Functional and metabolic alterations of gut microbiota in children with new-onset type 1 diabetes

The regulatory effect of chitooligosaccharides on islet inflammation in T2D individuals after islet cell transplantation: the mechanism behind Candida albicans abundance and macrophage polarization

Islet cell transplantation (ICT) represents a promising therapeutic approach for addressing diabetes mellitus. However, the islet inflammation during transplantation significantly reduces the surgical outcome rate, which is related to the polarization of macrophages. Chitooligosaccharides (COS) was previously reported which could modulate the immune system, alleviate inflammation, regulate gut microecology, and repair the intestinal barrier. Therefore, we hypothesized COS could relieve pancreatic inflammation by regulating macrophage polarization and gut microbiota. First, 18S rDNA gene sequencing was performed on fecal samples from the ICT population, showing abnormally increased amount of Candida albicans, possibly causing pancreatic inflammation. Functional oligosaccharides responsible for regulating macrophage polarization and inhibiting the growth of Candida albicans were screened. Afterwards, human flora-associated T2D (HMA-T2D) mouse models of gut microbiota were established, and the ability of the selected oligosaccharides were validated in vivo to alleviate inflammation and regulate gut microbiota. The results indicated that ICT significantly decreased the alpha diversity of gut fungal, altered fungal community structures, and increased Candida albicans abundance. Moreover, Candida albicans promoted M1 macrophage polarization, leading to islet inflammation. COS inhibited Candida albicans growth, suppressed the MyD88-NF-κB pathway, activated STAT6, inhibited M1, and promoted M2 macrophage polarization. Furthermore, COS-treated HMA-T2D mice displayed lower M1 macrophage differentiation and higher M2 macrophage numbers. Additionally, COS also enhanced ZO-1 and Occludin mRNA expression, reduced Candida albicans abundance, and balanced gut microecology. This study illustrated that COS modulated macrophage polarization via the MyD88/NF-κB and STAT6 pathways, repaired the intestinal barrier, and reduced Candida albicans abundance to alleviate islet inflammation.

Akkermansia muciniphila restrains type 1 diabetes onset by eliciting cDC2 and Treg cell differentiation in NOD and STZ-induced experimental models

AIMS

Akkermansia muciniphila (A. muciniphila), a Gram-negative anaerobic mucus-layer-degrading bacterium found in the intestinal mucosa, exhibits potential as a probiotic, showing promise in mitigating autoimmune and chronic inflammatory diseases. This study aims to investigate whether A. muciniphila supplementation might confer protection against type 1 diabetes (T1D) and to elucidate the immunological pathways through which it exerts its beneficial effects.

MATERIALS AND METHODS

Non-obese diabetic (NOD) mice and streptozotocin (STZ)-induced type 1 diabetes (T1D) models were used to evaluate the protective effects of A. muciniphila during T1D course. Body weight, blood glucose levels, and T1D incidence were monitored. Immune responses in the pancreas, pancreatic (PLN) and cecal lymph nodes (CLN) and bone marrow-derived dendritic cells (BMDC) were evaluated by flow cytometry and ELISA.

KEY FINDINGS

Viable A. muciniphila supplementation conferred protection against T1D onset in STZ-induced T1D and NOD mouse models. T1D modulation by A. muciniphila in the STZ model was independent of the gut microbiota, and it was associated with increased tolerogenic type-2 dendritic cells (SIRP-α+CD11b+CD103+) and regulatory T (Treg) cells in PLN and pancreas. BMDC differentiated in the presence of A. muciniphila exhibited a tolerogenic profile and induced Treg cell generation in vitro. A. muciniphila-induced protection in T1D outcome was abrogated in FOXP3-DTR mice depleted of Treg cells, indicating that its mechanism of action is dependent on the CD4+Foxp3+ Treg cells.

SIGNIFICANCE

A. muciniphila supplementation attenuates T1D development in mice by modulating the tolerogenic immune response and is a promising new therapeutic tool for this autoimmune disease.

Gut microbiota development across the lifespan: Disease links and health-promoting interventions

The gut microbiota plays a pivotal role in human life and undergoes dynamic changes throughout the human lifespan, from infancy to old age. During our life, the gut microbiota influences health and disease across life stages. This review summarizes the discussions and presentations from the symposium "Gut microbiota development from infancy to old age" held in collaboration with the Journal of Internal Medicine. In early infancy, microbial colonization is shaped by factors such as mode of delivery, antibiotic exposure, and milk-feeding practices, laying the foundation for subsequent increased microbial diversity and maturation. Throughout childhood and adolescence, microbial maturation continues, influencing immune development and metabolic health. In adulthood, the gut microbiota reaches a relatively stable state, influenced by genetics, diet, and lifestyle. Notably, disruptions in gut microbiota composition have been implicated in various inflammatory diseases-including inflammatory bowel disease, Type 1 diabetes, and allergies. Furthermore, emerging evidence suggests a connection between gut dysbiosis and neurodegenerative disorders such as Alzheimer's disease. Understanding the role of the gut microbiota in disease pathogenesis across life stages provides insights into potential therapeutic interventions. Probiotics, prebiotics, and dietary modifications, as well as fecal microbiota transplantation, are being explored as promising strategies to promote a healthy gut microbiota and mitigate disease risks. This review focuses on the gut microbiota's role in infancy, adulthood, and aging, addressing its development, stability, and alterations linked to health and disease across these critical life stages. It outlines future research directions aimed at optimizing the gut microbiota composition to improve health.

Restoration of intestinal secondary bile acid synthesis: A potential approach to improve pancreatic β cell function in type 1 diabetes

This study investigates the roles of gut microbiome and secondary bile acid dysfunctions in type 1 diabetes (T1D) and explores targeted interventions to address them. It finds that T1D is associated with reduced gut microbial diversity and imbalance favoring harmful bacteria over beneficial ones. Additionally, patients with T1D exhibited impaired secondary bile acid metabolism. Interventions aimed at modulating the gut microbiome and metabolites are safe and improve glycemic control, reduce daily insulin dose, and reduce inflammation. These interventions reshape the gut microbiome toward a healthier state and enhance secondary bile acid production. Responders to the interventions show increased levels of beneficial bacteria and secondary bile acids, along with improved C-peptide responses. Overall, these findings suggest that targeted modulation of the gut microbiome and secondary bile acid metabolism could be a promising therapeutic approach for T1D management. The trial is registered at Chinese Clinical Trial Registry (ChiCTR-ONN-17011279).

Scaffold-free endocrine tissue engineering: role of islet organization and implications in type 1 diabetes

Type 1 diabetes (T1D) is a chronic hyperglycemia disorder emerging from beta-cell (insulin secreting cells of the pancreas) targeted autoimmunity. As the blood glucose levels significantly increase and the insulin secretion is gradually lost, the entire body suffers from the complications. Although various advances in the insulin analogs, blood glucose monitoring and insulin application practices have been achieved in the last few decades, a cure for the disease is not obtained. Alternatively, pancreas/islet transplantation is an attractive therapeutic approach based on the patient prognosis, yet this treatment is also limited mainly by donor shortage, life-long use of immunosuppressive drugs and risk of disease transmission. In research and clinics, such drawbacks are addressed by the endocrine tissue engineering of the pancreas. One arm of this engineering is scaffold-free models which often utilize highly developed cell-cell junctions, soluble factors and 3D arrangement of islets with the cellular heterogeneity to prepare the transplant formulations. In this review, taking T1D as a model autoimmune disease, techniques to produce so-called pseudoislets and their applications are studied in detail with the aim of understanding the role of mimicry and pointing out the promising efforts which can be translated from benchside to bedside to achieve exogenous insulin-free patient treatment. Likewise, these developments in the pseudoislet formation are tools for the research to elucidate underlying mechanisms in pancreas (patho)biology, as platforms to screen drugs and to introduce immunoisolation barrier-based hybrid strategies.

