables into predictive models substantially enhanced their predictive capabilities.

Type-2 Diabetes Mellitus and the Gut Microbiota: Systematic Review

The gut microbiota is a community situated in the gastrointestinal tract that consists of bacteria thriving and contributing to the functions of our body. It is heavily influenced by what individuals eat, as the quality, amount, and frequency of food consumed can favor and inhibit specific bacteria. Type-2 diabetes mellitus (T2DM) is a common but detrimental condition that arises from excessive hyperglycemia, leading to either insulin resistance or damage to the B-cells that produce insulin in the pancreas. A poor diet high in sugar and fats leads to hyperglycemia, and as this persists, it can lead to the development of T2DM. Both insulin resistance and damage to B-cells are greatly affected by the diet an individual consumes, but is there a more involved relationship between the gut microbiota and T2DM? This paper aimed to evaluate the changes in the gut microbiota in patients with T2DM and the impacts of the changes in gut microbiota. Bacteroides, Proteobacteria, Firmicutes, and Actinobacteria prevailed in patients with T2DM and healthy control, but their abundance varied greatly. There was also a significant decrease in bacteria like Lactobacilli spp.and F. prausnitizii associated with insulin resistance. High levels of BMI in patients with T2DM have also been associated with increased levels of A. muciniphilia, which has been associated with decreased fat metabolism and increased BMI. Metabolites such as butyrates and melatonin have also been identified as influencing the development and progression of T2DM. Testosterone levels have also been greatly influenced by the gut microbiota changes in T2DM, such that males with lower testosterone have a greater abundance of bacteria like Gemella, Lachnospiraceae, and Massiia. Identifying these changes and how they impact the body may lead to a treatment addressing insulin dysfunction and the changes that the altered gut microbiota leads to. Future research should address how treatment methods such as healthy diets, exercise, and anti-diabetics affect the gut microbiota and see if they influence sustained changes and reduced hyperglycemia.

Angelica polysaccharides relieve blood glucose levels in diabetic KKAy mice possibly by modulating gut microbiota: an integrated gut microbiota and metabolism analysis

BACKGROUND

Angelica polysaccharides (AP) have numerous benefits in relieving type 2 diabetes (T2D). However, the underlying mechanisms have yet to be fully understood. Recent many reports have suggested that altering gut microbiota can have adverse effects on the host metabolism and contribute to the development of T2D. Here, we successfully established the T2D model using the male KKAy mice with high-fat and high-sugar feed. Meanwhile, the male C57BL/6 mice were fed with a normal feed. T2D KKAy mice were fed either with or without AP supplementation. In each group, we measured the mice's fasting blood glucose, weight, and fasting serum insulin levels. We collected the cecum content of mice, the gut microbiota was analyzed by targeted full-length 16S rRNA metagenomic sequencing and metabolites were analyzed by untargeted-metabolomics.

RESULTS

We found AP effectively alleviated glycemic disorders of T2D KKAy mice, with the changes in gut microbiota composition and function. Many bacteria species and metabolites were markedly changed in T2D KKAy mice and reversed by AP. Additionally, 16 altered metabolic pathways affected by AP were figured out by combining metagenomic pathway enrichment analysis and metabolic pathway enrichment analysis. The key metabolites in 16 metabolic pathways were significantly associated with the gut microbial alteration. Together, our findings showed that AP supplementation could attenuate the diabetic phenotype. Significant gut microbiota and gut metabolite changes were observed in the T2D KKAy mice and AP intervention.

CONCLUSIONS

Administration of AP has been shown to improve the composition of intestinal microbiota in T2D KKAy mice, thus providing further evidence for the potential therapeutic application of AP in the treatment of T2D.

