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

Early life gut microbiome and its impact on childhood health and chronic conditions

The development of the gut microbiome is crucial to human health, particularly during the first three years of life. Given its role in immune development, disturbances in the establishment process of the gut microbiome may have long term consequences. This review summarizes evidence for these claims, highlighting compositional changes of the gut microbiome during this critical period of life as well as factors that affect gut microbiome development. Based on human and animal data, we conclude that the early-life microbiome is a determinant of long-term health, impacting physiological, metabolic, and immune processes. The early-life gut microbiome field faces challenges. Some of these challenges are technical, such as lack of standardized stool collection protocols, inconsistent DNA extraction methods, and outdated sequencing technologies. Other challenges are methodological: small sample sizes, lack of longitudinal studies, and poor control of confounding variables. To address these limitations, we advocate for more robust research methodologies to better understand the microbiome's role in health and disease. Improved methods will lead to more reliable microbiome studies and a deeper understanding of its impact on health outcomes.

Microbiome and pediatric leukemia, diabetes, and allergies: Systematic review and meta-analysis

BACKGROUND

Despite the different pathologies and genetic susceptibilities of childhood ALL, T1DM and allergies, these conditions share epidemiological risk factors related to timing of infectious exposures and acquisition of the gut microbiome in infancy. We have assessed whether lower microbiome diversity (Shannon Index) and shared genus/species profiles are associated with pediatric ALL, allergies, and T1DM.

METHODS AND FINDINGS

Literature search was performed using PubMed, Embase, Cochrane, and Web of Science databases. Case-control, meta-analyses, and cohort studies were considered for inclusion. Inclusion criteria: (i) subjects age 1-18 years at diagnosis, (ii) reports effect of microbiome measured prior to/at time of diagnosis/first intervention (iii) outcome of ALL, allergies, asthma, or T1DM, (iv) English text. Exclusion criteria: (i) age < 1 or >18 years at diagnosis, (ii) Down Syndrome-associated ALL, (iii) non-English text, (iv) reviews, pre-print, or abstracts, (v) heavily biased studies. Abstract and full text screening were performed by two independent reviewers. Data extraction was performed by one reviewer following PRISMA guidelines. Data were pooled using a random-effects model. Eighty-eight studies were included in the analysis, with seventy-seven in the qualitative analysis and 54 in the meta-analysis. Cases were found to have lower alpha-diversity than controls in ALL (SMD:-0.78, 95%CI:-1.21, -0.34), T1DM (SMD:-1.26, 95%CI:-3.49, 0.96), eczema (SMD:-0.34, 95%CI:-0.56, -0.12), atopy (SMD:-0.06, 95%CI:-0.34, 0.22), asthma (SMD:-0.37, 95%CI:-1.16, 0.42), and food allergy (SMD:-0.11, 95%CI:-0.63, 0.41).

CONCLUSIONS

These results highlight similarities in the microbiome diversity and composition of children with ALL, T1DM, and allergies. This is compatible with a common risk factor related to immune priming in infancy and highlights the gut microbiome as a potentially modifiable risk factor and preventative strategy for these childhood diseases.

The biological and sociological implications of diversity, equity, and inclusion (DEI): life within microbiomes and on earth

From a biological point of view, Diversity, Equity, and Inclusion (DEI) are important at multiple levels, which include our genetics, microbiomes, diets, and all organ system interactions. Considering only DEI's sociological aspects is equivalent to the error of "throwing out the baby with the bath water." Variances in microbial diversity within our microbiomes might affect our health through systemic interactions affecting metabolites, maintaining immune homeostasis, and wound healing of cellular damage from an infection, physical stress, or psychological trauma. An imbalance of our immune cell subsets, both innate and adaptive, and the microbes in any of our microbiomes might lead to more cellular damage from excessive inflammation and oxidative stress and less immune regulation. The immune dysregulation may occur due to the loss of endometrial barriers enabling the spread of microbes, environmental pollutants, and allergens. Heat waves, sleep deprivation, and increased prevalence of pollutants such as polychlorinated biphenyls, which weaken endothelial barriers, may be responsible for the enhanced prevalence of physical and psychological stresses. Leakage of our useful gut microbiota into the periphery might initiate inflammatory responses, and an altered gut microbiome might affect the gut-brain axis that influences physical and mental health.

The microbiota-gut-brain axis in myalgic encephalomyelitis/chronic fatigue syndrome: a narrative review of an emerging field

The intricate relationship between gut microbiota and the brain has emerged as a pivotal area of research, particularly in understanding Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). This complex condition is characterized by debilitating fatigue, cognitive dysfunction, and a wide array of systemic manifestations, posing significant challenges for diagnosis and treatment. Recent studies highlight the microbiota-gut-brain axis as a crucial pathway in ME/CFS pathophysiology, suggesting that alterations in gut microbial composition may impact immune responses, neurochemical signaling, and neuronal health. This narrative review systematically explores English-language scholarly articles from January 1995 to January 2025, utilizing databases such as PubMed, Scopus, and Web of Science. The findings underscore the potential for targeted therapeutic interventions aimed at correcting gut dysbiosis. As research progresses, a deeper understanding of the microbiota-gut-brain connection could lead to innovative approaches for managing ME/CFS, ultimately enhancing the quality of life for affected individuals.

Using gut microbiome metagenomic hypervariable features for diabetes screening and typing through supervised machine learning

Diabetes mellitus is a complex metabolic disorder and one of the fastest-growing global public health concerns. The gut microbiota is implicated in the pathophysiology of various diseases, including diabetes. This study utilized 16S rRNA metagenomic data from a volunteer citizen science initiative to investigate microbial markers associated with diabetes status (positive or negative) and type (type 1 or type 2 diabetes mellitus) using supervised machine learning (ML) models. The diversity of the microbiome varied according to diabetes status and type. Differential microbial signatures between diabetes types and negative group revealed an increased presence of Brucellaceae, Ruminococcaceae, Clostridiaceae, Micrococcaceae, Barnesiellaceae and Fusobacteriaceae in subjects with diabetes type 1, and Veillonellaceae, Streptococcaceae and the order Gammaproteobacteria in subjects with diabetes type 2. The decision tree, elastic net, random forest (RF) and support vector machine with radial kernel ML algorithms were trained to screen and type diabetes based on microbial profiles of 76 subjects with type 1 diabetes, 366 subjects with type 2 diabetes and 250 subjects without diabetes. Using the 1000 most variable features, tree-based models were the highest-performing algorithms. The RF screening models achieved the best performance, with an average area under the receiver operating characteristic curve (AUC) of 0.76, although all models lacked sensitivity. Reducing the dataset to 500 features produced an AUC of 0.77 with sensitivity increasing by 74% from 0.46 to 0.80. Model performance improved for the classification of negative-status and type 2 diabetes. Diabetes type models performed best with 500 features, but the metric performed poorly across all model iterations. ML has the potential to facilitate early diagnosis of diabetes based on microbial profiles of the gut microbiome.

Therapeutic Strategies to Modulate Gut Microbial Health: Approaches for Chronic Metabolic Disorder Management

Numerous recent studies have suggested that the composition of the intestinal microbiota can trigger metabolic disorders, such as diabetes, prediabetes, obesity, metabolic syndrome, sarcopenia, dyslipidemia, hyperhomocysteinemia, and non-alcoholic fatty liver disease. Since then, considerable effort has been made to understand the link between the composition of intestinal microbiota and metabolic disorders, as well as the role of probiotics in the modulation of the intestinal microbiota. The aim of this review was to summarize the reviews and individual articles on the state of the art regarding ideal therapy with probiotics and prebiotics in order to obtain the reversion of dysbiosis (alteration in microbiota) to eubiosis during metabolic diseases, such as diabetes, prediabetes, obesity, hyperhomocysteinemia, dyslipidemia, sarcopenia, and non-alcoholic fatty liver diseases. This review includes 245 eligible studies. In conclusion, a condition of dysbiosis, or in general, alteration of the intestinal microbiota, could be implicated in the development of metabolic disorders through different mechanisms, mainly linked to the release of pro-inflammatory factors. Several studies have already demonstrated the potential of using probiotics and prebiotics in the treatment of this condition, detecting significant improvements in the specific symptoms of metabolic diseases. These findings reinforce the hypothesis that a condition of dysbiosis can lead to a generalized inflammatory picture with negative consequences on different organs and systems. Moreover, this review confirms that the beneficial effects of probiotics on metabolic diseases are promising, but more research is needed to determine the optimal probiotic strains, doses, and administration forms for specific metabolic conditions.

Effects of deep ocean-derived magnesium-enhanced water on metabolic diseases with microbiome changes

AIMS

To investigate the effects of magnesium (Mg) from deep ocean sources, we conducted a randomized clinical trial involving adults with hypertension, diabetes, or hyperlipidemia.

METHODS

Subjects consumed either Mg-enriched water (MEW) or a placebo (80 or 6 mg of Mg per 2 L/day, respectively) for 4 weeks. We examined the detoxifying effects of MEW on environmental toxicants, including polycyclic aromatic hydrocarbons (PAHs) and oxidative stress, and its impact on gut microbiome composition (N = 30; 49.26 ± 9.55 yrs).

