She also recommends a colon health probiotic and eating a healthy diet with a wide variety of plants and vegetables to improve the health of your saliva. She writes “Oral probiotics may seem a good idea, but many contain artificial sweeteners like Splenda, that can damage gut health… If you want an oral probiotic, I recommend Garden of Life Probiotic Smile lozenges, which contain strains of Streptococcus uberis KJ2, S.oralis KJ3 and S.rattus JH145, plus xylitol to feed probiotic bacteria.”
That said, as far as I know these recommendations were made for general oral health and not specifically about Fusobacterium nucleatum animalis C2.
My guess would be that certain bacteria or strains are better than others at outcompeting the undesirable colonies, but you'd have to look for specific research to say which ones. In lieu of that, though, it's not hard to experiment with probiotics and see which, if any, have a noticeable positive impact on you.
With longer wavelength UV, which is less absorbed by the cells, the light would penetrate deeper into the tissue and cause much more DNA damage. Still, broadband UV irradiation of throat, nose, and ear was a mainstream treatment in the USSR.