Prevention or early cure of type 1 diabetes by intranasal administration of gliadin in NOD mice

Factors Influencing Microbiota in Modulating Vaccine Immune Response: A Long Way to Go

Vaccine immunogenicity still represents an unmet need in specific populations, such as people from developing countries and "edge populations". Both intrinsic and extrinsic factors, such as the environment, age, and dietary habits, influence cellular and humoral immune responses. The human microbiota represents a potential key to understanding how these factors impact the immune response to vaccination, with its modulation being a potential step to address vaccine immunogenicity. The aim of this narrative review is to explore the intricate interactions between the microbiota and the immune system in response to vaccines, highlighting the state of the art in gut microbiota modulation as a novel therapeutic approach to enhancing vaccine immunogenicity and laying the foundation for future, more solid data for its translation to the clinical practice.

Effect of gluten-free diet and antibiotics on murine gut microbiota and immune response to tetanus vaccination

The purpose of this study was to compare the effect of a gluten-free diet and/or antibiotics on tetanus vaccine induced immunoglobulin G titers and immune cell levels in BALB/c mice. The gluten-free diet was associated with a reduced anti-tetanus IgG response, and it increased the relative abundance of the anti-inflammatory Bifidobacterium significantly in some of the mice. Antibiotics also led to gut microbiota changes and lower initial vaccine titer. After a second vaccination, neither gluten-free diet nor antibiotics reduced the titers. In the spleen, the gluten-free diet significantly increased regulatory T cell (T_reg) fractions, CD4⁺ T cell activation, and tolerogenic dendritic cell fractions and activation, which extend the downregulating effect of the T_reg. Therefore, the systemic effect of the gluten-free diet seems mainly tolerogenic. Antibiotics reduced the fractions of CD4⁺ T and B cells in the mesenteric lymph nodes. These results suggest that vaccine response in mice is under influence of their diet, the gut microbiota and the interplay between them. However, a gluten-free diet seems to work through mechanisms different from those induced by antibiotics. Therefore, diet should be considered when testing vaccines in mice and developing vaccines for humans.

The etiology and pathogenesis of type 1 diabetes - A personal, non-systematic review of possible causes, and interventions

In this review after a lifelong research career, my personal opinion on the development of type 1 diabetes (T1D) from its very start to clinical manifestation will be described. T1D is a disease of an increased intestinal permeability and a reduced pancreas volume. I am convinced that virus might be the initiator and that this virus could persist on strategically significant locations. Furthermore, intake of gluten is important both in foetal life and at later ages. Disturbances in sphingolipid metabolism may also be of crucial importance. During certain stages of T1D, T cells take over resulting in the ultimate destruction of beta cells, which manifests T1D as an autoimmune disease. Several preventive and early treatment strategies are mentioned. All together this review has more new theories than usually, and it might also be more speculative than ordinarily. But without new ideas and theories advancement is difficult, even though everything might not hold true during the continuous discovery of the etiology and pathogenesis of T1D.

Ancient wheats: beneficial effects on insulin resistance

Non-alcoholic fatty liver disease and type 2 diabetes mellitus are two conditions that commonly exist together in the context of the metabolic syndrome. Several scientific advances in understanding this association have identified insulin resistance as the key point in the pathogenesis of both diseases. The first line treatment suggested in the management of these diseases is represented by lifestyle changes and in particular the modification of alimentary regimen, with the transition to a healthy diet. In this context, several studies have focused their attention on the identification of food products with beneficial actions, like ancient wheat (AW). AW are defined as the early cereals that were domesticated in their places of origin in the "Fertile Crescent" of the Middle East, and played a central role as a main source of food for the early civilizations in that region. The present narrative review aims to provide a systematic overview of the state of the art on the effects of AW on insulin resistance.

Optimal Tolerogenic Dendritic Cells in Type 1 Diabetes (T1D) Therapy: What Can We Learn From Non-obese Diabetic (NOD) Mouse Models?

