Do Antibiotics affect performance?

Don’t think I quite got back to normal. The week on antibiotics was rough… low energy and sore legs. Here’s a calendar link for me at the time: - TrainerRoad
I was missing workouts left and right. I think the “sinus infection” annotation is the 10 day course of amox/clav I took. It was the last 6 weeks of cx season, so partly I was trying to ensure I’d at least be rested to race on the weekends. I did pull out a good cx states race shortly after (carried a peak?), but the next few races definitely were underperformed even though I was sort of getting my workouts back on track.