This study aims to investigate the impact of being on a gluten free diet the first three years of life compared to a daily intake of a probiotic supplementation or placebo on the risk of developing celiac disease autoimmunity or celiac disease in genetically susceptible children.

This is a three-arm (1:1:1) randomized trial where study participants are randomly allocated to one of the three study groups before the age of 4 months. Regular clinical visits (4 times/year) during the intervention phase and yearly there after, up to the age of 7 years.

The primary hypothesis to be tested is that a strictly gluten free diet during the first three years of life with a slow introduction of gluten during the follow-up period will induce tolerance to gluten. A similar hypothesis is tested if a daily supply of two different lactobacillus (LB) strains can suppress an inflammatory response to gluten in the intestine by stimulating regulatory T-cells and reduced permeability of gluten peptides in the intestine.

The secondary hypothesis tested is that celiac disease can not be prevented, but the onset of the disease will be delayed in children returning to a gluten-containing diet after the intervention period (gluten free diet) or probiotic treatment) during the first three years of life. The intervention period is 3 years and the follow-up period is further 4 years.

The primary aim is to study the proportion of children who develop celiac disease autoimmunity and progression to celiac disease by the age of 3 years. Secondary aim is to study the proportion of children who developed celiac disease at the age of 7 years.

Inclusion Criteria:

• Children screened positive for human leucocyte antigen (HLA) DR3-DQ2/DR3-DQ2
• Children must be enrolled to the study by 4 months of age (before gluten consumption has started).

Exclusion Criteria:

• Congenital chronic disorder where intervention with diet or probiotics may be affected.
• Written consent from both caregivers are missing