FIELD: medicine, immunology, microbiology. SUBSTANCE: lactoserum comprises antibodies raised against H. pylori, among them, against toxin and urease that are factors of its pathogenicity. Method of preparing involves immunization of calving cows with mixture of thermoinactivated culture H. pylori and antigenic extract from H. pylori biomass. Active fraction is isolated from milk in early period of lactation by its defatting, casein removal, clearing, diafiltration and concentrating. Lactoserum comprises antibodies raised to total antigen of H. pylori as active component with titer 1: 12 800, not above; to toxin 1:6 400, not less, and to urease 1:6400, not less, in the following ratio of components (as wt.-% of total protein content): immunoglobulin G, 25.95 ± 1.15; immunoglobulin A, 11.85 ± 0.75; immunoglobulin M, 16.95 ± 0.05; immunoglobulins of other classes, 0.75 ± 0.3; alpha-lactoglobulin, 10.65 ± 0.55; beta-lactoglobulin, 18.35 ± 0.25; serum albumin, 5.65 ± 0.65; residual proteins, the balance. EFFECT: improved method of preparing, enhanced specific activity of preparation. 3 cl, 1 tbl, 4 ex
