The Role of Gut Microbiota in Obesity and Type 2 and Type 1 Diabetes Mellitus: New Insights into "Old" Diseases

Advances in the mechanism of metformin with wide-ranging effects on regulation of the intestinal microbiota

Metformin is of great focus because of its high safety, low side effects, and various effects other than lowering blood sugar, such as anti-inflammation, anti-tumor, and anti-aging. Studies have shown that metformin has a modulating effect on the composition and function of the intestinal microbiota other than acting on the liver. However, the composition of microbiota is complex and varies to some extent between species and individuals, and the experimental design of each study is also different. Multiple factors present a major obstacle to better comprehending the effects of metformin on the gut microbiota. This paper reviews the regulatory effects of metformin on the gut microbiota, such as increasing the abundance of genus Akkermansia, enriching short-chain fatty acids (SCFAs)-producing bacterial genus, and regulating gene expression of certain genera. The intestinal microbiota is a large and vital ecosystem in the human body and is considered to be the equivalent of an "organ" of the human body, which is highly relevant to human health and disease status. There are a lot of evidences that the gut microbiota is responsible for metformin's widespread effects. However, there are only a few systematic studies on this mechanism, and the specific mechanism is still unclear. This paper aims to summarize the possible mechanism of metformin in relation to gut microbiota.

Effect of Moringa oleifera leaf polysaccharide on the composition of intestinal microbiota in mice with dextran sulfate sodium-induced ulcerative colitis

Moringa oleifera (M. oleifera) is a natural plant that has excellent nutritional and medicinal potential. M. oleifera leaves (MOL) contain several bioactive compounds. The aim of this study was to evaluate the potential effect of MOL polysaccharide (MOLP) on intestinal flora in dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) mice. DSS-induced colitis was deemed to be a well-characterized experimental colitis model for investigating the protective effect of drugs on UC. In this study, we stimulated the experimental mice with DSS 4% for 7 days and prepared the high dose of MOLP (MOLP-H) in order to evaluate its effect on intestinal flora in DSS-induced UC mice, comparing three experimental groups, including the control, DSS model, and DSS + MOLP-H (100 mg/kg/day). At the end of the experiment, feces were collected, and the changes in intestinal flora in DSS-induced mice were analyzed based on 16S rDNA high throughput sequencing technology. The results showed that the Shannon, Simpson, and observed species indices of abundance decreased in the DSS group compared with the control group. However, the indices mentioned above were increased in the MOLP-H group. According to beta diversity analysis, the DSS group showed low bacterial diversity and the distance between the control and MOLP-H groups, respectively. In addition, compared with the control group, the relative abundance of Firmicutes in the DSS group decreased and the abundance of Helicobacter increased, while MOLP-H treatment improves intestinal health by enhancing the number of beneficial organisms, including Firmicutes, while reducing the number of pathogenic organisms, such as Helicobacter. In conclusion, these findings suggest that MOLP-H may be a viable prebiotic with health-promoting properties.

Designer probiotics: Opening the new horizon in diagnosis and prevention of human diseases

Probiotic microorganisms have been used for therapeutic purposes for over a century, and recent advances in biotechnology and genetic engineering have opened up new possibilities for developing therapeutic approaches using indigenous probiotic microorganisms. Diseases are often related to metabolic and immunological factors, which play a critical role in their onset. With the help of advanced genetic tools, probiotics can be modified to produce or secrete important therapeutic peptides directly into mucosal sites, increasing their effectiveness. One potential approach to enhancing human health is through the use of designer probiotics, which possess immunogenic characteristics. These genetically engineered probiotics hold promise in providing novel therapeutic options. In addition to their immunogenic properties, designer probiotics can also be equipped with sensors and genetic circuits, enabling them to detect a range of diseases with remarkable precision. Such capabilities may significantly advance disease diagnosis and management. Furthermore, designer probiotics have the potential to be used in diagnostic applications, offering a less invasive and more cost-effective alternative to conventional diagnostic techniques. This review offers an overview of the different functional aspects of the designer probiotics and their effectiveness on different diseases and also, we have emphasized their limitations and future implications. A comprehensive understanding of these functional attributes may pave the way for new avenues of prevention and the development of effective therapies for a range of diseases.

An Exploratory Review on the Hypoglycemic Action of Unani Anti-diabetic Drugs via Possible Modulation of Gut Microbiota

BACKGROUND AND AIM

Diabetes mellitus is a chronic, multi-factorial metabolic disorder and also an important public health issue that requires multi-dimensional therapeutic strategies for effective control. Unani herbs have long been used to effectively mitigate diabetes through various mechanisms. In recent years, it has been speculated that the alteration of gut microbiome ecology is potentially one of the important mechanisms through which the Unani drugs exert hypoglycemic action. This review aims at the trans-disciplinary interpretation of the holistic concepts of the Unani system of medicine and the molecular insights of contemporary medicine for novel strategies for diabetes management.

METHODOLOGY

We searched scientific databases such as PubMed, Google Scholar, and Science-Direct, etc. Unani classical texts (Urdu, Arabic, and Persian), and medical books, for diabetic control with Unani medicine through the gut microbiome.

RESULTS

Unani medicine defines, diabetes as a urinary system disorder disrupting the transformational faculty (Quwwat Mughayyira) in the gastrointestinal tract. The Unani system and contemporary biomedicine use different epistemology and ontology for describing diabetes through gutderived factors in whole-body glucose homeostasis. Unani Pharmaceutics have reported in clinical and preclinical (in vitro/ in vivo) trials in improving diabetes by altering gut microbiota composition, microvascular dysfunction, and inflammation. However, the preventive plan is the preservance of six essential factors (Asbāb Sitta Ḍarūriyya) as a lifestyle plan.

CONCLUSION

This is the first study on the integrative strategy about the hypoglycemic effects of Unani herbs that could serve as a prerogative novel approach for cost-effective, holistic, rationalistic, and multi-targeted diabetes management.

Precision Nutrition to Improve Risk Factors of Obesity and Type 2 Diabetes

PURPOSE OF REVIEW

Existing dietary and lifestyle interventions and recommendations, to improve the risk factors of obesity and type 2 diabetes with the target to mitigate this double global epidemic, have produced inconsistent results due to interpersonal variabilities in response to these conventional approaches, and inaccuracies in dietary assessment methods. Precision nutrition, an emerging strategy, tailors an individual's key characteristics such as diet, phenotype, genotype, metabolic biomarkers, and gut microbiome for personalized dietary recommendations to optimize dietary response and health. Precision nutrition is suggested to be an alternative and potentially more effective strategy to improve dietary intake and prevention of obesity and chronic diseases. The purpose of this narrative review is to synthesize the current research and examine the state of the science regarding the effect of precision nutrition in improving the risk factors of obesity and type 2 diabetes.

RECENT FINDINGS

The results of the research review indicate to a large extent significant evidence supporting the effectiveness of precision nutrition in improving the risk factors of obesity and type 2 diabetes. Deeper insights and further rigorous research into the diet-phenotype-genotype and interactions of other components of precision nutrition may enable this innovative approach to be adapted in health care and public health to the special needs of individuals. Precision nutrition provides the strategy to make individualized dietary recommendations by integrating genetic, phenotypic, nutritional, lifestyle, medical, social, and other pertinent characteristics about individuals, as a means to address the challenges of generalized dietary recommendations. The evidence presented in this review shows that precision nutrition markedly improves risk factors of obesity and type 2 diabetes, particularly behavior change.

Quality Management of Probiotics: Ensuring Safety and Maximizing Health Benefits

Consumption of probiotics, which are beneficial live microorganisms, has received a lot of attention because of their potential to improve health and wellness. Robust quality control measures are necessary to ensure the safety of probiotics and maximize their health effects. This review delves into the topic of quality management in probiotics, highlighting the significance of sticking to strict guidelines from manufacture to storage to distribution. Probiotic quality standards, Good Manufacturing Practices (GMP) implementation, quality control and testing techniques, and documentation and traceability systems are all discussed in detail. The importance of taking precautions to avoid microbial contamination, meeting all applicable regulations, and clearly marking and packaging probiotic products is also emphasized. In addition, it reviews the clinical evidence supporting the possible health advantages of probiotics and investigates the processes through which probiotics enhance health. The review continues by stressing the significance of educating and informing consumers about probiotics and their proper use in order to maximize health benefits. Probiotics' potential health benefits can be maximized and consumer faith in these helpful microbes can be bolstered by adopting thorough quality management measures to ensure their safety, efficacy, and consistency.

Association between Residential Greenness and Human Microbiota: Evidence from Multiple Countries

BACKGROUND

Greenness, referring to a measurement of the density of vegetated land (e.g., gardens, parks, grasslands), has been linked with many human health outcomes. However, the evidence on greenness exposure and human microbiota remains limited, inconclusive, drawn from specific regions, and based on only modest sample size.