Recent insights of obesity-induced gut and adipose tissue dysbiosis in type 2 diabetes

An imbalance in microbial homeostasis, referred to as dysbiosis, is critically associated with the progression of obesity-induced metabolic disorders including type 2 diabetes (T2D). Alteration in gut microbial diversity and the abundance of pathogenic bacteria disrupt metabolic homeostasis and potentiate chronic inflammation, due to intestinal leakage or release of a diverse range of microbial metabolites. The obesity-associated shifts in gut microbial diversity worsen the triglyceride and cholesterol level that regulates adipogenesis, lipolysis, and fatty acid oxidation. Moreover, an intricate interaction of the gut-brain axis coupled with the altered microbiome profile and microbiome-derived metabolites disrupt bidirectional communication for instigating insulin resistance. Furthermore, a distinct microbial community within visceral adipose tissue is associated with its dysfunction in obese T2D individuals. The specific bacterial signature was found in the mesenteric adipose tissue of T2D patients. Recently, it has been shown that in Crohn's disease, the gut-derived bacterium Clostridium innocuum translocated to the mesenteric adipose tissue and modulates its function by inducing M2 macrophage polarization, increasing adipogenesis, and promoting microbial surveillance. Considering these facts, modulation of microbiota in the gut and adipose tissue could serve as one of the contemporary approaches to manage T2D by using prebiotics, probiotics, or faecal microbial transplantation. Altogether, this review consolidates the current knowledge on gut and adipose tissue dysbiosis and its role in the development and progression of obesity-induced T2D. It emphasizes the significance of the gut microbiota and its metabolites as well as the alteration of adipose tissue microbiome profile for promoting adipose tissue dysfunction, and identifying novel therapeutic strategies, providing valuable insights and directions for future research and potential clinical interventions.

Gut Microbiota Combined with Serum Metabolomics to Investigate the Hypoglycemic Effect of Actinidia arguta Leaves

Actinidia arguta leaves (AAL) are an excellent source of bioactive components for the food industry and possess many functional properties. However, the hypoglycemic effect and mechanism of AAL remain unclear. The aim of this work was to investigate the potential hypoglycemic effect of AAL and explore its possible mechanism using 16S rRNA sequencing and serum metabolomics in diabetic mice induced by high-fat feeding in combination with streptozotocin injection. A total of 25 flavonoids from AAL were isolated and characterized, and the contents of the extract from the AAL ranged from 0.14 mg/g DW to 8.97 mg/g DW. The compound quercetin (2) had the highest content of 8.97 ± 0.09 mg/g DW, and the compound kaempferol-3-O-(2'-O-D-glucopyl)-β-D-rutinoside (12) had the lowest content of 0.14 ± 0.01 mg/g DW. In vivo experimental studies showed that AAL reduced blood glucose and cholesterol levels, improved insulin sensitivity, and ameliorated oxidative stress and liver and kidney pathological damage. In addition, gut microbiota analysis found that AAL significantly reduced the F/B ratio, enriched the beneficial bacteria Bacteroides and Bifidobacterium, and inhibited the harmful bacteria Lactobacillus and Desulfovibrio, thereby playing an active role in intestinal imbalance. In addition, metabolomics analysis showed that AAL could improve amino acid metabolism and arachidonic acid metabolism, thereby exerting a hypoglycemic effect. This study confirmed that AAL can alleviate type 2 diabetes mellitus (T2DM) by regulating intestinal flora and interfering with related metabolic pathways, providing a scientific basis for its use as a dietary supplement and for further exploration of the mechanism of AAL against T2DM.

Evidence for the Beneficial Effects of Brazilian Native Fruits and Their By-Products on Human Intestinal Microbiota and Repercussions on Non-Communicable Chronic Diseases-A Review

Non-communicable chronic diseases (NCDs) are the most widespread cause of mortality worldwide. Intestinal microbiota balance can be altered by changes in the abundance and/or diversity of intestinal microbiota, indicating a role of intestinal microbiota in NCD development. This review discusses the findings of in vitro studies, pre-clinical studies and clinical trials on the effects of Brazilian native fruits, their by-products, as well as their bioactive compounds on human intestinal microbiota and NCD. The major bioactive compounds in Brazilian native fruits and their by-products, and the impacts of their administration on outcomes linked to intestinal microbiota modulation are discussed. Mechanisms of intestinal microbiota affecting NCD could be linked to the modulation of absorption and energy balance, immune and endocrine systems, and inflammatory response. Brazilian native fruits, such as acerola, açaí, baru, buriti, guava, jabuticaba, juçara, and passion fruit, have several bioactive compounds, soluble and insoluble fibers, and a variety of phenolic compounds, which are capable of changing these key mechanisms. Brazilian native fruits and their by-products can help to promote positive intestinal and systemic health benefits by driving alterations in the composition of the human intestinal microbiota, and increasing the production of distinct short-chain fatty acids and phenolic metabolites, thereby enhancing intestinal integrity and homeostasis. Evidence from available literature shows that the modulatory impacts of Brazilian native fruits and their by-products on the composition and metabolic activity of the intestinal microbiota could improve several clinical repercussions associated with NCD, reinforcing the influence of intestinal microbiota in extra-intestinal outcomes.

