Dietary profiles of wild carnivores and Blastocystis occurrence: The case of the endangered Iberian lynx (Lynx pardinus) and systematic review

Recent molecular and metagenomic studies have revealed that the obligate anaerobic protist Blastocystis is found more prevalently and with higher subtype diversities in herbivore species than in carnivore species. However, information on wild carnivore species is scarce. Here, we investigated the presence of Blastocystis by molecular methods in fecal DNA samples of free-ranging and captive Iberian lynxes from Spain (n = 243) and Portugal (n = 30). In addition, a systematic review was conducted to obtain information on the Blastocystis prevalence rates and subtype diversities reported in free-living and captive wild carnivores worldwide during the period 2000-2024. Blastocystis was not detected by PCR in any of the samples investigated. Analyses of the data gathered from our systematic review revealed that Blastocystis is uncommon either in free-living (2.1 %, 29/ 1377) or captive (8.5 %, 100/1175) wild carnivore species. Many of these findings seem to result from accidental acquisition via prey animals, scavenging, contaminated water/feed (free-ranging wild carnivores), or crossspecies transmission among animals sharing enclosures (captive wild carnivores). Comparative metagenomic studies analyzing gut microbiota profiles of carnivores are needed to fully understand how microbial communities affect Blastocystis colonization.