OBJECTIVES

We aimed to study the association between greenness exposure and human microbial diversity and composition in a large sample across 34 countries and regions.

METHODS

We explored associations between residential greenness and human microbial alpha-diversity, composition, and genus abundance using data from 34 countries. Greenness exposure was assessed using the normalized difference vegetation index and the enhanced vegetation index mean values in the month before sampling. We used linear regression models to estimate the association between greenness and microbial alpha-diversity and tested the effect modification of age, sex, climate zone, and pet ownership of participants. Differences in microbial composition were tested by permutational multivariate analysis of variance based on Bray-Curtis distance and differential taxa were detected using the DESeq2 R package between two greenness exposure groups split by median values of greenness.

RESULTS

We found that higher greenness was significantly associated with greater richness levels in the palm and gut microbiota but decreased evenness in the gut microbiota. Pet ownership and climate zone modified some associations between greenness and alpha-diversity. Palm and gut microbial composition at the genus level also varied by greenness. Higher abundances of the genera Lactobacillus and Bifidobacterium, and lower abundances of the genera Anaerotruncus and Streptococcus, were observed in people with higher greenness levels.

DISCUSSION

These findings suggest that residential greenness was associated with microbial richness and composition in the human skin and gut samples, collected across different geographic contexts. Future studies may validate the observed associations and determine whether they correspond to improvements in human health. https://doi.org/10.1289/EHP12186.

Mechanistic Insights into Immune-Microbiota Interactions and Preventive Role of Probiotics Against Autoimmune Diabetes Mellitus

Recent studies on genetically susceptible individuals and animal models revealed the potential role of the intestinal microbiota in the pathogenesis of type 1 diabetes (T1D) through complex interactions with the immune system. T1D incidence has been increasing exponentially with modern lifestyle altering normal microbiota composition, causing dysbiosis characterized by an imbalance in the gut microbial community. Dysbiosis has been suggested to be a potential contributing factor in T1D. Moreover, several studies have shown the potential role of probiotics in regulating T1D through various mechanisms. Current T1D therapies target curative measures; however, preventive therapeutics are yet to be proven. This review highlights immune microbiota interaction and the immense role of probiotics and postbiotics as important immunological interventions for reducing the risk of T1D.

Influence of Bifidobacterium breve on the Glycaemic Control, Lipid Profile and Microbiome of Type 2 Diabetic Subjects: A Preliminary Randomized Clinical Trial

Type 2 diabetes mellitus (T2DM) is one of the most highly prevalent metabolic disorders worldwide. Uncontrolled T2DM can lead to other health threats such as cardiac arrest, lower-limb amputation, blindness, stroke, impaired kidney function, and microvascular and macrovascular complications. Many studies have demonstrated the association between gut microbiota and diabetes development and probiotic supplementation in improving glycemic properties in T2DM. The study aimed to evaluate the influence of Bifidobacterium breve supplementation on glycemic control, lipid profile, and microbiome of T2DM subjects. Forty participants were randomly divided into two groups, and they received probiotics (50 × 10⁹ CFU/day) or placebo interventions (corn starch; 10 mg/day) for 12 weeks. The changes in the blood-urea nitrogen (BUN), aspartate aminotransferase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), fasting blood sugar (FBS), glycated hemoglobin (HbA1c), total cholesterol (TC), triglycerides (TG), high-density lipoprotein (HDL), low-density lipoprotein (LDL), creatinine levels, and other factors such as body-mass index, visceral fat, body fat, and body weight were assessed at baseline and after 12 weeks. B. breve supplementation significantly reduced BUN, creatinine, LDL, TG, and HbA1c levels compared to the placebo group. Significant changes were observed in the microbiome of the probiotic-treated group compared to the placebo group. Firmicutes and proteobacteria were predominant in the placebo and probiotic-treated groups. Genera Streptococcus, Butyricicoccus, and species Eubacterium hallii were significantly reduced in the probiotic-treated group compared to the placebo. Overall results suggested that B. breve supplementation could prevent worsening of representative clinical parameters in T2DM subjects. The current study has limitations, including fewer subjects, a single probiotic strain, and fewer metagenomic samples for microbiome analysis. Therefore, the results of the current study require further validation using more experimental subjects.

Effect of Non-Nutritive Sweeteners on the Gut Microbiota

The human gut microbiota, a complex community of microorganisms living in the digestive tract, consists of more than 1500 species distributed in more than 50 different phyla, with 99% of bacteria coming from about 30-40 species. The colon alone, which contains the largest population of the diverse human microbiota, can harbor up to 100 trillion bacteria. The gut microbiota is essential in maintaining normal gut physiology and health. Therefore, its disruption in humans is often associated with various pathological conditions. Different factors can influence the composition and function of the gut microbiota, including host genetics, age, antibiotic treatments, environment, and diet. The diet has a marked effect, impacting the gut microbiota composition, beneficially or detrimentally, by altering some bacterial species and adjusting the metabolites produced in the gut environment. With the widespread use of non-nutritive sweeteners (NNS) in the diet, recent investigations have focused on their effect on the gut microbiota as a mediator of the potential impact generated by gastrointestinal-related disturbances, such as insulin resistance, obesity, and inflammation. We summarized the results from pre-clinical and clinical studies published over the last ten years that examined the single effects of the most consumed NNS: aspartame, acesulfame-K, sucralose, and saccharin. Pre-clinical studies have given conflicting results for various reasons, including the administration method and the differences in metabolism of the same NNS among the different animal species. A dysbiotic effect of NNS was observed in some human trials, but many other randomized controlled trials reported a lack of significant impacts on gut microbiota composition. These studies differed in the number of subjects involved, their dietary habits, and their lifestyle; all factors related to the baseline composition of gut microbiota and their response to NNS. The scientific community still has no unanimous consensus on the appropriate outcomes and biomarkers that can accurately define the effects of NNS on the gut microbiota.

Metagenomic Shotgun Sequencing Reveals Specific Human Gut Microbiota Associated with Insulin Resistance and Body Fat Distribution in Saudi Women

(1) Background: Gut microbiota dysbiosis may lead to diseases such as insulin resistance and obesity. We aimed to investigate the relationship between insulin resistance, body fat distribution, and gut microbiota composition. (2) Methods: The present study included 92 Saudi women (18–25 years) with obesity (body mass index (BMI) ≥ 30 kg/m2, n = 44) and with normal weight (BMI 18.50–24.99 kg/m2, n = 48). Body composition indices, biochemical data, and stool samples were collected. The whole-genome shotgun sequencing technique was used to analyze the gut microbiota. Participants were divided into subgroups stratified by the homeostatic model assessment for insulin resistance (HOMA-IR) and other adiposity indices. (3) Results: HOMA-IR was inversely correlated with Actinobacteria (r = −0.31, p = 0.003), fasting blood glucose was inversely correlated with Bifidobacterium kashiwanohense (r = −0.22, p = 0.03), and insulin was inversely correlated with Bifidobacterium adolescentis (r = −0.22, p = 0.04). There were significant differences in α- and β-diversities in those with high HOMA-IR and waist–hip ratio (WHR) compared to low HOMA-IR and WHR (p = 0.02, 0.03, respectively). (4) Conclusions: Our findings highlight the relationship between specific gut microbiota at different taxonomic levels and measures of glycemic control in Saudi Arabian women. Future studies are required to determine the role of the identified strains in the development of insulin resistance.

Microbiome Changes in Pregnancy Disorders

The human microbiota comprises all microorganisms, such as bacteria, fungi, and viruses, found within a specific environment that live on our bodies and inside us. The last few years have witnessed an explosion of information related to the role of microbiota changes in health and disease. Even though the gut microbiota is considered the most important in maintaining our health, other regions of the human body, such as the oral cavity, lungs, vagina, and skin, possess their own microbiota. Recent work suggests a correlation between the microbiota present during pregnancy and pregnancy complications. The aim of our literature review was to provide a broad overview of this growing and important topic. We focused on the most significant changes in the microbiota in the four more common obstetric diseases affecting women's health. Thus, our attention will be focused on hypertensive disorders, gestational diabetes mellitus, preterm birth, and recurrent miscarriage. Pregnancy is a unique period in a woman's life since the body undergoes different adaptations to provide an optimal environment for fetal growth. Such changes also involve all the microorganisms, which vary in composition and quantity during the three trimesters of gestation. In addition, special attention will be devoted to the potential and fundamental advances in developing clinical applications to prevent and treat those disorders by modulating the microbiota to develop personalized therapies for disease prevention and tailored treatments.

