Ulusan Bağcı Özlem, Aral Akarsu Gülay
Department of Parasitology, Ankara University Faculty of Medicine, Ankara, Türkiye.
Acta Parasitol. 2025 Nov 10;70(6):208. doi: 10.1007/s11686-025-01145-5.
Blastocystis spp. is the most commonly identified protozoan in humans, yet its clinical significance and pathogenicity remain controversial. While often asymptomatic, it has been associated with gastrointestinal symptoms and urticaria. Metronidazole is the most frequently used first-line treatment; however, increasing reports of resistance and treatment failure have led to growing interest in alternative therapeutic options.
In this systematic review, we searched the Web of Science, Scopus, and PubMed databases using relevant keywords in article titles to identify studies related to the treatment of Blastocystis spp.
A total of 195 records were retrieved. After removing duplicates and applying inclusion and exclusion criteria, 39 studies were deemed eligible. Data extracted included author, publication year, country, number of participants or samples, diagnostic method, subtype, treatment agent, dosage, intervention details, and clinical and parasitological outcomes. Of the included studies, 17 were human studies (14 clinical trials and 3 case reports), and 22 were in vitro or animal studies.
Our findings suggest that metronidazole may be inappropriate as a first-line treatment, as it can increase the number of viable parasites and promote their transformation into apoptosis-resistant granular or more pathogenic amoeboid forms. Alternative agents-such as ronidazole, satranidazole, and C17 (2-position 5-nitroimidazoles), as well as ornidazole, secnidazole, and tinidazole (1-position 5-nitroimidazoles with different side chains compared with metronidazole)-show potential efficacy. Trimethoprim-sulfamethoxazole and nitazoxanide have also demonstrated promising results. Further studies, particularly subtype-specific and human clinical trials, are needed to assess the safety and efficacy of these alternative agents against Blastocystis spp.
芽囊原虫是人类中最常鉴定出的原生动物，但它的临床意义和致病性仍存在争议。虽然它通常无症状，但已与胃肠道症状和荨麻疹相关联。甲硝唑是最常用的一线治疗药物；然而，关于耐药性和治疗失败的报道日益增多，这使得人们对替代治疗方案的兴趣不断增加。
在本系统评价中，我们使用文章标题中的相关关键词搜索了Web of Science、Scopus和PubMed数据库，以识别与芽囊原虫治疗相关的研究。
共检索到195条记录。在去除重复记录并应用纳入和排除标准后，39项研究被认为符合要求。提取的数据包括作者、出版年份、国家、参与者或样本数量、诊断方法、亚型、治疗药物、剂量、干预细节以及临床和寄生虫学结果。纳入的研究中，17项是人体研究（14项临床试验和3项病例报告），22项是体外或动物研究。
我们的研究结果表明，甲硝唑作为一线治疗药物可能不合适，因为它会增加存活寄生虫的数量，并促使它们转变为抗凋亡的颗粒状或更具致病性的阿米巴样形态。替代药物——如罗硝唑、塞曲硝唑和C17（2位5-硝基咪唑），以及奥硝唑、司硝唑和替硝唑（与甲硝唑相比具有不同侧链的1位5-硝基咪唑）——显示出潜在疗效。甲氧苄啶-磺胺甲恶唑和硝唑尼特也已取得了有前景的结果。需要进一步的研究，尤其是亚型特异性和人体临床试验，以评估这些替代药物对芽囊原虫的安全性和疗效。
