Pathogens damage gut wall and cause leaky gut. There is also another cause for leaky gut, and it's food allergy .
And it is completely right again, you should get tested to find out whatever is the cause of your leaky gut.
I had Metametrix GI profile, and it showed two protozoa parasites - cryptosporidium and another non human parasite.
But I was very surprised to find out that alternative doctors here in Phoenix DO NOT TRUST Metametrix!!!
So you had better go with Genova Labs or another lab called Doctors Data Lab. This last one do a sensitivity test of herbs against the parasites they find in you.