Efficacy of lyophilised bacteria-rich faecal sediment and supernatant with reduced bacterial count for treating patients with Clostridioides difficile Infection - A novel method for capsule faecal microbiota transfer

Background and aims

Faecal microbiota transfer (FMT) has managed to earn its place in the Clostridioides difficile infection (CDI) guidelines by having comparable efficacy and recurrence rate of fidaxomicin. After more than 100 successful FMT administration through nasogastric tube, we started using hard gelatine capsules filled with lyophilised faecal sediment and supernatant. Our main question was whether uncoated capsules (containing faecal sediment or supernatant) are comparable to the widely used nasogastric tubes in CDI. We also investigated the effect of storage and time on the survival rate of bacteria in the samples.

Methods

We compared the efficacy of our capsules to other treatment options of CDI at the Department of Infectology at the University of Pécs (Hungary). For our study, stool was collected from a single donor. We treated 10 patients with relapsing CDI, 5 of them received supernatant, 5 received sediment. Donor samples were stored on 4 different temperatures and tested to determine the survival rates of bacteria. As pilot projects, we also assessed the changes of bacterial taxa, protein- and lipid compositions. Moreover, we selected 4 patients to compare their samples prior and after FMT by using microbiome (16S amplicon sequencing), protein, and lipid analyses.

Results

4 out of the 5 patients who received supernatant became symptomless within 2 days after FMT. In the sediment group 3 out of 5 patients were cured from CDI. Comparing the supernatant to the sediment, we found significantly lower number of colony-forming units in the supernatant. We found that -80°C is the most suitable temperature to store the samples. The stool lipid profiles of recipients showed a more diverse composition after FMT, and changes in the stool protein profiles were observed as well. In the microbiome analysis, we observed an increase in the alpha diversity after FMT.

Conclusions

Our study of 10 patients showed good efficacy of lyophilised faecal supernatant using capsules. The single donor approach proved to be effective in our investigation. A significantly lower CFU number was sufficient for the effect, the separation can be achieved by widely available instruments. For storage temperature, -20°C was sufficient in our clinical practice.

Plasma Prostaglandin E2 Metabolite Levels Predict Type 2 Diabetes Status and One-Year Therapeutic Response Independent of Clinical Markers of Inflammation

Over half of patients with type 2 diabetes (T2D) are unable to achieve blood glucose targets despite therapeutic compliance, significantly increasing their risk of long-term complications. Discovering ways to identify and properly treat these individuals is a critical problem in the field. The arachidonic acid metabolite, prostaglandin E₂ (PGE₂), has shown great promise as a biomarker of β-cell dysfunction in T2D. PGE₂ synthesis, secretion, and downstream signaling are all upregulated in pancreatic islets isolated from T2D mice and human organ donors. In these islets, preventing β-cell PGE₂ signaling via a prostaglandin EP3 receptor antagonist significantly improves their glucose-stimulated and hormone-potentiated insulin secretion response. In this clinical cohort study, 167 participants, 35 non-diabetic, and 132 with T2D, were recruited from the University of Wisconsin Hospital and Clinics. At enrollment, a standard set of demographic, biometric, and clinical measurements were performed to quantify obesity status and glucose control. C reactive protein was measured to exclude acute inflammation/illness, and white cell count (WBC), erythrocyte sedimentation rate (ESR), and fasting triglycerides were used as markers of systemic inflammation. Finally, a plasma sample for research was used to determine circulating PGE₂ metabolite (PGEM) levels. At baseline, PGEM levels were not correlated with WBC and triglycerides, only weakly correlated with ESR, and were the strongest predictor of T2D disease status. One year after enrollment, blood glucose management was assessed by chart review, with a clinically-relevant change in hemoglobin A1c (HbA1c) defined as ≥0.5%. PGEM levels were strongly predictive of therapeutic response, independent of age, obesity, glucose control, and systemic inflammation at enrollment. Our results provide strong support for future research in this area.

Pathophysiology of Type 1 Diabetes and Gut Microbiota Role

Type 1 diabetes (T1D) is a multifactorial autoimmune disease driven by T-cells against the insulin-producing islet β-cells, resulting in a marked loss of β-cell mass and function. Although a genetic predisposal increases susceptibility, the role of epigenetic and environmental factors seems to be much more significant. A dysbiotic gut microbial profile has been associated with T1D patients. Moreover, new evidence propose that perturbation in gut microbiota may influence the T1D onset and progression. One of the prominent features in clinically silent phase before the onset of T1D is the presence of a microbiota characterized by low numbers of commensals butyrate producers, thus negatively influencing the gut permeability. The loss of gut permeability leads to the translocation of microbes and microbial metabolites and could lead to the activation of immune cells. Moreover, microbiota-based therapies to slow down disease progression or reverse T1D have shown promising results. Starting from this evidence, the correction of dysbiosis in early life of genetically susceptible individuals could help in promoting immune tolerance and thus in reducing the autoantibodies production. This review summarizes the associations between gut microbiota and T1D for future therapeutic perspectives and other exciting areas of research.

Urine metabolomics and microbiome analyses reveal the mechanism of anti-tuberculosis drug-induced liver injury, as assessed for causality using the updated RUCAM: A prospective study

Background

Anti-tuberculosis drug-induced liver injury (ATB-DILI) is one of the most common adverse reactions that brings great difficulties to the treatment of tuberculosis. Thus, early identification of individuals at risk for ATB-DILI is urgent. We conducted a prospective cohort study to analyze the urinary metabolic and microbial profiles of patients with ATB-DILI before drug administration. And machine learning method was used to perform prediction model for ATB-DILI based on metabolomics, microbiome and clinical data.

Methods

A total of 74 new TB patients treated with standard first-line anti-TB treatment regimens were enrolled from West China Hospital of Sichuan University. Only patients with an updated RUCAM score of 6 or more were accepted in this study. Nontargeted metabolomics and microbiome analyses were performed on urine samples prior to anti-tuberculosis drug ingestion to screen the differential metabolites and microbes between the ATB-DILI group and the non-ATB-DILI group. Integrating electronic medical records, metabolomics, and microbiome data, four machine learning methods was used, including random forest algorithm, artificial neural network, support vector machine with the linear kernel and radial basis function kernel.

Results

Of all included patients, 69 patients completed follow-up, with 16 (23.19%) patients developing ATB-DILI after antituberculosis treatment. Finally, 14 ATB-DILI patients and 30 age- and sex-matched non-ATB-DILI patients were subjected to urinary metabolomic and microbiome analysis. A total of 28 major differential metabolites were screened out, involving bile secretion, nicotinate and nicotinamide metabolism, tryptophan metabolism, ABC transporters, etc. Negativicoccus and Actinotignum were upregulated in the ATB-DILI group. Multivariate analysis also showed significant metabolic and microbial differences between the non-ATB-DILI and severe ATB-DILI groups. Finally, the four models showed high accuracy in predicting ATB-DILI, with the area under the curve of more than 0.85 for the training set and 1 for the validation set.

Conclusion

This study characterized the metabolic and microbial profile of ATB-DILI risk individuals before drug ingestion for the first time. Metabolomic and microbiome characteristics in patient urine before anti-tuberculosis drug ingestion may predict the risk of liver injury after ingesting anti-tuberculosis drugs. Machine learning algorithms provides a new way to predict the occurrence of ATB-DILI among tuberculosis patients.

Helminth infection and helminth-derived products: A novel therapeutic option for non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is closely related to obesity, diabetes, and metabolic syndrome (MetS), and it has become the most common chronic liver disease. Helminths have co-evolved with humans, inducing multiple immunomodulatory mechanisms to modulate the host’s immune system. By using their immunomodulatory ability, helminths and their products exhibit protection against various autoimmune and inflammatory diseases, including obesity, diabetes, and MetS, which are closely associated with NAFLD. Here, we review the pathogenesis of NAFLD from abnormal glycolipid metabolism, inflammation, and gut dysbiosis. Correspondingly, helminths and their products can treat or relieve these NAFLD-related diseases, including obesity, diabetes, and MetS, by promoting glycolipid metabolism homeostasis, regulating inflammation, and restoring the balance of gut microbiota. Considering that a large number of clinical trials have been carried out on helminths and their products for the treatment of inflammatory diseases with promising results, the treatment of NAFLD and obesity-related diseases by helminths is also a novel direction and strategy.