Composition of the intestinal microbiota and its variations between the second and third trimesters in women with gestational diabetes mellitus and without gestational diabetes mellitus

Objective

This study was designed to explore the composition of the intestinal microbiota and its longitudinal variation between the second trimester (T2) and the third trimester (T3) in women with gestational diabetes mellitus (GDM) and pregnant women with normal glucose tolerance.

Methods

This observational study was conducted at Peking Union Medical College Hospital (PUMCH). Women with GDM and pregnant women with normal glucose tolerance were enrolled in the study, and fecal samples were collected during T2 (weeks 24~28) and T3 (weeks 34~38). Fecal samples were analyzed from 49 women with GDM and 42 pregnant women with normal glucose tolerance. The 16S rRNA gene amplicon libraries were sequenced to analyze the microbiota and QIIME2 was used to analyze microbiome bioinformatics.

Results

The four dominant phyla that Firmicutes, Bacteroidetes, Actinobacteria and Proteobacteria which accomplish about 99% of the total relative abundance did not significantly change between the T2 and T3 in the GDM and healthy groups. At the genus level, the relative abundance of Scardovia (0 vs. 0.25%, P = 0.041) and Propionibacterium (0 vs. 0.29%, P = 0.041) increased significantly in the control group, but not in the GDM group. At the phylum level, the relative abundance of Firmicutes and Actinobacteria was significantly different between women with GDM and pregnant women with normal glucose tolerance in both T2 and T3. In T2 and T3, the relative abundances of unidentified_Lachnospiraceae, Blautia, and Parabacteroides were significantly higher in the GDM group than in the control group (P<0.05). The relative abundance of Bifidobacterium in the GDM group was lower than in the control group in both T2 and T3.

Conclusions

The intestinal microbiota composition was stable from T2 to T3 in the GDM and control groups; however, the intestinal microbiota composition was different between the two groups.

Food System Transformation and Gut Microbiota Transition: Evidence on Advancing Obesity, Cardiovascular Diseases, and Cancers-A Narrative Review

Food, a vital component of our daily life, is fundamental to our health and well-being, and the knowledge and practices relating to food have been passed down from countless generations of ancestors. Systems may be used to describe this extremely extensive and varied body of agricultural and gastronomic knowledge that has been gathered via evolutionary processes. The gut microbiota also underwent changes as the food system did, and these alterations had a variety of effects on human health. In recent decades, the gut microbiome has gained attention due to its health benefits as well as its pathological effects on human health. Many studies have shown that a person's gut microbiota partially determines the nutritional value of food and that diet, in turn, shapes both the microbiota and the microbiome. The current narrative review aims to explain how changes in the food system over time affect the makeup and evolution of the gut microbiota, advancing obesity, cardiovascular disease (CVD), and cancer. After a brief discussion of the food system's variety and the gut microbiota's functions, we concentrate on the relationship between the evolution of food system transformation and gut microbiota system transition linked to the increase of non-communicable diseases (NCDs). Finally, we also describe sustainable food system transformation strategies to ensure healthy microbiota composition recovery and maintain the host gut barrier and immune functions to reverse advancing NCDs.

Changes in the Gut Microbiota after the Use of Herbal Medicines in Overweight and Obese Individuals: A Systematic Review

BACKGROUND

Herbal medicine is a low-cost treatment and has been increasingly applied in obesity treatment. Gut microbiota (GM) is strongly associated with obesity pathogenesis.

METHODS

We conducted a systematic review guided by the question: "Does the use of herbal medicine change the GM composition in obese individuals?" Randomized clinical trials with obese individuals assessing the effects of herbal medicine intervention in GM were retrieved from the Medline, Embase, Scopus, Web of Science, and Cochrane Library databases, including the Cochrane Controlled Trials Register. Two reviewers independently extracted data using standardized piloted data extraction forms and assessed the study-level risk of bias using an Excel template of the Cochrane "Risk of bias" tool 2-RoB 2.

