I believe that anything that can cause intestinal permeability or worsen an already exiting intestinal permeability (leaky gut), can cause cfs/me. I think Giardia is one possible way, to get or worsen a leaky gut but there are many others. Mast cells play a big role in intestinal disease or dysfunction.
I am convinced that my cfs started as a result of dozens of courses of antibiotics over many years. They decimated most of my healthy gut bacteria, lead to severe dysbiosis (confirmed through testing), caused a leaky gut and my cfs.
I am convinced that my cfs started as a result of dozens of courses of antibiotics over many years. They decimated most of my healthy gut bacteria, lead to severe dysbiosis (confirmed through testing), caused a leaky gut and my cfs.