Role of Gut Microbiota in the Development of Some Autoimmune Diseases

The gut microbiota is crucial for maintaining the homeostasis and function of the immune system. It interacts with the host's immune system through various mechanisms, including promoting immune tolerance, affecting the differentiation and function of immune cells, and participating in the metabolism of immune regulatory substances. The disruption of the gut microbiome may lead to impaired mucosal barrier function, allowing bacteria and their metabolites to invade into the host, activate or interfere with the immune system, and potentially trigger or exacerbate autoimmune responses. Understanding the relationship between the microbiome and autoimmune diseases may help develop new treatment strategies. This article reviewed the recent progresses of microbiome involved in the occurrence and development of some autoimmune diseases and the treatment methods based on regulation of the microbiome, highlighted the key role of microbiome in autoimmune diseases.

Development of a sodium hyaluronate-enriched therapeutic formulation with stevia glycoside and mogroside V for the comprehensive management of diabetes and its complications

Diabetes prevalence continues to increase as a result of people's increasing sugar intake. Diabetes mellitus and its complications (dry skin, constipation, depression, and dental caries), as well as the prohibition of sweets ingestion, seriously affect patients' physical and mental health. Therefore, it is crucial to develop a long-term food for special medical purposes (FSMP) that aids in managing diabetes and its complications. To ensure effective biomedical function and taste, we developed a FSMP beverage formulation containing stevia glycoside, mogroside V, and sodium hyaluronate (SMH-B), each at a concentration of 0.1 mg/mL. Meanwhile, this study verified that SMH-B is an environmentally friendly and biocompatible formulation. Furthermore, both in vivo and in vitro studies have demonstrated that SMH-B significantly lowers blood glucose and lipid levels, enhances skin moisture and elasticity, prevents dental caries, alleviates constipation, reduces oxidative stress, and mitigates depressive symptoms. Notably, the SMH-B compound formula exhibits a more effective adjuvant therapeutic effect compared to single-ingredient formulation composed of stevia glycosides, mogroside V, and sodium hyaluronate. Moreover, SMH-B provides the sweetness desired by diabetic patients without affecting blood glucose levels, while also offering an auxiliary therapeutic role, making it a potential FSMP for diabetes management.

From Microbes to Metabolites: Advances in Gut Microbiome Research in Type 1 Diabetes

Background: Type 1 diabetes (T1D) is a severe chronic T-cell mediated autoimmune disease that attacks the insulin-producing beta cells of the pancreas. The multifactorial nature of T1D involves both genetic and environmental components, with recent research focusing on the gut microbiome as a crucial environmental factor in T1D pathogenesis. The gut microbiome and its metabolites play an important role in modulating immunity and autoimmunity. In recent years, studies have revealed significant alterations in the taxonomic and functional composition of the gut microbiome associated with the development of islet autoimmunity and T1D. These changes include reduced production of short-chain fatty acids, altered bile acid and tryptophan metabolism, and increased intestinal permeability with consequent perturbations of host (auto)immune responses. Methods/Results: In this review, we summarize and discuss recent observational, mechanistic and etiological studies investigating the gut microbiome in T1D and elucidating the intricate role of gut microbes in T1D pathogenesis. Moreover, we highlight the recent advances in intervention studies targeting the microbiota for the prevention or treatment of human T1D. Conclusions: A deeper understanding of the evolution of the gut microbiome before and after T1D onset and of the microbial signals conditioning host immunity may provide us with essential insights for exploiting the microbiome as a prognostic and therapeutic tool.

Targeting gut S. aureofaciens Tü117 serves as a new potential therapeutic intervention for the prevention and treatment of hypertension

Currently, the regulation of specific gut microbial metabolism for the development and/or treatment of hypertension remains largely unexplored. Here, we show that α-lipomycin, produced by Streptomyces aureofaciens (S. aureofaciens) Tü117, is upregulated in the serum of high-salt diet (HSD) mice and patients with essential hypertension. α-lipomycin causes vasodilation impairment involving transient receptor potential vanilloid 4 (TRPV4)-mediated nitric oxide and endothelium-derived hyperpolarizing factor pathways in mice. We also find that Lactobacillus plantarum (L. plantarum) CCFM639 attenuates the increase in blood pressure (BP) potentially through inhibiting the proliferation of S. aureofaciens Tü117 in mice. An exploratory intervention trial indicates that L. plantarum CCFM639 supplementation reduces BPs in subjects newly diagnosed with pre-hypertension or stage 1 hypertension without antihypertensive medication. Our findings provide evidence for a role of S. aureofaciens Tü117-associated α-lipomycin elevation in the pathogenesis of HSD-induced hypertension, highlighting that targeting gut bacteria serves as a new therapeutic intervention for hypertension.

Gut Microbial Changes Associated With Obesity in Youth With Type 1 Diabetes

CONTEXT

Obesity is prevalent in type 1 diabetes (T1D) and is problematic with higher risk for diabetes complications. It is unknown to what extent gut microbiome changes are associated with obesity and T1D.

OBJECTIVE

This work aimed to describe the gut microbiome and microbial metabolite changes associated with obesity in T1D. We hypothesized statistically significant gut microbial and metabolite differences in lean T1D youth (body mass index [BMI]: 5%-<85%) vs those with obesity (BMI: ≥95%).

METHODS

We analyzed stool samples for gut microbial (using metagenomic shotgun sequencing) and short-chain fatty acid (SCFA) differences in lean (n = 27) and obese (n = 21) T1D youth in a pilot study. The mean ± SD age was 15.3 ± 2.2 years, glycated hemoglobin A1c 7.8 ± 1.3%, diabetes duration 5.1 ± 4.4 years, 42.0% female, and 94.0% were White.

RESULTS

Bacterial community composition showed between sample diversity differences (β-diversity) by BMI group (P = .013). There was a higher ratio of Prevotella to Bacteroides in the obese group (P = .0058). There was a differential distribution of significantly abundant taxa in either the lean or obese groups, including increased relative abundance of Prevotella copri, among other taxa in the obese group. Functional profiling showed an upregulation of branched-chain amino acid (BCAA) biosynthesis in the obese group and upregulation of BCAA degradation, tyrosine metabolism, and secondary bile acid biosynthesis in the lean group. Stool SCFAs were higher in the obese vs the lean group (P < .05 for all).

CONCLUSION

Our findings identify a gut microbiome and microbial metabolite signature associated with obesity in T1D. These findings could help identify gut microbiome-targeted therapies to manage obesity in T1D.

Bowel preparation before colonoscopy: Consequences, mechanisms, and treatment of intestinal dysbiosis

The term "gut microbiota" primarily refers to the ecological community of various microorganisms in the gut, which constitutes the largest microbial community in the human body. Although adequate bowel preparation can improve the results of colonoscopy, it may interfere with the gut microbiota. Bowel preparation for colonoscopy can lead to transient changes in the gut microbiota, potentially affecting an individual's health, especially in vulnerable populations, such as patients with inflammatory bowel disease. However, measures such as oral probiotics may ameliorate these adverse effects. We focused on the bowel preparation-induced changes in the gut microbiota and host health status, hypothesized the factors influencing these changes, and attempted to identify measures that may reduce dysbiosis, thereby providing more information for individualized bowel preparation for colonoscopy in the future.

Discovery of robust and highly specific microbiome signatures of non-alcoholic fatty liver disease

BACKGROUND

The pathogenesis of non-alcoholic fatty liver disease (NAFLD) with a global prevalence of 30% is multifactorial and the involvement of gut bacteria has been recently proposed. However, finding robust bacterial signatures of NAFLD has been a great challenge, mainly due to its co-occurrence with other metabolic diseases.

