Within the thousands of microorganisms that make up the intestinal microbiota, Clostridium difficile and Blastocystis can have a modulatory effect in different ways. The following study aimed to describe the bacteriome and eucariome of four patient groups: with Blastocystis and Clostridium difficile, only with infection by C. difficile, only with colonization by Blastocystis and patients without colonization/infection by the aforementioned microorganisms. Likewise, we identified Blastocystis subtypes in the samples, using amplicon sequencing of 16S-rRNA, 18S-rRNA. We found ST1 (36.4%), ST3 (37.5%) and ST5 (19.3%) as the most abundant subtypes of Blastocystis within the samples. Although it has been proposed that dysbiosis environments prevent the colonization by Blastocystis, this study showed a possible adaptation of Blastocystis to this scenario; due to the mechanisms of its hydrogenosome and to the resources that can be found in this environment. Hence, Blastocystis can favor the increasement of populations of beneficial bacteria of the microbiota, by performing its predatory role. Thus, our results would help clarify the debatable status of Blastocystis, leaning towards the hypothesis that it could be a beneficial member of the intestinal microbiota. The present study can also provide a holistic insight into the competition that exists among members of the microbiota under a scenario of dysbiosis, especially in the competition for resources between Blastocystis and some fungi. This study contributes to improve our knowledge about the composition of the intestinal microbiota and the interactions of its members.
