Which antibody protects from intestinal infection?

Ans. (a) IgA(Ref: Kuby immunology pg 419)IgA antibodies are found in circulation, they are the major isotype found in secretions, including mucus in the gut, milk from mammary glands, tears, and saliva. In these secretions, IgA can neutralize both toxins and pathogens, continually interacting with the resident (commensal) bacteria that colonize our mucosal surfaces and preventing them from entering the bloodstream