RESULTS

We identified 1094 articles in the databases. After removing duplicates and reading the title and abstract, 14 publications were fully evaluated, of which seven publications from six studies were considered eligible. The herbs analyzed were Moringa oleifera, Punica granatum, Scutellaria baicalensis, Schisandra chinensis, W-LHIT and WCBE. The analysis showed that Schisandra chinensis and Scutellaria baicalensis had significant effects on weight loss herbal intervention therapy composed by five Chinese herbal medicines Ganoderma lucidum, Coptis chinensis, Astragalus membranaceus, Nelumbo nucifera gaertn, and Fructus aurantii (W-LHIT) and white common bean extract (WCBE) on GM, but no significant changes in anthropometry and laboratory biomarkers.

CONCLUSIONS

Herbal medicine modulates GM and is associated with increased genera in obese individuals.

Combing fecal microbial community data to identify consistent obesity-specific microbial signatures and shared metabolic pathways

Obesity is associated with altered gut microbiome composition but data across different populations remain inconsistent. We meta-analyzed publicly available 16S-rRNA sequence datasets from 18 different studies and identified differentially abundant taxa and functional pathways of the obese gut microbiome. Most differentially abundant genera (Odoribacter, Oscillospira, Akkermansia, Alistipes, and Bacteroides) were depleted in obesity, indicating a deficiency of commensal microbes in the obese gut microbiome. From microbiome functional pathways, elevated lipid biosynthesis and depleted carbohydrate and protein degradation suggested metabolic adaptation to high-fat, low-carbohydrate, and low-protein diets in obese individuals. Machine learning models trained on the 18 studies were modest in predicting obesity with a median AUC of 0.608 using 10-fold cross-validation. The median AUC increased to 0.771 when models were trained in eight studies designed for investigating obesity-microbiome association. By meta-analyzing obesity-associated microbiota signatures, we identified obesity-associated depleted taxa that may be exploited to mitigate obesity and related metabolic diseases.

A Systematic Review on the Association between Obesity and Mood Disorders and the Role of Gut Microbiota

Obesity is a complex health condition that increases the susceptibility to developing cardiovascular diseases, diabetes, and numerous other metabolic health issues. The effect of obesity is not just limited to the conditions mentioned above; it is also seen to have a profound impact on the patient’s mental state, leading to the onset of various mental disorders, particularly mood disorders. Therefore, it is necessary to understand the mechanism underlying the crosstalk between obesity and mental disorders. The gut microbiota is vital in regulating and maintaining host physiology, including metabolism and neuronal circuits. Because of this newly developed understanding of gut microbiota role, here we evaluated the published diverse information to summarize the achievement in the field. In this review, we gave an overview of the association between obesity, mental disorders, and the role of gut microbiota there. Further new guidelines and experimental tools are necessary to understand the microbial contribution to regulate a balanced healthy life.

Key Stratification of Microbiota Taxa and Metabolites in the Host Metabolic Health-Disease Balance

Human gut microbiota seems to drive the interaction with host metabolism through microbial metabolites, enzymes, and bioactive compounds. These components determine the host health-disease balance. Recent metabolomics and combined metabolome-microbiome studies have helped to elucidate how these substances could differentially affect the individual host pathophysiology according to several factors and cumulative exposures, such as obesogenic xenobiotics. The present work aims to investigate and interpret newly compiled data from metabolomics and microbiota composition studies, comparing controls with patients suffering from metabolic-related diseases (diabetes, obesity, metabolic syndrome, liver and cardiovascular diseases, etc.). The results showed, first, a differential composition of the most represented genera in healthy individuals compared to patients with metabolic diseases. Second, the analysis of the metabolite counts exhibited a differential composition of bacterial genera in disease compared to health status. Third, qualitative metabolite analysis revealed relevant information about the chemical nature of metabolites related to disease and/or health status. Key microbial genera were commonly considered overrepresented in healthy individuals together with specific metabolites, e.g., Faecalibacterium and phosphatidylethanolamine; and the opposite, Escherichia and Phosphatidic Acid, which is converted into the intermediate Cytidine Diphosphate Diacylglycerol-diacylglycerol (CDP-DAG), were overrepresented in metabolic-related disease patients. However, it was not possible to associate most specific microbiota taxa and metabolites according to their increased and decreased profiles analyzed with health or disease. Interestingly, positive association of essential amino acids with the genera Bacteroides were observed in a cluster related to health, and conversely, benzene derivatives and lipidic metabolites were related to the genera Clostridium, Roseburia, Blautia, and Oscillibacter in a disease cluster. More studies are needed to elucidate the microbiota species and their corresponding metabolites that are key in promoting health or disease status. Moreover, we propose that greater attention should be paid to biliary acids and to microbiota-liver cometabolites and its detoxification enzymes and pathways.

