system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What is meant when it is said that a food is "alive," like yogurt or cheese or yeast? Secondarily, how is a "culture" different from a mold or other similar organism?
gpt
For the first part, “alive” means just that. There is living bacteria/mold/yeast in the food. For yogurt, it’s generally accepted to be good for your gut biome. For cheese, it serves as an advertisement (blue cheese) and a warning for those who are allergic. Yeast is less common to be served alive as it causes food to quickly change taste however, this may be desirable in things like baking. 
  
As for the second part, “culture” is just a word to describe that they intentionally added it in. In the case of yogurt, words like “acidophilus cultures” just tells you what bacteria are added. This is good for adults as our bodies may need assistance in regulating our gut biomes (bad diet, medicine, etc).