Since a restaurant likely wouldn’t admit to recycling bread, it might be worth keeping an eye out for other signs that the establishment cares (or not) about cleanliness — checking out how tidy the bathrooms are is one way to do this. If the place is generally nice and tidy, it’s probably trustworthy when it comes to following the health code (be it with bread baskets, food handling, or anything else).
But if you really can’t help but worry about the bread, there’s some evidence that can put you at ease. First, research by the Centers for Disease Control and Prevention has indicated that many food poisoning cases can be traced to restaurant workers (not other customers, as would be the case in recycled bread). Second, bread is really not a common cause of food poisoning. Meat and leafy greens are much more common sources of food poisoning, and food poisoning from bread doesn’t really factor into statistics in a notable way. Even though the (arguably minimal) risk of getting served recycled bread certainly has an ick factor for some people, it’s probably not a reason to fear for your health — and if you’re choosing responsible, high-quality restaurants, the owners and staff would be unlikely to take the risk of getting caught breaking the health code.