Hi Natalia88. This is a very complicated thing. I can tell you for a FACT you have parasites, but so does everyone else. You can find parasites, but it does not necessarily mean it is a disease source. Although, it could be a contributor, or just a factor which complicates things. It could also be something doing good for you at the expense of some mere symptoms.
There are some parasites however that should not be there at all. I say fluke falls into this catigory dispite the fact many people have 'em and don't know it.
I would use Great Smokies Labs, and request a whole profile which includes all the nasty guys.
It could be helpful if you need certain RX meds to handle the problem.
If you visit my website http://www.ummicrographic.com
and go to the research page under "current study" it has some explanation on how these things can connect to other problems like fungal, bacterial etc. Shroom