Oral probiotic administration induces interleukin-10 production and prevents spontaneous autoimmune diabetes in the non-obese diabetic mouse

Bacillus amyloliquefaciens Protect Against Atherosclerosis Through Alleviating Foam Cell Formation and Macrophage Polarization

This study was to investigate the therapeutic effect of Bacillus amyloliquefaciens (Ba) on atherosclerosis (AS). THP-1 monocyte was differentiated to THP-1 macrophage (THP-M) through phorbol 12-myristate 13-acetate. After pre-treatment by 108 cfu/ml Ba lasting 6 h, THP-M was induced with 100 mg/l ox-LDL lasting 48 h to form macrophage foam cell (THP-F). RT-qPCR and flow cytometry were employed to determine the polarization of THP-M and THP-F. ApoE-/- mice with high-fat and high-cholesterol diet were used for constructing an AS model to evaluate the effect of Ba on AS. Our in vitro results showed that Ba vegetative cells pre-treatment distinctly inhibited the levels of iNOS and CD16/CD32 (M1 macrophage markers), and increased the levels of FIZZ1, Ym1, Arg1, CD163, and CD206 (M2 macrophage markers), indicating that Ba pre-treatment promoted anti-inflammatory M2-like polarization both in THP-M and THP-F. Meanwhile, it also suppressed cholesterol uptake, esterification, and hydrolysis, and efflux by THP-M and THP-F. Additionally, our animal experiments demonstrated that Ba vegetative cells treatment suppressed high cholesterol, hyperglycemia, hyperlipidemia, and the release of inflammatory factors (TNF-α, IL-6 and IL-1β) in ApoE-/- AS mice. In a word, our results indicated that Ba may protect against AS through alleviating foam cell formation and macrophage polarization through targeting certain stages of AS.

Supplementation of High-Strength Oral Probiotics Improves Immune Regulation and Preserves Beta Cells among Children with New-Onset Type 1 Diabetes Mellitus: A Randomised, Double-Blind Placebo Control Trial

OBJECTIVES

To investigate the mechanism of glycemic control in children with type 1 diabetes (T1D) following high-strength probiotics supplementation by assessing immune-regulatory markers.

METHODS

In this single-centre randomised double-blinded placebo-controlled study, children with new-onset T1D on regular insulin therapy were randomised into probiotic or placebo groups with 30 children each. The probiotics group received oral powder of Vivomixx®, and the placebo group received corn starch for six months. The primary outcome parameters included induced T regulatory cells (i-Tregs) percentage, insulin autoantibodies (IAA), insulinoma associated 2 autoantibodies (IA2), glutamic acid decarboxylase autoantibodies (GAD 65) and plasma interleukin-10 (IL-10) levels. The secondary outcome variables were changes in plasma C-peptide levels and glycemic control parameters.

RESULTS

Twenty-three children in the placebo group and 27 in the probiotic group completed the study. There was a significant increase in the percentage of iTregs (3.40 in the probiotic vs. 2.46 in the placebo group; p = 0.034). Median glycated hemoglobin (HbA1c) levels significantly decreased from 68 mmol/mol (8.35%) in the placebo group to 60 mmol/mol (7.55%) in the probiotic group (p = 0.017). Median C-peptide levels were significantly higher in probiotics (0.72 ng/ml) vs. placebo group (0.11 ng/ml) (p = 0.036). The plasma IL-10 levels significantly increased in the probiotic group after six months of treatment (p = 0.002).

CONCLUSIONS

The high-strength probiotics improved the immunoregulatory milieu, thereby preserving the beta-cell function and better glycemic control.

Biomolecular Actions by Intestinal Endotoxemia in Metabolic Syndrome

Metabolic syndrome (MetS) is a combination of metabolic disorders that concurrently act as factors promoting systemic pathologies such as atherosclerosis or diabetes mellitus. It is now believed to encompass six main interacting conditions: visceral fat, imbalance of lipids (dyslipidemia), hypertension, insulin resistance (with or without impairing both glucose tolerance and fasting blood sugar), and inflammation. In the last 10 years, there has been a progressive interest through scientific research investigations conducted in the field of metabolomics, confirming a trend to evaluate the role of the metabolome, particularly the intestinal one. The intestinal microbiota (IM) is crucial due to the diversity of microorganisms and their abundance. Consequently, IM dysbiosis and its derivate toxic metabolites have been correlated with MetS. By intervening in these two factors (dysbiosis and consequently the metabolome), we can potentially prevent or slow down the clinical effects of the MetS process. This, in turn, may mitigate dysregulations of intestinal microbiota axes, such as the lung axis, thereby potentially alleviating the negative impact on respiratory pathology, such as the chronic obstructive pulmonary disease. However, the biomolecular mechanisms through which the IM influences the host's metabolism via a dysbiosis metabolome in both normal and pathological conditions are still unclear. In this study, we seek to provide a description of the knowledge to date of the IM and its metabolome and the factors that influence it. Furthermore, we analyze the interactions between the functions of the IM and the pathophysiology of major metabolic diseases via local and systemic metabolome's relate endotoxemia.

From Gut to Glucose: A Comprehensive Review on Functional Foods and Dietary Interventions for Diabetes Management

BACKGROUND

In the realm of diabetes research, considerable attention has been directed toward elucidating the intricate interplay between the gastrointestinal tract and glucose regulation. The gastrointestinal tract, once exclusively considered for its role in digestion and nutrient assimilation, is presently acknowledged as a multifaceted ecosystem with regulatory supremacy over metabolic homeostasis and glucose metabolism. Recent studies indicate that alterations in the composition and functionality of the gut microbiota could potentially influence the regulation of glucose levels and glucose homeostasis in the body. Dysbiosis, characterized by perturbations in the equilibrium of gut microbial constituents, has been irrevocably linked to an augmented risk of diabetes mellitus (DM). Moreover, research has revealed the potential influence of the gut microbiota on important factors, like inflammation and insulin sensitivity, which are key contributors to the onset and progression of diabetes. The key protagonists implicated in the regulation of glucose encompass the gut bacteria, gut barrier integrity, and the gut-brain axis. A viable approach to enhance glycemic control while concurrently mitigating the burden of comorbidities associated with diabetes resides in the strategic manipulation of the gut environment through adapted dietary practices.

OBJECTIVE

This review aimed to provide a deep understanding of the complex relationship between gut health, glucose metabolism, and diabetes treatment.

CONCLUSION

This study has presented an exhaustive overview of dietary therapies and functional foods that have undergone extensive research to explore their potential advantages in the management of diabetes. It looks into the role of gut health in glucose regulation, discusses the impact of different dietary elements on the course of diabetes, and evaluates how well functional foods can help with glycemic control. Furthermore, it investigates the mechanistic aspects of these therapies, including their influence on insulin sensitivity, β-cell activity, and inflammation. It deliberates on the limitations and potential prospects associated with integrating functional foods into personalized approaches to diabetes care.

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.