RESULTS

Here, we collected public metagenomic data and integrated the taxonomy profiles with in silico generated community metabolic outputs, and detailed clinical data, of 1206 Chinese subjects w/wo metabolic diseases, including NAFLD (obese and lean), obesity, T2D, hypertension, and atherosclerosis. We identified highly specific microbiome signatures through building accurate machine learning models (accuracy = 0.845-0.917) for NAFLD with high portability (generalizable) and low prediction rate (specific) when applied to other metabolic diseases, as well as through a community approach involving differential co-abundance ecological networks. Moreover, using these signatures coupled with further mediation analysis and metabolic dependency modeling, we propose synergistic defined microbial consortia associated with NAFLD phenotype in overweight and lean individuals, respectively.

CONCLUSION

Our study reveals robust and highly specific NAFLD signatures and offers a more realistic microbiome-therapeutics approach over individual species for this complex disease. Video Abstract.

Pre-Type 1 Diabetes in Adolescents and Teens: Screening, Nutritional Interventions, Beta-Cell Preservation, and Psychosocial Impacts

Type 1 Diabetes (T1D) is a progressive autoimmune disease often identified in childhood or adolescence, with early stages detectable through pre-diabetic markers such as autoantibodies and subclinical beta-cell dysfunction. The identification of the pre-T1D stage is critical for preventing complications, such as diabetic ketoacidosis, and for enabling timely interventions that may alter disease progression. This review examines the multifaceted approach to managing T1D risk in adolescents and teens, emphasizing early detection, nutritional interventions, beta-cell preservation strategies, and psychosocial support. Screening for T1D-associated autoantibodies offers predictive insight into disease risk, particularly when combined with education and family resources that promote lifestyle adjustments. Although nutritional interventions alone are not capable of preventing T1D, certain lifestyle interventions, such as weight management and specific nutritional choices, have shown the potential to preserve insulin sensitivity, reduce inflammation, and mitigate metabolic strain. Pharmacological strategies, including immune-modulating drugs like teplizumab, alongside emerging regenerative and cell-based therapies, offer the potential to delay disease onset by protecting beta-cell function. The social and psychological impacts of a T1D risk diagnosis are also significant, affecting adolescents' quality of life, family dynamics, and mental health. Supportive interventions, including counseling, cognitive-behavioral therapy (CBT), and group support, are recommended for managing the emotional burden of pre-diabetes. Future directions call for integrating universal or targeted screening programs within schools or primary care, advancing research into nutrition and psychosocial support, and promoting policies that enhance access to preventive resources. Advocacy for the insurance coverage of screening, nutritional counseling, and mental health services is also crucial to support families in managing T1D risk. By addressing these areas, healthcare systems can promote early intervention, improve beta-cell preservation, and support the overall well-being of adolescents at risk of T1D.

Reconstruction characteristics of gut microbiota from patients with type 1 diabetes affect the phenotypic reproducibility of glucose metabolism in mice

The human microbiota-associated (HMA) mice model, especially the germ-free (GF)-humanized mice, has been widely used to probe the causal relationships between gut microbiota and human diseases such as type 1 diabetes (T1D). However, most studies have not clarified the extent to which the reconstruction of the human donor microbiota in recipient mice correlates with corresponding phenotypic reproducibility. In this study, we transplanted fecal microbiota from five patients with T1D and four healthy people into GF mice, and microbiota from each donor were transplanted into 10 mice. Mice with similar microbiota structure to the donor exhibited better phenotypic reproducibility. The characteristics of the microbial community assembly of donors also influenced the phenotypic reproducibility in mice, and individuals with a higher proportion of stochastic processes showed more severe disorders. Microbes enriched in patients with T1D had a stronger colonization potential in mice with impaired glucose metabolism, and microbiota functional features related to T1D were better reproduced in these mice. This indicates that assembly traits and colonization efficacy of microbiota influence phenotypic reproducibility in GF-humanized mice. Our findings provide important insights for using HMA mice models to explore links between gut microbiota and human diseases.

Research Progress in the Relationship between Intestinal Flora and Diabetes Mellitus

Diabetes mellitus is a common chronic metabolic disease characterized by a high incidence and disability rate. Intestinal flora refers to the microbial community that lives in the intestines and plays a crucial role in maintaining intestinal health and the human immune system. In recent years, an increasing body of research has revealed a close relationship between intestinal flora and diabetes. The pathophysiological mechanisms between them have also been constantly uncovered, and the regulation of intestinal flora has shown promising efficacy in the adjuvant treatment of diabetes. This study mainly summarized the characteristics and mechanisms of intestinal flora in patients with diabetes in recent years, as well as the methods of regulating intestinal flora to prevent and treat diabetes, and prospected the future research direction. This will offer a theoretical basis for the clinical adjuvant treatment of diabetes with intestinal flora and the development of new drugs.

Sex-specific cytokine, chemokine, and growth factor signatures in T1D patients and progressors

Numerous studies have reported altered cytokine levels in type 1 diabetes (T1D) patients, yet findings remain inconsistent. In this pilot study, we tested the hypothesis that circulating immune markers exhibit sex-based differences in T1D, both prior to and after disease onset. We analyzed 47-48 cytokine, chemokine, and growth factor levels in two cohorts. To assess post-disease differences, we analyzed serum samples from 25 controls and 25 T1D patients. To examine pre-disease progression, we utilized samples from 21 control children and 16 T1D progressors, collected at age 5 years before disease onset. Across all T1D patients and controls, only macrophage colony-stimulating factor and interleukin (IL)-6 showed significant differences. However, we identified notable alterations when comparing sex-age-matched controls and T1D samples. Female T1D patients exhibited lower levels of inflammatory cytokines (tumor necrosis factor-α, IL-6, IL-1a), Th2 cytokines (IL-4, IL-13), and chemokines (macrophage inflammatory protein (MIP)-1α, regulated upon activation, normal T cell expressed and secreted, MIP-3) compared to female controls, differences that were not observed in males. Notably, IL-22 was lower in female T1D patients compared to female controls, whereas it was higher in male T1D patients compared to male controls. Male T1D patients showed elevated levels of growth factors (epidermal growth factor, platelet-derived growth factor-AB/BB) compared to male controls. In T1D progressors, growth-regulated alpha was lower compared to controls in both sexes. Multiple regression analysis further revealed associations between cytokine levels and factors such as age, BMI, and breastfeeding duration. Overall, our findings serve as a proof of concept, highlighting the importance of sex-specific differences in T1D pathogenesis. However, follow-up studies with larger sample sizes are needed to validate and generalize these results.

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.

Comprehensive assessment of rice bran dietary fiber on gut microbiota composition and metabolism during in vitro fermentation

Rice bran, a by-product of rice processing, is rich in various nutrients. As one of the main components of rice bran, dietary fiber has a variety of potential health benefits, especially its probiotic effects on gut health. This study involved the preparation and characterization of soluble rice bran dietary fibers (RB-SDF) and insoluble rice bran dietary fibers (RB-IDF), followed by an investigation into their gastrointestinal probiotic impact and principal metabolites. These results showed that rice bran dietary fiber could promote the production of short-chain fatty acids and the growth of probiotics during the fermentation in vitro. Specifically, RB-SDF significantly stimulated the growth of Bacteroides, Parabacteroides, and Acinetobacter, while RB-IDF encouraged the expansion of Tyzzerella, Pseudoflavonifractor, and Lachnospiraceae_UCG_004. Both dietary fibers could reduce the relative abundance of Escherichia_Shigella and Fusobacterium. The differential metabolites identified by untargeted metabolomics were l-pyroglutamic acid, d-(+)-tryptophan, indole-3-lactic acid, sulfolithocholic acid, 4-hydroxybenzaldehyde, indicating that different carbohydrates could significantly affect the metabolic profile of gut microbiota. Our finding indicated that rice bran dietary fiber can produce beneficial metabolites and modulate microbial ecosystems, which deserve further development for health applications.

