幽门螺杆菌是78%胃癌病例的主要病因,通过控制复杂的胃微生物群中的单一细菌病原体来提供预防癌症的机会。我们通过将幽门螺杆菌结合指导肽(MM1)与广谱抗菌肽融合,开发了针对幽门螺杆菌的高选择性抗微生物剂。然后将常见的乳制品益生菌乳酸乳球菌工程化以分泌这些指导的抗微生物肽(gAMP)。当与幽门螺杆菌体外共培养时,与未引导的AMP益生菌相比,gAMP益生菌对目标没有毒性,幽门螺杆菌,同时对两种测试的脱靶细菌失去>90%的毒性。为了测试与幽门螺杆菌的结合,MM1向导与绿色荧光蛋白(GFP)融合,导致与未引导的GFP相比增强的结合,如通过流式细胞术测量的。相比之下,MM1-GFP对5种不同的脱靶细菌没有表现出比GFP增加的结合。然后通过口服管饲法在感染幽门螺杆菌的小鼠中测试这些高选择性gAMP益生菌。作为一种治疗,益生菌优于抗生素治疗,在短短5天内有效消除幽门螺杆菌,并作为预防措施保护小鼠免受攻击感染。不出所料,gAMP益生菌对幽门螺杆菌的毒性与未引导的AMP益生菌一样。然而,选择性gAMP益生菌和非选择性AMP益生菌均发现胃物种多样性强烈反弹。消除由幽门螺杆菌引起的极端微生物菌群失调似乎是多样性恢复的主要因素。重要性在控制幽门螺杆菌和预防胃癌方面需要替代抗生素。幽门螺杆菌在人群中的高流行率,抗生素诱导微生物菌群失调,不断增加的抗生素耐药性要求采取更可持续的方法。通过选择性地消除病原体并保留共生群落,幽门螺杆菌控制可以在没有不良健康结果的情况下实现。抗生素通常用作感染后的治疗药物,但更有针对性的,破坏性较小的方法可以用作幽门螺杆菌的长期预防措施,通过延伸,对抗其他胃肠道病原体。此外,指导抗菌肽(gAMP)技术的模块化特性允许用不同的指导代替不同的病原体,并使用gAMP混合物来避免病原体耐药性的发展.
Helicobacter pylori is the primary cause of 78% of gastric cancer cases, providing an opportunity to prevent cancer by controlling a single bacterial pathogen within the complex gastric microbiota. We developed highly
selective antimicrobial agents against H. pylori by fusing an H. pylori-binding guide peptide (MM1) to broad-spectrum antimicrobial peptides. The common dairy probiotic Lactococcus lactis was then engineered to secrete these guided antimicrobial peptides (gAMPs). When co-cultured in vitro with H. pylori, the gAMP probiotics lost no toxicity compared to unguided AMP probiotics against the target, H. pylori, while losing >90% of their toxicity against two tested off-target bacteria. To test binding to H. pylori, the MM1 guide was fused to green fluorescent protein (GFP), resulting in enhanced binding compared to unguided GFP as measured by flow cytometry. In contrast, MM1-GFP showed no increased binding over GFP against five different off-target bacteria. These highly
selective gAMP probiotics were then tested by oral gavage in mice infected with H. pylori. As a therapy, the probiotics outperformed antibiotic treatment, effectively eliminating H. pylori in just 5 days, and also protected mice from challenge infection as a prophylactic. As expected, the gAMP probiotics were as toxic against H. pylori as the unguided AMP probiotics. However, a strong rebound in gastric species diversity was found with both the
selective gAMP probiotics and the non-
selective AMP probiotics. Eliminating the extreme microbial dysbiosis caused by H. pylori appeared to be the major factor in diversity recovery. IMPORTANCE Alternatives to antibiotics in the control of Helicobacter pylori and the prevention of gastric cancer are needed. The high prevalence of H. pylori in the human population, the induction of microbial dysbiosis by antibiotics, and increasing antibiotic resistance call for a more sustainable approach. By selectively eliminating the pathogen and retaining the commensal community, H. pylori control may be achieved without adverse health outcomes. Antibiotics are typically used as a therapeutic post-infection, but a more targeted, less disruptive approach could be used as a long-term prophylactic against H. pylori or, by extension, against other gastrointestinal pathogens. Furthermore, the modular nature of the guided antimicrobial peptide (gAMP) technology allows for the substitution of different guides for different pathogens and the use of a cocktail of gAMPs to avoid the development of pathogen resistance.