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

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

Lactiplantibacillus plantarum 299v supplementation modulates β-cell ER stress and antioxidative defense pathways and prevents type 1 diabetes in gluten-free BioBreeding rats

The increasing incidence of Type 1 diabetes has coincided with the emergence of the low-fiber, high-gluten Western diet and other environmental factors linked to dysbiosis. Since Lactiplantibacillus plantarum 299 v (Lp299v) supplementation improves gut barrier function and reduces systemic inflammation, we studied its effects in spontaneously diabetic DRlyp/lyp rats provided a normal cereal diet (ND) or a gluten-free hydrolyzed casein diet (HCD). All rats provided ND developed diabetes (62.5±7.7 days); combining ND with Lp299v did not improve survival. Diabetes was delayed by HCD (72.2±9.4 days, p = .01) and further delayed by HCD+Lp299v (84.9±14.3 days, p < .001). HCD+Lp299v pups exhibited increased plasma propionate and butyrate levels, which correlated with enriched fecal Bifidobacteriaceae and Clostridiales taxa. Islet transcriptomic and histologic analyses at 40-days of age revealed that rats fed HCD expressed an autophagy profile, while those provided HCD+Lp299v expressed ER-associated protein degradation (ERAD) and antioxidative defense pathways, including Nrf2. Exposing insulinoma cells to propionate and butyrate promoted the antioxidative defense response but did not recapitulate the HCD+Lp299v islet ERAD transcriptomic profile. Here, both diet and microbiota influenced diabetes susceptibility. Moreover, Lp299v supplement modulated antioxidative defense and ER stress responses in β-cells, potentially offering a new therapeutic direction to thwart diabetes progression and preserve insulin secretion.

Microbial dysbiosis in the gut drives systemic autoimmune diseases

Trillions of microbes survive and thrive inside the human body. These tiny creatures are crucial to the development and maturation of our immune system and to maintain gut immune homeostasis. Microbial dysbiosis is the main driver of local inflammatory and autoimmune diseases such as colitis and inflammatory bowel diseases. Dysbiosis in the gut can also drive systemic autoimmune diseases such as type 1 diabetes, rheumatic arthritis, and multiple sclerosis. Gut microbes directly interact with the immune system by multiple mechanisms including modulation of the host microRNAs affecting gene expression at the post-transcriptional level or production of microbial metabolites that interact with cellular receptors such as TLRs and GPCRs. This interaction modulates crucial immune functions such as differentiation of lymphocytes, production of interleukins, or controlling the leakage of inflammatory molecules from the gut to the systemic circulation. In this review, we compile and analyze data to gain insights into the underpinning mechanisms mediating systemic autoimmune diseases. Understanding how gut microbes can trigger or protect from systemic autoimmune diseases is crucial to (1) tackle these diseases through diet or lifestyle modification, (2) develop new microbiome-based therapeutics such as prebiotics or probiotics, (3) identify diagnostic biomarkers to predict disease risk, and (4) observe and intervene with microbial population change with the flare-up of autoimmune responses. Considering the microbiome signature as a crucial player in systemic autoimmune diseases might hold a promise to turn these untreatable diseases into manageable or preventable ones.

Role of gut microbiota in the pathogenesis and treatment of diabetes mullites: Advanced research-based review

Gut microbiota plays an important role in the proper functioning of human organisms, while its dysbiosis is associated with disease in various body organs. Diabetes mellitus (DM) is a set of heterogeneous metabolic diseases characterized by hyperglycemia caused by direct or indirect insulin deficiency. There is growing evidence that gut microbiota dysbiosis is closely linked to the development of DM. Gut microbiota composition changes in type 1 diabetes mullites (T1DM) and type 2 diabetes mullites (T2DM) patients, which may cause gut leakiness and uncontrolled entry of antigens into the circulation system, triggering an immune response that damages the isle β cells or metabolic disorders. This review summarizes gut microbiota composition in healthy individuals and compares it to diabetes mullites patients. The possible pathogenesis by which gut microbiota dysbiosis causes DM, particularly gut leakiness and changes in gut microbiota metabolites is also discussed. It also presents the process of microbial-based therapies of DM.

Safety and efficacy of fecal microbiota transplantation for autoimmune diseases and autoinflammatory diseases: A systematic review and meta-analysis

Objective

To evaluate the safety and efficacy of fecal microbiota transplantation for autoimmune diseases and autoinflammatory diseases.

Methods

Relevant literature was retrieved from the PubMed database, Embase database, Cochrane Library database, etc. The search period is from the establishment of the database to January 2022. The outcomes include clinical symptoms, improvement in biochemistry, improvement in intestinal microbiota, improvement in the immune system, and adverse events. Literature screening and data extraction were independently carried out by two researchers according to the inclusion and exclusion criteria, and RevMan 5.3 software was used for statistics and analysis.

Results

Overall, a total of 14 randomized controlled trials (RCTs) involving six types of autoimmune diseases were included. The results showed the following. 1) Type 1 diabetes mellitus (T1DM): compared with the autologous fecal microbiota transplantation (FMT) group (control group), the fasting plasma C peptide in the allogenic FMT group at 12 months was lower. 2) Systemic sclerosis: at week 4, compared with one of two placebo controls, three patients in the experimental group reported a major improvement in fecal incontinence. 3) Ulcerative colitis, pediatric ulcerative colitis, and Crohn’s disease: FMT may increase clinical remission, clinical response, and endoscopic remission for patients with ulcerative colitis and increase clinical remission for patients with Crohn’s disease. 4) Psoriatic arthritis: there was no difference in the ratio of ACR20 between the two groups.

Conclusion

Based on current evidence, the application of FMT in the treatment of autoimmune diseases is effective and relatively safe, and it is expected to be used as a method to induce remission of active autoimmune diseases.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021235055, identifier CRD42021235055.

Probiotic Mechanisms Affecting Glucose Homeostasis: A Scoping Review

The maintenance of a healthy status depends on the coexistence between the host organism and the microbiota. Early studies have already focused on the nutritional properties of probiotics, which may also contribute to the structural changes in the gut microbiota, thereby affecting host metabolism and homeostasis. Maintaining homeostasis in the body is therefore crucial and is reflected at all levels, including that of glucose, a simple sugar molecule that is an essential fuel for normal cellular function. Despite numerous clinical studies that have shown the effect of various probiotics on glucose and its homeostasis, knowledge about the exact function of their mechanism is still scarce. The aim of our review was to select in vivo and in vitro studies in English published in the last eleven years dealing with the effects of probiotics on glucose metabolism and its homeostasis. In this context, diverse probiotic effects at different organ levels were highlighted, summarizing their potential mechanisms to influence glucose metabolism and its homeostasis. Variations in results due to different methodological approaches were discussed, as well as limitations, especially in in vivo studies. Further studies on the interactions between probiotics, host microorganisms and their immunity are needed.

