婴儿肠道菌群的形成及其与食物过敏的关系

目的　观察健康婴儿肠道菌群的定植过程及其在食物过敏症患儿的变化 ,分析肠道菌群形成与婴幼儿食物过敏的相互关系。方法　采用荧光定量PCR技术测定细菌 16SrRNA ,经与标准曲线对照计算细菌数量 ,对 71例健康无过敏症母乳喂养婴儿和 10 0例食物过敏婴儿粪便乳酸杆菌、双歧杆菌和大肠杆菌行定量检测。结果　婴儿肠道菌群处于动态定植过程 ,随生长发育 ,双歧杆菌和乳酸杆菌在肠道定植增加 ,大肠杆菌数量减少。食物过敏婴幼儿肠道乳酸杆菌、双歧杆菌数量较健康婴幼儿低 ,而大肠杆菌数量较健康婴幼儿高。结论　婴儿期肠道菌群仍处于动态演替过程。食物过敏婴儿肠道菌群与健康婴儿不同

Relationship between formation of intestinal microflora and food allergy in infants

Objective To investigate the hypothesis that food allergy in infants may be associated with variation in their intestinal microflora. The formation of intestinal microflora in healthy infants and changes in food allergic infants were detected.Methods 16S rRNA gene sequences specific for bifidobacterium, lactobacillus and escherichia coli in fecal were quantitatively detected by real-time PCR. The three fecal floras were assessed in 71 healthy infants and 100 infants with food allergy. Results After birth,there were bifidobacteria colonized in infantile intestine,then the number increased rapidly up to 5 times at the sixth month, which was always the preponderant flora. Lactobacilli was also presented in infantile intestine 1 month after birth and augment gradually. The number of Escherichia coli was less than bifidobacteria and lactobacilli and appeared to decline during the early infants. The number of bifidobacteria and lactobacilli in the infants with food allergy were markedly less than that in the healthy infants, but escherichia coli was significantly more than that in the healthy infants.Conclusions During the first year of life,the intestinal microflora in infants is in a developing process. Compared with the healthy infants,bifidobacteria and lactobacilli decrease, but escherichia coli increase in the food allergic infants.These results indicate that the probiotics may be benefit to the prevention and treatment of food allergy.