Would making your nostrils smaller through nose job affect breathing?

Unlikely to obstruct: Hello thanks for your question, making the nostrils smaller can be done in different ways and usually does not affect breathing. I am sure there is a point a which making them way too small could affect breathing, however breathing is more so obstructed higher up in the nostril (nasal valve) or back near the septum or turbinates (especially if these are swollen or the septum is deviated).

Not usually: In most people, the critical area for breathing is located inside the nose (internal nasal valve) and the size of the nostril does not typically affect this unless abnormally small or scarred