Is LCT useful for gut health?

Whether the LCT gene is useful for gut health requires a nuanced answer. LCT encodes lactase, the enzyme that breaks down lactose. Genetic lactase persistence (e.g., variant rs4988235) allows lactose digestion in adulthood, while non-persistence leads to lactose intolerance with symptoms like bloating, diarrhea, and abdominal pain. Thus, LCT genotyping can help identify individual intolerances and guide dietary adjustments – this can improve gut health by avoiding discomfort. However, LCT is only one small piece. Gut health is shaped by the microbiome, gut barrier, inflammation, and many other genes. A standalone LCT test does not replace comprehensive gut diagnostics. The evidence for lactose intolerance is strong (human-strong), but for overall gut health it is moderate, as many other factors dominate. Caveat: A positive lactase persistence result does not guarantee a healthy gut flora.