Apigenin analogs as α-glucosidase inhibitors: Molecular docking, biochemical, enzyme kinetic, and an in vivo mouse model study

Due to the high incidence of diabetes and its associated complications, diabetes is widely recognized as a serious global health problem. In diabetes treatment strategies, targeting α-glucosidase, a key carbohydratehydrolyzing enzyme, has emerged as a highly regarded approach. To develop novel α-glucosidase inhibitors, we successfully synthesized a series of apigenin analogs, collectively referred to as H1-H27 compounds and examined their inhibitory effects on α-glucosidase activity. H7 showed a remarkable inhibitory effect, surpassing that of the standard drug acarbose. Further analysis revealed that H7, H10, and H24 act as non-competitive inhibitors of α- glucosidase. In vivo experiments using a type 2 diabetes mouse model demonstrated the diverse therapeutic potential of H7; it effectively lowered blood sugar levels, improved glucose tolerance, and corrected lipid metabolism. In addition, H7 showed hepatoprotective effects, highlighting its ability to improve liver function. H7 also positively influenced the gut microbiota composition in diabetic mice, increasing diversity and richness. These results highlight the promising therapeutic effects of apigenin analogs, such as H7, for treating type 2 diabetes and show how they could provide numerous benefits, including effective inhibition of α-glucosidase, improved glucose control, correction of lipid metabolism, hepatoprotection, and modulation of the intestinal microbiota.

Multi-omics insights implicate the remodeling of the intestinal structure and microbiome in aging

Background

Aging can impair the ability of elderly individuals to fight infections and trigger persistent systemic inflammation, a condition known as inflammaging. However, the mechanisms underlying the development of inflammaging remain unknown.

Methods

We conducted 16S rRNA sequencing of intestinal contents from young and old C57BL/6J mice to elucidate changes in gut microbiota diversity and microbial community composition after aging. Aging-related differential bacterial taxa were then identified, and their abundance trends were validated in human samples. The variances in intestinal barrier function and circulating endotoxin between groups were also assessed. Furthermore, widely targeted metabolomics was conducted to characterize metabolic profiles after aging and to investigate the key metabolic pathways enriched by the differential metabolites.

Results

Our findings demonstrated an increase in relative proportion of pathogenic bacteria with age, a trend also revealed in healthy populations of different age groups. Additionally, aging individuals exhibited reduced intestinal barrier function and increased circulating endotoxin levels. Widely targeted metabolomics revealed a significant increase in various secondary bile acid metabolites after aging, positively correlated with the relative abundance of several aging-related bacterial taxa. Furthermore, old group had lower levels of various anti-inflammatory or beneficial metabolites. Enrichment analysis identified the starch and sucrose metabolism pathway as potentially the most significantly impacted signaling pathway during aging.

Conclusion

This study aimed to provide insights into the complex interactions involved in organismal inflammaging through microbial multi-omics. These findings lay a solid foundation for future research aimed at identifying novel biomarkers for the clinical diagnosis of aging-related diseases or potential therapeutic targets.

Surface nanocoating-based universal platform for programmed delivery of microorganisms in complicated digestive tract

Microbial therapies have promising applications in the treatment of a broad range of diseases. However, effective colonization of the target region by therapeutic microorganisms remains a significant challenge owing to the complexity of the intestinal system. Here, we developed surface nanocoating-based universal platform (SNUP), which enabled the manipulation of controlled release and targeted colonization of therapeutic microbes in the digestive tract without the utilization of any targeting molecules. The system controlled the decomposition time of SNUP in the gut by regulating different modification layers and modification sequences on the microorganism's surface, so that the microorganism was released at a predetermined time and space. With the SNUP nanomodification technology, we could effectively deliver therapeutic microorganisms to specific complex intestinal regions such as the small intestine and colon, and protect the bioactivity of therapeutic microorganisms from destruction by both strong acids and digestive enzymes. In this study, we found that two layers SNUP-encapsulated Liiliilactobacillus salivarius (LS@CCMC) could efficiently colonize the small intestine and significantly improve the symptoms of a mouse model of Parkinson's disease through sustained secretion of γ-aminobutyric acid (GABA). This surface nanocoating-based universal platform system does not require the design of specific targeting molecules, providing a simple and universal method for colonized microbial therapy, target theranostics, precision medicine, and personalized medicine.

Intestinal microbiota dysbiosis contributes to the liver damage in subchronic arsenic-exposed mice

There is an extensive amount of evidence that links changes in the intestinal microbiota structure to the progression and pathophysiology of many liver diseases. However, comprehensive analysis of gut flora dysbiosis in arsenic-induced hepatotoxicity is lacking. Herein, C57BL/6 mice are exposed to arsenic (1, 2, or 4 mg/kg) for 12 weeks, after which fecal microbiota transplantation (FMT) study is conducted to confirm the roles of the intestinal microbiome in pathology. Treatment with arsenic results in pathological and histological changes in the liver, such as inflammatory cell infiltration and decreased levels of TP and CHE but increased levels of ALP, GGT, TBA, AST, and ALT. Arsenic causes an increase in the relative abundance of Escherichia-Shigella, Klebsiella and Blautia, but a decrease in the relative abundance of Muribaculum and Lactobacillus. In arsenic-exposed mice, protein expressions of Occludin, ZO-1, and MUC2 are significantly decreased, but the level of FITC in serum is increased, and FITC fluorescence is extensively dispersed in the intestinal tract. Importantly, FMT experiments show that mice gavaged with stool from arsenic-treated mice exhibit severe inflammatory cell infiltration in liver tissues. Arsenic-manipulated gut microbiota transplantation markedly facilitates gut flora dysbiosis in the recipient mice, including an up-regulation in Escherichia-Shigella and Bacteroides, and a down-regulation in Lactobacillus and Desulfovibrio. In parallel with the intestinal microbiota wreck, protein expressions of Occludin, ZO-1, and MUC2 are decreased. Our findings suggest that subchronic exposure to arsenic can affect the homeostasis of the intestinal microbiota, induce intestinal barrier dysfunction, increase intestinal permeability, and cause damage to liver tissues in mice.

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.

Increased intestinal permeability and lipopolysaccharide contribute to swainsonine-induced systemic inflammation

Long-term consumption of swainsonine could be poisonous to livestock, including facilitating apoptosis by impairing lysosomal function and inhibiting autophagic degradation, leading to liver inflammation and even death in livestock. However, the mechanism by swainsonine induced systemic inflammatory responses remained unclear, especially the effects of swainsonine on intestinal permeability, lipopolysaccharide (LPS) level and oxidative stress response were unknown. In this study, swainsonine increased intestinal permeability as evidenced by the significant down-regulation of colonic goblet cells, Akkermansia muciniphila and intestinal tight junction protein Occludin, Claudin 1 and ZO-1, and the significant up-regulation of mRNA expression level of the intestinal permeability indicator protein tyrosine phosphatase receptor type H (Ptprh) in the ileum of mice. Simultaneously, the elevated LPS biosynthetic genes in intestinal microbiota and increased intestinal permeability facilitated more bacterial endotoxin LPS to enter the blood. High concentration of free-form LPS induced high levels of proinflammatory cytokines and oxidative stress response, thereby causing the systemic inflammation. These findings provided a new perspective on swainsonine-induced systemic inflammation, suggesting that intestinal permeability and free-form LPS level may be the potential trigger factors.

