I have mentioned Lactofiltrum and Lactulose in candida forums many times.
I encourage all you to see this study. It is linked to candida albicans growth in the colon and Lactulose effects on it.
It looks like Lactulose doesn’t encourage candida growth.
Textbook of Natural Medicine – Page 972 – Google Books Result
Joseph E. Pizzorno, Michael T. Murray – 2012 – Health & Fitness
Growth In one of the original studies utilizing lactulose to change fecal flora, … also demonstrated the ability of lactulose to inhibit the growth of Candida albicans.