RESULTS

Most subjects consumed less Mg than the RDA, enabling their participation in the trial. Despite limitations in serum Mg measurement to assess Mg intake, MEW intake led to improvements in body mass index (BMI), insulin levels, triglycerides, glucose-BMI, and fatigue. Regardless of Mg content, water consumption reduced urinary levels of 1-hydroxypyrene, a major PAH metabolite, and malondialdehyde, an oxidative stress biomarker. Moreover, the MEW group exhibited greater diversity in gut microbiome composition than the placebo group. Notably, MEW kept the abundance of Clostridium, Dorea, or Desulfovibrio, indicating a balanced Mg intake.

CONCLUSION

MEW (80 mg of Mg/day) appears safe for RDA and effective for preventing CVD or T2DM, as evidenced by gut microbiome and biomarker outcomes.

Observational study protocol: the faecal microbiome in the acute stage of new-onset paediatric type 1 diabetes in an Irish cohort

INTRODUCTION

Type 1 diabetes (T1D) is an autoimmune-mediated disorder caused by the destruction of pancreatic beta cells. Although there is an underlying genetic predisposition to developing T1D, the trigger is multifactorial and likely includes environmental factors. The intestinal microbiome has been identified as one such factor. Previous studies have illustrated differences in the microbiota of people with T1D compared with healthy controls. This study aims to describe the evolution of the microbiome and metabolome during the first year of clinical T1D, or stage 3 T1D diagnosis, and investigate whether there are differences in the microbiome and metabolome of children who present with and without diabetic ketoacidosis. The study will also explore possible associations between the microbiome, metabolome, glycaemic control and beta cell reserve.

METHODS AND ANALYSIS

This prospective cohort study will include children with newly diagnosed T1D and sibling controls (n=100, males and females) and their faecal microbiome will be characterised using shotgun metagenomic sequencing at multiple time points during the first year of diagnosis. We will develop a microbial culture biobank based on culturomic studies of stool samples from the healthy controls that will support future investigation. Metabolomic analysis will aim to identify additional biomarkers which may be involved in disease presentation and progression. Through this initial exploratory study, we aim to identify specific microbial biomarkers which may be used as future interventional targets throughout the various stages of T1D progression.

ETHICS AND DISSEMINATION

This study has been approved by the Clinical Research Ethics Committee of the Cork Teaching Hospitals. Study results will be available to patients with T1D and their families, carers, support networks and microbiome societies and other researchers.

TRIAL REGISTRATION NUMBER

The clinicaltrials.gov registration number for this trial is NCT06157736.

Diabetes and gut microbiome

Diabetes mellitus represents a significant global health problem. The number of people suffering from this metabolic disease is constantly rising and although the incidence is heterogeneous depending on region, country, economic situation, lifestyle, diet and level of medical care, it is increasing worldwide, especially among youths and children, mainly due to lifestyle and environmental changes. The pathogenesis of the two most common subtypes of diabetes mellitus, type 1 (T1DM) and type 2 (T2DM), is substantially different, so each form is characterized by a different causation, etiology, pathophysiology, presentation, and treatment. Research in recent decades increasingly indicates the potential role of the gut microbiome in the initiation, development, and progression of this disease. Intestinal microbes and their fermentation products have an important impact on host metabolism, immune system, nutrient digestion and absorption, gut barrier integrity and protection against pathogens. This review summarizes the current evidence on the changes in gut microbial populations in both types of diabetes mellitus. Attention is focused on changes in the abundance of specific bacterial groups at different taxonomic levels in humans, and microbiome shift is also assessed in relation to geographic location, age, diet and antidiabetic drug. The causal relationship between gut bacteria and diabetes is still unclear, and future studies applying new methodological approaches to a broader range of microorganisms inhabiting the digestive tract are urgently needed. This would not only provide a better understanding of the role of the gut microbiome in this metabolic disease, but also the use of beneficial bacterial species in the form of probiotics for the treatment of diabetes.

Gut microbiota as a modulator of type 1 diabetes: A molecular perspective

Type 1 diabetes (T1D) is defined as an autoimmune metabolic disorder, characterized by destruction of pancreatic β-cells and high blood sugar levels. If left untreated, T1D results in severe health complications, including cardiovascular and kidney disease, as well as nerve damage, with ultimately grave consequences. Besides the role of genetic and certain environmental factors in T1D development, in the last decade, one new player emerged to affect T1D pathology as well, and that is a gut microbiota. Dysbiosis of gut bacteria can contribute to T1D by gut barrier disruption and the activation of autoimmune response, leading to the destruction of insulin producing cells, causing the development and aggravation of T1D symptoms. The relationship between gut microbiota and diabetes is complex and varies between individuals and additional research is needed to fully understand the effects of gut microbiome alternations in T1D pathogenesis. Therefore, the goal of this review is to understand the current knowledge in underlying molecular mechanism of gut microbiota effects, which leads to the new approaches for further studies in the prevention and treatment of T1D.

Functional Modulation of Gut Microbiota and Blood Parameters in Diabetic Rats Following Dietary Intervention with Free or Immobilized Pediococcus acidilactici SK Cells on Pistachio Nuts

BACKGROUND/OBJECTIVES

The gut microbiota is linked to the pathogenesis of type 1 diabetes mellitus (T1DM), while supplementation with probiotics may result in positive alterations in the composition of the gut microbiome. This research aimed to map the changes in the gut microbiome and blood markers of streptozotocin-induced diabetic rats after a dietary intervention with free or immobilized cells of the presumptive probiotic Pediococcus acidilactici SK on pistachio nuts.

METHODS

Twenty-four male Wistar rats were studied and divided into four groups (healthy or diabetic) which received the free or the immobilized P. acidilactici SK cells on pistachio nuts for 4 weeks. Blood, fecal, and intestinal tissue samples were examined.

RESULTS

The diabetic rats exhibited an elevated concentration of HDL-c, while the inflammatory IL-1β levels were significantly lower in the diabetic animals that received the immobilized cells compared to the group that received the free cells. The dietary intervention with immobilized cells led to decreased counts of fecal staphylococci and enterococci in the diabetic animals, while the diet with both free and immobilized P. acidilactici SK cells rendered levels of these populations in normal values in the feces and intestinal tissue of the diabetic animals. Noticeably, the Lactobacillus and Bifidobacterium genera were elevated after the supplementation with immobilized P. acidilactici SK cells on pistachio nuts.

CONCLUSIONS

Dietary supplementation with P. acidilactici SK cells (in free or in immobilized form) beneficially affected the gut microbiota/microbiome of streptozotocin-induced diabetic rats, leading to the alleviation of dysbiosis and inflammation and control over their lipid levels.

Alterations in the Gut Microbiota Composition in Obesity with and without Type 2 Diabetes: A Pilot Study

Purpose

Obesity has become a major public health concern worldwide, increasing the risk of T2DM. Growing evidence indicates gut microbiota dysbiosis is related to metabolic disorders. We aimed to firstly investigate the compositional and functional features of the gut microbiome between obesity with and without T2DM in the Chinese population.

Methods

A total of 32 obese individuals accompanied with T2DM and 18 age and gender-matched obesity with normal glucose tolerance (NGT) were enrolled. Fecal samples were collected, and the gut microbiota profile was determined using the Illumina MiSeq platform based on V3-V4 bacterial 16S rRNA gene.

Results

Compared with obesity- NGT, obesity-T2DM showed a significantly higher alpha diversity. Principal coordinates analysis based on both Bray-Curtis distance and weighted Unifrac revealed that the global microbial composition was significantly different between the two groups (P = 0.007 and P = 0.005, respectively). At the phylum level, Obesity-T2DM patients exhibited a significant decrease in Bacteroidetes, and a pronounced increase in Firmicutes. Regarding the genus level, Bacteroides and Escherichia-Shigella were found to increase considerably, while Prevotella_9 and Sutterella had an evident decrease in Obesity-T2DM. Furthermore, Spearman correlation analysis revealed that Prevotella_9 and Sutterella were negatively associated with HbA1c and fasting blood glucose.

Conclusion

We found clear differences in the gut microbiota composition in obesity-T2DM compared with obesity-NGT. Obesity accompanied with T2DM may aggravate the obesity-associated gut microbiota, and gut microbiota is expected to be a promising novel intervention target for obese management. However, larger sample size and more in-depth taxonomic identification studies are warranted.

Effects of Free or Immobilized Pediococcus acidilactici ORE5 on Corinthian Currants on Gut Microbiome of Streptozotocin-Induced Diabetic Rats

The present study aimed to investigate the effect of a dietary intervention including free or immobilized cells of the presumptive probiotic Pediococcus acidilactici ORE5 on Corinthian currants, a food with beneficial impact in the condition of Type-1 Diabetes Mellitus (T1DM), on the microbiome composition of STZ-induced diabetic rats. Twenty four male Wistar rats were divided into four groups (n = 6 per group): healthy animals, which received the free (H_FP) or the immobilized Pediococcus acidilactici ORE5 cells (H_IPC), and diabetic animals, which received the free (D_FP) or the immobilized Pediococcus acidilactici ORE5 cells(D_IPC) for 4 weeks (109 cfu/day, in all groups). At the end of the dietary intervention, the D_IPC group exerted a lower concentration of the inflammatory cytokine IL-1 beta compared to D_FP. Consumption of immobilized P. acidilactici ORE5 cells on Corinthian currants by diabetic animals led to increased loads of fecal lactobacilli and lower Enterobacteriaceae, coliforms, and Escherichia coli levels, while Actinobacteria phylum, Akkermansia, and Bifidobacterium genera abundances were increased, and fecal lactic acid was elevated. Overall, the results of the present research demonstrated that functional ingredients could ameliorate gut dysbiosis present in T1DM and could be used to design dietary patterns aiming at T1DM management. However, well-designed clinical trials are necessary, in order to confirm the beneficial effects in humans.