Tolerogenic dendritic cells (tolDCs) are explored as a promising standalone or combination therapy in type 1 diabetes (T1D). The therapeutic application of tolDCs, including in human trials, has been tested also in other autoimmune diseases, however, T1D displays some unique features. In addition, unlike in several disease-induced animal models of autoimmune diseases, the prevalent animal model for T1D, the NOD mouse, develops diabetes spontaneously. This review compares evidence of various tolDCs approaches obtained from animal (mainly NOD) models of T1D with a focus on parameters of this cell-based therapy such as protocols of tolDC preparation, antigen-specific vs. unspecific approaches, doses of tolDCs and/or autoantigens, application schemes, application routes, the migration of tolDCs as well as their preventive, early pre-onset intervention or curative effects. This review also discusses perspectives of tolDC therapy and areas of preclinical research that are in need of better clarification in animal models in a quest for effective and optimal tolDC therapies of T1D in humans.

Possible Prevention of Diabetes with a Gluten-Free Diet

Gluten seems a potentially important determinant in type 1 diabetes (T1D) and type 2 diabetes (T2D). Intake of gluten, a major component of wheat, rye, and barley, affects the microbiota and increases the intestinal permeability. Moreover, studies have demonstrated that gluten peptides, after crossing the intestinal barrier, lead to a more inflammatory milieu. Gluten peptides enter the pancreas where they affect the morphology and might induce beta-cell stress by enhancing glucose- and palmitate-stimulated insulin secretion. Interestingly, animal studies and a human study have demonstrated that a gluten-free (GF) diet during pregnancy reduces the risk of T1D. Evidence regarding the role of a GF diet in T2D is less clear. Some studies have linked intake of a GF diet to reduced obesity and T2D and suggested a role in reducing leptin- and insulin-resistance and increasing beta-cell volume. The current knowledge indicates that gluten, among many environmental factors, may be an aetiopathogenic factors for development of T1D and T2D. However, human intervention trials are needed to confirm this and the proposed mechanisms.

Occupation with grain crops is associated with lower type 1 diabetes incidence: Registry-based case-control study

Intranasal administration of gliadin prevents autoimmune diabetes in non-obese diabetic mice. The current study was designed to investigate if bakers are intranasally exposed to gluten during work and whether occupation as baker is inversely associated with type 1 diabetes. Gliadin was measured in nasal swabs from eight bakers and butchers. The odds ratio of type 1 diabetes in selected profession groups was analysed in a registry-based case-control study with data from 1980 to 2010 derived from Statistics Denmark. The cohort included 1,210,017 Danish individuals, thereof 15,451 with type 1 diabetes (1.28%). Average nasal gliadin swab content after full working days was 6.3 μg (confidence interval (CI): 2.8 to 9.7) among bakers, while no nasal gliadin was detected among butchers. The odds ratio of type 1 diabetes was lower among bakers (OR = 0.57; CI: 0.52 to 0.62) and agriculture workers occupied with production of grains (OR = 0.65; CI: 0.56 to 0.75). Bakers had a lower odds ratio of type 1 diabetes, which potentially could be attributed to exposure of nasal mucosal gluten during work, as observed in this study. If other studies confirm the present observations, intranasal gliadin administration could possibly be an easy and safe approach for the prevention of type 1 diabetes in high-risk individuals or prediabetic subjects.

Where genes meet environment-integrating the role of gut luminal contents, immunity and pancreas in type 1 diabetes

The rise in new cases of type 1 diabetes (T1D) in genetically susceptible individuals over the past half century has been attributed to numerous environmental "triggers" or promoters such as enteroviruses, diet, and most recently, gut bacteria. No single cause has been identified in humans, likely because there are several pathways by which one can develop T1D. There is renewed attention to the role of the gut and its immune system in T1D pathogenesis based largely on recent animal studies demonstrating that altering the gut microbiota affects diabetes incidence. Although T1D patients display dysbiosis in the gut microbiome, it is unclear whether this is cause or effect. The heart of this question involves several moving parts including numerous risk genes, diet, viruses, gut microbiota, timing, and loss of immune tolerance to β-cells. Most clinical trials have addressed only one aspect of this puzzle using some form of immune suppression, without much success. The key location where our genes meet and deal with the environment is the gastrointestinal tract. The influence of all of its major contents, including microbes, diet, and immune system, must be understood as part of the integrative biology of T1D before we can develop durable means of preventing, treating, or curing this disease. In the present review, we expand our previous gut-centric model based on recent developments in the field.