The therapeutic effect and possible mechanisms of alginate oligosaccharide on metabolic syndrome by regulating gut microbiota

Metabolic syndrome (MetS) is a disease condition incorporating the abnormal accumulation of various metabolic components, including overweight or abdominal obesity, insulin resistance and abnormal glucose tolerance, hypertension, atherosclerosis, or dyslipidemia. It has been proved that the gut microbiota and microbial-derived products play an important role in regulating lipid metabolism and thus the onset and development of MetS. Previous studies have demonstrated that oligosaccharides with prebiotic effects, such as chitosan oligosaccharides, can regulate the structure of the microbial community and its derived products to control weight and reduce MetS associated with obesity. Alginate oligosaccharides (AOS), natural products extracted from degraded alginate salts with high solubility and extensive biological activity, have also been found to modulate gut microbiota. This review aims to summarize experimental evidence on the positive effects of AOS on different types of MetS while providing insights into mechanisms through which AOS regulates gut microbiota for preventing and treating MetS.

Fecal microbiota transplantation from patients with polycystic ovary syndrome induces metabolic disorders and ovarian dysfunction in germ-free mice

BACKGROUND

Dysbiosis of the microbiome is a key hallmark of polycystic ovary syndrome (PCOS). However, the interaction between the host and microbiome and its relevance to the pathogenesis of PCOS remain unclear.

METHODS

To evaluate the role of the commensal gut microbiome in PCOS, we gavaged germ-free mice with the fecal microbiota from patients with PCOS or healthy individuals and evaluated the reproductive endocrine features of the recipient mice.

RESULTS

Mice transplanted with fecal microbiota from PCOS patients and those transplanted from healthy controls presented different bacterial profiles and reproductive endocrine features. The fecal microbiota of the mice in the PCOS group was enriched in Phocaeicola, Mediterraneibacter, Oscillospiraceae, Lawsonibacter and Rikenellaceae. Fecal microbiota transplantation (FMT) from PCOS patients induced increased disruption of ovarian functions, lipo-metabolic disturbance, insulin resistance and an obese-like phenotype in recipient mice.

CONCLUSION

Our findings suggest that the microbiome may govern the set point of PCOS-bearing individuals and that gut ecosystem manipulation may be a useful marker and target for the management of PCOS.

The protective effect of the intestinal microbiota in type-1 diabetes in NOD mice is limited to a time window in early life

Introduction

The incidence of type-1 diabetes is on the rise, particularly in developed nations, and predominantly affects the youth. While genetic predisposition plays a substantial role, environmental factors, including alterations in the gut microbiota, are increasingly recognized as significant contributors to the disease.

Methods

In this study, we utilized germ-free non-obese diabetic mice to explore the effects of microbiota colonization during early life on type-1 diabetes susceptibility.

Results

Our findings reveal that microbiota introduction at birth, rather than at weaning, significantly reduces the risk of type-1 diabetes, indicating a crucial window for microbiota-mediated modulation of immune responses. This protective effect was independent of alterations in intestinal barrier function but correlated with testosterone levels in male mice. Additionally, early life colonization modulated T cell subset frequencies, particularly T helper cells and regulatory T cells, in the intestine, potentially shaping type-1 diabetes predisposition.

Discussion

Our findings underscore the pivotal role of early-life microbial interactions in immune regulation and the development of autoimmune diseases.

Disruption of glucose homeostasis by bacterial infection orchestrates host innate immunity through NAD+/NADH balance

Metabolic reprogramming is crucial for activating innate immunity in macrophages, and the accumulation of immunometabolites is essential for effective defense against infection. The NAD+/NADH (ratio of nicotinamide adenine dinucleotide and its reduced counterpart) redox couple serves as a critical node that integrates metabolic pathways and signaling events, but how this metabolite couple engages macrophage activation remains unclear. Here, we show that the NAD+/NADH ratio serves as a molecular signal that regulates proinflammatory responses and type I interferon (IFN) responses divergently. Salmonella Typhimurium infection leads to a decreased NAD+/NADH ratio by inducing the accumulation of NADH. Further investigation shows that an increased NAD+/NADH ratio correlates with attenuated proinflammatory responses and enhanced type I IFN responses. Conversely, a decreased NAD+/NADH ratio is linked to intensified proinflammatory responses and restrained type I IFN responses. These results show that the NAD+/NADH ratio is an essential cell-intrinsic factor that orchestrates innate immunity, which enhances our understanding of how metabolites fine-tune innate immunity.

Sex-Specific Cytokine, Chemokine, and Growth Factor Signatures in T1D Patients and Progressors

While studies have reported altered levels of cytokines in type 1 diabetes (T1D) patients, the results are inconsistent, likely because of variable factors. This study tests the hypothesis that there are sex-based differences in cytokine levels in T1D, prior to and after disease onset. We analyzed 48 blood cytokine, chemokine, and growth factor levels using a multiplex assay. We found only two cytokines, M-CSF and IL-6, with significant differences between T1D patients (n=25) versus controls overall (n=25). However, we identified notable alterations when comparing sex-age-matched controls and T1D samples. Inflammatory cytokines (TNF-α, IL-6, IL-1a), Th2 cytokines (IL-4, IL-13), and chemokines (MIP-1α, RANTES, MIP-3) were lower in female T1D patients compared to female controls, but not in males. IL-22 was lower in female T1D patients compared to female controls, while it was higher in male T1D patients compared to male controls. In contrast, growth factors (EGF, PDGF-AB/BB) were higher in male T1D patients compared to male controls. In T1D progressors (children who developed the disease years after the sample collection, n=16-21), GROa was lower compared to controls in both sexes. Our findings underscore the importance of understanding sex-specific differences in T1D pathogenesis and their implications for developing personalized treatments.

Gut microbiome shifts in people with type 1 diabetes are associated with glycaemic control: an INNODIA study

AIMS/HYPOTHESIS

The gut microbiome is implicated in the disease process leading to clinical type 1 diabetes, but less is known about potential changes in the gut microbiome after the diagnosis of type 1 diabetes and implications in glucose homeostasis. We aimed to analyse potential associations between the gut microbiome composition and clinical and laboratory data during a 2 year follow-up of people with newly diagnosed type 1 diabetes, recruited to the Innovative approaches to understanding and arresting type 1 diabetes (INNODIA) study. In addition, we analysed the microbiome composition in initially unaffected family members, who progressed to clinical type 1 diabetes during or after their follow-up for 4 years.

METHODS

We characterised the gut microbiome composition of 98 individuals with newly diagnosed type 1 diabetes (ND cohort) and 194 autoantibody-positive unaffected family members (UFM cohort), representing a subgroup of the INNODIA Natural History Study, using metagenomic sequencing. Participants from the ND cohort attended study visits within 6 weeks from the diagnosis and 3, 6, 12 and 24 months later for stool sample collection and laboratory tests (HbA1c, C-peptide, diabetes-associated autoantibodies). Participants from the UFM cohort were assessed at baseline and 6, 12, 18, 24 and 36 months later.

RESULTS

We observed a longitudinal increase in 21 bacterial species in the ND cohort but not in the UFM cohort. The relative abundance of Faecalibacterium prausnitzii was inversely associated with the HbA1c levels at diagnosis (p=0.0019). The rate of the subsequent disease progression in the ND cohort, as assessed by change in HbA1c, C-peptide levels and insulin dose, was associated with the abundance of several bacterial species. Individuals with rapid decrease in C-peptide levels in the ND cohort had the lowest gut microbiome diversity. Nineteen individuals who were diagnosed with type 1 diabetes in the UFM cohort had increased abundance of Sutterella sp. KLE1602 compared with the undiagnosed UFM individuals (p=1.2 × 10-4).

CONCLUSIONS/INTERPRETATION

Our data revealed associations between the gut microbiome composition and the disease progression in individuals with recent-onset type 1 diabetes. Future mechanistic studies as well as animal studies and human trials are needed to further validate the significance and causality of these associations.

