Dairy products do not interfere with probiotics that I know of. Cottage cheese is good for you if it contains live cultures (probiotics). Many probiotics grow the "friendlies" in a dairy-based solution. Also, the cultures help to break down lactose, which means cultured dairy (yogurt, kefir, cottage cheese, etc.) is usually tolerated by those with lactose intolerance. I don't know anything about dairy and antibiotics interactions other than doxycycline shouldn't be taken with a meal containing dairy.
Chronic Lyme Disease, Gluten & Sulfite Sensitivity, Many Food/Inhalant/Medication/Chemical Allergies & Intolerances, Asthma, Gut issues (dysmotility, non-specific inflammation), UCTD ("Secondary Lupus-Like Syndrome"), Osteoporosis, Pancytopenia, chronic malabsorption/malnutrition, etc.; G-Tube; Currently TPN-dependent.
Meds: Zofran, Pulmicort, IV Ceftazidime, Heparin (to flush PICC line), Claritin, Colloidal Silver (used topically), probiotics, homeopathy.