was hat kohlenhydrate — what are common causes?

Common causes of carbohydrate-related issues are multifactorial. Genetic variants (e.g., LCT for lactose intolerance, MCM6 for primary lactase deficiency) are well-established but only explain part of the picture. Gut microbiome imbalances, fructose malabsorption, irritable bowel syndrome, and hereditary fructose intolerance (aldolase B deficiency) also play roles. Lifestyle factors like high sugar intake, stress, and medications can further impair carbohydrate digestion. Importantly, a DNA test alone does not diagnose a condition—it only indicates risk tendencies. Reliable assessment requires clinical tests (e.g., hydrogen breath test, blood glucose monitoring). Evidence is mixed: strong for lactose intolerance, but for other causes often mechanistic or population-based. Consumer tests should not be mistaken for medical diagnosis.