Antibiotics in the pathogenesis of diabetes and inflammatory diseases of the gastrointestinal tract

Antibiotic use is increasing worldwide. However, the use of antibiotics is clearly associated with changes in gut microbiome composition and function, and perturbations have been identified as potential environmental risk factors for chronic inflammatory disorders of the gastrointestinal tract. In this Review, we examine the association between the use of antibiotics and the onset and development of both type 1 and type 2 diabetes, inflammatory bowel disease, including ulcerative colitis and Crohn's disease, as well as coeliac disease and eosinophilic oesophagitis. We discuss the key findings of epidemiological studies, provide mechanistic insights into the pathways by which the gut microbiota might contribute to these diseases, and assess clinical trials investigating the effects of antibiotics. Such studies indicate that antibiotic exposures, varying in type, timing and dosage, could explain differences in disease risk. There seems to be a critical window in early life in which perturbation of the microbiome has a substantial effect on disease development. Identifying the antibiotic-perturbed gut microbiota as a factor that contributes to the pathophysiology of these inflammatory disorders might stimulate new approaches to prevention, diagnosis and treatment.

Characterization of the Gut Microbiota in Urban Thai Individuals Reveals Enterotype-Specific Signature

Gut microbiota play vital roles in human health, utilizing indigestible nutrients, producing essential substances, regulating the immune system, and inhibiting pathogen growth. Gut microbial profiles are dependent on populations, geographical locations, and long-term dietary patterns resulting in individual uniqueness. Gut microbiota can be classified into enterotypes based on their patterns. Understanding gut enterotype enables us to interpret the capability in macronutrient digestion, essential substance production, and microbial co-occurrence. However, there is still no detailed characterization of gut microbiota enterotype in urban Thai people. In this study, we characterized the gut microbiota of urban Thai individuals by amplicon sequencing and classified their profiles into enterotypes, including Prevotella (EnP) and Bacteroides (EnB) enterotypes. Enterotypes were associated with lifestyle, dietary habits, bacterial diversity, differential taxa, and microbial pathways. Microbe-microbe interactions have been studied via co-occurrence networks. EnP had lower α-diversities than those in EnB. A correlation analysis revealed that the Prevotella genus, the predominant taxa of EnP, has a negative correlation with α-diversities. Microbial function enrichment analysis revealed that the biosynthesis pathways of B vitamins and fatty acids were significantly enriched in EnP and EnB, respectively. Interestingly, Ruminococcaceae, resistant starch degraders, were the hubs of both enterotypes, and strongly correlated with microbial diversity, suggesting that traditional Thai food, consisting of rice and vegetables, might be the important drivers contributing to the gut microbiota uniqueness in urban Thai individuals. Overall findings revealed the biological uniqueness of gut enterotype in urban Thai people, which will be advantageous for developing gut microbiome-based diagnostic tools.

Impact of gut-peripheral nervous system axis on the development of diabetic neuropathy

Diabetes is a chronic metabolic disease caused by a reduction in the production and/or action of insulin, with consequent development of hyperglycemia. Diabetic patients, especially those who develop neuropathy, presented dysbiosis, with an increase in the proportion of pathogenic bacteria and a decrease in the butyrate-producing bacteria. Due to this dysbiosis, diabetic patients presented a weakness of the intestinal permeability barrier and high bacterial product translocation to the bloodstream, in parallel to a high circulating levels of pro-inflammatory cytokines such as TNF-α. In this context, we propose here that dysbiosis-induced increased systemic levels of bacterial products, like lipopolysaccharide (LPS), leads to an increase in the production of pro-inflammatory cytokines, including TNF-α, by Schwann cells and spinal cord of diabetics, being crucial for the development of neuropathy.