Unravelling the Role of Gut and Oral Microbiota in the Pediatric Population with Type 1 Diabetes Mellitus

Type 1 Diabetes Mellitus (T1DM) is a chronic autoimmune disease that results in the destruction of pancreatic β cells, leading to hyperglycaemia and the need for lifelong insulin therapy. Although genetic predisposition and environmental factors are considered key contributors to T1DM, the exact causes of the disease remain partially unclear. Recent evidence has focused on the relationship between the gut, the oral cavity, immune regulation, and systemic inflammation. In individuals with T1DM, changes in the gut and oral microbial composition are commonly observed, indicating that dysbiosis may contribute to immune dysregulation. Gut dysbiosis can influence the immune system through increased intestinal permeability, altered production of short chain fatty acids (SCFAs), and interactions with the mucosal immune system, potentially triggering the autoimmune response. Similarly, oral dysbiosis may contribute to the development of systemic inflammation and thus influence the progression of T1DM. A comprehensive understanding of these relationships is essential for the identification of biomarkers for early diagnosis and monitoring, as well as for the development of therapies aimed at restoring microbial balance. This review presents a synthesis of current research on the connection between T1DM and microbiome dysbiosis, with a focus on the gut and oral microbiomes in pediatric populations. It explores potential mechanisms by which microbial dysbiosis contributes to the pathogenesis of T1DM and examines the potential of microbiome-based therapies, including probiotics, prebiotics, synbiotics, and faecal microbiota transplantation (FMT). This complex relationship highlights the need for longitudinal studies to monitor microbiome changes over time, investigate causal relationships between specific microbial species and T1DM, and develop personalised medicine approaches.

Gut Microbiome Dysbiosis in Patients with Pemphigus and Correlation with Pathogenic Autoantibodies

BACKGROUND

Pemphigus is a group of potentially life-threatening autoimmune bullous diseases induced by pathogenic autoantibodies binding to the surface of epidermal cells. The role of the gut microbiota (GM) has been described in various autoimmune diseases. However, the impact of the GM on pemphigus is less understood. This study aimed to investigate whether there was alterations in the composition and function of the GM in pemphigus patients compared to healthy controls (HCs).

METHODS

Fecal samples were collected from 20 patients with active pemphigus (AP), 11 patients with remission pemphigus (PR), and 47 HCs. To sequence the fecal samples, 16S rRNA was applied, and bioinformatic analyses were performed.

RESULTS

We found differences in the abundance of certain bacterial taxa among the three groups. At the family level, the abundance of Prevotellaceae and Coriobacteriaceae positively correlated with pathogenic autoantibodies. At the genus level, the abundance of Klebsiella, Akkermansia, Bifidobacterium, Collinsella, Gemmiger, and Prevotella positively correlated with pathogenic autoantibodies. Meanwhile, the abundance of Veillonella and Clostridium_XlVa negatively correlated with pathogenic autoantibodies. A BugBase analysis revealed that the sum of potentially pathogenic bacteria was elevated in the AP group in comparison to the PR group. Additionally, the proportion of Gram-negative bacteria in the PR group was statistically significantly lower in comparison to the HC group.

CONCLUSION

The differences in GM composition among the three groups, and the correlation between certain bacterial taxa and pathogenic autoantibodies of pemphigus, support a linkage between the GM and pemphigus.

Predicting the role of the human gut microbiome in type 1 diabetes using machine-learning methods

Gut microbes is a crucial factor in the pathogenesis of type 1 diabetes (T1D). However, it is still unclear which gut microbiota are the key factors affecting T1D and their influence on the development and progression of the disease. To fill these knowledge gaps, we constructed a model to find biomarker from gut microbiota in patients with T1D. We first identified microbial markers using Linear discriminant analysis Effect Size (LEfSe) and random forest (RF) methods. Furthermore, by constructing co-occurrence networks for gut microbes in T1D, we aimed to reveal all gut microbial interactions as well as major beneficial and pathogenic bacteria in healthy populations and type 1 diabetic patients. Finally, PICRUST2 was used to predict Kyoto Encyclopedia of Genes and Genomes (KEGG) functional pathways and KO gene levels of microbial markers to investigate the biological role. Our study revealed that 21 identified microbial genera are important biomarker for T1D. Their AUC values are 0.962 and 0.745 on discovery set and validation set. Functional analysis showed that 10 microbial genera were significantly positively associated with D-arginine and D-ornithine metabolism, spliceosome in transcription, steroid hormone biosynthesis and glycosaminoglycan degradation. These genera were significantly negatively correlated with steroid biosynthesis, cyanoamino acid metabolism and drug metabolism. The other 11 genera displayed an inverse correlation. In summary, our research identified a comprehensive set of T1D gut biomarkers with universal applicability and have revealed the biological consequences of alterations in gut microbiota and their interplay. These findings offer significant prospects for individualized management and treatment of T1D.

Gastrodin alleviates the deterioration of depressive-like behavior and glucolipid metabolism promoted by chronic stress in type 2 diabetic mice

The growing burden of psychological stress among diabetes patients has contributed to a rising incidence of depression within this population. It is of significant importance to conduct research on the impact of stress on diabetes patients and to explore potential pharmacological interventions to counteract the stress-induced exacerbation of their condition. Gastrodin is a low molecular weight bioactive compound extracted from the rhizome of Gastrodiae elata Blume, and it may be a preventive strategy for diabetes and a novel treatment for depression symptoms. However, its relevant pharmacological mechanisms for protecting against the impacts of psychological stress in diabetic patients are unclear. In this study, we performed 5 weeks CUMS intervention and simultaneously administered gastrodin (140 mg/kg, once daily) on T2DM mice, to investigate the potential protective effects of gastrodin. The protective effect of gastrodin was evaluated by behavioral tests, biochemical analysis, histopathological examination, RT-qPCR and gut microbiota analysis. We found that the depressive-like behavior and glucolipid metabolism could be deteriorated by chronic stress in type 2 diabetic mice, while gastrodin showed a protective effect against these exacerbations by regulating HPA hormones, activating FXR and Cyp7a1, reducing inflammatory and oxidative stress responses, and regulating ileal gut microbiota abundance. Gastrodin might be a potential therapeutic agent for mitigating the deterioration of diabetes conditions due to chronic stress.

A pilot study on the characterization and correlation of oropharyngeal and intestinal microbiota in children with type 1 diabetes mellitus

Background

Type 1 Diabetes Mellitus (T1DM) is one of the most common endocrine disorders of childhood and adolescence, showing a rapidly increasing prevalence worldwide. A study indicated that the composition of the oropharyngeal and gut microbiota changed in T1DM. However, no studies have yet associated the changes between the microbiomes of the oropharyngeal and intestinal sites, nor between the flora and clinical indicators. In this study, we examined the composition and characteristics of oropharyngeal and intestinal flora in patients with T1DM in compared to healthy children. We identified correlations between oropharyngeal and intestinal flora and evaluated their association with clinical laboratory tests in patients with T1DM.

Methods

The oropharyngeal and fecal samples from 13 T1DM and 20 healthy children were analyzed by high-throughput sequencing of the V3-V4 region of 16S rRNA. The associations between microbes and microorganisms in oropharyngeal and fecal ecological niches, as well as the correlation between these and clinical indicators were further analyzed.

Results

It was revealed that T1DM children had distinct microbiological characteristics, and the dominant oropharyngeal microbiota genus included Streptococcus, Prevotella, Leptotrichia, and Neisseria; that of intestinal microbiota included Blautia, Fusicatenibacter, Bacteroides, and Eubacterium_hallii_group. Furthermore, oropharyngeal Staphylococcus was significantly positively correlated with intestinal norank_f__Ruminococcaceae and Ruminococcus_torques_group in TIDM children. Moreover, in these children, differential genes in oropharyngeal and intestinal samples were enriched in metabolic pathways such as amino acid generation, fatty acid metabolism, and nucleotide sugar biosynthesis. Additionally, correlation analysis between the oropharyngeal/intestinal microbiome with laboratory tests showed significant correlations between several bacterial taxa in the oropharynx and intestines and glycated hemoglobin and C-peptide.

Conclusion

Unique microbial characteristics were found in the oropharynx and intestine in children with T1DM compared to healthy children. Positive correlations were found between changes in the relative abundance of oropharyngeal and gut microbiota in children with T1DM. Associations between the oropharyngeal/intestinal microbiota and laboratory investigations in children with T1DM suggest that the composition of the oropharyngeal and intestinal flora in children with T1DM may have some impact on glycemic control.