Alterations of the Composition and Neurometabolic Profile of Human Gut Microbiota in Major Depressive Disorder

Major depressive disorder (MDD) is among the most prevalent mental disorders worldwide. Factors causing the pathogenesis of MDD include gut microbiota (GM), which interacts with the host through the gut–brain axis. In previous studies of GM in MDD patients, 16S rRNA sequencing was used, which provided information about composition but not about function. In our study, we analyzed whole metagenome sequencing data to assess changes in both the composition and functional profile of GM. We looked at the GM of 36 MDD patients, compared with that of 38 healthy volunteers. Comparative taxonomic analysis showed decreased abundances of Faecalibacterium prausnitzii, Roseburia hominis, and Roseburia intestinalis, and elevated abundances of Escherichia coli and Ruthenibacterium lactatiformans in the GM of MDD patients. We observed decreased levels of bacterial genes encoding key enzymes involved in the production of arginine, asparagine, glutamate, glutamine, melatonin, acetic, butyric and conjugated linoleic acids, and spermidine in MDD patients. These genes produced signature pairs with Faecalibacterium prausntizii and correlated with decreased levels of this species in the GM of MDD patients. These results show the potential impact of the identified biomarker bacteria and their metabolites on the pathogenesis of MDD, and should be confirmed in future metabolomic studies.

Feсal microbiota transplantation in the format of complex therapy in obesive siblings: clinical case

Obesity and associated metabolic diseases are often accompanied by changes in the gut microbiota leading to metagenome gene diversity decrease. Fecal microbiota transplantation (FMT) is one of the most effective methods for correcting the  intestinal microflora. FMT obtained from healthy donors has been proven to be an effective treatment of infections caused by Clostridium difficile. The use of FMT for correction of metabolic disorders is promising, however, data on its application is limited and has contradictory results. In our work, two patients (siblings) presented with obesity grade II and various types of diabetes mellitus (DM): the older brother (44 years old) with diabetes mellitus type 2 (DM 2), a younger brother (39 years old) with diabetes mellitus type 1 (DM 1). Both patients underwent FMT as part of complex antidiabetic therapy. During the course of treatment, a decrease in body weight was noted in both patients (4–5 kg for the first month of observation, then -1–2 kg per month). One year after FMT, a patient with type 2 diabetes showed a decrease in the severity of insulin resistance (IR), measured by the hyperinsulinemic euglycemic clamp test (initial M-index 2.42 mg/kg*min, after 1 year — 3.83 mg/kg* min) as well as the maintenance of satisfactory carbohydrate metabolism compensation against the diminishing the hypoglycemic therapy. In a patient with DM 1, no significant dynamics of carbohydrate exchange indices, including detected glycated hemoglobin (HbA1c), insulin dose and IR were during the observation period. Metagenomic sequencing of stool samples (n = 20) collected from both patients before and within 1 year after FMT showed no significant changes in the taxonomic profile of the microbiota at the level of microbial families. Metabolomic analysis of the composition of feces showed no directed changes in the composition of metabolites after the FMT procedure, the nature of changes within the samples from each patient during the entire study period was random. Thus, FMT had no effect on the course of DM1, but served as a starting point for weight loss and improvement glucose profile in DM2. However, convincing data confirming a causal correlation between FMT and improvement in the course of T2DM have not been obtained.

The mechanism of berberine alleviating metabolic disorder based on gut microbiome

With socioeconomic advances and improved living standards, metabolic syndrome has increasingly come into the attention. In recent decades, a growing number of studies have shown that the gut microbiome and its metabolites are closely related to the occurrence and development of many metabolic diseases, and play an important role that cannot be ignored, for instance, obesity, type 2 diabetes (T2DM), non-alcoholic fatty liver disease (NAFLD), cardiovascular disease and others. The correlation between gut microbiota and metabolic disorder has been widely recognized. Metabolic disorder could cause imbalance in gut microbiota, and disturbance of gut microbiota could aggravate metabolic disorder as well. Berberine (BBR), as a natural ingredient, plays an important role in the treatment of metabolic disorder. Studies have shown that BBR can alleviate the pathological conditions of metabolic disorders, and the mechanism is related to the regulation of gut microbiota: gut microbiota could regulate the absorption and utilization of berberine in the body; meanwhile, the structure and function of gut microbiota also changed after intervention by berberine. Therefore, we summarize relevant mechanism research, including the expressions of nitroreductases-producing bacteria to promote the absorption and utilization of berberine, strengthening intestinal barrier function, ameliorating inflammation regulating bile acid signal pathway and axis of bacteria-gut-brain. The aim of our study is to clarify the therapeutic characteristics of berberine further and provide the theoretical basis for the regulation of metabolic disorder from the perspective of gut microbiota.

Changes in the Gut Microbiome and Pathologies in Pregnancy

Pregnancy is a special period in a woman's life when her organism undergoes multiple physiological changes so that the fetus has optimal conditions for growth and development. These include modifications in the composition of the microbiome that occur between the first and third trimesters of pregnancy. There is an increase in Akkermansia, Bifidobacterium, and Firmicutes, which have been associated with an increase in the need for energy storage. The growth in Proteobacteria and Actinobacteria levels has a protective effect on both the mother and the fetus via proinflammatory mechanisms. The aim of the study is to review the research on the relationship between the mother's intestinal microbiome and gestational pathologies. Changes in the maternal gut microbiome is probably one of the mechanisms that occurs in various pregnancy diseases such as preeclampsia, fetal growth restriction, gestational diabetes mellitus, excessive gestational weight gain, and premature birth. For this reason, it seems vital to pay attention to certain interventions that can benefit the affected patients both in the short term, by preventing complications during pregnancy, and in the long term, as one of the mechanisms occurring in various gestational diseases is dysbiosis of the maternal intestinal flora.

Positive Effects of α-Lactalbumin in the Management of Symptoms of Polycystic Ovary Syndrome

To date, the involvement of α-Lactalbumin (α-LA) in the management of polycystic ovary syndrome (PCOS) refers to its ability to improve intestinal absorption of natural molecules like inositols, overcoming the inositol resistance. However, due to its own aminoacidic building blocks, α-LA is involved in various biological processes that can open new additional applications. A great portion of women with PCOS exhibit gastrointestinal dysbiosis, which is in turn one of the triggering mechanisms of the syndrome. Due to its prebiotic effect, α-LA can recover dysbiosis, also improving the insulin resistance, obesity and intestinal inflammation frequently associated with PCOS. Further observations suggest that altered gut microbiota negatively influence mental wellbeing. Depressive mood and low serotonin levels are indeed common features of women with PCOS. Thanks to its content of tryptophan, which is the precursor of serotonin, and considering the strict link between gut and brain, using α-LA contributes to preserving mental well-being by maintaining high levels of serotonin. In addition, considering women with PCOS seeking pregnancy, both altered microbiota and serotonin levels can induce later consequences in the offspring. Therefore, a deeper knowledge of potential applications of α-LA is required to transition to preclinical and clinical studies extending its therapeutic advantages in PCOS.

Gut microbiota interactions with anti-diabetic medications and pathogenesis of type 2 diabetes mellitus

Microorganisms including bacteria, viruses, protozoa, and fungi living in the gastrointestinal tract are collectively known as the gut microbiota. Dysbiosis is the imbalance in microbial composition on or inside the body relative to healthy state. Altered Firmicutes to Bacteroidetes ratio and decreased abundance of Akkermansia muciniphila are the predominant gut dysbiosis associated with the pathogenesis of type 2 diabetes mellitus (T2DM) and metabolic syndrome. Pathophysiological mechanisms linking gut dysbiosis, and metabolic diseases and their complications include altered metabolism of short-chain fatty acids and bile acids, interaction with gut hormones, increased gut microbial metabolite trimethylamine-N-oxide, bacterial translocation/Leaky gut syndrome, and endotoxin production such as lipopolysaccharides. The association between the gut microbiota and glycemic agents, however, is much less understood and is the growing focus of research and conversation. Recent studies suggest that the gut microbiota and anti-diabetic medications are interdependent on each other, meaning that while anti-diabetic medications alter the gut microbiota, the gut microbiota also alters the efficacy of anti-diabetic medications. With increasing evidence regarding the significance of gut microbiota, it is imperative to review the role of gut microbiota in the pathogenesis of T2DM. This review also discusses the interaction between gut microbiota and the various medications used in the treatment of T2DM.

Obesity aggravates contact hypersensitivity reaction in mice

BACKGROUND

Obesity is associated with chronic, low-grade inflammation in tissues and predisposes to various complications, including inflammatory skin diseases. However, the link between obesity and contact hypersensitivity (CHS) is not fully understood.

OBJECTIVES

We sought to determine the influence of obesity on T helper 1 (Th1)-mediated CHS.

METHODS

The activity/phenotype/cytokine profile of the immune cells was tested in vivo and in vitro. Using quantitative polymerase chain reaction (qPCR) and fecal microbiota transplantation (FMT), we tested the role of a high-fat diet (HFD)-induced gut microbiota (GM) dysbiosis in increasing the effects of CHS.

