When you say you've been "glutened," that something "glutens" you, or that something is "glutening" you, it means you're getting symptoms of gluten ingestion from that food product.
People with celiac disease and gluten intolerance use the term "glutened" to refer to recurring symptoms from foods (mostly from foods they mistakenly thought were gluten-free). Please note this is not a medically accepted term.
You can use the colloquial term "glutened" as a verb i.e., "That gluten-free bread glutened me." You also can use the term "glutening" as a noun i.e., "I had a glutening at my friend's house."
Since foods labeled "gluten-free" still can contain a minute amount of gluten, it's possible to be "glutened," or to get gluten symptoms, from "gluten-free" foods, especially if you're more sensitive than average.
It's also possible to get "glutened" at home (if you have a shared kitchen), at a friend's house, or at a restaurant, despite taking precautions against cross-contamination.
I've been glutened.
That product always glutens me.
I just had a really bad glutening.