Western diet components that increase intestinal permeability with implications on health

Intestinal permeability is a physiological property that allows necessary molecules to enter the organism. This property is regulated by tight junction proteins located between intestinal epithelial cells. However, various factors can increase intestinal permeability (IIP), including diet. Specific components in the Western diet (WD), such as monosaccharides, fat, gluten, salt, alcohol, and additives, can affect the tight junctions between enterocytes, leading to increased permeability. This review explains how these components promote IIP and outlines their potential implications for health. In addition, we describe how a reduction in WD consumption may help improve dietary treatment of diseases associated with IIP. Research has shown that some of these components can cause changes in the gut microbiota, leading to dysbiosis, which can promote greater intestinal permeability and displacement of endotoxins into the bloodstream. These endotoxins include lipopolysaccharides derived from gram-negative bacteria, and their presence has been associated with various diseases, such as autoimmune, neurological, and metabolic diseases like diabetes and cardiovascular disease. Therefore, nutrition professionals should promote the reduction of WD consumption and consider the inclusion of healthy diet components as part of the nutritional treatment for diseases associated with increased intestinal permeability.

The Effect of Microbiome-Modulating Agents (MMAs) on Type 1 Diabetes: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Gut microbiome-modulating agents (MMAs), including probiotics, prebiotics, postbiotics, and synbiotics, are shown to ameliorate type 1 diabetes (T1D) by restoring the microbiome from dysbiosis. The objective of this systematic review and meta-analysis was to assess the impact of MMAs on hemoglobin A1c (HbA1c) and biomarkers associated with (T1D). A comprehensive search was conducted in PubMed, Web of Science, Embase, Cochrane Library, National Knowledge Infrastructure, WeiPu, and WanFang Data up to 30 November 2023. Ten randomized controlled trials (n = 630) were included, with study quality evaluated using the Cochrane risk-of-bias tool. Random-effect models with standardized mean differences (SMDs) were utilized. MMA supplementation was associated with improvements in HbA1c (SMD = -0.52, 95% CI [-0.83, -0.20]), daily insulin usage (SMD = -0.41, 95% confidence interval (CI) [-0.76, -0.07]), and fasting C-peptide (SMD = 0.99, 95% CI [0.17, 1.81]) but had no effects on FBG, CRP, TNF-α, IL-10, LDL, HDL, and the Shannon index. Subgroup analysis of HbA1c indicated that a long-term intervention (>3 months) might exert a more substantial effect. These findings suggest an association between MMAs and glycemic control in T1D. Further large-scale clinical trials are necessary to confirm these findings with investigations on inflammation and gut microbiota composition while adjusting confounding factors such as diet, physical activity, and the dose and form of MMA intervention.

Unraveling the Microbiome-Human Body Axis: A Comprehensive Examination of Therapeutic Strategies, Interactions and Implications

This review scrutinizes the intricate interplay between the microbiome and the human body, exploring its multifaceted dimensions and far-reaching implications. The human microbiome, comprising diverse microbial communities inhabiting various anatomical niches, is increasingly recognized as a critical determinant of human health and disease. Through an extensive examination of current research, this review elucidates the dynamic interactions between the microbiome and host physiology across multiple organ systems. Key topics include the establishment and maintenance of microbiota diversity, the influence of host factors on microbial composition, and the bidirectional communication pathways between microbiota and host cells. Furthermore, we delve into the functional implications of microbiome dysbiosis in disease states, emphasizing its role in shaping immune responses, metabolic processes, and neurological functions. Additionally, this review discusses emerging therapeutic strategies aimed at modulating the microbiome to restore host-microbe homeostasis and promote health. Microbiota fecal transplantation represents a groundbreaking therapeutic approach in the management of dysbiosis-related diseases, offering a promising avenue for restoring microbial balance within the gut ecosystem. This innovative therapy involves the transfer of fecal microbiota from a healthy donor to an individual suffering from dysbiosis, aiming to replenish beneficial microbial populations and mitigate pathological imbalances. By synthesizing findings from diverse fields, this review offers valuable insights into the complex relationship between the microbiome and the human body, highlighting avenues for future research and clinical interventions.

Exploring potential polysaccharide utilization loci involved in the degradation of typical marine seaweed polysaccharides by Bacteroides thetaiotaomicron

Introduction

Research on the mechanism of marine polysaccharide utilization by Bacteroides thetaiotaomicron has drawn substantial attention in recent years. Derived from marine algae, the marine algae polysaccharides could serve as prebiotics to facilitate intestinal microecological balance and alleviate colonic diseases. Bacteroides thetaiotaomicron, considered the most efficient degrader of polysaccharides, relates to its capacity to degrade an extensive spectrum of complex polysaccharides. Polysaccharide utilization loci (PULs), a specialized organization of a collection of genes-encoded enzymes engaged in the breakdown and utilization of polysaccharides, make it possible for Bacteroides thetaiotaomicron to metabolize various polysaccharides. However, there is still a paucity of comprehensive studies on the procedure of polysaccharide degradation by Bacteroides thetaiotaomicron.

Methods

In the current study, the degradation of four kinds of marine algae polysaccharides, including sodium alginate, fucoidan, laminarin, and Pyropia haitanensis polysaccharides, and the underlying mechanism by Bacteroides thetaiotaomicron G4 were investigated. Pure culture of Bacteroides thetaiotaomicron G4 in a substrate supplemented with these polysaccharides were performed. The change of OD600, total carbohydrate contents, and molecular weight during this fermentation were determined. Genomic sequencing and bioinformatic analysis were further performed to elucidate the mechanisms involved. Specifically, Gene Ontology (GO) annotation, Clusters of Orthologous Groups (COG) annotation, and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment were utilized to identify potential target genes and pathways.

Results

Underlying target genes and pathways were recognized by employing bioinformatic analysis. Several PULs were found that are anticipated to participate in the breakdown of these four polysaccharides. These findings may help to understand the interactions between these marine seaweed polysaccharides and gut microorganisms.

Discussion

The elucidation of polysaccharide degradation mechanisms by Bacteroides thetaiotaomicron provides valuable insights into the utilization of marine polysaccharides as prebiotics and their potential impact on gut health. Further studies are warranted to explore the specific roles of individual PULs and their contributions to polysaccharide metabolism in the gut microbiota.

A comparative study of the gut microbiome in Indian children with type 1 diabetes and healthy controls

INTRODUCTION

Type 1 diabetes mellitus (T1DM) occurs in genetically susceptible individuals due to certain environmental triggers causing destruction of insulin secreting beta cells. One of the environmental triggers studied recently in the pathogenesis and progression of T1DM is the role of gut microbiome.

OBJECTIVES

(1) To compare the gut microbiome profile of T1DM children with healthy age, gender, and body mass index (BMI) matched controls. (2) To assess the relationship of abundance of genera with glycemic control in children with T1DM.

METHODS

Cross-sectional, case-control study. Sixty-eight children with T1DM and 61 age-, gender-, and BMI-matched healthy controls were enrolled. QIAamp Fast DNA Stool Mini kit protocol and reagents were used for DNA isolation and Miseq sequencing platform for targeted gene sequencing.

RESULTS

Alpha and beta diversity analysis showed no significant differences in the abundance of microbes between the groups. At phylum level, Firmicutes was the dominant phylum followed by Actinobacteria and Bacteroidota in both groups. Analysis of microbiome at the genera level showed that percentage abundance for Parasutterella was higher in children with T1DM as compared to the healthy group (p < .05). A linear regression analysis showed that increase in abundance of Haemophilus (adjusted R2 = -1.481 p < .007) was associated with a significant decrease in glycated hemoglobin (HbA1c) concentrations (p < .05).

CONCLUSION

Our comparative study of gut microbiome profile showed significant differences in the taxonomial composition between Indian children with T1DM and healthy controls. Short chain fatty acid producers may play an important role in glycemic control.

Characterization of the gut bacterial and viral microbiota in latent autoimmune diabetes in adults

Latent autoimmune diabetes in adults (LADA) is a heterogeneous disease characterized by autoantibodies against insulin producing pancreatic beta cells and initial lack of need for insulin treatment. The aim of the present study was to investigate if individuals with LADA have an altered gut microbiota relative to non-diabetic control subjects, individuals with type 1 diabetes (T1D), and individuals with type 2 diabetes (T2D). Bacterial community profiling was performed with primers targeting the variable region 4 of the 16S rRNA gene and sequenced. Amplicon sequence variants (ASVs) were generated with DADA2 and annotated to the SILVA database. The gut virome was sequenced, using a viral particle enrichment and metagenomics approach, assembled, and quantified to describe the composition of the viral community. Comparison of the bacterial alpha- and beta-diversity measures revealed that the gut bacteriome of individuals with LADA resembled that of individuals with T2D. Yet, specific genera were found to differ in abundance in individuals with LADA compared with T1D and T2D, indicating that LADA has unique taxonomical features. The virome composition reflected the stability of the most dominant order Caudovirales and the families Siphoviridae, Podoviridae, and Inoviridae, and the dominant family Microviridae. Further studies are needed to confirm these findings.