Alterations of the gut microbiota in type 2 diabetics with or without subclinical hypothyroidism

Background

Diabetes and thyroid dysfunction are two closely related endocrine diseases. Increasing evidences show that gut microbiota plays an important role in both glucose metabolism and thyroid homeostasis. Meanwhile, copy number variation (CNV) of host salivary α-amylase gene (AMY1) has been shown to correlate with glucose homeostasis. Hence, we aim to characterize the gut microbiota and CNV of AMY1 in type 2 diabetes (T2D) patients with or without subclinical hypothyroidism (SCH).

Methods

High-throughput sequencing was used to analyze the gut microbiota of euthyroid T2D patients, T2D patients with SCH and healthy controls. Highly sensitive droplet digital PCR was used to measure AMY1 CN.

Results

Our results revealed that T2D patients have lower gut microbial diversity, no matter with or without SCH. The characteristic taxa of T2D patients were Coriobacteriales, Coriobacteriaceae, Peptostreptococcaceae, Pseudomonadaceae, Collinsella, Pseudomonas and Romboutsia. Meanwhile, Escherichia/Shigella, Lactobacillus_Oris, Parabacteroides Distasonis_ATCC_8503, Acetanaerobacterium, Lactonifactor, uncultured bacterium of Acetanaerobacterium were enriched in T2D patients with SCH. Moreover, serum levels of free triiodothyronine (FT3) and free thyroxine (FT4) in T2D patients were both negatively correlated with richness of gut microbiota. A number of specific taxa were also associated with clinical parameters at the phylum and genus level. In contrast, no correlation was found between AMY1 CN and T2D or T2D_SCH.

Conclusion

This study identified characteristic bacterial taxa in gut microbiota of T2D patients with or without SCH, as well as the taxa associated with clinical indices in T2D patients. These results might be exploited in the prevention, diagnosis and treatment of endocrine disorders in the future.

Extensive Summary of the Important Roles of Indole Propionic Acid, a Gut Microbial Metabolite in Host Health and Disease

Increasing evidence suggests that metabolites produced by the gut microbiota play a crucial role in host-microbe interactions. Dietary tryptophan ingested by the host enters the gut, where indole-like metabolites such as indole propionic acid (IPA) are produced under deamination by commensal bacteria. Here, we summarize the IPA-producing bacteria, dietary patterns on IPA content, and functional roles of IPA in various diseases. IPA can not only stimulate the expression of tight junction (TJ) proteins to enhance gut barrier function and inhibit the penetration of toxic factors, but also modulate the immune system to exert anti-inflammatory and antioxidant effects to synergistically regulate body physiology. Moreover, IPA can act on target organs through blood circulation to form the gut-organ axis, which helps maintain systemic homeostasis. IPA shows great potential for the diagnosis and treatment of various clinical diseases, such as NAFLD, Alzheimer's disease, and breast cancer. However, the therapeutic effect of IPA depends on dose, target organ, or time. In future studies, further work should be performed to explore the effects and mechanisms of IPA on host health and disease to further improve the existing treatment program.

Unique Pakistani gut microbiota highlights population-specific microbiota signatures of type 2 diabetes mellitus

Biogeographic variations in the gut microbiota are pivotal to understanding the global pattern of host-microbiota interactions in prevalent lifestyle-related diseases. Pakistani adults, having an exceptionally high prevalence of type 2 diabetes mellitus (T2D), are one of the most understudied populations in microbiota research to date. The aim of the present study is to examine the gut microbiota across individuals from Pakistan and other populations of non-industrialized and industrialized lifestyles with a focus on T2D. The fecal samples from 94 urban-dwelling Pakistani adults with and without T2D were profiled by bacterial 16S ribosomal RNA gene and fungal internal transcribed spacer (ITS) region amplicon sequencing and eubacterial qPCR, and plasma samples quantified for circulating levels of lipopolysaccharide-binding protein (LBP) and the activation ability of Toll-like receptor (TLR)-signaling. Publicly available datasets generated with comparable molecular methods were retrieved for comparative analysis of the bacterial microbiota. Overall, urbanized Pakistanis' gut microbiota was similar to that of transitional or non-industrialized populations, depleted in Akkermansiaceae and enriched in Prevotellaceae (dominated by the non-Westernized clades of Prevotella copri). The relatively high proportion of Atopobiaceae appeared to be a unique characteristic of the Pakistani gut microbiota. The Pakistanis with T2D had elevated levels of LBP and TLR-signaling in circulation as well as gut microbial signatures atypical of other populations, e.g., increased relative abundance of Libanicoccus/Parolsenella, limiting the inter-population extrapolation of gut microbiota-based classifiers for T2D. Taken together, our findings call for a more global representation of understudied populations to extend the applicability of microbiota-based diagnostics and therapeutics.