Gut Microbiota Dysbiosis, Oxidative Stress, Inflammation, and Epigenetic Alterations in Metabolic Diseases

Gut dysbiosis, resulting from an imbalance in the gut microbiome, can induce excessive production of reactive oxygen species (ROS), leading to inflammation, DNA damage, activation of the immune system, and epigenetic alterations of critical genes involved in the metabolic pathways. Gut dysbiosis-induced inflammation can also disrupt the gut barrier integrity and increase intestinal permeability, which allows gut-derived toxic products to enter the liver and systemic circulation, further triggering oxidative stress, inflammation, and epigenetic alterations associated with metabolic diseases. However, specific gut-derived metabolites, such as short-chain fatty acids (SCFAs), lactate, and vitamins, can modulate oxidative stress and the immune system through epigenetic mechanisms, thereby improving metabolic function. Gut microbiota and diet-induced metabolic diseases, such as obesity, insulin resistance, dyslipidemia, and hypertension, can transfer to the next generation, involving epigenetic mechanisms. In this review, we will introduce the key epigenetic alterations that, along with gut dysbiosis and ROS, are engaged in developing metabolic diseases. Finally, we will discuss potential therapeutic interventions such as dietary modifications, prebiotics, probiotics, postbiotics, and fecal microbiota transplantation, which may reduce oxidative stress and inflammation associated with metabolic syndrome by altering gut microbiota and epigenetic alterations. In summary, this review highlights the crucial role of gut microbiota dysbiosis, oxidative stress, and inflammation in the pathogenesis of metabolic diseases, with a particular focus on epigenetic alterations (including histone modifications, DNA methylomics, and RNA interference) and potential interventions that may prevent or improve metabolic diseases.

The potential role of gut microbiota-derived metabolites as regulators of metabolic syndrome-associated mitochondrial and endolysosomal dysfunction in Alzheimer's disease

Although the role of gut microbiota (GMB)-derived metabolites in mitochondrial and endolysosomal dysfunction in Alzheimer's disease (AD) under metabolic syndrome remains unclear, deciphering these host-metabolite interactions represents a major public health challenge. Dysfunction of mitochondria and endolysosomal networks (ELNs) plays a crucial role in metabolic syndrome and can exacerbate AD progression, highlighting the need to study their reciprocal regulation for a better understanding of how AD is linked to metabolic syndrome. Concurrently, metabolic disorders are associated with alterations in the composition of the GMB. Recent evidence suggests that changes in the composition of the GMB and its metabolites may be involved in AD pathology. This review highlights the mechanisms of metabolic syndrome-mediated AD development, focusing on the interconnected roles of mitochondrial dysfunction, ELN abnormalities, and changes in the GMB and its metabolites. We also discuss the pathophysiological role of GMB-derived metabolites, including amino acids, fatty acids, other metabolites, and extracellular vesicles, in mediating their effects on mitochondrial and ELN dysfunction. Finally, this review proposes therapeutic strategies for AD by directly modulating mitochondrial and ELN functions through targeting GMB metabolites under metabolic syndrome.

Probiotic treatment with viable α-galactosylceramide-producing Bacteroides fragilis reduces diabetes incidence in female nonobese diabetic mice

BACKGROUND

We aimed to investigate whether alpha-galactosylceramide (α-GalCer)-producing Bacteroides fragilis could induce natural killer T (NKT) cells in nonobese diabetic (NOD) mice and reduce their diabetes incidence.

METHODS

Five-week-old female NOD mice were treated orally with B. fragilis, and islet pathology and diabetes onset were monitored. Immune responses were analyzed by flow cytometry and multiplex technology. Effects of ultraviolet (UV)-killed α-GalCer-producing B. fragilis and their culture medium on invariant NKT (iNKT) cells were tested ex vivo on murine splenocytes, and the immunosuppressive capacity of splenocytes from B. fragilis-treated NOD mice were tested by adoptive transfer to nonobese diabetic/severe combined immunodeficiency (NOD/SCID) mice.

RESULTS

B. fragilis reduced the diabetes incidence from 69% to 33% and the percent of islets with insulitis from 40% to 7%, which doubled the serum insulin level compared with the vehicle-treated control mice. Furthermore, the early treatment reduced proinflammatory mediators in the serum, whereas the proportion of CD4+ NKT cell population was increased by 33%. B. fragilis growth media stimulated iNKT cells and anti-inflammatory M2 macrophages ex vivo in contrast to UV-killed bacteria, which had no effect, strongly indicating an α-GalCer-mediated effect. Adoptive transfer of splenocytes from B. fragilis-treated NOD mice induced a similar diabetes incidence as splenocytes from untreated NOD mice.

CONCLUSIONS

B. fragilis induced iNKT cells and M2 macrophages and reduced type 1 diabetes in NOD mice. The protective effect seemed to be more centered on gut-pancreas interactions rather than a systemic immunosuppression. B. fragilis should be considered for probiotic use in individuals at risk of developing type 1 diabetes.

Can fecal microbiota transplantations modulate autoimmune responses in type 1 diabetes?

Type 1 diabetes (T1D) is a chronic autoimmune disease targeting insulin-producing pancreatic beta cells. T1D is a multifactorial disease incorporating genetic and environmental factors. In recent years, the advances in high-throughput sequencing have allowed researchers to elucidate the changes in the gut microbiota taxonomy and functional capacity that accompany T1D development. An increasing number of studies have shown a role of the gut microbiota in mediating immune responses in health and disease, including autoimmunity. Fecal microbiota transplantations (FMT) have been largely used in murine models to prove a causal role of the gut microbiome in disease progression and have been shown to be a safe and effective treatment in inflammatory human diseases. In this review, we summarize and discuss recent research regarding the gut microbiota-host interactions in T1D, the current advancement in therapies for T1D, and the usefulness of FMT studies to explore microbiota-host immunity encounters in murine models and to shape the course of human type 1 diabetes.

Short-chain fatty acids: linking diet, the microbiome and immunity

The short-chain fatty acids (SCFAs) butyrate, propionate and acetate are microbial metabolites and their availability in the gut and other organs is determined by environmental factors, such as diet and use of antibiotics, that shape the diversity and metabolism of the microbiota. SCFAs regulate epithelial barrier function as well as mucosal and systemic immunity via evolutionary conserved processes that involve G protein-coupled receptor signalling or histone deacetylase activity. Indicatively, the anti-inflammatory role of butyrate is mediated through direct effects on the differentiation of intestinal epithelial cells, phagocytes, B cells and plasma cells, and regulatory and effector T cells. Intestinally derived SCFAs also directly and indirectly affect immunity at extra-intestinal sites, such as the liver, the lungs, the reproductive tract and the brain, and have been implicated in a range of disorders, including infections, intestinal inflammation, autoimmunity, food allergies, asthma and responses to cancer therapies. An ecological understanding of microbial communities and their interrelated metabolic states, as well as the engineering of butyrogenic bacteria may support SCFA-focused interventions for the prevention and treatment of immune-mediated diseases.

Involvement of gut microbiota in multiple sclerosis-review of a new pathophysiological hypothesis and potential treatment target

Multiple sclerosis (MS) is a chronic inflammatory disease that leads to demyelination and damage to the central nervous system. It is well known, the significance of the involvement and influence of the immune system in the development and course of MS. Nowadays, more and more studies are demonstrating that an important factor that affects the action of the immune system is the gut microbiota. Changes in the composition and interrelationships in the gut microbiota have a significant impact on the course of MS. Dysbiosis affects the disease course mainly by influencing the immune system directly but also by modifying the secreted metabolites and increasing mucosal permeability. The essential metabolites affecting the course of MS are short-chain fatty acids, which alter pro- and anti-inflammatory responses in the immune system but also increase the permeability of the intestinal wall and the blood-brain barrier. Dietary modification alone can have a significant impact on MS. Based on these interactions, new treatments for MS are being developed, including probiotics administration, supplementation of bacterial metabolites, fecal microbiota transplantation, and dietary changes. Further studies may serve to develop new drugs and therapeutic approaches for MS.

