栄養による宇宙での免疫機能維持

Immunity decreases in the microgravity condition. For the prevention of infection in the space constant use of antibiotics is not recommended. There are some foods and nutrients which are reported to enhance immunity. Their benefit in space is desirable. Glutamine and arginine have various physiological functions. We have seen that these two amino acids promote the resistance against pathogenic bacterial infection by increasing immunity and the recovery of intestinal tissues from damage by endotoxin. We have also shown that nucleotides have similar effects as the two amino acids at much smaller quantities. Nucleotides are more stable and palatable than these amino acids. In this paper, we described ; 1 ) the comparison of physiological functions of glutamine, arginine and nucleotides, 2 ) the role of nucleotides on the immunity and 3 ) the usefulness of nucleotides to maintain immunity in microgravity environment.