I have now been put on a course of Anti-Biotics. Will this kill off my gut biome?
If this is the case then how best can I build it up to it’s former glory?
Any polite answers much appreciated – thank you.

Which anti-biotics and for what purpose? You might want to beef up your diet with additional pre-and-pro biotics for a couple of months too. Yes in general antibiotics kill of the bad guys AND the good guys but the extent very much depends on which antibiotic you take; how long for; whether its one or several courses; and how resilient your microbiome is in the first place