Helminth Infections and Diabetes: Mechanisms Accounting for Risk Amelioration

The global prevalence of type 2 diabetes mellitus (T2D) is increasing rapidly, with an anticipated 600 million cases by 2035. While infectious diseases such as helminth infections have decreased due to improved sanitation and health care, recent research suggests a link between helminth infections and T2D, with helminths such as Schistosoma, Nippostrongylus, Strongyloides, and Heligmosomoides potentially mitigating or slowing down T2D progression in human and animal models. Helminth infections enhance host immunity by promoting interactions between innate and adaptive immune systems. In T2D, type 1 immune responses are suppressed and type 2 responses are augmented, expanding regulatory T cells and innate immune cells, particularly type 2 immune cells and macrophages. This article reviews recent research shedding light on the favorable effects of helminth infections on T2D. The potential defense mechanisms identified include heightened insulin sensitivity and reduced inflammation. The synthesis of findings from studies investigating parasitic helminths and their derivatives underscores promising avenues for defense against T2D.

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.

The profile of blood microbiome in new-onset type 1 diabetes children

Blood microbiome signatures in patients with type 1 diabetes (T1D) remain unclear. We profile blood microbiome using 16S rRNA gene sequencing in 77 controls and 64 children with new-onset T1D, and compared it with the gut and oral microbiomes. The blood microbiome of patients with T1D is characterized by increased diversity and perturbed microbial features, with a significant increase in potentially pathogenic bacteria compared with controls. Thirty-six representative genera of blood microbiome were identified by random forest analysis, providing strong discriminatory power for T1D with an AUC of 0.82. PICRUSt analysis suggested that bacteria capable of inducing inflammation were more likely to enter the bloodstream in T1D. The overlap of the gut and oral microbiome with the blood microbiome implied potential translocation of bacteria from the gut and oral cavity to the bloodstream. Our study raised the necessity of further mechanistic investigations into the roles of blood microbiome in T1D.

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.

The Role of Short Chain Fatty Acids in Inflammation and Body Health

Short chain fatty acids (SCFAs), mainly including acetate, propionate and butyrate, are produced by intestinal bacteria during the fermentation of partially digested and indigestible polysaccharides. SCFAs play an important role in regulating intestinal energy metabolism and maintaining the homeostasis of the intestinal environment and also play an important regulatory role in organs and tissues outside the gut. In recent years, many studies have shown that SCFAs can regulate inflammation and affect host health, and two main signaling mechanisms have also been identified: the activation of G-protein coupled receptors (GPCRs) and inhibition of histone deacetylase (HDAC). In addition, a growing body of evidence highlights the importance of every SCFA in influencing health maintenance and disease development. In this review, we summarized the recent advances concerning the biological properties of SCFAs and their signaling pathways in inflammation and body health. Hopefully, it can provide a systematic theoretical basis for the nutritional prevention and treatment of human diseases.

A bibliometric study of global trends in T1DM and intestinal flora research

Background

Type 1 diabetes mellitus (T1DM) is a chronic metabolic disease that seriously jeopardizes human physical and mental health and reduces quality of life. Intestinal flora is one of the critical areas of exploration in T1DM research.

Objective

This study aims to explore the research hotspot and development trend of T1DM and intestinal flora to provide research direction and ideas for researchers.

Methods

We used the Web of Science (WOS) Core Collection and searched up to 18 November 2023, for articles on studies of the correlation between T1DM and intestinal flora. CiteSpace, VOSviewers and R package "bibliometrix" were used to conduct this bibliometric analysis.

Results

Eventually, 534 documents met the requirements to be included, and as of 18 November 2023, there was an upward trend in the number of publications in the field, with a significant increase in the number of articles published after 2020. In summary, F Susan Wong (UK) was the author with the most publications (21), the USA was the country with the most publications (198), and the State University System of Florida (the United States) was the institution with the most publications (32). The keywords that appeared more frequently were T cells, fecal transplants, and short-chain fatty acids. The results of keywords with the most robust citation bursts suggest that Faecalibacterium prausnitzii and butyrate may become a focus of future research.

Conclusion

In the future, intestinal flora will remain a research focus in T1DM. Future research can start from Faecalibacterium prausnitzii and combine T cells, fecal bacteria transplantation, and short-chain fatty acids to explore the mechanism by which intestinal flora affects blood glucose in patients with T1DM, which may provide new ideas for the prevention and treatment of T1DM.

Harnessing human microbiomes for disease prediction

The human microbiome has been increasingly recognized as having potential use for disease prediction. Predicting the risk, progression, and severity of diseases holds promise to transform clinical practice, empower patient decisions, and reduce the burden of various common diseases, as has been demonstrated for cardiovascular disease or breast cancer. Combining multiple modifiable and non-modifiable risk factors, including high-dimensional genomic data, has been traditionally favored, but few studies have incorporated the human microbiome into models for predicting the prospective risk of disease. Here, we review research into the use of the human microbiome for disease prediction with a particular focus on prospective studies as well as the modulation and engineering of the microbiome as a therapeutic strategy.

Sodium butyrate ameliorates high glucose-suppressed neuronal mitophagy by restoring PRKN expression via inhibiting the RELA-HDAC8 complex

Damaged mitochondria accumulation in diabetes is one of the main features that contribute to increased incidence of cognitive impairment by inducing apoptosis. Butyrate is a major metabolite produced by microbiota that has neuroprotective effects by regulating mitochondrial function. However, detailed mechanisms underlying how butyrate can regulate neuronal mitophagy remain unclear. Here, we examined the regulatory effects of sodium butyrate (NaB) on high glucose-induced mitophagy dysregulation, neuronal apoptosis, and cognitive impairment and its underlying mechanisms in human-induced pluripotent stem cell-derived neurons, SH-SY5Ys, and streptozotocin (STZ)-induced diabetic mice. In our results, diabetic mice showed gut-microbiota dysbiosis, especially a decreased number of butyrate-producing bacteria and reduced NaB plasma concentration. NaB ameliorated high glucose-induced neuronal mitochondrial dysfunction by recovering PRKN/Parkin-mediated mitophagy. High glucose-induced reactive oxygen species (ROS) and -inhibited PRKAA/AMPKα stimulated the RELA/p65-HDAC8 complex, which downregulated PRKN protein expression by binding to the PRKN promoter region. NaB restored PRKN expression by blocking RELA nuclear translocation and directly inhibiting HDAC8 in the nucleus. In addition, HDAC8 overexpression inhibited the positive effect of NaB on high glucose-induced mitophagy dysfunction and neuronal apoptosis. Oral administration of NaB improved cognitive impairment in diabetic mice by restoring mitophagy in the hippocampus. Taken together, NaB ameliorates neuronal mitophagy through PRKN restoration by inhibiting RELA-HDAC8 complexes, suggesting that NaB is an important substance for protecting neuronal apoptosis in diabetes-associated cognitive impairment.

