The present invention relates to the Lactobacillus genus that have the ability to survive in high temperature environments. These thermostable microorganisms have the ability to produce viable antibacterial agents in different food products after heat 5 treatment. The thermostable microorganisms of the Lactobacillus genus may be included in food products that demand high temperature. A further object of the present invention is the ability of a food product comprising the thermostable microorganisms of the Lactobacillus genus for promoting immunotolerance in autoimmune diseases such as coeliac disease. Furthermore, two novel strains of lactobacillus 10 genus are disclosed, Lactobacillus plantarum LB3e and Lactobacillus plantarum LB7c deposited at Deutsche Sammlung von Mikroorganismen und Zeelkulturen, which have been assigned accession number 17852 and 17853 respectively.