Gut–Skin Axis: Unravelling the Connection between the Gut Microbiome and Psoriasis

Evidence has shown that gut microbiome plays a role in modulating the development of diseases beyond the gastrointestinal tract, including skin disorders such as psoriasis. The gut–skin axis refers to the bidirectional relationship between the gut microbiome and skin health. This is regulated through several mechanisms such as inflammatory mediators and the immune system. Dysregulation of microbiota has been seen in numerous inflammatory skin conditions such as atopic dermatitis, rosacea, and psoriasis. Understanding how gut microbiome are involved in regulating skin health may lead to development of novel therapies for these skin disorders through microbiome modulation, in particularly psoriasis. In this review, we will compare the microbiota between psoriasis patients and healthy control, explain the concept of gut–skin axis and the effects of gut dysbiosis on skin physiology. We will also review the current evidence on modulating gut microbiome using probiotics in psoriasis.

Environmental Factors and the Risk of Developing Type 1 Diabetes-Old Disease and New Data

Simple Summary

Despite many studies, the risk factors of type 1 diabetes (T1DM) in children and adolescents are still not fully understood and remain a big challenge. Therefore, an extensive online search for scientific research on factors related to diabetes has been performed for the identification of new factors of unexplained etiology. A better understanding of the role of viral, bacterial, and yeast-like fungi infections related to the risk of T1DM in children and adolescents and the identification of new risk factors, especially those spread by the droplet route, is of great importance for people and families with diabetes.

Abstract

The incidence of type 1 diabetes (T1D) is increasing worldwide. The onset of T1D usually occurs in childhood and is caused by the selective destruction of insulin-producing pancreatic islet cells (β-cells) by autoreactive T cells, leading to insulin deficiency. Despite advanced research and enormous progress in medicine, the causes of T1D are still not fully understood. Therefore, an extensive online search for scientific research on environmental factors associated with diabetes and the identification of new factors of unexplained etiology has been carried out using the PubMed, Cochrane, and Embase databases. The search results were limited to the past 11 years of research and discovered 143 manuscripts published between 2011 and 2022. Additionally, 21 manuscripts from between 2000 and 2010 and 3 manuscripts from 1974 to 2000 were referenced for historical reference as the first studies showcasing a certain phenomenon or mechanism. More and more scientists are inclined to believe that environmental factors are responsible for the increased incidence of diabetes. Research results show that higher T1D incidence is associated with vitamin D deficiency, a colder climate, and pollution of the environment, as well as the influence of viral, bacterial, and yeast-like fungi infections. The key viral infections affecting the risk of developing T1DM are rubella virus, mumps virus, Coxsackie virus, cytomegalovirus, and enterovirus. Since 2020, i.e., from the beginning of the COVID-19 pandemic, more and more studies have been looking for a link between Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) and diabetes development. A better understanding of the role of viral, bacterial, and yeast-like fungi infections related to the risk of T1DM in children and adolescents and the identification of new risk factors, especially those spread by the droplet route, is of great importance for people and families with diabetes.

Long-term drench of exopolysaccharide from Leuconostoc pseudomesenteroides XG5 protects against type 1 diabetes of NOD mice via stimulating GLP-1 secretion

BACKGROUND

Type 1 diabetes is an autoimmune disease that results in the specific destruction of insulin-producing beta cells in the pancreas. The aim of this study was to investigate the mechanism of exopolysaccharide from Leuconostoc pseudomesenteroides XG5 (XG5 EPS) against type 1 diabetes.

RESULTS

Long-term drench of XG5 EPS delayed the onset of autoimmune diabetes and had fewer islets with high-grade infiltration (an insulitis score of 3 or 4) than untreated NOD mice. Oral administration of 50 mg kg^-1  d^-1 XG5 EPS increased the insulin and glucagon-like peptide-1 (GLP-1) levels of serum, stimulated GLP-1 secretion and upregulated gcg mRNA expression of colon in NOD mice. Moreover, oral administration of 50 mg kg^-1  d^-1 XG5 EPS significantly increased total short-chain fatty acids levels in the colon contents, especially those of acetic acid and butyric acid. In NCI-H716 cells, 500 and 1000 μmol L^-1 sodium butyrate promoted the secretion of GLP-1 and upregulated the mRNA expression of gcg and PC3, while XG5 EPS and sodium acetate did not stimulate the GLP-1 secretion. Therefore, long-term drench of XG5 EPS delayed the onset of autoimmune diabetes, which may be directly correlated with the increase of butyrate in the colon of NOD mice.

CONCLUSION

Long-term drench of 50 mg kg^-1  d^-1 XG5 EPS promoted the expression and secretion of GLP-1 by increasing the production of butyric acid, thereby delaying T1D onset in NOD mice. © 2021 Society of Chemical Industry.

Probiotic normalization of systemic inflammation in siblings of type 1 diabetes patients: an open-label pilot study

The incidence of type 1 diabetes (T1D) has increased, coinciding with lifestyle changes that have likely altered the gut microbiota. Dysbiosis, gut barrier dysfunction, and elevated systemic inflammation consistent with microbial antigen exposure, have been associated with T1D susceptibility and progression. A 6-week, single-arm, open-label pilot trial was conducted to investigate whether daily multi-strain probiotic supplementation could reduce this familial inflammation in 25 unaffected siblings of T1D patients. Probiotic supplementation was well-tolerated as reflected by high participant adherence and no adverse events. Community alpha and beta diversity were not altered between the pre- and post-supplement stool samplings. However, LEfSe analyses identified post-supplement enrichment of the family Lachnospiraceae, producers of the anti-inflammatory short chain fatty acid butyrate. Systemic inflammation was measured by plasma-induced transcription and quantified with a gene ontology-based composite inflammatory index (I.I._com). Post-supplement I.I._com was significantly reduced and pathway analysis predicted inhibition of numerous inflammatory mediators and activation of IL10RA. Subjects with the greatest post-supplement reduction in I.I._com exhibited significantly lower CD4+ CD45RO+ (memory):CD4+ CD45RA+ (naïve) T-cell ratios after supplementation. Post-supplement IL-12p40, IL-13, IL-15, IL-18, CCL2, and CCL24 plasma levels were significantly reduced, while post-supplement butyrate levels trended 1.4-fold higher. Probiotic supplementation may modify T1D susceptibility and progression and warrants further study.

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

Abstract

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

Highlights

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

Gut Dysbiosis in Pancreatic Diseases: A Causative Factor and a Novel Therapeutic Target

Pancreatic-related disorders such as pancreatitis, pancreatic cancer, and type 1 diabetes mellitus (T1DM) impose a substantial challenge to human health and wellbeing. Even though our understanding of the initiation and progression of pancreatic diseases has broadened over time, no effective therapeutics is yet available for these disorders. Mounting evidence suggests that gut dysbiosis is closely related to human health and disease, and pancreatic diseases are no exception. Now much effort is under way to explore the correlation and eventually potential causation between the gut microbiome and the course of pancreatic diseases, as well as to develop novel preventive and/or therapeutic strategies of targeted microbiome modulation by probiotics, prebiotics, synbiotics, postbiotics, and fecal microbiota transplantation (FMT) for these multifactorial disorders. Attempts to dissect the intestinal microbial landscape and its metabolic profile might enable deep insight into a holistic picture of these complex conditions. This article aims to review the subtle yet intimate nexus loop between the gut microbiome and pancreatic diseases, with a particular focus on current evidence supporting the feasibility of preventing and controlling pancreatic diseases via microbiome-based therapeutics and therapies.