Structural characterization of squash polysaccharide and its effect on STZ-induced diabetes mellitus model in MIN6 cells

A novel natural water-soluble acidic polysaccharide (PWESP-3) was isolated from squash with a molecular mass of 140.519 kDa, which was composed of arabinose (Ara, 35.30 mol%), galactose (Gal, 61.20 mol%), glucose (Glc, 1.80 mol%), and Mannuronic acid (ManA, 1.70 mol%) and contained Araf-(1→, →3)-Araf-(1→, →5)-Araf-(1→, Glcp-(1→, Galp-(1→, →3,5)-Araf-(1→, →2)-Glcp-(1→, →2)-Manp-(1→, →3)-Glcp-(1→, →4)-Galp-(1→, →3)-Galp-(1→, →6)-Galp-(1→, →3,4)-Galp-(1→, →4,6)-Galp-(1→ residues in the backbone. Moreover, the structure of PWESP-3 was identified by NMR spectra. The branch chain was connected to the main chain by the O-3 and O-4 atom of Gal. In addition, the effect of PWESP-3 on STZ-induced type I diabetes mellitus model in MIN6 cells was investigated. The results showed that PWESP-3 can increase the viability and insulin secretion of MIN6 cells and reduce the oxidative stress caused by ROS and NO. Meanwhile, PWESP-3 can also reduce the content of ATP, Ca2+, mitochondrial membrane potential and Caspase-3 activity in MIN6 cells. Furthermore, treatment with PWESP-3 can prevent single or double stranded DNA breaking to form DNA fragments and improve DNA damage in MIN6 cells, thereby avoiding apoptosis. Therefore, the above data highlight that PWESP-3 can improve the function of insulin secretion in STZ-induced MIN6 cells in vitro and can be used as an alternative food supplement to diabetes drugs.

Advances in fecal microbiota transplantation for the treatment of diabetes mellitus

Diabetes mellitus (DM) refers to a group of chronic diseases with global prevalence, characterized by persistent hyperglycemia resulting from various etiologies. DM can harm various organ systems and lead to acute or chronic complications, which severely endanger human well-being. Traditional treatment mainly involves controlling blood sugar levels through replacement therapy with drugs and insulin; however, some patients still find a satisfactory curative effect difficult to achieve. Extensive research has demonstrated a close correlation between enteric dysbacteriosis and the pathogenesis of various types of DM, paving the way for novel therapeutic approaches targeting the gut microbiota to manage DM. Fecal microbiota transplantation (FMT), a method for re-establishing the intestinal microbiome balance, offers new possibilities for treating diabetes. This article provides a comprehensive review of the correlation between DM and the gut microbiota, as well as the current advancements in FMT treatment for DM, using FMT as an illustrative example. This study aims to offer novel perspectives and establish a theoretical foundation for the clinical diagnosis and management of DM.

Harnessing and delivering microbial metabolites as therapeutics via advanced pharmaceutical approaches

Microbial metabolites have emerged as key players in the interplay between diet, the gut microbiome, and host health. Two major classes, short-chain fatty acids (SCFAs) and tryptophan (Trp) metabolites, are recognized to regulate inflammatory, immune, and metabolic responses within the host. Given that many human diseases are associated with dysbiosis of the gut microbiome and consequent reductions in microbial metabolite production, the administration of these metabolites represents a direct, multi-targeted treatment. While a multitude of preclinical studies showcase the therapeutic potential of both SCFAs and Trp metabolites, they often rely on high doses and frequent dosing regimens to achieve systemic effects, thereby constraining their clinical applicability. To address these limitations, a variety of pharmaceutical formulations approaches that enable targeted, delayed, and/or sustained microbial metabolite delivery have been developed. These approaches, including enteric encapsulations, esterification to dietary fiber, prodrugs, and nanoformulations, pave the way for the next generation of microbial metabolite-based therapeutics. In this review, we first provide an overview of the roles of microbial metabolites in maintaining host homeostasis and outline how compromised metabolite production contributes to the pathogenesis of inflammatory, metabolic, autoimmune, allergic, infectious, and cancerous diseases. Additionally, we explore the therapeutic potential of metabolites in these disease contexts. Then, we provide a comprehensive and up-to-date review of the pharmaceutical strategies that have been employed to enhance the therapeutic efficacy of microbial metabolites, with a focus on SCFAs and Trp metabolites.

Recent advances in host-focused molecular tools for investigating host-gut microbiome interactions

Microbial communities in the human gut play a significant role in regulating host gene expression, influencing a variety of biological processes. To understand the molecular mechanisms underlying host-microbe interactions, tools that can dissect signaling networks are required. In this review, we discuss recent advances in molecular tools used to study this interplay, with a focus on those that explore how the microbiome regulates host gene expression. These tools include CRISPR-based whole-body genetic tools for deciphering host-specific genes involved in the interaction process, Cre-loxP based tissue/cell-specific gene editing approaches, and in vitro models of host-derived organoids. Overall, the application of these molecular tools is revolutionizing our understanding of how host-microbiome interactions contribute to health and disease, paving the way for improved therapies and interventions that target microbial influences on the host.

Application of a derivative of human defensin 5 to treat ionizing radiation-induced enterogenic infection

Enterogenic infection is a common complication for patients with radiation injury and requires efficient therapeutics in the clinic. Herein, we evaluated the promising drug candidate T7E21RHD5, which is a peptide derived from intestinal Paneth cell-secreted human defensin 5. Oral administration of this peptide alleviated the diarrhea symptoms of mice that received total abdominal irradiation (TAI, γ-ray, 12 Gy) and improved survival. Pathologic analysis revealed that T7E21RHD5 elicited an obvious mitigation of ionizing radiation (IR)-induced epithelial damage and ameliorated the reduction in the levels of claudin, zonula occluden 1 and occludin, three tight junction proteins in the ileum. Additionally, T7E21RHD5 regulated the gut microbiota in TAI mice by remodeling β diversity, manifested as a reversal of the inverted proportion of Bacteroidota to Firmicutes caused by IR. T7E21RHD5 treatment also decreased the abundance of pathogenic Escherichia-Shigella but significantly increased the levels of Alloprevotella and Prevotellaceae_NK3B31, two short-chain fatty acid-producing bacterial genera in the gut. Accordingly, the translocation of enterobacteria and lipopolysaccharide to the blood, as well as the infectious inflammatory responses in the intestine after TAI, was all suppressed by T7E21RHD5 administration. Hence, this versatile antimicrobial peptide possesses promising application prospects in the treatment of IR-induced enterogenic infection.

Characterization of the gut microbiota and fecal and blood metabolomes under various factors in urban children from Northwest China

Introduction

Children have regional dynamics in the gut microbiota development trajectory. Hitherto, the features and influencing factors of the gut microbiota and fecal and plasma metabolites in children from Northwest China remain unclear.

Methods

Shotgun metagenomic sequencing and untargeted metabolomics were performed on 100 healthy volunteers aged 2-12 years.

Results

Age, body mass index (BMI), regular physical exercise (RPE), and delivery mode (DM) significantly affect gut microbiota and metabolites. Lactobacillus, Butyricimonas, Prevotella, Alistipes, and predicted pathway propanoate production were significantly increased with age while Bifidobacterium breve, B. animalis, B. pseudocatenulatum, Streptococcus infantis, and carbohydrate degradation were decreased. Fecal metabolome revealed that the metabolism of caffeine, amino acids, and lipid significantly increased with age while galactose metabolism decreased. Noticeably, BMI was positively associated with pathogens including Erysipelatoclostridium ramosum, Parabacteroides distasonis, Ruminococcus gnavus, and amino acid metabolism but negatively associated with beneficial Akkermansia muciniphila, Alistipes finegoldii, Eubacterium ramulus, and caffeine metabolism. RPE has increased probiotic Faecalibacterium prausnitzii and Anaerostipes hadrus, acetate and lactate production, and major nutrient metabolism in gut and plasma, but decreased pathobiont Bilophila wadsworthia, taurine degradation, and pentose phosphate pathway. Interestingly, DM affects the gut microbiota and metabolites throughout the whole childhood. Bifidobacterium animalis, Lactobacillus mucosae, L. ruminis, primary bile acid, and neomycin biosynthesis were enriched in eutocia, while anti-inflammatory Anaerofustis stercorihominis, Agathobaculum butyriciproducens, Collinsella intestinalis, and pathogenic Streptococcus salivarius, Catabacter hongkongensis, and amino acid metabolism were enriched in Cesarean section children.

Discussion

Our results provided theoretical and data foundation for the gut microbiota and metabolites in preadolescent children's growth and development in Northwest China.