Abstract: Compositions for oral delivery of silica nanoparticles and/or aluminosilicate nanoparticles, and methods of use thereof. The individual nanoparticles comprise a silica core or an aluminosilicate core and, optionally, polyethylene glycol (PEG) groups each disposed on a surface of the nanoparticle. In various examples, the nanoparticles have a size of about 20 nm or less. In various examples, the nanoparticles can be delivered to an individual's gastrointestinal tract, pass through the mucus layer thereof, and permeate the epithelial lining thereof. In various examples, the nanoparticles comprise various targeting, diagnostic, or therapeutic group(s) and can retain one or more said activit(ies) after delivery. Methods of oral delivery and methods of treating a disease can comprise orally administering composition(s) to an individual.