Flukes are actually worms or trematodes.They are not bacteria or viruses.
You should undergo fecal smearing or stool analysis to get this diagnosed.
Blood testing will not show infestation with fluke.
However,blood testing can tell presence of some worm infestation.
However,to diagnose it properly you need 'fecal smearing'.
Nothing to worry about.As these flukes can be treated by anthelminitics (anti worm medicines) like praziquantal.
Probiotics and holistics are of little use.However,you can try using odourless garlic capsules or fresh garlic as a natural remedy.
Garlic is a powerful drug against such infestations being used from centuries.
Hope it helped.
Feel free to ask any more questions.