Alteration of gut bacteria composition among individuals with asymptomatic Blastocystis infection: A case-control study

Prevalence of intestinal parasitic infections in patients with diabetes: a systematic review and meta-analysis

Patients with diabetes are at an increased risk of intestinal parasitic infections (IPIs). We evaluated the pooled prevalence and OR of IPIs in patients with diabetes through a systematic review and meta-analysis. A systematic search was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol for studies reporting IPIs in patients with diabetes through 1 August 2022. The collected data were analyzed using comprehensive meta-analysis software version 2. Thirteen case-control studies and nine cross-sectional studies were included in this study. The overall prevalence of IPIs in patients with diabetes was calculated to be 24.4% (95% CI 18.8 to 31%). Considering the case-control design, the prevalence of IPIs in case (25.7%; 95% CI 18.4 to 34.5%) was higher than controls (15.5%; 95% CI 8.4 to 26.9%) and a significant correlation was observed (OR, 1.80; 95% CI 1.08 to 2.97%). Moreover, a significant correlation was seen in the prevalence of Cryptosporidium spp. (OR, 3.30%; 95% CI 1.86 to 5.86%), Blastocystis sp. (OR, 1.57%; 95% CI 1.11 to 2.22%) and hookworm (OR, 6.09%; 95% CI 1.11 to 33.41%) in the cases group. The present results revealed a higher prevalence of IPIs in patients with diabetes than in controls. Therefore, the results of this study suggest a proper health education program to preventing measures for the acquisition of IPIs in patients with diabetes.

Gut bacteria influence Blastocystis sp. phenotypes and may trigger pathogenicity

Whilst the influence of intestinal microbiota has been shown in many diseases such as irritable bowel syndrome, colorectal cancer, and aging, investigations are still scarce on its role in altering the nature of other infective organisms. Here we studied the association and interaction of Blastocystis sp. and human intestinal microbiota. In this study, we investigated the gut microbiome of Blastocystis sp.-free and Blastocystis sp. ST3-infected individuals who are symptomatic and asymptomatic. We tested if the expression of phenotype and pathogenic characteristics of Blastocystis sp. ST3 was influenced by the alteration of its accompanying microbiota. Blastocystis sp. ST3 infection alters bacterial composition. Its presence in asymptomatic individuals showed a significant effect on microbial richness compared to symptomatic ones. Inferred metagenomic findings suggest that colonization of Blastocystis sp. ST3 could contribute to the alteration of microbial functions. For the first time, we demonstrate the influence of bacteria on Blastocystis sp. pathogenicity. When Blastocystis sp. isolated from a symptomatic individual was co-cultured with bacterial suspension of Blastocystis sp. from an asymptomatic individual, the parasite demonstrated increased growth and reduced potential pathogenic expressions. This study also reveals that Blastocystis sp. infection could influence microbial functions without much effect on the microbiota diversity itself. Our results also demonstrate evidence on the influential role of gut microbiota in altering the characteristics of the parasite, which becomes the basis for the contradictory findings on the parasite's pathogenic role seen across different studies. Our study provides evidence that asymptomatic Blastocystis sp. in a human gut can be triggered to show pathogenic characteristics when influenced by the intestinal microbiota.

Frequency, subtypes distribution, and risk factors of Blastocystis spp. in COVID-19 patients in Tehran, capital of Iran: A case-control study

Background

Recent theories on the possible interactions between the intestinal parasites and COVID-19 have stated that these co-infections may cause immune imbalance and further complications in the affected patients. Until now, there is no data about Blastocystis subtypes as an intestinal parasite in COVID-19 patients. Therefore, the present work was done to evaluate the molecular prevalence of Blastocystis spp. and related risk factors in Iranian patients with COVID-19.

Method

Stool samples were gathered from 200 COVID-19 patients and 200 control, being matched regarding age, gender and residence. Then, stool samples were surveyed by parasitological methods, including direct slide smear and formalin-ether concentration. In the following, PCR and sequencing were used to detect Blastocystis spp. and their subtypes.

Results

The frequency of Blastocystis spp. in patients with COVID-19 (7.5%; 15/200 by molecular method vs. 6%; 12/200 by microscopy method) was slightly higher than in individuals without COVID-19 (4.5%; 9/200 by molecular method vs. 4%; 8/200 by microscopy method), this difference was not statistically significant (P value = 0.57 for molecular method vs. P value = 0.81 for microscopy method). Regarding associated factors for Blastocystis spp., we found significant differences regarding the residence (rural), loose and watery stool with diarrhea, and duration of treatment (6 weeks <) in the COVID-19 group. Blastocystis ST3 was the most common subtype in the patients with COVID-19 and control group.

Conclusions

Based on this results, health education, improved sanitation and good personal hygiene are highly recommended to prevent Blastocystis in COVID-19 patients.