Controversially but famously, "chronic Lyme disease" involves course of multiple super strong antibiotics over potentially years. Then things to try to save your organs from antibiotics. Then pills to help you digest those. Taking 50 pills on regular basis is apparently common enough.
Any non-treatble illness that causes a buildup/environment for bacteria that trigger debilitating symptoms.
The human body has many defenses and mechanics to keep bacteria in balance. I would point particularly towards the gut/intestant, the skin, ears, anus, bladder and genitalia for places where bacteria need to be constatly kept at the correct balance. Some things are treatable. Some things are possible to cut off. Some things are less known/fixable, in which case symptoms is the only thing possible to addressed at this time.
acne is bacterial but chronic. it's standard practice for dermatologists to prescribe long-term antibiotics for severe acne, rather than turn to accutane.
I have rosacea and it of course goes up and down. used tgel for a while then decided to only apply it to my right side of face. After a ~year there was never ever difference between two sides of my face, they went up and down together depending on temperature, environment, sweat, stress, food, etc. My doctor could not believe that I would try that, but it seemed a super simple way to check if all those antibiotics actually Did anything. For me at least they didn't.
Which debilitating, non-bacterial chronic illnesses are treated with antibiotics as a stopgap measure?