It depends
The word doing the work is "food", not "modified" — modified only means the starch has been treated to change how it thickens, which tells you nothing about what it came from. On an FDA-regulated packaged food it is corn unless the label says wheat, because wheat is a major food allergen and must be declared. On a USDA-regulated product — meat, poultry or egg — only the common name is required, so this can be wheat starch and the label need never say so. Same three words, two different guarantees, and which one applies depends on what kind of food you are holding.
Ordinary starch that has been treated — with acid, enzymes, heat or a cross-linking agent — so it thickens at a different temperature, survives freezing, or holds up in something acidic. Nothing is added to it in the sense people usually imagine when they read the word modified, and it has nothing to do with genetic modification, which is the association the phrase triggers in most readers.
Because "modified" is the alarming word and "food" is the one carrying the information. The treatment is irrelevant to gluten. What matters is the starch underneath, and the ingredient name deliberately does not say what that is.
On a packaged food with an FDA label, this one is fine and does not need a second thought. On anything under USDA — meat, poultry, egg — the word does not settle it, and the thing that does is a gluten-free claim on the same package. Failing that it is a phone call, and "is the modified food starch in this wheat-derived?" is a question manufacturers answer routinely.
This is one of the entries where the engine asks which agency regulates the label before it answers, because the honest answer changes with it. Where the agency is unknown CiCi returns cannot-verify rather than assuming the common case — which on this ingredient means assuming corn, and would be right most of the time and wrong in exactly the situation that matters.
Every one of these is the same ingredient. The number of names is a large part of why gluten slips past people who read every label.
Point CiCi at the barcode on the product you're holding and get this same reasoning in about two seconds, plus the carbs and the full nutrition panel. 360,000+ packaged foods are already read and waiting.
This answer comes from CiCi's ingredient lexicon — the same rules the scanner uses, not a separate article. Where reputable sources disagree, CiCi takes the conservative position and says so.