Diabetes and other autoimmune endocrine diseases
Environmental factors play a substantial role in the pathogenesis/prevention of type 1 diabetes (T1D) and its increased incidence in developed countries. Studies in spontaneous animal model of T1D, the NOD mouse, documented that the quality of SPF housing conditions and instestinal microbiom (e.g. re-derivation of breeding nucleus) modify penetrance of the diabetes incidence. In this study we tested the effect of three human probiotic bacteria Lactobacillus plantarum, Lactobacillus casei, and E. coli Nissle on the development of spontaneous diabetes incidence in the NOD mice both in the context of instestinal microbiom in SPF conditions as well as in ex-germ-free conditions. Three-weekly intragastric applications of 109 CFU for period of 3 weeks at age of 4 weeks led to slightly delayed and decreased diabetes incidence in SPF NOD mice, being highest for the Lactobacillus casei species. Parallel results were obtained in germ-free NOD mice colonized at age of 4 weeks. Changes in proportions of CD4+Foxp3+ Tregs, CD3+CD4+CD45RBlow, CD3+CD4+CD62L+ and gamma/delta T cells were monitored by flow cytometry. Flow cytometry analysis revealed increased proportion of CD4+Foxp3+ Tregs in mesenteric lymph nodes and draining pancreatic lymph nodes, but not within the non-mucosal lymphoid compartments. We think that probiotic bacteria and immune mechanisms by which they modify development of T1D may represent a promising and inexpensive approach for a primary prevention of type 1 diabetes and/or should be also tested in combinatorial therapies. This work was in part supported by grant AZV 16-27994A from the Ministry of Health of the Czech Republic.