The incidence of autoimmune diseases (celiac disease, type 1 diabetes, thyroid disease) have increased over the past 30 years. Although most autoimmune diseases have a strong link to different risk genes, the rapid increase is thought to be due to changes in environmental factors. There is currently no cure for autoimmune diseases, but the treatment is lifelong and either involves suppressing the inflammation and / or substituting the organs that are affected to maintain vital functions. Being able to predict who is affected and identifying factors that trigger autoimmunity is necessary for developing new treatment methods that prevent the occurrence of autoimmune diseases. The bacterial flora's composition in the gut can affect both the intestinal barrier properties and the immune system's response to various dietary components. An adverse composition of the intestinal flora can activate parts of the immune system that are involved in chronic inflammation in celiac disease and inflammatory bowel disease. Probiotics are defined as living microorganisms which, when ingested in sufficient amounts, produce a health effect (FAO / WHO). The aim of the study is to investigate whether a daily oral intake of a mixture of L.paracasei and L.plantarum can affect the autoimmune process in children who are screened positive for any of the autoantibodies associated with development of celiac disease, type 1 diabetes and / or thyroid disease. Our hypothesis is that lactobacilli can directly regulate the autoimmune process in the small intestinal mucosa by stimulating regulatory T-cells, but also by affecting the permeability of the small intestinal mucosa by of antigen that stimulates specific T-cells.

The incidence of autoimmune diseases (celiac disease, type 1 diabetes, thyroid disease) have increased over the past 30 years. Although most autoimmune diseases have a strong link to different risk genes, the rapid increase is thought to be due to changes in environmental factors. There is currently no cure for autoimmune diseases, but the treatment is lifelong and either involves suppressing the inflammation and / or substituting the organs that are affected to maintain vital functions. Being able to predict who is affected and identifying factors that trigger autoimmunity is necessary for developing new treatment methods that prevent the occurrence of autoimmune diseases.

The bacterial flora's composition in the gut can affect both the intestinal barrier properties and the immune system's response to various dietary components. An adverse composition of the intestinal flora can activate parts of the immune system that are involved in chronic inflammation in celiac disease and inflammatory bowel disease.

Probiotics are defined as living microorganisms which, when ingested in sufficient amounts, produce a health effect (FAO / WHO). Certain probiotic strains has been used to hamper pro-inflammatory immune system triggered by gluten protein in conjunction with celiac disease. Earlier studies have shown that Lactobacillus reduced the permeability in the small intestinal mucosa. But to our knowledge, no randomized clinical trials have tested the effect on probiotic supplementation and development of autoimmune disease such as celiac disease.

The aim of the study is to investigate whether a daily oral intake of a mixture of L.paracasei and L.plantarum can affect the autoimmune process in children who are screened positive for any of the autoantibodies associated with development of celiac disease, type 1 diabetes and / or thyroid disease. Our hypothesis is that lactobacilli can directly regulate the autoimmune process in the small intestinal mucosa by stimulating regulatory T-cells, but also by affecting the permeability of the small intestinal mucosa by of antigen that stimulates specific T-cells.

The aims of this study are:

• will supplementation of L.paracasei and L.plantarum during a 12 month period compared to placebo increase the levels of regulatory T-cells (CD4+CD25+) and decrease B-cells and/or NK-cells in children and adolescents screened persistent positive with auto-antibodies associated with celiac disease, type 1 diabetes and / or thyroid disease?
• will supplementation of L.paracasei and L.plantarum during a 12 month period compared to placebo increase the abundance of bacteroides in gut and oral cavity in children and adolescents screened persistent positive with auto-antibodies associated with celiac disease, type 1 diabetes and / or thyroid disease?
• will supplementation of L.paracasei and L.plantarum during a 12 month period compared to placebo lower the levels of auto-antibodies associated with celiac disease, type 1 diabetes and / or thyroid disease in children and adolescents with persistent positive auto-antibodies.

A total of 200 children genetically at-risk for celiac disease, type 1 diabetes and thyroid disease who are persistent positive for any of the following auto-antibodies will be invited to the study.

Participants who signed a informed consent will be randomized (double blinded) into the probiotic or placebo group. A venous blood sample, saliva- and feces sample will be collected at every clinic visit, 3 months apart (0, 3, 6, 9 and 12 months). A short questionnaire collecting information about illnesses, medication- and dietary supplement use, food habits, and demographic factors will be used.

Blood sample will be analyzed for auto-antibodies (tTGA, GADA, IA-2A, IAA, Zn-T8A, and TPOA). FACS analyses will be used for a panel of inflammatory markers (CD3, CD4, CD8, CD25 etc). Feces- and saliva samples will be analysed using T-RFLP (PCR) of 16S rRNA.

The benefit if this study are the increased knowledge about specific probiotics strains impact on autoimmunity in genetically at-risk children, and hopes of reducing the risk for developing autoimmune diseases as celiac disease, type 1 diabetes and thyroid disease.

Inclusion Criteria:

• Screened persistent positive for any of the auto-antibodies associated with celiac disease (tTGa), type 1 diabetes (IAA, GADA, IA-2A, Zn-T8) and/or thyroid disease (TPOA)

Exclusion Criteria:

• None