RESULTS

Exacerbated CHS correlates with an increased inflammation-inducing GM in obese mice. We showed a proinflammatory milieu in the subcutaneous adipose tissue of obese mice, accompanied by proinflammatory CD4+ T cells and dendritic cells in skin draining lymph nodes and spleen. Obese interleukin (IL)-17A-/-B6 mice are protected from CHS aggravation, suggesting the importance of IL-17A in CHS aggravation in obesity.

CONCLUSIONS

Obesity creates a milieu that induces more potent CHS-effector cells but does not have effects on already activated CHS-effector cells. IL-17A is essential for the pathogenesis of enhanced CHS during obesity. Our study provides novel knowledge about antigen-specific responses in obesity, which may help with the improvement of existing treatment and/or in designing novel treatment for obesity-associated skin disorders.

Predictive and Prognostic Roles of Gut Microbial Variation in Liver Transplant

Patients undergoing liver transplant (LTX) typically confront a challenging postoperative journey. A dysbiotic gut microbiome is associated with the development of complications, including post-LTX allograft rejection, metabolic diseases and de novo or recurrent cancer. A major explanation of this are the bipartite interactions between the gut microbiota and host immunity, which modulates the alloimmune response towards the liver allograft. Furthermore, bacterial translocation from dysbiosis causes pathogenic changes in the concentrations of microbial metabolites like lipopolysaccharides, short-chain fatty acids (SCFAs) and Trimethylamine-N-Oxide, with links to cardiovascular disease development and diabetes mellitus. Gut dysbiosis also disrupts bile acid metabolism, with implications for various post-LTX metabolic diseases. Certain taxonomy of microbiota such as lactobacilli, F.prausnitzii and Bacteroides appear to be associated with these undesired outcomes. As such, an interesting but as yet unproven hypothesis exists as to whether induction of a “beneficial” composition of gut microbiota may improve prognosis in LTX patients. Additionally, there are roles of the microbiome as predictive and prognostic indicators for clinicians in improving patient care. Hence, the gut microbiome represents an exceptionally exciting avenue for developing novel prognostic, predictive and therapeutic applications.

The Microbiome and Gut Endocannabinoid System in the Regulation of Stress Responses and Metabolism

The endocannabinoid system, with its receptors and ligands, is present in the gut epithelium and enteroendocrine cells, and is able to modulate brain functions, both indirectly through circulating gut-derived factors and directly through the vagus nerve, finally acting on the brain’s mechanisms regarding metabolism and behavior. The gut endocannabinoid system also regulates gut motility, permeability, and inflammatory responses. Furthermore, microbiota composition has been shown to influence the activity of the endocannabinoid system. This review examines the interaction between microbiota, intestinal endocannabinoid system, metabolism, and stress responses. We hypothesize that the crosstalk between microbiota and intestinal endocannabinoid system has a prominent role in stress-induced changes in the gut-brain axis affecting metabolic and mental health. Inter-individual differences are commonly observed in stress responses, but mechanisms underlying resilience and vulnerability to stress are far from understood. Both gut microbiota and the endocannabinoid system have been implicated in stress resilience. We also discuss interventions targeting the microbiota and the endocannabinoid system to mitigate metabolic and stress-related disorders.

Association between residential greenness and gut microbiota in Chinese adults

BACKGROUND

A growing body of studies have reported the health benefits of greenness. However, less is known about the potential beneficial effects of residential greenness on gut microbiota, which is essential to human health. In this study, we aim to examine the association between residential greenness and gut microbiota in a population-based cohort study.

METHODS

We included 1758 participants based on the China Multi-Ethnic Cohort (CMEC) study and collected their stool samples for 16S sequencing to derive gut microbiota data. Residential greenness was estimated using the satellite-based data on enhanced vegetation index (EVI) and the normalized differential vegetation index (NDVI) in circular buffers of 250 m, 500 m, and 1000 m. The relationships between residential greenness levels and the composition of gut microbiota, measured by standardized α-diversity and taxonomic composition, were assessed using linear regression and Spearman correlation weighted by generalized propensity scores.

RESULTS

Higher greenness levels were significantly positively associated with standardized α-diversity. Per interquartile range (IQR) increase of EVI and NDVI in the circular buffer of 250 m were associated with the increments of 0.995(95% confidence interval (CI): 0.212-1.778) and 0.653(95% CI: 0.160-1.146) in the standardized Shannon index. For the taxonomic composition of gut microbiota, higher greenness levels were significantly correlated with 29 types of microbial taxonomic composition. NDVI in the circular buffer of 250 m was associated with increased Firmicutes (r = 0.102, adjusted p value = 0.004), which was the dominant composition in the gut microbiota.

CONCLUSIONS

Increased amounts of residential greenness may support healthy gut microbiota by benignly altering their composition. These findings suggested that green spaces should be designed to support diverse gut microbiota and ultimately optimize health benefits.

Short-Term Metformin Treatment Enriches Bacteroides dorei in an Obese Liver Steatosis Zucker Rat Model

Obesity is the leading cause of health-related diseases in the United States and World. Previously, we reported that obesity can change gut microbiota using the Zucker rat model. Metformin is an oral anti-hyperglycemic agent approved by the FDA to treat type 2 diabetes (T2D) in adults and children older than 10 years of age. The correlation of short-term metformin treatment and specific alterations to the gut microbiota in obese models is less known. Short-term metformin has been shown to reduce liver steatosis. Here we investigate the effects of short-term metformin treatment on population of gut microbiota profile in an obese rat model. Five week old obese (n = 12) female Zucker rats after 1 week of acclimation, received AIN-93 G diet for 8 weeks and then rats were randomly assigned into two groups (6 rats/group): (1) obese without metformin (ObC), or (2) obese with metformin (ObMet). Metformin was mixed with AIN-93G diet at 1,000 mg/kg of diet. Rats were weighed twice per week. All rats were sacrificed at the end of metformin treatment at 10 weeks and fecal samples were collected and kept at -80°C. Total microbial DNA was collected directly from the fecal samples used for shotgun-metagenomics sequencing and subsequently analyzed using MetaPlAn and HUMAnN. After stringent data filtering and quality control we found significant differences (p = 0.0007) in beta diversity (Aitchison distances) between the ObC vs. ObMet groups. Supervised and unsupervised analysis of the log-ratios Bacteroides dorei and B. massiliensis vs. all other Bacteroides spp., revealed that B. dorei and B. massiliensis were enriched in the ObMet group, while the remaining Bacteroides spp. where enriched in the ObC group (p = 0.002). The contributional diversity of pathways is also significantly associated by treatment group (p = 0.008). In summary, in the obese Zucker rat model, short-term metformin treatment changes the gut microbiota profile, particularly altering the composition Bacteroides spp. between ObC and ObMet.

Evidence and possible mechanisms of probiotics in the management of type 1 diabetes mellitus

Abstract

Type 1 diabetes mellitus (T1DM) is one of the most common chronic immune-mediated diseases. The prevalence is worldwide especially among children and young adults. The destruction of the pancreatic β-cells due to some abnormalities in the immune system characterizes T1DM. Considering the high burden of the disease and its impact on human health, researchers have made great efforts during the last decades; investigating the disease pathogenesis and discovering new strategies for its management. Fortunately, probiotics have been found as potential remedies for T1DM. This review aims to explore the potentialities of probiotics in managing T1DM and its complications. Based on the outcomes of human and animal studies carried out from 2016 to 2021, the review hopes to assess the effectiveness of probiotics in the prevention and treatment of T1DM and its complications. We first tried to explain the disease's pathogenesis, and highlighted the possible mechanisms involved in these potentialities of probiotics. We concluded that, probiotics can be used as possible therapeutic tools for the management of T1DM. Possible mechanisms of action of probiotics include; the modulation of the gut microbiota, the regulation of inflammation-related cytokines, the production of short chain fatty acids (SCFAs), and the regulation of GLP-1. However, we recommend further studies especially human trials should be carried out to investigate these potentialities of probiotics.

Highlights

• T1DM is highly prevalent worldwide, causing high morbidity and mortality especially among children and young adults• Gut microbiota plays a significant role in the pathogenesis of T1DM via an interconnection with the immune system• Probiotics can be used as possible therapeutic tools for the management of T1DM• Possible mechanisms of action of probiotics include the modulation of the gut microbiota, the regulation of inflammation-related cytokines, the production of SCFAs, and the regulation of GLP-1.

