My neighbor says nattokinase and serrapeptase makes him feel like not enough oxygen reaches his brain..normal breathing, though. why is this?

Enzymes: Nattokinase, derived from fermented soybean paste (natto), is eaten in japan. It has anti-coagulant effects and is said to be effective in amyloid forming tissues, but unproven for human disease. Serrapeptase is from serratia sp e-15 and said to have anti-inflammatory effects. Why is your neighbor taking either of these unproven substances. Have no idea why they would produce the effect he claims.