Wold A E, Adlerberth I
Department of Clinical Immunology, Göteborg University, Sweden.
Adv Exp Med Biol. 2000;478:77-93. doi: 10.1007/0-306-46830-1_7.
Human breast milk contains an array of factors with anti-infectious potential, such as immunoglobulins (especially secretory IgA), oligosaccharides and glycoproteins with anti-adhesive capacity, and cytokines. Breast-feeding is associated with protection from the following infections or infection-related conditions: gastroenteritis, upper and lower respiratory tract infection, acute otitis media, urinary tract infection, neonatal septicaemia and necrotizing enterocolitis. Some of the protective effects may derive from an altered mucosal colonization pattern in the breast-fed infant. In other instances breast-fed infants develop less symptoms to the same microbe which causes disease in the bottle-fed infant. An example of an altered colonization pattern is that breast-fed infants have less P-fimbriated, but more type 1-fimbriated E. coli. This may protect against urinary tract infection in the breast-fed infant since P. fimbriae are the major virulence factor for urinary tract infection. An example of changed consequences of the same microbial colonization is that secretory IgA in the breast-milk protects very efficiently from translocation of intestinal bacteria across the gut mucosa by coating intestinal bacteria and blocking their interaction with the epithelium. This mechanism may protect the infant from septicaemia of gut origin and, possibly, necrotizing enterocolitis. Breast-milk is also highly anti-inflammatogenic and contains hormone like factors which counteract diarrhea. Thus, breast-fed infants may be colonized by recognized diarrheal pathogens and still remain healthy. Due to a less virulent intestinal microflora and decreased translocation breast-fed infants will obtain less stimuli for the gut immune system, resulting, in e.g., lower salivary IgA antibody titres.
人乳含有一系列具有抗感染潜力的因子，如免疫球蛋白（尤其是分泌型IgA）、具有抗黏附能力的寡糖和糖蛋白以及细胞因子。母乳喂养与预防以下感染或感染相关疾病有关：胃肠炎、上呼吸道和下呼吸道感染、急性中耳炎、尿路感染、新生儿败血症和坏死性小肠结肠炎。一些保护作用可能源于母乳喂养婴儿黏膜定植模式的改变。在其他情况下，母乳喂养的婴儿对导致人工喂养婴儿患病的同一微生物产生的症状较轻。定植模式改变的一个例子是，母乳喂养的婴儿带有P菌毛的大肠杆菌较少，但1型菌毛的大肠杆菌较多。这可能保护母乳喂养的婴儿免受尿路感染，因为P菌毛是尿路感染的主要毒力因子。同一微生物定植产生不同后果的一个例子是，母乳中的分泌型IgA通过包裹肠道细菌并阻断它们与上皮细胞的相互作用，非常有效地保护肠道细菌不穿过肠黏膜移位。这种机制可能保护婴儿免受源自肠道的败血症以及可能的坏死性小肠结肠炎。母乳还具有很强的抗炎症作用，并且含有类似激素的因子，可对抗腹泻。因此，母乳喂养的婴儿可能被公认的腹泻病原体定植，但仍保持健康。由于肠道微生物群的毒性较低且移位减少，母乳喂养的婴儿对肠道免疫系统的刺激较少，例如导致唾液中IgA抗体滴度较低。