Microbial and metabolomic profiles of type 1 diabetes with depression: A case-control study

BACKGROUND

Depression is the most common psychological disorder in patients with type 1 diabetes (T1D). However, the characteristics of microbiota and metabolites in these patients remain unclear. This study aimed to investigate microbial and metabolomic profiles and identify novel biomarkers for T1D with depression.

METHODS

A case-control study was conducted in a total of 37 T1D patients with depression (TD+), 35 T1D patients without depression (TD-), and 29 healthy controls (HCs). 16S rRNA gene sequencing and liquid chromatography-mass spectrometry (LC-MS) metabolomics analysis were conducted to investigate the characteristics of microbiota and metabolites. The association between altered microbiota and metabolites was explored by Spearman's rank correlation and visualized by a heatmap. The microbial signatures to discriminate TD+ from TD- were identified by a random forest (RF) classifying model.

RESULTS

In microbiota, 15 genera enriched in TD- and 2 genera enriched in TD+, and in metabolites, 14 differential metabolites (11 upregulated and 3 downregulated) in TD+ versus TD- were identified. Additionally, 5 genera (including Phascolarctobacterium, Butyricimonas, and Alistipes from altered microbiota) demonstrated good diagnostic power (area under the curve [AUC] = 0.73; 95% CI, 0.58-0.87). In the correlation analysis, Butyricimonas was negatively correlated with glutaric acid (r = -0.28, p = 0.015) and malondialdehyde (r = -0.30, p = 0.012). Both Phascolarctobacterium (r = 0.27, p = 0.022) and Alistipes (r = 0.31, p = 0.009) were positively correlated with allopregnanolone.

CONCLUSIONS

T1D patients with depression were characterized by unique profiles of gut microbiota and serum metabolites. Phascolarctobacterium, Butyricimonas, and Alistipes could predict the risk of T1D with depression. These findings provide further evidence that the microbiota-gut-brain axis is involved in T1D with depression.

Gut microbiota in relationship to diabetes mellitus and its late complications with a focus on diabetic foot syndrome: A review

Diabetes mellitus is a chronic disease affecting glucose metabolism. The pathophysiological reactions underpinning the disease can lead to the development of late diabetes complications. The gut microbiota plays important roles in weight regulation and the maintenance of a healthy digestive system. Obesity, diabetes mellitus, diabetic retinopathy, diabetic nephropathy and diabetic neuropathy are all associated with a microbial imbalance in the gut. Modern technical equipment and advanced diagnostic procedures, including xmolecular methods, are commonly used to detect both quantitative and qualitative changes in the gut microbiota. This review summarises collective knowledge on the role of the gut microbiota in both types of diabetes mellitus and their late complications, with a particular focus on diabetic foot syndrome.

The association between interleukin family and diabetes mellitus and its complications: An overview of systematic reviews and meta-analyses

OBJECTIVE

To evaluate and summarize the association between interleukin (IL) concentrations and diabetes mellitus (DM) and its complications.

METHODS

Meta-analyses and eligible individual studies of observational studies investigating the associations between IL and DM and its complications were included. The random-effects model was used to estimate the summary effect, and the heterogeneity among studies was assessed using the Q-statistic and the I2 metric; The Egger's regression and the χ2 test were used to test for small study effects and excess significance bias.

RESULTS

This overview identified 34 meta-analyses that investigated the association between IL concentrations and DM and its complications. Meta-analyses of prospective studies indicated that elevated circulating IL-6 and IL-1β had predictive value for the incident of type 2 diabetes mellitus (T2DM), type 1 diabetes mellitus (T1DM) as well as gestational diabetes mellitus (GDM), and the overall Hazard Ratio (HR) of T2DM was 1.28 (95 % CI: 1.17, 1.40; P＜0.001) per 1 log pg/ml increment in IL-6 levels, however, there was no correlation between circulating IL-10 levels and DM. Meanwhile, the increased level of IL-6 was significantly associated several diabetic complications (Diabetic kidney disease[DKD], diabetic peripheral neuropathy[DPN], and cognitive impairment[CI]), and for the diabetic retinopathy (DR), the levels of IL-1β, IL-8 and IL-10 in the aqueous humor and vitreous humor, but not the blood were significantly correlated with it.

CONCLUSION

Multiple ILs, such as the IL-6 and IL-1β, are definitively linked to DM and its complications, and they may be new targets for the diagnosis and treatment, but stronger evidence needs to be confirmed by prospective studies with larger sample sizes and longer observation periods.

Imbalance of gut microbiota in gestational diabetes

AIM

To investigate the differences in gut microbiota composition among nonpregnant women of reproductive age, healthy pregnant women, and gestational diabetes (GD) patients.

METHODS

A total of 45 outpatients were enrolled and divided into three groups: nonpregnant women of reproductive age (control group, n = 23), healthy pregnant women (normal group, n = 10), and GD patients (GD group, n = 12). Faecal samples were collected and sequenced using 16S rRNA gene sequencing to analyse the microbial composition.

RESULTS

(1) Pregnant patients exhibited an increase in the abundance of Streptococcus (Pnormal = 0.01286, PGD = 0.002965) and Blautia (Pnormal = 0.0003924, PGD = 0.000246) but a decrease in the abundance of Roseburia (Pnormal = 0.0361, PGD = 0.007075), Phascolarctobacterium (Pnormal = 0.0003906, PGD = 0.02499) and Lachnoclostridium (Pnormal = 0.0003906, PGD = 0.03866). (2) Compared with healthy pregnant women, GD patients had an excessive increase in Streptococcus abundance and decrease in Roseburia abundance. The increase in Blautia abundance and the decrease in Phascolarctobacterium and Lachnoclostridium abundance in GD patients were less than those in healthy pregnant women. (3) The abundance of Faecalibacterium prausnitzii decreased significantly in GD patients (PGD = 0.02985) but not in healthy pregnant patients (Pnormal = 0.1643).

CONCLUSIONS

Abnormal increases and decreases in the abundances of gut microbiota components, especially Faecalibacterium prausnitzii, were observed in GD patients.

TRIAL REGISTRATION

The cross-sectional research was conducted in accordance with the Declaration of Helsinki, and approved by Sir Run Run Shaw Hospital Clinical Trials and Biomedical Ethics Committee. The study has been registered in the Chinese Clinical Trial Registry (ChiCTR1900026164, 24/09/2019, http://www.chictr.org.cn/showproj.aspx?proj=43,455 ).

Use of probiotics and similar in pediatric patients with Type 1 Diabetes Mellitus: a systematic review

OBJECTIVE

To perform a systematic review of randomized controlled trials, evaluating the effect of probiotics, prebiotics or symbiotics supplementation on glycemic and inflammatory control in children with Type 1 Diabetes Mellitus (T1DM).

DATA SOURCE

The Medical Literature Analysis and Retrieval System Online (MEDLINE/PubMed), Clinical Trials, Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS) and Scientific Electronic Library Online (SciELO) databases were searched. Randomized clinical trials of pediatric patients with DM1 using probiotics, prebiotics or symbiotics were included, regardless of year or language of publication. Studies that did not evaluate glycated hemoglobin (HbA1c) were excluded. Metabolic results (HbA1c, total insulin dose and C-peptide) and inflammatory control [interleukin-10 (IL-10), tumor necrosis factor-alpha (TNF-α) and interferon-gamma (IFN-γ)] during probiotic supplementation or similar, related to modification of the intestinal microbiota, were analyzed. PROSPERO ID: CRD42022384485.

DATA SYNTHESIS

Five studies were selected for a systematic review. Regarding metabolic markers, only one of the articles that analyzed HbA1c showed a significant decrease (p=0.03) in the intervention group. One study identified a reduction in the total dose of insulin and increased C-peptide levels. Regarding the evaluation of inflammatory parameters (IL-10, TNF-α, INF-γ), there were no statistical relevant modifications.

CONCLUSIONS

Current data from the literature were not conclusive in identifying an improvement in glycemic control and did not observe changes in inflammatory parameters with the use of probiotics, prebiotics or symbiotics in pediatric patients with T1DM.

Association between Gut Microbiota and Biological Aging: A Two-Sample Mendelian Randomization Study

Recent observational studies revealed an association between gut microbiota and aging, but whether gut microbiota are causally associated with the aging process remains unknown. We used a two-sample Mendelian randomization approach to investigate the causal association between gut microbiota and biological age acceleration using the largest available gut microbiota GWAS summary data from the MiBioGen consortium and GWAS data on biological age acceleration. We further conducted sensitivity analysis using MR-PRESSO, MR-Egger regression, Cochran Q test, and reverse MR analysis. Streptococcus (IVW, β = 0.16, p = 0.0001) was causally associated with Bioage acceleration. Eubacterium (rectale group) (IVW, β = 0.20, p = 0.0190), Sellimonas (IVW, β = 0.06, p = 0.019), and Lachnospira (IVW, β = -0.18, p = 0.01) were suggestive of causal associations with Bioage acceleration, with the latter being protective. Actinomyces (IVW, β = 0.26, p = 0.0083), Butyricimonas (IVW, β = 0.21, p = 0.0184), and Lachnospiraceae (FCS020 group) (IVW, β = 0.24, p = 0.0194) were suggestive of causal associations with Phenoage acceleration. This Mendelian randomization study found that Streptococcus was causally associated with Bioage acceleration. Further randomized controlled trials are needed to investigate its role in the aging process.

