Histamine distribution in the gastrointestinal wall of germ free and conventional chicken: evidence of the role of the digestive microflora.

The digestive microflora produces a decrease of the mucosal histamine content in the wall of the chicken colon but has no significant incidence in the upper part of the digestive tract. The anatomical and physiological particularities of the chicken digestive tract permitted to observe that wall histamine concentration depends on different factors. Endogenous factors control the wall histamine content in the proventriculus, independantly of the diet and/or of the presence of a microflora. Diet has a specific incidence upon the gastrointestinal wall of the host in the crop and in the colon. The colon microflora decreases the effect of the diet essentially when the chicken are fed a semi synthetic diet. Interactions between the diet and the microflora could induce physiopathological manifestations.