Sure but food is is almost too clean now. For example an unpasteurized cheese has a whole ecosystem of bacteria, each keeping the others in check. The cheese

Sure but food is is almost too clean now. For example an unpasteurized cheese has a whole ecosystem of bacteria, each keeping the others in check. The cheese like substances in most American grocery stores however are almost sterile, so a single bacteria like Campylobacter can colonize it and take it over unopposed. Not all bacterial contamination leaves a detectable smell.