Type of Intestinal Bacteria May Affect Humoral Immunity in Infants
The therapeutic benefits of probiotics both for treating human disease as well as modulating human defenses continues to mount. Establishing and maintaining healthy intestinal flora, I believe, is one of the most important events that occurs in a newborn and infant. The GI tract is the area where most of our interaction with our environment occurs, and our bodies need to be able to decide what to keep and what to discard. High use of antibiotics is instrumental in destroying this normal flora, and may very well be an underlying cause of the increase in chronic diseases common today.
Arch Dis Child Fetal Neonatal Ed 2000;83:F186-F192 The maturation of humoral immunity in infants may depend on what types of bacteria colonize in their intestines as well as on the timing of this colonization. Intestinal colonization with B. fragilis was a greater predictor of elevated levels of IgA-secreting and IgM-secreting cells than was intestinal colonization with other bacteria or diet, Dr. Gronlund and colleagues report. The highest number of IgA-secreting cells at 2 months and IgM-secreting cells at 6 months occurred in infants who had B. fragilis colonization at 1 to 2 months. “To our knowledge, this is the first report of an association between Bacteroides sp and maturation of humoral immunity in humans, and it provides a fresh view of the role of these predominant bacteria of the human gut,” the authors write. “Our observations add an interesting facet to the discussion on the possible protective role of microbial contacts in the prevention of allergic diseases,” the authors write. They note that infants born via cesarean delivery were more likely to experience a delay in intestinal colonization with B. fragilis. According to Dr. Gronlund’s team, “It may therefore be no coincidence that the incidence of allergic diseases is increasing in parallel with the rate of sterile cesarean sections.”