Gut Microbiota and Autoimmune Diseases: A Charming Real World Together with Probiotics

BACKGROUND

The role of gut microbiota in human disease is fascinating for hundreds of researchers worldwide. Many works have highlighted that gut microbiota modulates the immune system and that its disruption can trigger autoimmune and inflammatory immune-mediated diseases. Probiotics are able to positively modify microbiota composition.

OBJECTIVE

The aim of this review is to report the most important findings regarding the effects of probiotics administration in the most common autoimmune disease and inflammatory immune-mediated diseases.

METHODS

Literature research was performed in PubMed, Google Scholar, and Medline, as well as in specific journal websites using the keywords: "autoimmunity", "microbiota", and "probiotics". The article selection has been made independently by three authors, and controversies have been solved by a fourth researcher. Only English-language articles were included and preference was given to clinical trials, meta-analysis, and case series. After the review process, 68 articles have been considered.

RESULTS

Relying on this evidence, many studies have investigated the potential of probiotics in restoring gut eubiosis, thus affecting pathogenesis, clinical manifestations, and course of these pathologies. Even in the light of few and sometimes contradictory studies, physicians should start to consider these preliminary findings when approaching patients suffering from autoimmune disease. After an accurate case-by-case evaluation of potential candidates, probiotics might be introduced besides the standard therapeutic plan as supportive measures.

Is Fecal Calprotectin an Applicable Biomarker of Gut Immune System Activation in Chronic Inflammatory Demyelinating Polyneuropathy? - A Pilot Study

Introduction: Chronic inflammatory demyelinating polyneuropathy (CIDP) is a complex autoimmune disease caused by dysregulated response to not fully recognized antigens. Some association between CIDP and inflammatory bowel disease (IBD) has been reported, but the exact pathophysiological links of these disorders are not well understood.

Aim of the Study: To evaluate fecal calprotectin as a biomarker of gut inflammation in CIDP patients without IBD.

Methods: Fifteen patients with CIDP and 15 healthy controls were included in the study. The CIDP diagnosis was based on the EFNS/PNS criteria. The occurrence of bowel symptoms was assessed based on a questionnaire. The quantitative evaluation of fecal calprotectin level was performed by the ELISA test.

Results: The fecal calprotectin level (μg/g) expressed as median along with the lower and upper quartiles [25Q–75Q] was significantly higher in CIDP patients compared to the controls: 26.6 [17.5–109.0] vs 15.6 [7.1–24.1], p = 0.0066. Abnormal fecal calprotectin level (>50 μg/g) was found in 33% of all CIDP patients and in none of the control subjects. The patients with abnormal fecal calprotectin level did not differ from the rest of the study group regarding the neurological status. The most common bowel symptoms reported by CIDP patients included constipation (33%), feeling of incomplete evacuation (33%), bloating (27%), and alternating bowel movement pattern (27%).

Conclusion: In one-third of CIDP patients the signs of gut immune system activation have been observed. This finding may be associated with CIDP pathogenesis and induction of autoimmune response as well as concomitant dysautonomia with gastrointestinal symptoms.

A high potency multi-strain probiotic improves glycemic control in children with new-onset type 1 diabetes mellitus: A randomized, double-blind, and placebo-controlled pilot study

BACKGROUND

Studies in animal models and humans with type 1 diabetes mellitus (T1DM) have shown that probiotic supplementation leads to decreased pro-inflammatory cytokines (responsible for damaging β-cells of the pancreas), improved gut barrier function, and induction of immune tolerance.

OBJECTIVE

To study the effect of supplementation of probiotics in children with T1DM on glycemic control, insulin dose, and plasma C-peptide levels.

METHODS

A single-centered, double-blinded, and randomized placebo-controlled pilot trial was conducted in children (2-12 years) with new-onset T1DM. Ninety-six children were randomized and allocated to Placebo or Intervention groups. The intervention included high dose (112.5 billion viable lyophilized bacteria per capsule) multi-strain probiotic De Simone formulation (manufactured by Danisco-Dupont) sold as Visbiome® in India. The probiotic was supplemented for 3 months and HbA1c, fasting C-peptide, blood sugar records, and insulin dose was recorded at baseline and 3 months.

RESULTS

A total of 90 patients (45 in each group) were analyzed for outcome parameters. We found a significant decrease in HbA1c (5.1 vs. 3.8; p = 0.021) and a significant decline in total and bolus insulin dose (U/kg/day; p = 0.037 and 0.018, respectively) in the intervention group when compared with the placebo group. A significantly higher (p = 0.023) number of children achieved remission in the treatment group. We did not notice adverse effects in either of the study groups.

CONCLUSION

Children with newly diagnosed T1DM managed with standard treatment along with probiotics showed better glycemic control and a decrease in insulin requirements; however, more extensive studies are further warranted.

Lactobacillus reuteri FYNLJ109L1 Attenuating Metabolic Syndrome in Mice via Gut Microbiota Modulation and Alleviating Inflammation

Metabolic syndrome is caused by an excessive energy intake in a long-term, high-fat and/or high-sugar diet, resulting in obesity and a series of related complications, which has become a global health concern. Probiotics intervention can regulate the gut microbiota and relieve the systemic and chronic low-grade inflammation, which is an alternative to relieving metabolic syndrome. The aim of this work was to explore the alleviation of two different Lactobacillusreuteri strains on metabolic syndrome. Between the two L. reuteri strains, FYNLJ109L1 had a better improvement effect on blood glucose, blood lipid, liver tissue damage and other related indexes than NCIMB 30242. In particular, FYNLJ109L1 reduced weight gain, food intake and fat accumulation. Additionally, it can regulate the gut microbiota, increase IL-10, and reduce IL-6 and tumor necrosis factor-α (TNF-α), as well as liver injury, and further reduce insulin resistance and regulate lipid metabolism disorders. In addition, it could modulate the gut microbiota, particularly a decreased Romboutsia and Clostridium sensu stricto-1, and an increased Acetatifactor. The results indicated that FYNLJ109L1 could improve metabolic syndrome significantly via alleviating inflammation and gut microbiota modulation.

The Effect of Probiotics on Various Diseases and their Therapeutic Role: An Update Review

Probiotic bacteria play a critical and functional role in clinical and nutritional applications. In the present study, the ability of various probiotics and their metabolites in the prevention and treatment of different diseases, infections and disorders was reviewed. The issues that were noticed are included: Fibrocystic, diabetes, acne, colon cancer, cardiovascular, urinary tract infections, atopic eczema syndrome, food allergies and obesity. Enhancement in using drug treatment has led to the appearance of drug-resistance concern, thus probiotics can be a suitable choice. This review focuses on the effect of probiotic bacteria and their metabolites on immune-boosting, prevention and treatment of these diseases. For this purpose, after a short glance at each disease, infection and disorder, the mechanism of probiotic action and recent studies about that disease are reviewed. It could be recommended that probiotics consumption, perhaps from birth to all stages of life, would be effective in the life-long, development of health effects and disease treatments.