Important Recommendations Regarding the Test-and-Treat Strategy for Helicobacter pylori Infection in Children

Helicobacter pylori is a commonly encountered pathogen in medical practice. It causes chronic gastritis in patients of different ages. Many published papers have provided different opinions on whether the test-and-treat strategy for H. pylori infection should be implemented in children. It is critical that the opinion in favor of this strategy was published in Europe, where ESPGHAN/NASPGHAN guidelines have not recommended the use of test-and-treat strategy for H. pylori in children. Herein, I propose my opinion regarding this debate using 4 main points. First, this strategy should be implemented in areas where its benefits outweigh the associated risks. Thus, if it is not tailored to the locality, the results of the test-and-treat strategy for H. pylori in children may be erroneous. Second, the association between H. pylori infection and other diseases such as asthma and other allergic diseases should not be factored in when considering the test-and-treat strategy. This is because these diseases are associated with H. pylori noninfection and not with its posteradication status. Third, there is evidence that H. pylori infection can significantly alter children's intestinal microbiota. Finally, gastroscopy should not be performed in all H. pylori-positive children, particularly if the drug susceptibility test is not available. In the near future, it will be possible to easily conduct drug susceptibility tests for H. pylori using fecal samples. I believe that this report may expand the test-and-treat strategy for children infected with asymptomatic H. pylori outside of Japan and prevent not only gastric cancer but also minor diseases such as iron deficiency anemia, chronic idiopathic thrombocytopenic purpura, and failure to thrive. Pediatricians are responsible for keeping children healthy not only during childhood but also in adulthood. Thus, even if there are only a few H. pylori-related diseases and no severe cases in children, it is necessary to take early measures to prevent problems (eg, incidence of gastric cancer) in adulthood.

Impact of gut microbiota and associated mechanisms on postprandial glucose levels in patients with diabetes

Diabetes and its complications are serious medical and global burdens, often manifesting as postprandial hyperglycemia. In recent years, considerable research attention has focused on relationships between the gut microbiota and circulating postprandial glucose (PPG). Different population studies have suggested that PPG is closely related to the gut microbiota which may impact PPG via short-chain fatty acids (SCFAs), bile acids (BAs) and trimethylamine N-oxide (TMAO). Studies now show that gut microbiota models can predict PPG, with individualized nutrition intervention strategies used to regulate gut microbiota and improve glucose metabolism to facilitate the precision treatment of diabetes. However, few studies have been conducted in patients with diabetes. Therefore, little is known about the relationships between the gut microbiota and PPG in this cohort. Thus, more research is required to identify key gut microbiota and associated metabolites and pathways impacting PPG to provide potential therapeutic targets for PPG.

Assessment of selected muscle damage markers and zonulin concentration after maximum-intensity exercise in men with type 1 diabetes treated with a personal insulin pump

AIM

Exercise-induced muscle damage depends on exercise intensity and duration and on individual susceptibility. Mechanical and metabolic stress may disturb the intestinal microflora. The study evaluated selected muscle damage markers and zonulin concentration after maximum-intensity exercise in type 1 diabetes (T1D) men compared with healthy controls.

METHODS

The study involved 16 T1D participants and 28 controls matched by age (22.7 [21.3-25.1] vs. 22.6 [20.9-26.3] years), body mass index (24.2 ± 1.6 vs. 24.2 ± 1.9 kg/m2), and body fat percentage (16.1 ± 5.2 vs. 14.9 ± 4.6%). The T1D group had 11.3 ± 5.1 years of diabetes duration and a suboptimal mean glycated haemoglobin level of 7.2 ± 1.1%. The subjects underwent a graded running treadmill test until exhaustion. Lactate concentration was assessed in arterialized blood at baseline and 3 and 20 min after the test. Cortisol, testosterone, tumour necrosis factor α, myoglobin, lactate dehydrogenase, zonulin, and vitamin D levels were evaluated in cubital fossa vein blood before and 60 min after the test.

RESULTS

T1D patients presented higher baseline zonulin, myoglobin concentration, testosterone/cortisol ratio, and lower maximal oxygen uptake. On adjusting for the baseline values, the groups differed in zonulin, lactate dehydrogenase, and myoglobin levels, testosterone/cortisol ratio, and lactate concentration determined 20 min after exercise (P < 0.05).

CONCLUSION

Maximum-intensity exercise increased muscle and intestinal damage in T1D participants. In patients with lower physical activity, very-high-intensity exercise should be recommended with caution. Observing the anabolic-catabolic index may help individualize effort intensity in T1D individuals.

Gut microbiome and blood glucose control in type 1 diabetes: a systematic review

Objective

The risk of developing micro- and macrovascular complications is higher for individuals with type 1 diabetes (T1D). Numerous studies have indicated variations in gut microbial composition between healthy individuals and those with T1D. These changes in the gut ecosystem may lead to inflammation, modifications in intestinal permeability, and alterations in metabolites. Such effects can collectively impact the metabolic regulation system, thereby influencing blood glucose control. This review aims to explore the relationship between the gut microbiome, inflammation, and blood glucose parameters in patients with T1D.

Methods

Google Scholar, PubMed, and Web of Science were systematically searched from 2003 to 2023 using the following keywords: "gut microbiota," "gut microbiome," "bacteria," "T1D," "type 1 diabetes," "autoimmune diabetes," "glycemic control," "glucose control," "HbA1c," "inflammation," "inflammatory," and "cytokine." The examination has shown 18,680 articles with relevant keywords. After the exclusion of irrelevant articles, seven observational papers showed a distinct gut microbial signature in T1D patients.

Results

This review shows that, in T1D patients, HbA1c level was negatively correlated with abundance of Prevotella, Faecalibacterium, and Ruminococcaceae and positively correlated with abundance of Dorea formicigenerans, Bacteroidetes, Lactobacillales, and Bacteriodes. Instead, Bifidobacteria was negatively correlated with fasting blood glucose. In addition, there was a positive correlation between Clostridiaceae and time in range. Furthermore, a positive correlation between inflammatory parameters and gut dysbiosis was revealed in T1D patients.

Conclusion

We draw the conclusion that the gut microbiome profiles of T1D patients and healthy controls differ. Patients with T1D may experience leaky gut, bacterial translocation, inflammation, and poor glucose management due to microbiome dysbiosis. Direct manipulation of the gut microbiome in humans and its effects on gut permeability and glycemic control, however, have not been thoroughly investigated. Future research should therefore thoroughly examine other potential pathophysiological mechanisms in larger studies.

Quantitative profiling and diagnostic potential of one-carbon and central metabolism pools in MODY2 and T1DM

BACKGROUND

Maturity-onset diabetes of the young type 2 (MODY2) is a rare genetic disorder characterized as mild fasting hyperglycemia with low risk of vascular complications caused by glucokinase gene mutation. This study aims to investigate metabolites alteration associated with MODY2, exploring possible mechanism underlying characteristic clinical manifestations and low cardiovascular risks of MODY2 and providing serum metabolite biomarkers to facilitating MODY2 diagnosis.

METHODS

Fasting serum samples from MODY2, type 1 diabetes (T1DM) and healthy individuals were collected. By using targeted metabolomics via liquid chromatography-tandem mass spectrometry platform, we quantified the metabolites involved in tricarboxylic acid (TCA) cycle and one-carbon metabolism.

RESULTS

Metabolomic profiling revealed significant difference of intermediates from central metabolism cycle, methionine cycle and several amino acids between MODY2 and T1DM groups. Among these, serum citrate, α-ketoglutaric acid, serine, glycine, glutamine and homocysteine were significantly elevated in MODY2 patients compared with T1DM patients; and compared with healthy subjects, malate and methionine levels were significantly increased in the two groups of diabetic patients. The correlation analysis with clinical indexes showed that α- ketoglutarate, serine, glycine, and glutamine were negatively correlated with blood glucose indicators including fasting blood glucose, HbA1c, and GA, while citrate was positively correlated with C-peptide. And homocysteine displayed positive correlation with HDL and negative with C-reactive protein, which shed light on the mechanism of mild symptoms and low risk of cardiovascular complications in MODY2 patients. A panel of 4 metabolites differentiated MODY2 from T1DM with AUC of 0.924, and a combination of clinical indices and metabolite also gained good diagnostic value with AUC 0.948.

CONCLUSION

In this research, we characterized the metabolite profiles of TCA cycle and one-carbon metabolism in MODY2 and T1DM and identified promising diagnostic biomarkers for MODY2. This study may provide novel insights into the pathogenesis and clinical manifestations of MODY2.