PM2.5 and Serum Metabolome and Insulin Resistance, Potential Mediation by the Gut Microbiome: A Population-Based Panel Study of Older Adults in China

BACKGROUND

Insulin resistance (IR) affects the development of type 2 diabetes mellitus (T2DM), which is also influenced by accumulated fine particle air pollution [particulate matter (PM) with aerodynamic diameter of <2.5μm (PM2.5)] exposure. Previous experimental and epidemiological studies have proposed several potential mechanisms by which PM2.5 contributes to IR/T2DM, including inflammation imbalance, oxidative stress, and endothelial dysfunction. Recent evidence suggests that the imbalance of the gut microbiota affects the metabolic process and may precede IR. However, the underlying mechanisms of PM2.5, gut microbiota, and metabolic diseases are unclear.

OBJECTIVES

We investigated the associations between personal exposure to PM2.5 and fasting blood glucose and insulin levels, the IR index, and other related biomarkers. We also explored the potential underlying mechanisms (systemic inflammation and sphingolipid metabolism) between PM2.5 and insulin resistance and the mediating effects between PM2.5 and sphingolipid metabolism.

METHODS

We recruited 76 healthy seniors to participate in a repeated-measures panel study and conducted clinical examinations every month from September 2018 to January 2019. Linear mixed-effects (LME) models were used to analyze the associations between PM2.5 and health data (e.g., functional factors, the IR index, inflammation and other IR-related biomarkers, metabolites, and gut microbiota). We also performed mediation analyses to evaluate the effects of mediators (gut microbiota) on the associations between exposures (PM2.5) and featured metabolism outcomes.

RESULTS

Our prospective panel study illustrated that exposure to PM2.5 was associated with an increased risk of higher IR index and functional biomarkers, and our study provided mechanistic evidence suggesting that PM2.5 exposure may contribute to systemic inflammation and altered sphingolipid metabolism.

DISCUSSION

Our findings demonstrated that PM2.5 was associated with the genera of the gut microbiota, which partially mediated the association between PM2.5 and sphingolipid metabolism. These findings may extend our current understanding of the pathways of PM2.5 and IR. https://doi.org/10.1289/EHP9688.

Intestinal microbiota and their metabolic contribution to type 2 diabetes and obesity

Obesity and type 2 diabetes mellitus (T2DM) are common, chronic metabolic disorders with associated significant long-term health problems at global epidemic levels. It is recognised that gut microbiota play a central role in maintaining host homeostasis and through technological advances in both animal and human models it is becoming clear that gut microbiota are heavily involved in key pathophysiological roles in the aetiology and progression of both conditions. This review will focus on current knowledge regarding microbiota interactions with short chain fatty acids, the host inflammatory response, signaling pathways, integrity of the intestinal barrier, the interaction of the gut-brain axis and the subsequent impact on the metabolic health of the host.

Naturally Acquired Lactic Acid Bacteria from Fermented Cassava Improves Nutrient and Anti-dysbiosis Activity of Soy Tempeh

Introduction: Gut microbiota dysbiosis indicated by increased gram-negative bacteria and reduced Firmicutes-producing short chain fatty acids bacteria has been linked with impairment in glucose metabolism. Tempeh is traditional fermented soy food that can stimulate the growth of beneficial bacteria. In Indonesia, some tempeh was produced by adding acidifier that contains lactic acid bacteria. This process may impact the nutrient and anti-dysbiosis activity of tempeh.   Objectives: To evaluate the impact of acidifier on nutrient and gut microbiota profile of diabetic animal model.  Method: Modified tempeh was made by addition of water extract of fermented cassava. Standard and modified tempeh were subjected to proximate analysis and dietary fibre. Diabetic animals were received standard tempeh or modified tempeh diet replacing 15% and 30% of protein in the diet for 4 weeks of intervention. At the end of experiment, caecal content was collected. Short chain fatty acids and microbiota composition were analysed using 16s rDNA next generation sequencing (NGS). Result: There is significant different (p<0.05) on fat, protein, water and dietary fibre content between regular soy tempeh and modified tempeh. There is significant different (p<0.05) on serum glucose and short chain fatty acid composition among group. Diabetic animal has low ratio of Firmicutes/Bacteroidetes. Supplementation of both tempeh increased bacterial diversity, Firmicutes /Bacteroidetes ratio and short chain fatty acids producing bacteria.   Conclusion: Addition of naturally occurred lactic acid bacteria from fermented cassava during tempeh processing improved both nutrient and microbiota composition in the gut of diabetes mellitus.  

Anti-diabetics and antimicrobials: Harmony of mutual interplay

Diabetes is one of the four major non-communicable diseases, and appointed by the world health organization as the seventh leading cause of death worldwide. The scientists have turned over every rock in the corners of medical sciences in order to come up with better understanding and hence more effective treatments of diabetes. The continuous research on the subject has elucidated the role of immune disorders and inflammation as definitive factors in the trajectory of diabetes, assuring that blood glucose adjustments would result in a relief in the systemic stress leading to minimizing inflammation. On a parallel basis, microbial infections usually take advantage of immunity disorders and propagate creating a pro-inflammatory environment, all of which can be reversed by antimicrobial treatment. Standing at the crossroads between diabetes, immunity and infection, we aim in this review at projecting the interplay between immunity and diabetes, shedding the light on the overlapping playgrounds for the activity of some antimicrobial and anti-diabetic agents. Furthermore, we focused on the anti-diabetic drugs that can confer antimicrobial or anti-virulence activities.

The Microbiome Tumor Axis: How the Microbiome Could Contribute to Clonal Heterogeneity and Disease Outcome in Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) is one of the most malignant cancers. It is characterized by a poor prognosis with a 5-year survival rate of only around 10% and an ongoing increase in death rate. Due to the lack of early and specific symptoms, most patients are diagnosed at an advanced or even metastasized stage, essentially limiting curative treatment options. However, even curative resection of the primary tumor and adjuvant therapy often fails to provide a long-term survival benefit. One reason for this dismal situation can be seen in the evolution of therapy resistances. Furthermore, PDAC is characterized by high intratumor heterogeneity, pointing towards an abundance of cancer stem cells (CSCs), which are regarded as essential for tumor initiation and drug resistance. Additionally, it was shown that the gut microbiome is altered in PDAC patients, promotes Epithelial-Mesenchymal-Transition (EMT), determines responses towards chemotherapy, and affects survival in PDAC patients. Given the established links between CSCs and EMT as well as drug resistance, and the emerging role of the microbiome in PDAC, we postulate that the composition of the microbiome of PDAC patients is a critical determinant for the abundance and plasticity of CSC populations and thus tumor heterogeneity in PDAC. Unravelling this complex interplay might pave the way for novel treatment strategies.

Manipulation of intestinal microbiome as potential treatment for insulin resistance and type 2 diabetes

PURPOSE

Increasing evidence suggests that the intestinal microbiome (IM) and bacterial metabolites may influence glucose homeostasis, energy expenditure and the intestinal barrier integrity and lead to the presence of systemic low-grade inflammation, all of which can contribute to insulin resistance (IR) and type 2 diabetes (T2D). The purpose of this review is to explore the role of the IM and bacterial metabolites in the pathogenesis and treatment of these conditions.

RESULTS

This review summarizes research focused on how to modulate the IM through diet, prebiotics, probiotics, synbiotics and fecal microbiota transplant in order to treat IR and T2D.

CONCLUSION

There is an abundance of evidence suggesting a role for IM in the pathogenesis of IR and T2D based on reviewed studies using various methods to modulate IM and metabolites. However, the results are inconsistent. Future research should further assess this relationship.

Biological effects of stevia, sucralose and sucrose in citrus-maqui juices on overweight subjects

BACKGROUND

In the last few years there has been emerging interest in substituting added sugars from juices with other sweeteners to make them healthier. But their long-term effects have been poorly evaluated. The aim of this study is to evaluate the effect of the addition of stevia, sucralose and sucrose (control) to maqui-citrus beverages on antioxidant and inflammatory status.

METHODS

a 3-arm parallel, randomized and triple blind clinical trial was performed in overweight subjects (n = 138), who consumed the test beverage (330 mL day-1) for 60 days. The following markers were determined: antioxidant status (ORAC, homocysteine, and oxidized LDL), safety parameters (ALP, AST, ALT, and total bilirubin), lipid profile (total cholesterol, LDL-cholesterol, HDL-cholesterol, and triglycerides) and inflammatory biomarkers (IL-6, TNF-α, and IL-10).

RESULTS

The homocysteine levels significantly increased after consumption of sucralose (27%, p = 0.001) and sucrose (40%, p = 0.006). A significant increase in the IL-10 concentration after consumption of the stevia sweetened beverage, and in ORAC values (21%) in subjects with lower basal antioxidant status were observed. The HDL and total cholesterol levels significantly increased after consumption of sucralose (p = 0.039) and sucrose (p = 0.001), respectively. No changes in triglycerides, LDL or oxidized LDL were observed.

