1. The strain of Lactobacillus mucosae, deposited in CNCM under the number I-4429.2. A method of obtaining a strain of Lactobacillus mucosae, capable of reducing the permeability of the intestinal barrier, characterized in that it includes the stage of mutagenesis or genetic transformation of strain CNCM I-4429.3. A method of obtaining a cell fraction capable of lowering the permeability of the intestinal barrier, characterized in that said cell fraction is obtained from a strain of Lactobacillus mucosae, as claimed in claim 1.4. A composition comprising a strain of Lactobacillus mucosae according to claim 1, or a strain of Lactobacillus mucosae obtained by the method according to claim 2, or a cell fraction obtained by the method according to claim 3.5. The composition according to claim 4, characterized in that it is a food product. A method of obtaining a composition according to claim 4 and 5, characterized in that it comprises obtaining a strain of Lactobacillus mucosae according to claim 1, or a strain of Lactobacillus mucosae obtained by the method according to claim 2 or a cell fraction obtained by the method according to claim 3 and including the specified strain or fraction in the specified composition. 7. The strain of Lactobacillus mucosae according to claim 1 or the composition according to claim 4 for use as a medicine for the treatment or prevention of conditions leading to intestinal barrier dysfunctions.1. Штамм Lactobacillus mucosae, депонированный в CNCM под номером I-4429.2. Способ получения штамма Lactobacillus mucosae, способного снижать проницаемость кишечного барьера, отличающийся тем, что он включает стадию мутагенеза или генетической трансформации штамма CNCM I-4429.3. Способ получения клеточной фракции, способной понижать проницаемость кишечного барьера, отличающийся тем, что указанную клеточную фракцию получают из штамма Lactobacillus mucosae, как заявлено по п. 1.4. Композиция, содержащая штамм Lactobacillus mucosae по п. 1, или штамм La