Inflammasomes and Type 1 Diabetes

Microbiota have been identified as an important modulator of susceptibility in the development of Type 1 diabetes in both animal models and humans. Collectively these studies highlight the association of the microbiota composition with genetic risk, islet autoantibody development and modulation of the immune responses. However, the signaling pathways involved in mediating these changes are less well investigated, particularly in humans. Importantly, understanding the activation of signaling pathways in response to microbial stimulation is vital to enable further development of immunotherapeutics, which may enable enhanced tolerance to the microbiota or prevent the initiation of the autoimmune process. One such signaling pathway that has been poorly studied in the context of Type 1 diabetes is the role of the inflammasomes, which are multiprotein complexes that can initiate immune responses following detection of their microbial ligands. In this review, we discuss the roles of the inflammasomes in modulating Type 1 diabetes susceptibility, from genetic associations to the priming and activation of the inflammasomes. In addition, we also summarize the available inhibitors for therapeutically targeting the inflammasomes, which may be of future use in Type 1 diabetes.

Hygiene hypothesis and autoimmune diseases: A narrative review of clinical evidences and mechanisms

Since the start of the "modern era", characterized by the increase in urbanization, a progressive attention to hygiene and autoimmune conditions has considerably grown. Although these diseases are often multifactorial, it was demonstrated that environment factors such as pollution, diet and lifestyles may play a crucial role together with genetic signature. Our research, based on the newest and most significant literature of this topic, highlights that the progressive depletion of microbes and parasites due to increased socioeconomic improvement, may lead to a derangement of immunoregulatory mechanisms. Moreover, special attention was given to the complex interplay between microbial agents, as gut microbiome, diet and vitamin D supplementation with the aim of identifying promising future therapeutic options. In conclusion, autoimmunity cannot be limited to hygiene-hypothesis, but from the point of view of precision medicine, this theory represents a fundamental element together with the study of genomics, the microbiome and proteomics, in order to understand the complex functioning of the immune system.

A Triple Threat? The Role of Diet, Nutrition, and the Microbiota in T1D Pathogenesis

In recent years the role of the intestinal microbiota in health and disease has come to the forefront of medical research. Alterations in the intestinal microbiota and several of its features have been linked to numerous diseases, including type 1 diabetes (T1D). To date, studies in animal models of T1D, as well as studies in human subjects, have linked several intestinal microbiota alterations with T1D pathogenesis. Features that are most often linked with T1D pathogenesis include decreased microbial diversity, the relative abundance of specific strains of individual microbes, and altered metabolite production. Alterations in these features as well as others have provided insight into T1D pathogenesis and shed light on the potential mechanism by which the microbiota plays a role in T1D pathogenesis, yet the underlying factors leading to these alterations remains unknown. One potential mechanism for alteration of the microbiota is through diet and nutrition. Previous studies have shown associations of diet with islet autoimmunity, but a direct contributing factor has yet to be identified. Diet, through introduction of antigens and alteration of the composition and function of the microbiota, may elicit the immune system to produce autoreactive responses that result in the destruction of the beta cells. Here, we review the evidence associating diet induced changes in the intestinal microbiota and their contribution to T1D pathogenesis. We further provide a roadmap for determining the effect of diet and other modifiable factors on the entire microbiota ecosystem, including its impact on both immune and beta cell function, as it relates to T1D. A greater understanding of the complex interactions between the intestinal microbiota and several interacting systems in the body (immune, intestinal integrity and function, metabolism, beta cell function, etc.) may provide scientifically rational approaches to prevent development of T1D and other childhood immune and allergic diseases and biomarkers to evaluate the efficacy of interventions.

The crucial role of early-life gut microbiota in the development of type 1 diabetes

Early-life healthy gut microbiota has a profound implication on shaping the mucosal immune system as well as maintaining healthy status later in life, especially at the prenatal or neonatal stages, while intestinal dysbiosis in early life is associated with several autoimmune diseases, including type 1 diabetes (T1D). Since the gut microbiome is potentially modifiable, optimizing the intestinal bacterial composition in early life may be a novel option for T1D prevention. In this review, we will review current data depicting the crucial role of early-life intestinal microbiome in the development of T1D and discuss the possible mechanisms whereby early-life intestinal microbiome influences the T1D progression. We also summarize recent findings on environmental factors affecting gut microbiota colonization and interventions that may successfully alter microbial composition to discuss potential means of preventing T1D progression in at-risk children.

Modulating gut microbiota in a mouse model of Graves' orbitopathy and its impact on induced disease

BACKGROUND

Graves' disease (GD) is an autoimmune condition in which autoantibodies to the thyrotropin receptor (TSHR) cause hyperthyroidism. About 50% of GD patients also have Graves' orbitopathy (GO), an intractable disease in which expansion of the orbital contents causes diplopia, proptosis and even blindness. Murine models of GD/GO, developed in different centres, demonstrated significant variation in gut microbiota composition which correlated with TSHR-induced disease heterogeneity. To investigate whether correlation indicates causation, we modified the gut microbiota to determine whether it has a role in thyroid autoimmunity. Female BALB/c mice were treated with either vancomycin, probiotic bacteria, human fecal material transfer (hFMT) from patients with severe GO or ddH2O from birth to immunization with TSHR-A subunit or beta-galactosidase (βgal; age ~ 6 weeks). Incidence and severity of GD (TSHR autoantibodies, thyroid histology, thyroxine level) and GO (orbital fat and muscle histology), lymphocyte phenotype, cytokine profile and gut microbiota were analysed at sacrifice (~ 22 weeks).

RESULTS

In ddH2O-TSHR mice, 84% had pathological autoantibodies, 67% elevated thyroxine, 77% hyperplastic thyroids and 70% orbital pathology. Firmicutes were increased, and Bacteroidetes reduced relative to ddH2O-βgal; CCL5 was increased. The random forest algorithm at the genus level predicted vancomycin treatment with 100% accuracy but 74% and 70% for hFMT and probiotic, respectively. Vancomycin significantly reduced gut microbiota richness and diversity compared with all other groups; the incidence and severity of both GD and GO also decreased; reduced orbital pathology correlated positively with Akkermansia spp. whilst IL-4 levels increased. Mice receiving hFMT initially inherited their GO donors' microbiota, and the severity of induced GD increased, as did the orbital brown adipose tissue volume in TSHR mice. Furthermore, genus Bacteroides, which is reduced in GD patients, was significantly increased by vancomycin but reduced in hFMT-treated mice. Probiotic treatment significantly increased CD25+ Treg cells in orbital draining lymph nodes but exacerbated induced autoimmune hyperthyroidism and GO.

CONCLUSIONS

These results strongly support a role for the gut microbiota in TSHR-induced disease. Whilst changes to the gut microbiota have a profound effect on quantifiable GD endocrine and immune factors, the impact on GO cellular changes is more nuanced. The findings have translational potential for novel, improved treatments. Video abstract.

