Can antioxidants prevent bacterial infection?

Yes and no: Antioxidants help biochemical reactions run smoothly in the body (co-factors), some may be vitamins or minerals, some are different. Most will behave as either anti-ox or pro-ox, depending on the chem circumstance. Certain amount is needed, more may not confer any extra benefit. No clinical data to support claims that any product (juice, fruit, "miracle") actually cheats death, prolongs life.

Not by themselves: We need a balance of oxidants and antioxidants. If the fuel (food) is right and the non caloric nutrients are balanced, we reach maximum immune potential. But a bacterium is an attacking enemy and a war sometimes has to be fought------we call that "flu". The better the defenses the more likely that a war will not have to be fought!

No: There is no evidence that antioxidants prevent infections.