Yeast Beta-Glucan Supplementation with Multivitamins Attenuates Cognitive Impairments in Individuals with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Randomized, Double-Blind, Placebo-Controlled Trial

This research aimed to examine the potential alleviative effects of beta-glucan administration on fatigue, unrefreshing sleep, anxiety/depression symptoms and health-related quality of life in ME/CFS. A 36-week unicenter, randomized, double-blind, placebo-controlled trial was conducted in 65 ME/CFS patients, who were randomly allocated to one of two arms to receive four capsules each one of 250 mg beta-glucan, 3.75 µg vitamin D3, 1.05 mg vitamin B6, and 7.5 mg zinc (n = 35), or matching placebo including only microcrystalline cellulose as an excipient (n = 30) once daily. The findings showed that the beta-glucan supplementation significantly improved cognitive fatigue (assessed with FIS-40 scores) after the 36-week treatment compared to the baseline (p = 0.0338). Taken together, this study presents the novel finding that yeast-derived beta-glucan may alleviate cognitive fatigue symptoms in ME/CFS. Thus, it offers valuable scientific insights into the potential use of yeast beta-glucan as a nutritional supplement and/or functional food to prevent or reduce cognitive dysfunction in patients with ME/CFS. Further interventions are warranted to validate these findings and also to delve deeper into the possible immunometabolic pathomechanisms of beta-glucans in ME/CFS.

Pilot Study on Gut Microbiota Profile in Indian Children with Type 1 Diabetes

Background

Non-genetic factors like microbial dysbiosis may be contributing to the increasing incidence/progression of type 1 diabetes mellitus (T1DM).

Objectives

To analyse the gut microbiota profile in Indian children with T1DM and its effect on glycaemic control.

Methodology

Faecal samples of 29 children with T1DM were collected and faecal microbial DNA was extracted and subjected to 16S rRNA (ribosomal RNA) sequencing and further analysis.

Results

The dominant phyla in children with T1DM were Firmicutes and Bacteroidetes. Butyrate-producing bacteria Blautia and Ruminococcus showed a significant negative correlation with the glycosylated haemoglobin (HbA1C) levels (p < 0.05). Coprococcus and Propionibacterium were important negative predictors of glycaemic control (p < 0.05).

Conclusion

Our study suggests that Indian children with T1DM have a distinct gut microbiome taxonomic composition and that short-chain fatty acid-producing bacteria like Ruminococcus and Blautia (butyrate-producing) may play an important role in the glycaemic control of subjects with T1DM.

Exploring the interactive mechanism of acarbose with the amylase SusG in the starch utilization system of the human gut symbiont Bacteroides thetaiotaomicron through molecular modeling

The α-amylase, SusG, is a principal component of the Bacteroides thetaiotaomicron (Bt) starch utilization system (Sus) used to metabolize complex starch molecules in the human gastrointestinal (GI) tract. We previously reported the non-microbicidal growth inhibition of Bt by the acarbose-mediated arrest of the Sus as a potential therapeutic strategy. Herein, we report a computational approach using density functional theory (DFT), molecular docking, and molecular dynamics (MD) simulation to explore the interactive mechanism between acarbose and SusG at the atomic level in an effort to understand how acarbose shuts down the Bt Sus. The docking analysis reveals that acarbose binds orthosterically to SusG with a binding affinity of -8.3 kcal/mol. The MD simulation provides evidence of conformational variability of acarbose at the active site of SusG and also suggests that acarbose interacts with the main catalytic residues via a general acid-base double-displacement catalytic mechanism. These results suggest that small molecule competitive inhibition against the SusG protein could impact the entire Bt Sus and eliminate or reduce the system's ability to metabolize starch. This computational strategy could serve as a potential avenue for structure-based drug design to discover other small molecules capable of inhibiting the Sus of Bt with high potency, thus providing a holistic approach for selective modulation of the GI microbiota.

Fecal microbial biomarkers in older adults with autoimmune diseases

Aim: To analyze the alterations in the fecal microbiota of older adults with autoimmune disease and determine the diagnostic capabilities of microbial biomarkers. Methods: The raw data of fecal samples from 444 older adults from the publicly available American Gut Project database was analyzed. Results: It was found that there were no significant differences in the microbiota richness and evenness between older adults with autoimmune disease and healthy controls. However, significant differences were observed in the microbiota composition and structure. The subject operating characteristic curve of the eight key microbiota was obtained, and the area under curve value was 70.0%. Conclusion: Older adults with autoimmune disease showed changes in intestinal microbiota composition, which can be used as microbial biomarkers.

Fecal microbiota transplantation in childhood: past, present, and future

BACKGROUND

Fecal microbiota transplantation (FMT) has been well described in the treatment of pediatric diseases; however, the latest updates regarding its use in children are unclear and the concepts involved need to be revisited.

DATA SOURCES

We performed advanced searches in the MEDLINE, EMBASE, and Cochrane databases using the keywords "Fecal microbiota transplantation OR Fecal microbiota transfer" in the [Title/Abstract] to identify relevant articles published in English within the last five years. To identify additional studies, reference lists of review articles and included studies were manually searched. Retrieved manuscripts (case reports, reviews, and abstracts) were assessed by the authors.

RESULTS

Among the articles, studies were based on the mechanism (n = 28), sample preparation (n = 9), delivery approaches (n = 23), safety (n = 26), and indications (n = 67), including Clostridium difficile infection (CDI) and recurrent C. difficile infection (rCDI; n = 21), non-alcoholic fatty liver disease (NAFLD; n = 10), irritable bowel syndrome (IBS; n = 5), inflammatory bowel disease (IBD; n = 15), diabetes (n = 5), functional constipation (FC; n = 4), and autism spectrum disorder (ASD; n = 7).

CONCLUSIONS

Concepts of FMT in pediatric diseases have been updated with respect to underlying mechanisms, methodology, indications, and safety. Evidence-based clinical trials for the use of FMT in pediatric diseases should be introduced to resolve the challenges of dosage, duration, initiation, and the end point of treatment.

Distinct signatures of gut microbiota and metabolites in different types of diabetes: a population-based cross-sectional study

BACKGROUND

Patients with type 1 diabetes (T1D) and type 2 diabetes (T2D) present intestinal disturbances. Recent epidemiological data have showed that, worldwide, over half of newly diagnosed T1D patients were adults. However, the gut microbial alterations in adult-onset T1D are unclear. We aimed to identify the signatures of gut microbiota and metabolites in patients with adult-onset T1D systematically, comparing with T2D patients and healthy controls (HCs).

METHODS

This study enrolled 218 subjects from February 2019 to April 2022 (discovery cohort: 36 HCs, 51 patients with adult-onset T1D and 56 patients with T2D; validation cohort: 28 HCs, 27 patients with adult-onset T1D and 20 patients with T2D). Gut microbial profiles of the study subjects were investigated by metagenomic sequencing, and their faecal and serum metabolites were measured with targeted metabolomics. The study was registered on ClinicalTrials.gov (NCT05252728).

FINDINGS

Patients with adult-onset T1D had significant differences in the composition of bacteria and their metabolites, characterized by notable depletion of short-chain fatty acid-producing bacteria, especially Eubacterium rectale. This was associated with a severe loss of phenolic acids and their derivatives, including gallic acid (associated with glucose metabolism) and 3,4-dihydroxyhydrocinnamic acid (linked with glucose metabolism and pancreatic beta cell autoimmunity). A predictive model based on six bacteria and six metabolites simultaneously discriminated adult-onset T1D from T2D and HCs with high accuracy. Interestingly, bacterial-viral or bacterial-fungal trans-kingdom relationships, especially positive correlations between bacteriophages and beneficial bacteria, were significantly reduced in adult-onset T1D compared to HCs.

INTERPRETATION

Adult-onset T1D patients exhibit unique changes in host-microbiota-metabolite interactions. Gut microbiota and metabolite-based algorithms could be used as additional tools for differential diagnosis of different types of diabetes and beyond.

FUNDING

National Key Research and Development Program of China, the National Natural Science Foundation of China.

Correlation between gut microbiota and the development of Graves' disease: A prospective study

The association between gut microbiota and development of Graves' disease (GD) remains unclear. This study aimed to profile the gut microbiota of 65 patients newly diagnosed with GD before and after treatment and 33 physical examination personnel via 16S rRNA sequencing. Significant differences in the gut microbiota composition were observed between the two groups, showing relative bacterial abundances of 1 class, 1 order, 5 families, and 14 genera. After treatment, the abundance of the significantly enriched biota in the GD group decreased considerably, whereas that of the previously decreased biota increased considerably. Further, interleukin-17 levels decreased significantly. The random forest method was used to identify 12 genera that can distinguish patients with GD from healthy controls. Our study revealed that the gut microbiota of patients with GD exhibit unique characteristics compared with that of healthy individuals, which may be related to an imbalance in the immune system and gut microbiota.

Evaluation of Gut Microbiota in Healthy Persons and Type 1 Diabetes Mellitus Patients in North-Western Russia

Bacterial microbiota in stool may vary over a wide range, depending on age, nutrition, etc. The purpose of our work was to discriminate phyla and genera of intestinal bacteria and their biodiversity within a healthy population (North-Western Russia) compared to the patients with type 1 diabetes mellitus (T1DM). The study group included 183 healthy persons 2 to 53 years old (a mean of 26.5±1.0 years old), and 41 T1DM patients (mean age 18.2±1.8 years old). The disease onset was at 11±1.5 years, with a T1DM experience of 7±1.5 years. Total DNA was isolated from the stool samples, and sequencing libraries were prepared by amplifying the V3-V4 region of the 16S rRNA gene sequenced by Illumina MiSeq. Bioinformatic processing of NGS databases was adapted for microbiota evalutaion. Despite the broad scatter, the biological diversity for bacterial microbiota expressed as the Shannon index was significantly increased from younger to older ages in the comparison group, higher in adult healthy persons, with a trend for decrease in the Actinomycetota phylum which includes Bifidobacterium longum species. Similar but non-significant age trends were noted in the T1DM group. Concordant with the Bacillota prevalence in stool samples of diabetic patients, some anaerobic bacteria (Faecalibacteria, Lachnospira and Ruminococcae, Roseburia) were enriched in the T1DM microbiome against controls. Hence, correction of microbiota for Ruminococcus and Lachnospiraceae requires future search for new probiotics. Lower abundance of Actinomycetota and Bifidobacter in T1DM suggests potential usage of Bifidobacter-based probiotics in this cohort.

