Immunopotentiation of the Small Intestine of Weaning Piglets by Peptidoglycan Derived from Bifidobacterium thermophilum

One of the most serious problems in large-scale commercial pig farms is the post weaning diarrhea syndrome in piglets aged 4-6 weeks. It is clear that the major causative agent of the syndrome is an enteropathogenic Escherichia coli (5, 7, 13, 15, 16). M oreover, it is well known that peptidoglycan , which is derived from the cell wall of gram-positive organisms, is an immunopotentiator; peptidoglycan has been used to treat various kinds of immunodeficiencies , especially in humans (2, 3, 10, 11, 18). The purpose of the present study was to investigate the immunological effect of peptidoglycan from Bifidobacterium thermophilum in piglets and see whether an enhancement of the local immune response is obtained or not in weaning piglets aged 5-6 weeks, as well as to investigate changes in the size of the E . coli population in various parts of the small intestine.