While scientists have long known that the different bacteria that live in our gut affect our health, the public has been much less aware of this fact. Over the past decade, however, advances in analytical technology have begun to reveal the specific mechanisms. For example, scientists have discovered that gut bacteria are involved in aspects previously thought to be strongly influenced by our genome, such as our body weight and physical constitution, as well as the efficacy of drugs. Research into postbiotics —— metabolites produced by gut bacteria —— and the symbiotic relationship between different species of bacteria is also reported to be progressing. At the moment, gut bacteria are attracting as much attention as our genes.