You can indeed take microbz alongside any antibiotics and chemotherapy.
Of course it will knock out some of the beneficial microbes but research has found that side effects from both are much reduced and bounce back is faster when the microbiome is supported all the way through. Just aim to take microbz at a separate time to the antibiotics and perhaps not on the actual day but the day after the chemo.
Of course you must be guided by how you are feeling too, and take things step by step.
In other countries it has long been standard to offer both together.