Beta-galactosidase, commonly known as lactase, is an enzyme that catalyzes the hydrolysis of lactose, a disaccharide sugar found in milk, into glucose and galactose. Its primary role in the small intestine is to facilitate the digestion of lactose, a process that is critical for individuals who are lactose intolerant due to insufficient endogenous lactase production. There is robust scientific evidence supporting the use of exogenous beta-galactosidase supplements to help manage lactose intolerance symptoms such as bloating, diarrhea, and abdominal pain. These symptoms are a direct result of undigested lactose passing into the colon, where it is fermented by bacteria, leading to gas and discomfort.

Numerous clinical trials and meta-analyses have demonstrated that lactase supplements, when taken orally with dairy products, significantly reduce the severity of lactose intolerance symptoms by improving lactose digestion in the small intestine. Regulatory agencies, such as the FDA and EFSA, recognize lactase supplements as safe and effective for this purpose. However, it is important to note that the benefit is primarily for those with lactose intolerance and does not extend to broader support of small intestine health in the absence of this condition. In summary, the use of beta-galactosidase to support the small intestine, specifically for lactose digestion, is strongly supported by scientific evidence.