1. A prebiotic composition for oral administration to humans, comprising 2'-fucosyllactose, 3'-sialyllactose and 6'-sialyllactose, where the amount of 3'-sialyllactose by weight is at least the same as the amount of 2'-fucosyllactose. 2. The composition according to claim 1, wherein 2'-fucosyllactose, 3'-sialyllactose and 6'-sialyllactose comprise about 1.6-6.0% of the dry weight of the composition. The composition according to claim 1 or 2, in which the composition contains 2'-fucosyllactose, 6'-sialyllactose and 3'-sialyllactose in a mass ratio of about 0.5-2.0 to 0.5-2.0 to 1.0- 4.0, respectively. 4. The composition according to claim 3, in which the mass ratio is about 0.9-1.1 to 0.9-1.1 to 1.8-2.2, respectively. The composition according to claim 1, which is a baby mixture. The infant formula according to claim 5, which is a liquid containing about 0.1-10 mg / ml 2'-fucosyllactose, about 0.1-10 mg / ml 6'-sialyllactose and about 0.1-20 mg / ml 3'-sialyllactoses. 7. The infant formula according to claim 5, which is a liquid containing about 0.5-2 mg / ml 2'-fucosyllactose, about 0.5-2 mg / ml 6'-sialyllactose and about 1-4 mg / ml 3 ' -sialyllactoses. 8. The infant formula according to claim 5, which is a liquid containing about 1 mg / ml 2'-fucosyllactose, about 1 mg / ml 6'-sialyllactose and about 2 mg / ml 3'-sialyllactose. The infant formula according to claim 5, which is a dry powder containing about 0.4-1.5 wt.% 2'-fucosyllactose, about 0.4-1.5 wt.% 6'-sialyllactose and about 0.8 -3.0 wt.% 3'-sialyllactose. 10. The infant formula according to claim 9, containing about 0.7-0.9 wt.% 2'-fucosyllactose, about 0.7-0.9 wt.% 6'-sialyllactose and about 1.4-1.7 wt. % 3'-sialyllactoses. 11. A method for modulating or stimulating the growth of Bifidobacteria in the human gastrointestinal tract, including1. Пребиотический состав для перорального введения человеку, содержащий 2'-фукозиллактозы, 3'-сиалиллактозы и 6'-сиалиллактозы, где количество 3'-сиалиллактозы по мас
