AUTHOR=Labania Lena , Zoughbor Sumaya , Ajab Suad , Olanda Marie , Shantour Sulaiman N. M. , Al Rasbi Zakeya 

TITLE=The associated risk of Blastocystis infection in cancer: A case control study

JOURNAL=Frontiers in Oncology

VOLUME=Volume 13 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/oncology/articles/10.3389/fonc.2023.1115835

DOI=10.3389/fonc.2023.1115835

ISSN=2234-943X

ABSTRACT=Background: Blastocystis is an anaerobic intestinal protozoan. Nine Blastocystis subtypes (STs) were detected in humans. A subtype-dependent association between Blastocystis and colorectal cancer (CRC) has been debated in many studies. Thus, this study aims to assess the possible association between Blastocystis infection and CRC condition compared to cancer outside the gastrointestinal tract (COGT) and cancer-free control (CF). We also checked for the presence of gut fungi and their association with Blastocystis and cancer.
Methods: We used a case-control design; cancer patients and CF participants. The cancer group was further sub-grouped into CRC group and COGT group. Macroscopic and microscopic examinations were performed to identify intestinal parasites in participants’ stool samples. Molecular and phylogenetic analyses were conducted to identify and subtype Blastocystis. Furthermore, gut fungi were investigated molecularly.
Results: 104 stool samples were collected and matched between CF (n=52) and cancer patients (n=52); CRC (n=15) and COGT (n=37). Blastocystis prevalence was significantly higher among CRC patients (60%, P=0.002) and insignificant in COGT patients (32.4%, P=0.161) compared to CF group (17.3%). Blastocystis infection between the two cancer groups was statistically insignificant (P=0.209). The most common subtypes were ST2 among cancer group and ST3 in the CF group.
Conclusion: CRC patients have a higher risk of Blastocystis infection compared to cancer-free individuals (OR= 5.66, P=0.009). Nevertheless, further studies are required to understand the underlying mechanisms of Blastocystis and CRC association.