Abstract
Peptidoglycan (PG) derived from Bifidobacterium thermophilum, an intestinal flora of swine, was given orally to suckling piglets, and a comparison was made of the immunoresponsiveness of the lamina propria in the small intestinal mucosa and the numbers of E. coli in various parts of the intestines of treated and non-treated piglets 5 and 6 weeks old. After PG treatment, the numbers of IgA-bearing cells of the lamina propria in the middle of the jejunum and in the ileum were significantly higher than those of the non-treated group at 5 and 6 weeks of age (p<0.01), respectively. The number of IgA-bearing cells in the lamina propria was much higher than that of IgM-bearing cells in the treated piglets, whereas the number of IgM-bearing cells in the lamina propria was much larger than that of IgA-bearing cells in the control. As a result of these findings, it was concluded that local immunoresponsiveness developed with the oral administration of PG. The lower numbers of E. coli found in various portions of the small intestines of the treated animals as compared with the control group suggested that the count of E. coli was inversely proportional to the IgA-bearing cells in both the PG administration group and the non-treated group.
