On the plus side yogurt, cheeses, and ice cream have a much reduced effect due to how they're processed, so they don't have as much of an impact as fresh milk does.
I'm the person who wrote the article on milk and acne on AcneEinstein.com. Not to rain on your parade, but I'm not aware of any reason why cheese and ice cream would be less acnegenic than milk. In fact, I think they can be more acnegenic because they are concentrated forms of dairy (at least cheese).
Yogurt may, and I emphasize the word may, have less of an impact because during the fermentation process bacteria consume a lot of the IGF-1 hormones in the milk. That said, yogurt still has whey and other substances that will spike insulin. Thread carefully.
Nobody can really say how much damage a course in antibiotics causes. To my knowledge it has never been thoroughly studied. I looked into this once, and the papers on this generally note that the gut microbiota is fairly stable and bounces back after a disturbance (such as antibiotics).
Many studies note that the microbiota had rebounded back within a few weeks of finishing the antibiotics, but I'm not sure that's the whole story. The problem is that scientists have a limited ability to detect changes in the gut microbiota. And earlier studies used techniques that weren't sensitive enough to detect minor changes. More recent studies have shown that small disturbances persist 2 and 4 years after a 7-day course or clindamycin. To be fair, it's hard to know whether these small disturbances have any health effects.
Our scientific understanding of the gut microbiota still leaves a lot to be desired. There's a lot we don't know. So this question can't be answered definitively yet.
I would be careful with antibiotics. Simply because there's no evidence they have any long-term beneficial effects. They work while you take them, but that's all. Acne comes back when you stop them. And there's a definitive possibility of risk. Not to mention the coming antibiotic shortages because of resistance bacteria.
This is a summary of a more detailed post on the topic I wrote here:
The only thing this proves is fallacious logic. Diet for acne is less about eating healthy and more about avoiding your specific trigger foods. Of course it helps if you avoid high GI carbs and dairy products, but there's rarely the need to get into extremely healthy diets.
As I mentioned, I can go on a McD binge and probably not see a pimple on my face until a few weeks later. But [cencored] help me if I eat an onion, apple or some other 'healthy' foods I know will trigger a breakout for me. 1/2 an onion and 2 days later my scalp breaks out in horribly painful pimples.
So I can eat unhealthy and have clear skin or 'eat healthy' and have horrrible acne. But this doens't mean diet wouldn't affect my skin.
Don't listen to these people. They have "zero" credentials and do nothing but spread their misinformation about acne based upon what they read online.
Acne has nothing to do with diet, as every REAL doctor, dermatologist, endocrinologist will tell you. It is based entirely around genetics and doesn't come about because you drink a glass of "milk" or eat a "hamburger"; acne comes about because the person has defective pores and is overly sensitive to androgen hormones (through genetics) which overstimulates the sebaceous glands causing acne.
*Moderator edit - Please keep the insults to yourself!*
Unfortunately it's you who is both dogmatic and demonstrably wrong. There has NEVER been any good quality scientific evidence that diet does NOT affect acne. The myth was born from a few very sloppy studies in the 60s and 70s. Studies that even your high school science teacher would fail you today.
Unfortunately, and I still can't understand why, those very bad quality studies were enough to persuade dermatologists that diet has no effect on acne. And most have not changed their stance despite the fact that several far more conclusive studies have shown a connection between diet and acne.
Pretty much every scientific review paper on acne mentions diet. It's true that we still need to know much more about diet and how it affects acne, but it's been shown to affect acne.
I do agree with you that people tend to put too much faith into diet. And the natural health industry is especially bad at blaming diet for diseases it has no effect on (such as autism).
I get your frustration. I also used to think that in order to get clear I just have to eat healthier. That's almost NEVER the answer though. I mostly get acne now after eating foods that irritate my gut, like onions and apples (I suspect I have fructose intolerance), but I can binge at McD and never see a pimple on my face.
But just because somebody has given you bad advice before doesn't mean diet has no effect on acne. It just means you've followed bad advice before.