Early Nutrition and Risk of Type 1 Diabetes: The Role of Gut Microbiota

Type 1 diabetes (T1D) appears most frequently in childhood, with an alarming increasing incidence in the last decades. Although the genetic predisposition is a major risk factor, it cannot solely explain the complex etiology of T1D which is still not fully understood. In this paper, we reviewed the most recent findings on the role of early nutrition and the involvement of the gut microbiota in the etiopathogenesis of T1D. The main conclusions that are withdrawn from the current literature regarding alleviating the risk of developing T1D through nutrition are the encouragement of long-term breast-feeding for at least the first 6 months of life and the avoidance of early complementary foods and gluten introduction (before 4 months of age) as well as cow milk introduction before 12 months of life. These detrimental feeding habits create a gut microbiota dysbiotic state that can contribute to the onset of T1D in infancy. Finally, we discussed the possibility to introduce probiotics, prebiotics and post-biotics in the prevention of T1D.

100 years post-insulin: immunotherapy as the next frontier in type 1 diabetes

Type 1 diabetes (T1D) is an autoimmune disease characterised by T cell-mediated destruction of the insulin-producing β cells in the pancreas. Similar to other autoimmune diseases, the incidence of T1D is increasing globally. The discovery of insulin 100 years ago dramatically changed the outlook for people with T1D, preventing this from being a fatal condition. As we celebrate the centenary of this milestone, therapeutic options for T1D are once more at a turning point. Years of effort directed at developing immunotherapies are finally starting to pay off, with signs of progress in new onset and even preventative settings. Here, we review a selection of immunotherapies that have shown promise in preserving β cell function and highlight future considerations for immunotherapy in the T1D setting.

Why is the Incidence of Type 1 Diabetes Increasing?

Type 1 diabetes is a condition that can lead to serious long-term complications and can have significant psychological and quality of life implications. Its incidence is increasing in all parts of the world, but the reasons for this are incompletely understood. Genetic factors alone cannot explain such a rapid increase in incidence; therefore, environmental factors must be implicated. Lifestyle factors have been classically associated with type 2 diabetes. However, there are data implicating obesity and insulin resistance to type 1 diabetes as well (accelerator hypothesis). Cholesterol has also been shown to be correlated with the incidence of type 1 diabetes; this may be mediated by immunomodulatory effects of cholesterol. There is considerable interest in early life factors, including maternal diet, mode of delivery, infant feeding, childhood diet, microbial exposure (hygiene hypothesis), and use of anti-microbials in early childhood. Distance from the sea has recently been shown to be negatively correlated with the incidence of type 1 diabetes. This may contribute to the increasing incidence of type 1 diabetes since people are increasingly living closer to the sea. Postulated mediating mechanisms include hours of sunshine (and possibly vitamin D levels), mean temperature, dietary habits, and pollution. Ozone, polychlorinated biphenyls, phthalates, trichloroethylene, dioxin, heavy metals, bisphenol, nitrates/nitrites, and mercury are amongst the chemicals which may increase the risk of type 1 diabetes. Another area of research concerns the role of the skin and gut microbiome. The microbiome is affected by many of the factors mentioned above, including the mode of delivery, infant feeding, exposure to microbes, antibiotic use, and dietary habits. Research on the reasons why the incidence of type 1 diabetes is increasing not only sheds light on its pathogenesis but also offers insights into ways we can prevent type 1 diabetes.

Microbial modulation of intestinal T helper cell responses and implications for disease and therapy

Induction of intestinal T helper cell subsets by commensal members of the intestinal microbiota is an important component of the many immune adaptations required to establish host-microbial homeostasis. Importantly, altered intestinal T helper cell profiles can have pathological consequences that are not limited to intestinal sites. Therefore, microbial-mediated modulation of the intestinal T helper cell profile could have strong therapeutic potentials. However, in order to develop microbial therapies that specifically induce the desired alterations in the intestinal T helper cell compartment one has to first gain a detailed understanding of how microbial composition and the metabolites derived or induced by the microbiota impact on intestinal T helper cell responses. Here we summarize the milestone findings in the field of microbiota-intestinal T helper cell crosstalk with a focus on the role of specific commensal bacteria and their metabolites. We discuss mechanistic mouse studies and are linking these to human studies where possible. Moreover, we highlight recent advances in the field of microbial CD4 T cell epitope mimicry in autoimmune diseases and the role of microbially-induced CD4 T cells in cancer immune checkpoint blockade therapy.

Epigenetic Effects of Gut Metabolites: Exploring the Path of Dietary Prevention of Type 1 Diabetes

Type 1 diabetes (T1D) has increased over the past half century and has now become the second most frequent autoimmune disease in childhood and one of major public health concern worldwide. Evidence suggests that modern lifestyles and rapid environmental changes are driving factors that underlie this increase. The integration of these two factors brings about changes in food intake. This, in turn, alters epigenetic regulations of the genome and intestinal microbiota composition, which may ultimately play a role in pathogenesis of T1D. Recent evidence shows that dysbiosis of the gut microbiota is closely associated with T1D and that a dietary intervention can influence epigenetic changes associated with this disease and may modify gene expression patterns through epigenetic mechanisms. In this review focus on how a diet can shape the gut microbiome, its effect on the epigenome in T1D, and the future of T1D management by microbiome therapy.

Amelioration of Autoimmune Diabetes of NOD Mice by Immunomodulating Probiotics

Type 1 autoimmune diabetes is an autoimmune disease characterized by specific destruction of pancreatic β-cells producing insulin. Recent studies have shown that gut microbiota and immunity are closely linked to systemic immunity, affecting the balance between pro-inflammatory and regulatory immune responses. Altered gut microbiota may be causally related to the development of immune-mediated diseases, and probiotics have been suggested to have modulatory effects on inflammatory diseases and immune disorders. We studied whether a probiotic combination that has immunomodulatory effects on several inflammatory diseases can reduce the incidence of diabetes in non-obese diabetic (NOD) mice, a classical animal model of human T1D. When Immune Regulation and Tolerance 5 (IRT5), a probiotic combination comprising Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus reuteri, Bifidobacterium bifidium, and Streptococcus thermophiles, was administered 6 times a week for 36 weeks to NOD mice, beginning at 4 weeks of age, the incidence of diabetes was significantly reduced. Insulitis score was also significantly reduced, and β-cell mass was conversely increased by IRT5 administration. IRT5 administration significantly reduced gut permeability in NOD mice. The proportion of total regulatory T cells was not changed by IRT5 administration; however, the proportion of CCR9⁺ regulatory T (Treg) cells expressing gut-homing receptor was significantly increased in pancreatic lymph nodes (PLNs) and lamina propria of the small intestine (SI-LP). Type 1 T helper (Th1) skewing was reduced in PLNs by IRT5 administration. IRT5 could be a candidate for an effective probiotic combination, which can be safely administered to inhibit or prevent type 1 diabetes (T1D).

