Ger is a medical immunologist from The Netherlands. He obtained his PhD in 1980 and his registration as medical immunologist in 1984. Ger has a strong interest in the interaction between gut microbiota and the human immune system and has published widely on the health promoting effects of probiotics, e.g. for allergic diseases and immunotherapy of cancer. At University College Roosevelt in Middelburg, he teaches a variety of courses in the life sciences and supervises students.