That is a good question. You can go to the bottom of the article and click on refences. None of the references mentiin research. The first reference does not actually work. The second reference describes a neutropenic diet ( what is being recommended here ) but then states this “ In a review of studies, the neutropenic diet was never proven to decrease exposure to bacteria in foods. This diet does not seem to benefit patients in any way. Safe preparation and handling of foods is more important than restricting intake of specific food groups, as balanced diet and nutrition is important for coping with chemotherapy and other treatments.”
Another refence about an iv cancer medication mentions absolutely nothing about diet at all so is not relevant.
Given that biologics reduce white blood cell count , I know mine is always low, your immunity would be lowered.
I think good food hygeine is imprtant. How much should we restrict our diet though. I eat soft cheeses, runny eggs, sprout my own seeds ( I guess that means I know the water source is clean) and even ferment foods and make kombucha sometimes. It has never occured to me not to do that.
It would be good to have a focus also on what we can eat as this life is restrictive already.