Institute for Clinical Immunotherapy and Advanced Biological Treatments, 65100 Pescara, Italy.
Center for Advanced Science and Technology (CAST), G. d'Annunzio University, 66100 Chieti, Italy.
Biomolecules. 2024 Oct 2;14(10):1249. doi: 10.3390/biom14101249.
Bacterial Lysates are immunostimulants clinically prescribed for the prevention of respiratory tract infections (RTIs). It has been shown that Bacterial Lysates upregulate the immune system, acting both on innate and adaptive reactions. In fact, there are demonstrations of their efficacy in restoring the integrity and immune function of epithelial barriers, activating ILC3 and dendritic cells with an enhanced Th1 response, and producing serum IgG and serum and salivary IgA specific to the administered bacterial antigens. The activated immune system also protects against other bacteria and viruses due to a trained immunity effect. Most studies show that the number of RTIs and their severity decrease in Bacterial Lysates-pretreated patients, without relevant side effects. The Bacterial Lysates treatment, in addition to reducing the number of RTIs, also prevents the deterioration of the underlying disease (i.e., COPD) induced by repeated infections. Despite these positive data, the most recent meta-analyses evidence the weakness of the studies performed, which are of low quality and have an inadequate number of patients, some of which were non-randomized while others were without a control group or were performed contemporarily in different clinical conditions or with different ages. The high heterogeneity of the studies does not allow us to state Bacterial Lysates' effectiveness in preventing RTIs with sufficient certainty. To completely define their indications, double-blind, placebo-controlled, multicenter, randomized clinical trials should be performed for each product and for each indication. The study population should be adequate for each indication. For this purpose, an adequate run-in phase will be necessary.
细菌裂解物是一种临床上被用于预防呼吸道感染（RTIs）的免疫刺激剂。已经证明，细菌裂解物可上调免疫系统，对先天和适应性反应均有作用。事实上，有证据表明它们在恢复上皮屏障的完整性和免疫功能方面具有功效，能够激活 ILC3 和树突状细胞，并增强 Th1 反应，产生针对所施用细菌抗原的血清 IgG 和血清及唾液 IgA。激活的免疫系统还通过训练免疫效应来预防其他细菌和病毒。大多数研究表明，细菌裂解物预处理患者的 RTIs 数量及其严重程度减少，而没有相关的副作用。细菌裂解物治疗除了减少 RTIs 的数量外，还可以预防反复感染引起的基础疾病（即 COPD）恶化。尽管有这些积极的数据，但最近的荟萃分析表明所进行研究的质量较差，数量不足，其中一些是非随机的，另一些则没有对照组，或者在不同的临床条件下或不同的年龄组同时进行。研究的高度异质性使得我们无法足够确定地说明细菌裂解物在预防 RTIs 方面的有效性。为了完全确定其适应证，应针对每种产品和每种适应证进行双盲、安慰剂对照、多中心、随机临床试验。研究人群应适合每种适应证。为此，需要进行适当的预试验阶段。