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

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

The Promising Role of Probiotics in Managing the Altered Gut in Autism Spectrum Disorders

Gastrointestinal symptoms (GIS) have been reported repeatedly in people with autism spectrum disorder (ASD) and studies have reported interesting correlations between severity of behavioral and gastrointestinal symptoms. Growing evidence indicates that the gut microbiota in ASD is altered with various shifts described at different taxonomic levels, pointing to the importance of considering the gut-brain axis in treatment of these disorders. Probiotics are live beneficial bacteria that are ingested as food or customized pills. These beneficial bacteria, when added in sufficient amounts, can correct the dysbiosis. Because probiotics have shown success in treating irritable bowel syndrome (IBS), it is plausible to investigate whether they can induce alleviation of behavioral symptoms as well. Probiotics show, in some clinical studies, their potential benefits (1) in improving gastrointestinal dysfunction, (2) in correcting dysbiosis, (3) in consequently reducing the severity of ASD symptoms. This review compiles data from selected studies that investigate these benefits and the mechanisms that mediate these effects, which include the production of metabolites, hormones, and neurotransmitters and the regulation of pro-inflammatory and regulatory cytokines. Future research based on more randomized, controlled studies with a larger population size and standardized use of strains, concentration of probiotics, duration of treatments, and methods of DNA extraction is still needed in this area, which may lead to more robust results.

Depletion of the diabetic gut microbiota resistance enhances stem cells therapy in type 1 diabetes mellitus

Microbiome, considered as the "second genome" of the host, is altered in type 1 diabetes mellitus (T1DM) patients to a state of dysbiosis. Mesenchymal stem cell (MSC) transplantation is a promising treatment for T1DM but is limited by several factors in the diabetic host. In this study, we tested the hypothesis that dysbiotic gut microbiota may limit MSC therapy, and modulating gut microbiota may help to improve the effects of MSC transplantation. Methods: NOD/Ltj mice, treated with adipose-derived stem cells (ADSCs), were fed with an antibiotics cocktails (Abx) for 1 week. The blood glucose levels, insulitis, intestinal permeability and gut bacteria translocation to the pancreas were evaluated. 16s rRNA and colon tissue transcription sequencing were performed to analyze beneficial bacteria and reactive host biomolecules in the ADSCs+Abx group. Based on the sequencing results, specific bacteria were gavaged orally to diabetic mice to confirm their effect on ADSCs transplantation in T1DM was determined. Results: We found that the recolonized the diabetic gut microbiota abolished the therapeutic effect of ADSCs. On the contrary, depletion of the diabetic gut microbiota by antibiotics treatment in diabetic mice significantly enhanced the therapeutic effects of ADSCs as measured by reversal of hyperglycemia, insulitis, and increased insulin output. Mechanistically, treatment with antibiotics increased the abundance of Bifidobacterium in the gut and reduced bacterial translocation to the pancreas by promoting Mucin2 expression and thickening the mucus layer through TRPM7. The mechanism was confirmed the re-colonization of the gut by B.breve through oral gavage that produced similar results. Conclusions: These results provide the rationale for a new approach to improve MSC therapy for T1DM by altering the gut microbiota.

Leuconostoc mesenteroides fermentation produces butyric acid and mediates Ffar2 to regulate blood glucose and insulin in type 1 diabetic mice

Type 1 diabetic patients have lower counts of butyric acid-producing bacteria in the dysbiotic gut microbiome. In this study, we demonstrate that a butyric acid-producing Leuconostoc mesenteroides (L. mesenteroides) EH-1 strain isolated from Mongolian curd cheese can reduce blood glucose and IL-6 in the type 1 diabetic mouse model. L. mesenteroides EH-1 fermentation yielded high concentrations of butyric acid both in vitro and in vivo. Butyric acid or L. mesenteroides EH-1 increased the amounts of insulin in Min6 cell culture and streptozotocin (STZ)-induced diabetic mice. Inhibition or siRNA knockdown of free fatty acid receptor 2 (Ffar2) considerably reduced the anti-diabetic effect of probiotic L. mesenteroides EH-1 or butyric acid by lowering the level of blood glucose. We here demonstrate that Ffar2 mediated the effects of L. mesenteroides EH-1 and butryic acid on regulation of blood glucose and insulin in type 1 diabetic mice.

Probiotic mixture VSL#3: An overview of basic and clinical studies in chronic diseases

Probiotics are known as “live microorganisms” and have been proven to have a health effect on hosts at the proper dose. Recently, a kind of probiotic mixture including eight live bacterial strains, VSL#3, has attracted considerable attention for its combined effect. VSL#3 is the only probiotic considered as a kind of medical food; it mainly participates in the regulation of the intestinal barrier function, including improving tight junction protein function, balancing intestinal microbial composition, regulating immune-related cytokine expression and so on. The objective of this review is to discuss the treatment action and mechanism for the administration of VSL#3 in chronic diseases of animals and humans (including children). We found that VSL#3 has a therapeutic or preventive effect in various systemic diseases per a large number of studies, including digestive systemic diseases (gastrointestinal diseases and hepatic diseases), obesity and diabetes, allergic diseases, nervous systemic diseases, atherosclerosis, bone diseases, and female reproductive systemic diseases.

Classical methods and perspectives for manipulating the human gut microbial ecosystem

A healthy Human Gut Microbial Ecosystem (HGME) is a necessary condition for maintaining the orderly function of the whole body. Major alterations in the normal gut microbial composition, activity and functionality (dysbiosis) by an environmental or host-related disruptive event, can compromise metabolic, inflammatory, and neurological processes, causing disorders such as obesity, inflammatory bowel disease, colorectal cancer, and depressive episodes. The restore or the maintaining of the homeostatic balance of Gut Microbiota (GM) populations (eubiosis) is possible through diet, the use of probiotics, prebiotics, antibiotics, and even Fecal Microbiota Transplantation (FMT). Although these "classic methods" represent an effective and accepted way to modulate GM, the complexity of HGME requires new approaches to control it in a more appropriate way. Among the most promising emergent strategies for modulating GM are the use of engineered nanomaterials (metallic nanoparticles (NP), polymeric-NP, quantum dots, micelles, dendrimers, and liposomes); phagotherapy (i.e., phages linked with the CRISPR/Cas9 system), and the use of antimicrobial peptides, non-antibiotic drugs, vaccines, and immunoglobulins. Here we review the current state of development, implications, advantages, disadvantages, and perspectives of the different approaches for manipulating HGME.

Calcitriol Regulates the Differentiation of IL-9-Secreting Th9 Cells by Modulating the Transcription Factor PU.1

Vitamin D can modulate the innate and adaptive immune system. Vitamin D deficiency has been associated with various autoimmune diseases. Th9 cells are implicated in the pathogenesis of numerous autoimmune diseases. Thus, we investigated the role of calcitriol (active metabolite of vitamin D) in the regulation of Th9 cell differentiation. In this study, we have unraveled the molecular mechanisms of calcitriol-mediated regulation of Th9 cell differentiation. Calcitriol significantly diminished IL-9 secretion from murine Th9 cells associated with downregulated expression of the Th9-associated transcription factor, PU.1. Ectopic expression of VDR in Th9 cells attenuated the percentage of IL-9-secreting cells. VDR associated with PU.1 in Th9 cells. Using a series of mutations, we were able to dissect the VDR domain involved in the regulation of the Il9 gene. The VDR-PU.1 interaction prevented the accessibility of PU.1 to the Il9 gene promoter, thereby restricting its expression. However, the expression of Foxp3, regulatory T cell-specific transcription factor, was enhanced in the presence of calcitriol in Th9 cells. When Th9 cells are treated with both calcitriol and trichostatin A (histone deacetylase inhibitor), the level of IL-9 reached to the level of wild-type untreated Th9 cells. Calcitriol attenuated specific histone acetylation at the Il9 gene. In contrast, calcitriol enhanced the recruitment of the histone modifier HDAC1 at the Il9 gene promoter. In summary, we have identified that calcitriol blocked the access of PU.1 to the Il9 gene by reducing its expression and associating with it as well as regulated the chromatin of the Il9 gene to regulate expression.

