What is the Origin of Lactose Persistence LCT Gene?

This concept originates from evolutionary genetics and human physiological adaptation, recognizing that adult lactose digestion is a relatively recent evolutionary development in human populations. The LCT gene encodes the lactase enzyme, and the genetic variant responsible for persistence is located in an adjacent gene, MCM6, which acts as a transcriptional enhancer. Clinical understanding of this gene-trait relationship is vital for personalized dietary recommendations and managing gut health.

What is the Mechanism of Lactose Persistence LCT Gene?

In individuals with lactose persistence, the genetic polymorphism ensures that the LCT gene continues to be transcribed into the lactase enzyme well into adulthood. This enzyme hydrolyzes lactose into the readily absorbable monosaccharides, glucose and galactose, in the small intestine. Without this genetic trait, lactase production declines after weaning, causing undigested lactose to ferment in the colon, which can disrupt the gut microbiome and impact systemic inflammatory and hormonal signaling.

Lactose Persistence LCT Gene ∞ Area

Lactose Persistence LCT Gene

Meaning

Lactose Persistence mediated by the LCT Gene refers to the lifelong ability of an adult to digest lactose, the primary sugar in milk, due to the sustained expression of the lactase enzyme. This physiological trait is governed by a specific genetic polymorphism in the regulatory region of the LCT (Lactase) gene. Individuals lacking this persistence experience primary adult-onset lactase non-persistence, leading to gastrointestinal symptoms and potential nutritional compromise.