Your gut bacteria can override your DNA to let you digest milk even if you are "genetically" lactose intolerant.

Lactose intolerance is usually seen as a fixed genetic trait where the body stops producing a specific enzyme. Scientists discovered that many people across the globe who lack this gene can still drink milk without any symptoms. This is because their gut microbiome has evolved to produce the missing enzyme for them. These bacteria effectively patch the host's genetic deficiency, allowing for a broader diet. This reveals that our nutritional limits are not just written in our cells, but are managed by a partnership with trillions of microbes.