CONCLUSIONS

Oxidative stress and an inflammatory response were observed after consumption of these sweetened beverages, with the exception of stevia, which produced an anti-inflammatory response. The possible antioxidative effects of this polyphenol-rich beverage may only benefit those individuals with poorer antioxidant status. Many randomized controlled trials at normal levels of consumption using commonly consumed sweeteners are necessary to clarify their roles in health.

A review on gut microbiota: a central factor in the pathophysiology of obesity

Obesity and its complications constitute a substantial burden. Considerable published research describes the novel relationships between obesity and gut microbiota communities. It is becoming evident that microbiota behave in a pivotal role in their ability to influence homeostatic mechanisms either to the benefit or detriment of host health, the extent of which is not fully understood. A greater understanding of the contribution of gut microbiota towards host pathophysiology is revealing new therapeutic avenues to tackle the global obesity epidemic. This review focuses on causal relationships and associations with obesity, proposed central mechanisms encouraging the development of obesity and promising prospective methods for microbiota manipulation.

Beyond probiotic legend: ESSAP gut microbiota health score to delineate SARS-COV-2 infection severity

COVID-19 pandemic continues to be a global health crisis. The gut microbiome critically affects the immune system, and some respiratory infections are associated with changes in the gut microbiome; here, we evaluated the role of nutritional and lifestyle habits that modulate gut microbiota on COVID-19 outcomes in a longitudinal cohort study that included 200 patients infected with COVID-19. Of these, 122 cases were mild and seventy-eight were moderate, according to WHO classification. After detailed explanation by a consultant in clinical nutrition, participants responded to a written questionnaire on daily sugar, prebiotic intake in food, sleeping hours, exercise duration and antibiotic prescription, during the past 1 year before infection. Daily consumption of prebiotic-containing foods, less sugar, regular exercise, adequate sleep and fewer antibiotic prescriptions led to a milder disease and rapid virus clearance. Additionally, data on these factors were compiled into a single score, the ESSAP score (Exercise, Sugar consumption, Sleeping hours, Antibiotics taken, and Prebiotics consumption; 0–11 points), median ESSAP score was 5 for both mild and moderate cases; however, the range was 4–8 in mild cases, but 1–6 in moderate (P = 0·001, OR: 4·2, 95 % CI 1·9, 9·1); our results showed a negative correlation between regular consumption of yogurt containing probiotics and disease severity (P = 0·007, OR: 1·6, 95 % CI 1·1, 2·1). Mild COVID-19 disease was associated with 10–20 min of daily exercise (P = 0·016), sleeping at least 8 h daily, prescribed antibiotics less than 5 times per year (P = 0·077) and ate plenty of prebiotic-containing food.

Impact of the Gut Microbiota Balance on the Health-Disease Relationship: The Importance of Consuming Probiotics and Prebiotics

Gut microbiota is a group of microorganisms that are deposited throughout the entire gastrointestinal tract. Currently, thanks to genomic tools, studies of gut microbiota have pointed towards the understanding of the metabolism of important bacteria that are not cultivable and their relationship with human homeostasis. Alterations in the composition of gut microbiota could explain, at least in part, some epidemics, such as diabetes and obesity. Likewise, dysbiosis has been associated with gastrointestinal disorders, neurodegenerative diseases, and even cancer. That is why several studies have recently been focused on the direct relationship that these types of conditions have with the specific composition of gut microbiota, as in the case of the microbiota-intestine-brain axis. In the same way, the control of microbiota is related to the diet. Therefore, this review highlights the importance of gut microbiota, from its composition to its relationship with the human health-disease condition, as well as emphasizes the effect of probiotic and prebiotic consumption on the balance of its composition.

The gut microbiome in pancreatogenic diabetes differs from that of Type 1 and Type 2 diabetes

We hypothesized that the gut microbiome in patients with diabetes secondary to chronic pancreatitis (Type 3c) is different from those with Type 1 and Type 2 diabetes. This was a cross-sectional preliminary study that included 8 patients with Type 1, 10 with Type 2, 17 with Type 3c diabetes and 9 healthy controls. Demographic, clinical, biochemical, imaging and treatment data were recorded and sequencing of the V3-V4 region of the bacterial 16SrRNA was done on fecal samples. Bioinformatics and statistical analyses was performed to evaluate the differences in the diversity indices, distance matrices, relative abundances and uniqueness of organisms between the types of diabetes. There was significant difference in the species richness. Beta diversity was significantly different between patients with Type 3c diabetes and the other groups. 31 genera were common to all the three types of diabetes. There was significant differences in the species level taxa between Type 3c diabetes and the other groups. The unique bacterial species signature in Type 3c diabetes compared to Type 1 and Type 2 diabetes included Nesterenkonia sp. AN1, Clostridium magnum, Acinetobacter lwoffii, Clostridium septicum, Porphyromonas somerae, Terrabacter tumescens, and Synechococus sp.

Association of gestational diabetes mellitus with changes in gut microbiota composition at the species level

Background

Gestational diabetes mellitus (GDM), a common endocrine disorder with rising prevalence in pregnancy, has been reported to be associated with alteration of gut microbiota in recent years. However, the role of gut microbiome in GDM physiopathology remains unclear. This pilot study aims to characterize the alteration of gut microbiota in GDM on species-level resolution and evaluate the relationship with occurrence of GDM.

Methods

An analysis based on 16S rRNA microarray was performed on fecal samples obtained from 30 women with GDM and 28 healthy pregnant women.

Results

We found 54 and 141 differentially abundant taxa between GDM and control group at the genus and the species level respectively. Among GDM patients, Peptostreptococcus anaerobius was inversely correlated with fasting glucose while certain species (e.g., Aureimonas altamirensis, Kosakonia cowanii) were positively correlated with fasting glucose.

Conclusions

This study suggests that there are large amounts of differentially abundant taxa between GDM and control group at the genus and the species level. Some of these taxa were correlated with blood glucose level and might be used as biomarkers for diagnoses and therapeutic targets for probiotics or synbiotics.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12866-021-02207-0.

Inulin Fermentable Fiber Ameliorates Type I Diabetes via IL22 and Short-Chain Fatty Acids in Experimental Models

BACKGROUND & AIMS

Nourishment of gut microbiota via consumption of fermentable fiber promotes gut health and guards against metabolic syndrome. In contrast, how dietary fiber impacts type 1 diabetes is less clear.

METHODS

To examine impact of dietary fibers on development of type 1 diabetes in the streptozotocin (STZ)-induced and spontaneous non-obese diabetes (NOD) models, mice were fed grain-based chow (GBC) or compositionally defined diets enriched with a fermentable fiber (inulin) or an insoluble fiber (cellulose). Spontaneous (NOD mice) or STZ-induced (wild-type mice) diabetes was monitored.

RESULTS

Relative to GBC, low-fiber diets exacerbated STZ-induced diabetes, whereas diets enriched with inulin, but not cellulose, strongly protected against or treated it. Inulin's restoration of glycemic control prevented loss of adipose depots, while reducing food and water consumption. Inulin normalized pancreatic function and markedly enhanced insulin sensitivity. Such amelioration of diabetes was associated with alterations in gut microbiota composition and was eliminated by antibiotic administration. Pharmacologic blockade of fermentation reduced inulin's beneficial impact on glycemic control, indicating a role for short-chain fatty acids (SCFA). Furthermore, inulin's microbiota-dependent anti-diabetic effect associated with SCFA-independent restoration of interleukin 22, which was necessary and sufficient to ameliorate STZ-induced diabetes. Inulin-enriched diets significantly delayed diabetes in NOD mice.

CONCLUSIONS

Fermentable fiber confers microbiota-dependent increases in SCFA and interleukin 22 that, together, may have potential to prevent and/or treat type 1 diabetes.

Drug Response Diversity: A Hidden Bacterium?

Interindividual heterogeneity in response to treatment is a real public health problem. It is a factor that can be responsible not only for ineffectiveness or fatal toxicity but also for hospitalization due to iatrogenic effects, thus increasing the cost of patient care. Several research teams have been interested in what may be at the origin of these phenomena, particularly at the genetic level and the basal activity of organs dedicated to the inactivation and elimination of drug molecules. Today, a new branch is being set up, explaining the enigmatic part that could not be explained before. Pharmacomicrobiomics attempts to investigate the interactions between bacteria, especially those in the gut, and drug response. In this review, we provide a state of the art on what this field has brought as new information and discuss the challenges that lie ahead to see the real application in clinical practice.