Microbial taxonomic and functional shifts in adolescents with type 1 diabetes are associated with clinical and dietary factors

BACKGROUND

Evidence indicates a link between the pathogenesis of type 1 diabetes (T1D) and the gut microbiome. However, the regulation of microbial metabolic pathways and the associations of bacterial species with dietary factors in T1D are largely unknown. We investigated whether microbial metagenomic signatures in adolescents with T1D are associated with clinical/dietary factors.

METHODS

Adolescents with T1D (case) and healthy adolescents (control) were recruited, and microbiome profiling in participants' stool samples was performed using shotgun metagenomic sequencing. The bioBakery3 pipeline (Kneaddata, Metaphlan 4 and HUMAnN) was used to assign taxonomy and functional annotations. Clinical (HbA1c) and dietary information (3-day food record) were collected for conducting association analysis using Spearman's correlation.

FINDINGS

Adolescents with T1D exhibited modest changes in taxonomic composition of gut microbiome. Nineteen microbial metabolic pathways were altered in T1D, including downregulation of biosynthesis of vitamins (B2/flavin, B7/biotin and B9/folate), enzyme cofactors (NAD+ and s-adenosyl methionine) and amino acids (aspartate, asparagine and lysine) with an upregulation in the fermentation pathways. Furthermore, bacterial species associated with dietary and clinical factors differed between healthy adolescents and adolescents with T1D. Supervised models modeling identified taxa predictive of T1D status, and the top features included Coprococcus and Streptococcus.

INTERPRETATION

Our study provides new insight into the alteration of microbial and metabolic signatures in adolescents with T1D, suggesting that microbial biosynthesis of vitamins, enzyme cofactors and amino acids may be potentially altered in T1D.

FUNDING

Research grants from NIH/NCCIH: R01AT010247 and USDA/NIFA: 2019-67017-29253; and Larry & Gail Miller Family Foundation Assistantship.

Gut microbiota short-chain fatty acids and their impact on the host thyroid function and diseases

Thyroid disorders are clinically characterized by alterations of L-3,5,3',5'-tetraiodothyronine (T4), L-3,5,3'-triiodothyronine (T3), and/or thyroid-stimulating hormone (TSH) levels in the blood. The most frequent thyroid disorders are hypothyroidism, hyperthyroidism, and hypothyroxinemia. These conditions affect cell differentiation, function, and metabolism. It has been reported that 40% of the world's population suffers from some type of thyroid disorder and that several factors increase susceptibility to these diseases. Among them are iodine intake, environmental contamination, smoking, certain drugs, and genetic factors. Recently, the intestinal microbiota, composed of more than trillions of microbes, has emerged as a critical player in human health, and dysbiosis has been linked to thyroid diseases. The intestinal microbiota can affect host physiology by producing metabolites derived from dietary fiber, such as short-chain fatty acids (SCFAs). SCFAs have local actions in the intestine and can affect the central nervous system and immune system. Modulation of SCFAs-producing bacteria has also been connected to metabolic diseases, such as obesity and diabetes. In this review, we discuss how alterations in the production of SCFAs due to dysbiosis in patients could be related to thyroid disorders. The studies reviewed here may be of significant interest to endocrinology researchers and medical practitioners.

Association Between Intestinal Prevotella copri Abundance and Glycemic Fluctuation in Patients with Brittle Diabetes

Objective

Previous studies have demonstrated an association between gut microbiota composition and non-brittle type 2 diabetes (NBT2DM) pathogenesis. However, little is known about the correlation between the abundance of intestinal Prevotella copri and glycemic fluctuations in patients with brittle diabetes mellitus (BDM). In this context, we conducted a case-control study of BDM patients and patients with NBT2DM, aiming to determine and analyze the relationship between the abundance of intestinal Prevotella copri and glycemic fluctuations in patients with BDM.

Research Design and methods

We performed a metagenomic analysis of the gut microbiome obtained from fecal samples of 10 BDM patients, and compared their microbial composition and function to NBT2DM patients (1:1 ratio). Then further collected data including age, sex, BMI, glycated hemoglobin (HbA1c), blood lipids, and alpha diversity of the gut microbiota, which were comparable between the BDM and NBT2DM patients by t-test.

Results

A significant difference existed in the beta diversity of the gut microbiota between the two groups (PCoA, R² = 0.254, P = 0.0001). The phylum-level abundance of Bacteroidetes in the gut microbiota of the BDM patients was significantly lower, by 24.9% (P = 0.001), than that of the NBT2DM patients. At the gene level, the abundance of Prevotella copri was obviously reduced, Correlation analysis showed that the Prevotella copri abundance was inversely correlated to the standard deviation of blood glucose (SDBG) (r = -0.477, P = 0.034). Quantitative PCR confirmed that the abundance of Prevotella copri in the BDM patients in the validation cohort was significantly lower than that in NBT2DM patients, and was negatively correlated with SDBG (r = -0.318, P = 0.043). Glycemic variability in BDM was inversely correlated with the abundance of intestinal Prevotella copri.

Conclusion

The decreased abundance of Prevotella copri in patients with BDM may be associated with glycemic fluctuation.

Gut microbiota and type 1 diabetes: a two-sample bidirectional Mendelian randomization study

Objective

The real causal relationship between human gut microbiota and T1D remains unclear and difficult to establish. Herein, we adopted a two-sample bidirectional mendelian randomization (MR) study to evaluate the causality between gut microbiota and T1D.

Methods

We leveraged publicly available genome-wide association study (GWAS) summary data to perform MR analysis. The gut microbiota-related GWAS data from 18,340 individuals from the international consortium MiBioGen were used. The summary statistic data for T1D (n = 264,137) were obtained from the latest release from the FinnGen consortium as the outcome of interest. The selection of instrumental variables conformed strictly to a series of preset inclusion and exclusion criteria. MR-Egger, weighted median, inverse variance weighted (IVW), and weighted mode methods were used to assess the causal association. The Cochran's Q test, MR-Egger intercept test, and leave-one-out analysis were conducted to identify heterogeneity and pleiotropy.

Results

At the phylum level, only Bacteroidetes was indicated to have causality on T1D (OR = 1.24, 95% CI = 1.01-1.53, P = 0.044) in the IVW analysis. When it comes to their subcategories, Bacteroidia class (OR = 1.28, 95% CI = 1.06-1.53, P = 0.009, P _FDR = 0.085), Bacteroidales order (OR = 1.28, 95% CI = 1.06-1.53, P = 0.009, P _FDR = 0.085), and Eubacterium eligens group genus (OR = 0.64, 95% CI = 0.50-0.81, P = 2.84×10^-4, P _FDR = 0.031) were observed to have a causal relationship with T1D in the IVW analysis. No heterogeneity and pleiotropy were detected.

Conclusions

The present study reports that Bacteroidetes phylum, Bacteroidia class, and Bacteroidales order causally increase T1D risk, whereas Eubacterium eligens group genus, which belongs to the Firmicutes phylum, causally decreases T1D risk. Nevertheless, future studies are warranted to dissect the underlying mechanisms of specific bacterial taxa's role in the pathophysiology of T1D.

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.

Astragalus polysaccharides alleviate type 1 diabetes via modulating gut microbiota in mice

Type 1 diabetes (T1D) is a serious health problem that needs to be addressed worldwide. Astragalus polysaccharides (APS), the main chemical components of Astragali Radix, have anti-diabetic activity. As most plant polysaccharides are difficult to digest and absorb, we hypothesised that APS exert hypoglycaemic effects through the gut. This study intends to investigate the modulation of T1D associated with gut microbiota by neutral fraction of Astragalus polysaccharides (APS-1). T1D mice were induced with streptozotocin and then treated with APS-1 for 8 weeks. Fasting blood glucose levels were decreased and the insulin levels were increased in T1D mice. The results demonstrated that APS-1 improved gut barrier function by regulating ZO-1, Occludin and Claudin-1 expression, and reconstructed gut microbiota by increasing the relative abundance of Muribaculum, Lactobacillus and Faecalibaculum. In addition, APS-1 significantly increased the levels of acetic acid, propionic acid, butyric acid and inhibited the expression of pro-inflammatory factors IL-6 and TNF-α in T1D mice. Further exploration revealed that APS-1 alleviation of T1D may be associated with short-chain fatty acids (SCFAs)-producing bacteria, and that SCFAs binds to GPRs and HDACs proteins and modulate the inflammatory responses. In conclusion, the study supports the potential of APS-1 as a therapeutic agent for T1D.