1. A method of maintaining resistance to a disease or condition in humans, comprising administering to a human a nutritional composition comprising: a) a source of fats or lipids； b) a source of proteins； c) lactoferrin produced by a source other than the human body, wherein lactoferrin is characterized by at least 48% homology with the amino acid sequence AVGEQELRKCNQWSGL in fragment (349-364) HLf.2. The method according to claim 1, wherein the disease or condition is caused by at least one pathogen selected from the group consisting of enterotoxigenic E. coli, enteropathogenic E. coli, Haemophilus influenza, shigatoxin-producing E. coli, enteroaggregative E. coli, Salmonella serotype Typhimurium, Shigella flexneri, rotavirus, norovirus, respiratory syncytial virus, adenovirus, and combinations thereof. 3. The method of claim 1, wherein the disease or condition is a viral infection of the respiratory tract. The method of claim 1, wherein the person is an infant or child. The method of claim 1, wherein a source of fat or lipid is present at a level of from about 3 g / 100 kcal to about 7 g / 100 kcal, and a protein source is present at a level of from about 1 g / 100 kcal to about 5 g / 100 kcal .6. The method of claim 1, wherein the lactoferrin is present at a level of at least about 10 mg / 100 kcal. The method of claim 6, wherein the lactoferrin is present at a level of from about 70 mg / 100 kcal to about 220 mg / 100 kcal. The method of claim 1, wherein the lactoferrin is selected from the group consisting of lactoferrin other than human lactoferrin produced by a genetically modified human lactoferrin organism and combinations thereof. The method according to claim 1, in which the varnish1. Способ поддержания устойчивости к заболеванию или состоянию у человека, включающий введение человеку питательной композиции, содержащей:a) источник жиров или липидов；b) источник белков； иc) лактоферрин, произведенный отличным от человеческого организма источником, при этом л