Probiotic mediated NF-κB regulation for prospective management of type 2 diabetes

Diabetes and other lifestyle disorders have been recognized as the leading cause of morbidity and mortality globally. Nuclear factor kappa B (NF-κB) is a major factor involved in the early pathobiology of diabetes and studies reveal that hyperglycemic conditions in body leads to NF-κB mediated activation of several cytokines, chemokines and inflammatory molecules. NF-κB family comprises of certain DNA-binding protein factors that elicit the transcription of pro-inflammatory molecules. Various studies have identified NF-κB as a promising target for diabetic management. Probiotics have been proposed as bio-therapeutic agents for treatment of inflammatory disorders and many other chronic clinical stages. The precise mechanisms by which probiotics acts is yet to be fully understood, however research findings have indicated their role in NF-κB modulation. The current review highlights NF-κB as a bio-therapeutic target for probable management of type 2 diabetes through probiotic intervention.

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

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

Increasing Co-occurrence of Additional Autoimmune Disorders at Diabetes Type 1 Onset Among Children and Adolescents Diagnosed in Years 2010-2018-Single-Center Study

Objectives: The prevalence of type 1 diabetes mellitus (T1D) in children is growing, but its relation to other autoimmune disorders that coexist since the onset of diabetes is not recognized. The objective of this study was to assess the incidence of T1D and the prevalence of autoimmune illnesses additionally coexisting since the diabetes mellitus onset in children during a period of 9 years' observation. Methods: In this retrospective study, the incidence rate (IR) of the T1D was calculated as the total number of all cases that were newly diagnosed per 100,000 population people between 0 and 18 years of age. The selected age groups (0-4, 5-9, 10-14, and 15-18 years) were examined, respectively. The studied group included 493 children (264 [53.55%] boys) between 0 and 18 years old newly diagnosed with T1D in one of the Polish centers in the years 2010-2018. Other autoimmune illnesses diagnoses were obtained from medical records taken from the first hospital treatment, when T1D was recognized. Results: The annual standardized IR of T1D increased from 19.2/100,000 in year 2010 to 31.7/100,000 in 2018 (1.7-fold over 9 years' observation), with an increase in the incidence rate ratio (IRR) by 4% per year. The highest growth in IR was recorded in 5- to 9-year-olds (from 19.61 in 2010 to 43.45 in 2018). In 61 (12.4%) of the studied group, at least one additional autoimmune disease was diagnosed. The prevalence doubled from 10.4% in the year 2010 to 20.8% in the year 2018. Autoimmune thyroid illnesses were found in 37 children (7.5%); their incidence increased from 6.3% to almost 2-fold, 12.5%, in 2018. In 26 children (5.3%), celiac disease was recognized; the prevalence increased from 4.2 to 9.8% in the study period. The prevalence of additional autoimmune thyroid disease was higher in glutamic acid decarboxylase-positive antibodies (χ² = 3.4, p = 0.04) patients, the oldest age group (15-18 years) (χ² =7.1, p = 0.06), and in girls (χ² =7.1, p = 0.007). Conclusions:The standardized IR of T1D in children increased 1.7-fold over the 9-year observation period, and IRR increased 4% per year. Additional autoimmunity represents a significant comorbidity in patients with new-onset T1D. The number of children diagnosed with additional autoimmune diseases that accompany T1D is rapidly growing in all age groups throughout recent years.

Gastrointestinal Microbiota and Type 1 Diabetes Mellitus: The State of Art

The incidence of autoimmune type 1 diabetes (T1DM) is increasing worldwide and disease onset tends to occur at a younger age. Unfortunately, clinical trials aiming to detect predictive factors of disease, in individuals with a high risk of T1DM, reported negative results. Hence, actually there are no tools or strategies to prevent T1DM onset. The importance of the gut microbiome in autoimmune diseases is increasingly recognized and recent data suggest that intestinal dysbiosis has a pathogenic role in T1DM by affecting both intestinal immunostasis and the permeability of the gut barrier. An improved understanding of the mechanisms whereby dysbiosis in the gut favors T1DM development may help develop new intervention strategies to reduce both the incidence and burden of T1DM. This review summarizes available data on the associations between gut microbiota and T1DM in both experimental animals and humans and discusses future perspectives in this novel and exciting area of research.

Targeting gut microbiota and barrier function with prebiotics to alleviate autoimmune manifestations in NOD mice

AIMS/HYPOTHESIS

Adopting a diet containing indigestible fibre compounds such as prebiotics to fuel advantageous bacteria has proven beneficial for alleviating inflammation. The effect of the microbial changes on autoimmunity, however, remains unknown. We studied the effects of prebiotic xylooligosaccharides (XOS) on pancreatic islet and salivary gland inflammation in NOD mice and tested whether these were mediated by the gut microbiota.

METHODS

Mother and offspring mice were fed an XOS-supplemented diet until diabetes onset or weaning and were compared with a control-fed group. Diabetes incidence was monitored, insulitis and sialadenitis were scored in histological sections from adult mice, and several metabolic and immune variables were analysed in mice before the development of diabetes. Gut barrier function was assessed using an in vivo FITC-dextran permeability test. The importance of XOS-mediated gut microbial changes were evaluated in antibiotic-treated mice fed either XOS or control diet or given a faecal microbiota transplant from test animals.

RESULTS

Diabetes onset was delayed in the XOS-fed mice, which also had fewer cellular infiltrations in their pancreatic islets and salivary glands. Interestingly, insulitis was most reduced in the XOS-fed groups when the mice were also treated with an antibiotic cocktail. There was no difference in sialadenitis between the dietary groups treated with antibiotics; the mice were protected by microbiota depletion regardless of diet. Faecal microbiota transplantation was not able to transfer protection. No major differences in glucose-insulin regulation, glucagon-like peptide-1, or short-chain fatty acid production were related to the XOS diet. The XOS diet did, however, reduce gut permeability markers in the small and large intestine. This was accompanied by a more anti-inflammatory environment locally and systemically, dominated by a shift from M1 to M2 macrophages, a higher abundance of activated regulatory T cells, and lower levels of induction of natural killer T cells and cytotoxic T cells.

CONCLUSIONS/INTERPRETATION

Prebiotic XOS have microbiota-dependent effects on salivary gland inflammation and microbiota-independent effects on pancreatic islet pathology that are accompanied by an improved gut barrier that seems able to heighten control of intestinal diabetogenic antigens that have the potential to penetrate the mucosa to activate autoreactive immune responses.