Gut microbiota dysbiosis as an inflammaging condition that regulates obesity-related retinopathy and nephropathy

Diabetes-specific microvascular disease is a leading cause of blindness, renal failure and nerve damage. Epidemiological data demonstrated that the high morbidity of T2DM occurs as a result of obesity and gradually develops into serious complications. To date, the mechanisms that underlie this observation are still ill-defined. In view of the effect of obesity on the gut microflora, Lepr^db/db mice underwent antibiotic treatment and microbiota transplants to modify the gut microbiome to investigate whether microbes are involved in the development of diabetic nephropathy (DN) and/or diabetic retinopathy (DR). The mouse feces were collected for bacterial 16S ribosomal RNA gene sequencing. Cytokines including TNF-α, TGF-β1, IFN-γ, IL-1β, IL-6, IL-17A, IL-10, and VEGFA were detected by enzyme-linked immunosorbent assay (ELISA), flow cytometry, real-time PCR and immunofluorescent assay. Eyes and kidney were collected for histopathological assay. Intestinal permeability was also detected using Evans Blue. The results showed that obesity influenced metabolic variables (including fast/fed glucose, insulin, and triglyceride), retinopathy and nephropathy, and the gut microbiota. Obesity mainly reduced the ratio of Bacteroidetes/Firmicutes and influenced relative abundance of Proteobacteria, Actinobacteria, and Spirochetes. Obesity also increased intestinal permeability, metabolic endotoxemia, cytokines, and VEGFA. Microbiota transplants confirm that obesity aggravates retinopathy and nephropathy through the gut microbiota. These findings suggest that obesity exacerbates retinopathy and nephropathy by inducing gut microbiota dysbiosis, which further enhanced intestinal permeability and chronic low-grade inflammation.

Intestinal microbiota regulates diabetes and cancer progression by IL-1β and NOX4 dependent signaling cascades

Diabetes changes the host microbiota, a condition known as dysbiosis. Dysbiosis is an important factor for the pathogenesis of diabetes and colorectal cancer (CRC). We aimed at identifying the microbial signature associated with diabetes and CRC; and identifying the signaling mechanism altered by dysbiosis and leading to CRC progression in diabetes. MKR mice that can spontaneously develop type 2 diabetes were used. For CRC induction, another subset of mice was treated with azoxymethane and dextran sulfate sodium. To identify the role of microbiota, microbiota-depleted mice were inoculated with fecal microbial transplant from diabetic and CRC mice. Further, a mouse group was treated with probiotics. At the end of the treatment, 16S rRNA sequencing was performed to identify microbiota in the fecal samples. Blood was collected, and colons were harvested for molecular, anatomical, and histological analysis. Our results show that diabetes is associated with a microbial signature characterized by reduction of butyrate-forming bacteria. This dysbiosis is associated with gastrointestinal complications reflected by a reduction in colon lengths. These changes are reversed upon treatment with probiotics, which rectified the observed dysbiosis. Inoculation of control mice with diabetic or cancer microbiota resulted in the development of increased number of polyps. Our data also show that inflammatory cytokines (mainly interleukin (IL)-1β) and NADPH oxidase (NOX)4 are over-expressed in the colon tissues of diabetic mice. Collectively our data suggest that diabetes is associated with dysbiosis characterized by lower abundance of butyrate-forming bacteria leading to over-expression of IL-1β and NOX4 leading to gastrointestinal complications and CRC.