Genetic characterization of enteric protozoan microorganisms in newly arrived migrants in Italy and correlation with the gut microbiome layout

The prevalence of the enteric protozoan microorganisms, its genetic characterization as well as its associated gut microbiome has been molecularly and 16S metagenomic characterized in a cohort of newly arrived migrants in Italy from African countries over the period 2022–2024. Out of 199 individuals, 92 (46.2%) were found to be carrier of protozoan microorganisms with a higher prevalence of Blastocystis sp. (15.5%), followed by Giardia duodenalis (12.6%), Dientamoeba fragilis (7.5%), Cryptosporidium parvum (6.5%), and Entamoeba histolytica (4%). Subtypes ST1, ST2 and ST3 were genetically characterized for Blastocystis sp., assemblages A and B for G. duodenalis, subtypes families IIa and IIc for C. parvum and genotype 1 for D. fragilis. High prevalence of Butyrivibrio, Lachnospiraceae UGC 10 and Paraprevotella, were identified in the protozoan non-carrier individual group. This work shed lights on the circulation of enteric protozoan microorganisms in apparently healthy migrants from African countries and the potential relationship with the host-microbiome composition. Moreover, these results give an overview of the importance of microbiological surveys among migrants and asylum seekers arriving to hosting countries in order to evaluate the reliable risk of several microorganisms introduction though migration. Ultimately, further investigation of interplays between the intestinal microbiota and protozoan microorganisms will provide new approaches in the diagnosis and treatment of intestinal infections.