Is Metamucil gluten-free?

Metamucil claims its products are gluten-free. The exception is the Metamucil wafers, which contain wheat flour and are not gluten free. This fiber brand comes in both powdered and capsule varieties, as well as several flavors, such as lemonade, orange or mixed-berry.

References
Konsyl: Psyllium Fiber Supplements
Metamucil: Frequently Asked Questions; Does Metamucil Contain Gluten?
Dr. Natura: UniFiber