Are Blastocystis hominis and Cryptosporidium spp. playing a positive role in colorectal cancer risk? A systematic review and meta-analysis

Abstract

Objective Intestinal protozoa Blastocystis hominis and Cryptosporidium spp. are two influential factors in intestinal complications and malignancies. In present study, we estimated the pooled prevalence and odds ratio (OR) of the two parasites in colorectal cancer (CRC) patients and their possible association with the deadly disease. Method Our systematic search was conducted for published researches between January 1, 2000 and April 30, 2022 by using four international databases include Scopus, PubMed, and Web of Science as well as Google scholar search engine. The random- and fixed-effects models were used to estimate the pooled prevalence, OR, and 95% confidence interval (CI) by comprehensive meta-analysis (V2.2, Bio stat) software. Inclusion and exclusion criteria were applied. Results Thirteen papers (seven case–control and six cross-sectional studies) for B. hominis/CRC and six papers (two case–control and four cross-sectional studies) for Cryptosporidium spp./CRC were eligible to include in data synthesis. Pooled prevalence of B. hominis and Cryptosporidium spp. in CRC patients was calculated to be 26.8% (95% CI 19.4–35.7%) and 12.7% (95% CI 6.8–22.5%), respectively. Based on case–control studies, significant difference was found between case and controls in both protozoa (B. hominis OR 2.10; 95% CI 1.39–3.18% vs. Cryptosporidium spp. OR 5.06; 95% CI 1.8–13.6%). Considering the Blastocystis subtypes, ST1 (5/6; 83.33% studies) and ST3 (5/6; 83.33% studies) had the highest number of reports in CRC patients. Regarding the Cryptosporidium species, only C. parvum and C. hominis were reported. Conclusion Given the significant prevalence of both parasites in CRC patients and their statistically significant association, there is a need to pay more attention to these two intestinal parasites in under treatment patients.

First Epidemiological Survey on the Prevalence and Subtypes Distribution of the Enteric Parasite Blastocystis sp. in Vietnam

“…On the other hand, and considering only investigations performed in southeast Asia using molecular detection assays, the prevalence in Vietnam was close to the average frequency reported from neighboring countries, such as Thailand (22.3%), Indonesia (31.8%) or Malaysia (24.7%), but significantly lower than those observed in the Philippines (49.1%) and Cambodia (55.2%), even if this frequency was based on a single epidemiological study for the latter country [ 1 , 2 ]. Moreover, in some of these countries, for which a relatively large number of surveys have been conducted, such as Thailand, the Philippines and Malaysia, the prevalence observed varies greatly depending on the geographical area or the cohort considered, ranging from 5.2 to 40.6%, 15.3 to 82.9% and 9.2 to 40.3%, respectively [ 1 , 23 ]. All these data clearly highlight the active circulation of Blastocystis sp.…”

“…Moreover, several findings suggest that colorectal cancer may be related with elevated risk of Blastocystis sp. infection [ 23 ]. Recent in vitro studies, coupled with genomic data, resulted in the identification of different virulence factors involved in the pathophysiology of this parasite, which could be associated with the genetic diversity of Blastocystis sp.…”

<i>Cryptosporidium spp</i>. and <i>Blastocystis spp.</i> coinfection as a reason of an acute diarrhea in a young healthy veterinary Polish student – Case report

“…The role of Blastocystis spp. in human pathology has widely discussed and is now even egarded as a parasitic pathogen [18][19][20]; therefore, it is worthwhile highlighting this in the diagnosis..Combination treatment might decrease the risk of post-infectious irritable bowel syndrome.…”

Role of Cryptosporidium spp in Development of Colorectal Cancer

“…In Egypt, cancer colon constitutes about 6.5% of all cancers and represents the sixth most common cancer diagnosed (Hassan et al, 2021). Chronic inflammatory conditions together with chronic long-standing infections and unhealthy diet and lifestyle are among the most common risk factors for its development (Taghipour et al, 2022).…”

“…It was postulated that Cryptosporidium spp. infections might be related to the development and progression of cancer colon via triggering colonic mucosal dysplasia (Taghipour et al, 2022).…”