Coeliac disease frequency increases by obscure reasons and affects in some Western countries as much as 1% of the populations. The second one of monozygotic twins does not develop the disease in 100% but only in 20-50%. To unravel these mysteries, literature was searched to determine the disease background and find suggestions for research and prevention. The causal antigen of coeliac disease is gluten of wheat that is neutralised in the intestine by secretory immune globulin A (sIgA). SIgA is secreted by the secondary (lymphoid) immune system that develops in a newborn infant after the primary (central) immune organs thymus and bone marrow have been primed with antigens of the intestine. Predisposed infants are sensitive for development of coeliac disease during the time without sIgA secretion into the intestine. The risk of the disease diminishes when sIgA cycles of gluten neutralisation develop. Peyer's patches (PP) of the secondary immune system play a central role in the cycles and possibly do not function well in the case of coeliac disease. Coeliac disease in predisposed infants may be prevented by delay of bread consumption till the time of normal sIgA secretion and by application of a challenge period with gluten (see Discussion). It is concluded that sIgA secretion into body cavities and malfunction of immune cells in PP should be included in the future research of coeliac disease as well as in more allergic diseases (type 1 diabetes, Crohn disease, asthma, hay fever).