I just looked at the ubiome.com website. It's set up differently so that I don't see an option to order the mouth kit alone. If you email them for a direct link to order a mouth kit, it may be easier to order.
*I called a dentist on the list. He analyzes plaque on a slide to determine which type of bacteria is in it. He also can take an image (I forgot the name of the test since I never heard of it, but it starts with the letter C) of a tooth to see if it is infected. I asked what treatment they provide if you have pathogen bacteria. They recommended a waterpik with an oxygenating rinse mixed in the water. I had a waterpik I just threw away because I was concerned it might have mold inside where water partiicles are trapped.