Effects of enteric microflora on mucosal and systemic immune development in infants at risk of allergic disease

过敏性疾病在过去20-30年中的增加归因于出生后对2型过敏性免疫反应的免疫倾向的增加。有人提出，这可能是由于早期生命中逆调节型免疫反应相对不足所致。因此，在这个早期阶段，人们对可能影响I型成熟的因素越来越感兴趣。有人提出，逐步清洁的社会可能会有更多的过敏症，因为在免疫发展过程中对1型反应的刺激较少。细菌产物为发育中的免疫系统提供重要的成熟信号，并可能有利于1型反应。最大的早期接触细菌发生在人类的肠道，出生后不久就被细菌定植。这些细菌在保持健康方面发挥着重要作用，无论是在保护免受有害细菌侵害方面，还是在发展对食物的耐受性方面。有证据表明，在清洁的社会中，婴儿的肠道菌群可能会发生变化。多年来，益生菌制剂(包含这些健康细菌的菌株)一直被安全地用于治疗胃肠炎儿童，以缩短腹泻的持续时间。最近，有人提出，这些制剂在治疗甚至预防过敏性疾病方面具有作用。需要进一步的研究来证实这一点，并确定潜在的免疫学过程。这项随机双盲对照研究将确定补充益生菌菌群(在怀孕后期和婴儿早期)是否有利于影响肠道定植，改变随后的免疫发育，并有助于预防高危婴儿(来自过敏家庭)的过敏性疾病。

The increase in allergic diseases over the last 20-30 years has been attributed to an increased immunological propensity to Type-2 allergic immune responses in the postnatal period. It has been proposed that this may be due to a relative deficiency of counter-regulatory Type 1 immune responses in early life. Thus, there is growing interest in factors that might affect Type 1 maturation in this early period. It has been proposed that progressively cleaner societies may have more allergies because there is less stimulation of the Type 1 responses during immune development. Bacterial products provide important maturation signals to the developing immune system, and may favour Type 1 responses. The largest early exposure to bacteria in occurs in the human gut, which is colonised with bacteria soon after birth. These bacteria play an important role in maintaining health, both in the protection from harmful bacteria, and in the development of food tolerance. There is evidence that infants in cleaner sociaeties may have alterations in bowel flora. For many years probiotic formulations (containing strains of these healthy bacteria) have been used safely to treat children with gastroenteritis to reduce the duration of diarrhoea. More recently it has been suggested that these formulations have a role in treating and even preventing allergic disease. Further research is needed to confirm this, and to define the underlying immunological processes. This randomised double blind control study will determine if supplementation with probiotic flora (in late pregnancy and in early infancy) can favourably influence gut colonisation, alter subsequent immune development, and help prevent allergic disease in infants at high risk (from allergic families).