ACE2 as therapeutic agent

The angiotensin-converting enzyme 2 (ACE2) has emerged as a critical regulator of the renin-angiotensin system (RAS), which plays important roles in cardiovascular homeostasis by regulating vascular tone, fluid and electrolyte balance. ACE2 functions as a carboxymonopeptidase hydrolyzing the cleavage of a single C-terminal residue from Angiotensin-II (Ang-II), the key peptide hormone of RAS, to form Angiotensin-(1-7) (Ang-(1-7)), which binds to the G-protein-coupled Mas receptor and activates signaling pathways that counteract the pathways activated by Ang-II. ACE2 is expressed in a variety of tissues and overwhelming evidence substantiates the beneficial effects of enhancing ACE2/Ang-(1-7)/Mas axis under many pathological conditions in these tissues in experimental models. This review will provide a succinct overview on current strategies to enhance ACE2 as therapeutic agent, and discuss limitations and future challenges. ACE2 also has other functions, such as acting as a co-factor for amino acid transport and being exploited by the severe acute respiratory syndrome coronaviruses (SARS-CoVs) as cellular entry receptor, the implications of these functions in development of ACE2-based therapeutics will also be discussed.

Plant Prebiotics and Their Role in the Amelioration of Diseases

Prebiotics are either natural or synthetic non-digestible (non-)carbohydrate substances that boost the proliferation of gut microbes. Undigested fructooligosaccharides in the large intestine are utilised by the beneficial microorganisms for the synthesis of short-chain fatty acids for their own growth. Although various food products are now recognized as having prebiotic properties, several others, such as almonds, artichoke, barley, chia seeds, chicory, dandelion greens, flaxseeds, garlic, and oats, are being explored and used as functional foods. Considering the benefits of these prebiotics in mineral absorption, metabolite production, gut microbiota modulation, and in various diseases such as diabetes, allergy, metabolic disorders, and necrotising enterocolitis, increasing attention has been focused on their applications in both food and pharmaceutical industries, although some of these food products are actually used as food supplements. This review aims to highlight the potential and need of these prebiotics in the diet and also discusses data related to the distinct types, sources, modes of action, and health benefits.

Ramadan Fasting Leads to Shifts in Human Gut Microbiota Structured by Dietary Composition

The structure and diversity of human gut microbiota are directly related to diet, though less is known about the influences of ethnicity and diet-related behaviors, such as fasting (intermittent caloric restriction). In this study, we investigated whether fasting for Ramadan altered the microbiota in Chinese and Pakistani individuals. Using high-throughput 16S rRNA gene sequencing and self-reported dietary intake surveys, we determined that both the microbiota and dietary composition were significantly different with little overlap between ethnic groups. Principal Coordinate Analyses (PCoA) comparison of samples collected from both groups before and after fasting showed partial separation of microbiota related to fasting in the Pakistani group, but not in the Chinese group. Measurement of alpha diversity showed that Ramadan fasting significantly altered the coverage and ACE indices among Chinese subjects, but otherwise incurred no changes among either group. Specifically, Prevotella and Faecalibacterium drove predominance of Bacteroidetes and Firmicutes in the Pakistani group, while Bacteroides (phylum Bacteroidetes) were the most prevalent among Chinese participants both before and after fasting. We observed significant enrichment of some specific taxa and depletion of others in individuals of both populations, suggesting that fasting could affect beta diversity. Notably, Dorea, Klebsiella, and Faecalibacterium were more abundant in the Chinese group after fasting, while Sutterella, Parabacteroides, and Alistipes were significantly enriched after fasting in the Pakistani group. Evaluation of the combined groups showed that genera Coprococcus, Clostridium_XlV, and Lachnospiracea were all significantly decreased after fasting. Analysis of food intake and macronutrient energy sources showed that fat-derived energy was positively associated with Oscillibacter and Prevotella, but negatively associated with Bacteroides. In addition, the consumption of sweets was significantly positively correlated with the prevalence of Akkermansia. Our study indicated that diet was the most significant influence on microbiota, and correlated with ethnic groups, while fasting led to enrichment of specific bacterial taxa in some individuals. Given the dearth of understanding about the impacts of fasting on microbiota, our results provide valuable inroads for future study aimed at novel, personalized, behavior-based treatments targeting specific gut microbes for prevention or treatment of digestive disorders.

Systemic Metabolic Alterations Correlate with Islet-Level Prostaglandin E2 Production and Signaling Mechanisms That Predict β-Cell Dysfunction in a Mouse Model of Type 2 Diabetes

The transition from β-cell compensation to β-cell failure is not well understood. Previous works by our group and others have demonstrated a role for Prostaglandin EP3 receptor (EP3), encoded by the Ptger3 gene, in the loss of functional β-cell mass in Type 2 diabetes (T2D). The primary endogenous EP3 ligand is the arachidonic acid metabolite prostaglandin E₂ (PGE₂). Expression of the pancreatic islet EP3 and PGE₂ synthetic enzymes and/or PGE₂ excretion itself have all been shown to be upregulated in primary mouse and human islets isolated from animals or human organ donors with established T2D compared to nondiabetic controls. In this study, we took advantage of a rare and fleeting phenotype in which a subset of Black and Tan BRachyury (BTBR) mice homozygous for the Leptin^ob/ob mutation—a strong genetic model of T2D—were entirely protected from fasting hyperglycemia even with equal obesity and insulin resistance as their hyperglycemic littermates. Utilizing this model, we found numerous alterations in full-body metabolic parameters in T2D-protected mice (e.g., gut microbiome composition, circulating pancreatic and incretin hormones, and markers of systemic inflammation) that correlate with improvements in EP3-mediated β-cell dysfunction.

Berberine Slows the Progression of Prediabetes to Diabetes in Zucker Diabetic Fatty Rats by Enhancing Intestinal Secretion of Glucagon-Like Peptide-2 and Improving the Gut Microbiota

BACKGROUND

Berberine is a plant alkaloid that has multiple beneficial effects against intestine inflammation. In our previous study, we have found that berberine also possesses an antidiabetic effect. However, whether berberine is useful in the prevention of type 2 diabetes mellitus (T2DM) through its effect on intestine endocrine function and gut microbiota is unclear.

AIM

To investigate the effects of berberine in the prevention of T2DM, as well as its effects on intestine GLP-2 secretion and gut microbiota in ZDF rats.

METHODS

Twenty Zucker Diabetic Fatty (ZDF) rats were fed a high-energy diet until they exhibited impaired glucose tolerance (IGT). The rats were then divided into two groups to receive berberine (100 mg/kg/d; berberine group) or vehicle (IGT group) by gavage for 3 weeks. Five Zucker Lean (ZL) rats were used as controls. Fasting blood glucose (FBG) was measured, an oral glucose tolerance test was performed, and the Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) was calculated. Intestinal expression of TLR-4, NF-κB, TNF-α, mucin, zona occludens-1 (ZO-1) and occludin were assessed (immunohistochemistry). Plasma levels and glutamine-induced intestinal secretion of glucagon-like peptide-1 (GLP-1) and GLP-2 were measured (enzyme-linked immunosorbent assay). The plasma lipopolysaccharide (LPS) level was measured. Fecal DNA extraction, pyrosequencing, and bioinformatics analysis were performed.

RESULTS

After 3 weeks of intervention, diabetes developed in all rats in the IGT group, but only 30% of rats in the berberine group. Treatment with berberine was associated with reductions in food intake, FBG level, insulin resistance, and plasma LPS level, as well as increases in fasting plasma GLP-2 level and glutamine-induced intestinal GLP-2 secretion. Berberine could increase the goblet cell number and villi length, and also reverse the suppressed expressions of mucin, occludin, ZO-1 and the upregulated expressions of TLR-4, NF-κB and TNF-α induced in IGT rats (P<0.05). Berberine also improved the structure of the gut microbiota and restored species diversity.

CONCLUSION

Berberine may slow the progression of prediabetes to T2DM in ZDF rats by improving GLP-2 secretion, intestinal permeability, and the structure of the gut microbiota.

Consensus on Medical Nutrition Therapy for Diabesity (CoMeND) in Adults: A South Asian Perspective

Diabetes and obesity are both increasing at a fast pace and giving rise to a new epidemic called diabesity. Lifestyle interventions including diet play a major role in the treatment of diabetes, obesity and diabesity. There are many guidelines on dietary management of diabetes or obesity globally and also from South Asia. However, there are no global or South Asian guidelines on the non-pharmacological management of diabesity. South Asia differs from the rest of the world as South Asians have different phenotype, cooking practices, food resources and exposure, medical nutrition therapy (MNT) practices, and availability of trained specialists. Therefore, South Asia needs its own guidelines for non-pharmacological management of diabesity in adults. The aim of the Consensus on Medical Nutrition Therapy for Diabesity (CoMeND) in Adults: A South Asian Perspective is to recommend therapeutic and preventive MNT in the South-Asians with diabesity.