微生态制剂及在儿童的应用.pptVIP

* * * * Optional Speaker Notes: Environmental changes in the industrialized world, as well as changes of life style in western societies, and medicine, have reduced the extent of microbial contact at an early age. These changes affect the initial establishment of the microflora. The hygiene hypothesis, first proposed by Strachan in 1989, offered, in part, an explanation to the increasing prevalence of atopic conditions. The idea was based on epidemiological observations, suggesting an inverse correlation between family size and the prevalence of allergic rhinitis. Today, an extended hygiene hypothesis is emerging that suggests that the modern infant may lack interactions with specific bacteria that promote the development of an anti-inflammatory and tolerogenic immune environment. The initial composition of gut microflora, through exposure to bacteria, may be considered a key determinant in the development and regulation of immune factors. * * Optional Speaker Notes: The increased occurrence of allergy in infants has also been associated with differences in intestinal flora. The prevalence of colonization with bifidobacteria in infants who developed allergy during the first 2 years of life was significantly less than for those that did not develop atopy. As shown, less than 30% of the atopic infants were colonized with bifidobacteria soon after birth, at 3 months, or at 1 year. Differences in intestinal flora in infants developing allergy suggest that factors in early life (such as sterile formula feeding and birth by C-section) may be a determinant in the later development of immunologic disease, including allergy. * * * * Optional Speaker Notes: The occurrence of differences in intestinal flora in infants with allergic disease has led to the use of probiotic agents for the management of atopy. In a double-blind, randomized placebo-controlled trial, probiotics were given prenatally to mothers who had at least one first-degree relative