Lombardo L
Department of Gastroenterology, Mauriziano Hospital, Turin, Italy.
Minerva Gastroenterol Dietol. 2008 Sep;54(3):287-93.
Intestinal microflora can be considered as a ''dynamic system'' that actively interacts with the intestinal epithelium and the local immune system. It synthesizes antimicrobial substances (bacteriocins), vitamins (PP, B1, B6, B12), it produces a major intestinal nutrient (butyric acid) and interacts in a competitive fashion with the pathogens. Lactobacilli concentration (Gram+, Gram variable, facultative anaerobes) is generally decreased in irritable bowel syndrome (IBS) patients. This syndrome has, until recently been considered to be ''functional'', whereas, in fact, it may result from previous enteritis (in up to 31% of patients), featuring a persistent low-grade intestinal inflammation and a reduction in interleukin-10 (IL-10) concentration. Some Lactobacilli strains (e.g. L. paracasei subsp. paracasei) in vitro lead to normalisation of the hypercontractility of the smooth muscle cells. A growing body of clinical findings indicates that some ''genetically stable'' strains of Lactobacilli may be useful in the treatment, even long term, of IBS, and reduce the postoperative infection rate, especially in critically ill patients (orthotopic liver transplant, severe pancreatitis). However, some Lactobacilli, ''not genetically stable'', used in the treatment of neutropenic patients during chemotherapy and in pediatric patients submitted to gastrojejunostomy, have been reported to lead to bacteremia and endocarditis. These effects may be due to transfer of bacteria and genetic material. Therefore, the confirmed genetic stability and the fact that no antibiotic resistance occurs are fundamental requisites for the use of Lactobacilli in certain disorders of the gastrointestinal tract, such as, for instance, IBS. In conclusion, ''genetically stable'' Lactobacilli (L. paracasei subsp. Paracasei F19) have recently become available, representing an exiting new field in clinical studies and for treatment purposes, offering guarantees of safety also for long-term use. Careful personalized evaluation, as always in medical practice, is necessary in order to gain further insight into, and to validate with additional studies, the role of ''genetically stable'' Lactobacilli in the treatment of IBS.
肠道微生物群可被视为一个与肠上皮和局部免疫系统积极相互作用的“动态系统”。它能合成抗菌物质（细菌素）、维生素（维生素PP、B1、B6、B12），产生一种主要的肠道营养物质（丁酸），并与病原体进行竞争性相互作用。在肠易激综合征（IBS）患者中，乳酸杆菌浓度（革兰氏阳性、革兰氏可变、兼性厌氧菌）通常会降低。直到最近，这种综合征一直被认为是“功能性的”，而实际上，它可能是由先前的肠炎引起的（高达31%的患者），其特征是持续性轻度肠道炎症和白细胞介素-10（IL-10）浓度降低。一些乳酸杆菌菌株（如副干酪乳杆菌副干酪亚种）在体外可使平滑肌细胞的过度收缩恢复正常。越来越多的临床研究结果表明，一些“基因稳定”的乳酸杆菌菌株可能对IBS具有治疗作用，甚至可长期使用，并能降低术后感染率，尤其是在危重症患者（原位肝移植、重症胰腺炎）中。然而，据报道，一些用于化疗期间中性粒细胞减少患者和接受胃空肠吻合术的儿科患者治疗的“基因不稳定”乳酸杆菌会导致菌血症和心内膜炎。这些影响可能是由于细菌和遗传物质的转移。因此，已证实的遗传稳定性以及不产生抗生素耐药性这一事实，是在某些胃肠道疾病（如IBS）中使用乳酸杆菌的基本要求。总之，“基因稳定”的乳酸杆菌（副干酪乳杆菌副干酪亚种F19）最近已可获得，这代表了临床研究和治疗领域一个令人兴奋的新方向，也为长期使用提供了安全保障。与医疗实践中一贯的做法一样，进行仔细的个性化评估是必要的，以便进一步深入了解并通过更多研究验证“基因稳定”乳酸杆菌在IBS治疗中的作用。
