Lastase
Also known as: Lactase, lactase supplement, lactase enzyme supplement, β-galactosidase, EC 3.2.1.108, Lactase enzyme
Overview
Lactase is an enzyme naturally produced in the small intestine that plays a crucial role in the digestion of lactose, a sugar found in dairy products. It breaks down lactose into simpler sugars, glucose and galactose, which can then be absorbed by the body. Individuals with lactose intolerance have a deficiency in this enzyme, leading to digestive discomfort when consuming dairy. Lactase supplements are commercially produced, often from microbial sources, and are primarily used to aid digestion in these individuals. By providing exogenous lactase, these supplements help break down lactose in ingested dairy, thereby reducing common symptoms such as bloating, diarrhea, and abdominal pain. While its efficacy in managing adult lactose intolerance is well-established, its role in conditions like infant colic is still under investigation, with current evidence being inconclusive. Lactase supplementation aims to compensate for the body's inability to produce sufficient lactase, improving overall lactose tolerance.
Benefits
Lactase supplementation primarily benefits individuals with lactose intolerance by improving lactose digestion and significantly reducing associated gastrointestinal symptoms. Meta-analyses support its effectiveness in adults, with studies showing improved lactose tolerance and symptom reduction. For instance, research indicates that individuals with inflammatory bowel disease, particularly Crohn's disease, may have an increased likelihood of lactose maldigestion, and lactase supplementation can be beneficial in these subgroups. The strength of evidence for adult lactose intolerance is moderate to strong, with several randomized controlled trials and meta-analyses demonstrating positive outcomes. However, for infant colic, the evidence is inconclusive. A recent systematic review and meta-analysis of five RCTs (n=391 infants) found no statistically significant reduction in crying duration or fussing time compared to placebo, suggesting that lactase may not be effective for this condition. The clinical significance for adults is high, as it allows individuals to consume dairy products without experiencing discomfort, thereby improving quality of life and dietary flexibility.
How it works
Lactase functions by catalyzing the hydrolysis of lactose, a disaccharide, into its constituent monosaccharides: glucose and galactose. This enzymatic reaction occurs directly within the lumen of the small intestine. By breaking down lactose, lactase enables these simpler sugars to be readily absorbed through the intestinal wall into the bloodstream. The enzyme acts locally within the gastrointestinal tract and is not absorbed systemically, meaning its activity is confined to the digestive system. There are no known molecular targets beyond the lactose substrate itself, and its mechanism is purely enzymatic, facilitating the breakdown of a complex sugar into absorbable components.
Side effects
Lactase is generally considered safe with a low incidence of adverse effects. Common side effects are rare but may include mild gastrointestinal discomfort, such as gas or bloating, which are typically transient and mild. There are no well-documented uncommon or rare side effects, though, as with any supplement, allergic reactions are theoretically possible but extremely rare. No significant drug interactions have been reported with lactase supplementation. Contraindications are limited to individuals with known hypersensitivity or allergy to lactase or any of the excipients used in the supplement formulation. For special populations, such as infants, lactase is considered safe, but its efficacy in conditions like infant colic remains uncertain and is not consistently supported by research. Overall, lactase supplements have a favorable safety profile when used as directed.
Dosage
The recommended dosage of lactase varies depending on the product's enzyme activity, typically measured in FCC (Food Chemical Codex) units, and the amount of lactose consumed. For adults, a common dosage ranges from 3,000 to 9,000 FCC units per meal or serving of lactose-containing food. The optimal dosage is highly dependent on the individual's degree of lactose intolerance and the specific lactose content of the food being ingested; higher lactose loads may require higher enzyme doses. There is no established maximum safe dose, as excess enzyme is generally not harmful and is simply excreted. Lactase supplements should be taken immediately before or concurrently with the first bite or sip of lactose-containing foods or beverages. They are available in various forms, including chewable tablets, capsules, and drops, with the choice of form often depending on personal preference and ease of administration. Since lactase acts locally in the gut lumen, its activity is influenced by gastric emptying and intestinal transit time, but it is not absorbed systemically. No specific cofactors are required for its enzymatic activity.
FAQs
Is lactase supplementation effective for infant colic?
Current evidence from systematic reviews indicates no clear benefit in reducing crying or fussing time in infants with colic. Further well-designed studies are needed to confirm any potential efficacy.
Can lactase supplements prevent lactose intolerance symptoms?
Yes, in lactose-intolerant adults, lactase supplementation can effectively reduce or prevent symptoms like bloating, gas, and diarrhea when taken with dairy products.
When should lactase be taken?
Lactase supplements should be taken just before or at the very beginning of consuming lactose-containing foods or beverages to ensure the enzyme is present when lactose enters the digestive system.
Are there risks of overdose?
No significant risks of overdose have been reported with lactase supplements. Excess enzyme is generally not harmful and is simply passed through the digestive system.
Does lactase work for all lactose-intolerant individuals?
While generally effective, the degree of effectiveness can vary among individuals depending on the severity of their lactase deficiency and their specific response to the supplement.
Research Sources
- https://pmc.ncbi.nlm.nih.gov/articles/PMC4942986/ – This systematic review and meta-analysis investigated lactose malabsorption in patients with inflammatory bowel disease (IBD). It found an increased odds of lactose maldigestion in Crohn's disease patients (OR 2.29, 95% CI 1.09–4.80, p=0.03) but not in ulcerative colitis, highlighting a potential benefit of lactase in this specific subgroup. The study noted methodological heterogeneity among included studies.
- https://pubmed.ncbi.nlm.nih.gov/38426798/ – This systematic review and meta-analysis assessed the efficacy of lactase supplementation for infant colic, including five RCTs (n=391 infants). The meta-analysis concluded that there was no statistically significant reduction in crying or fussing time compared to placebo, indicating that evidence for its benefit in infant colic is inconclusive and further research is needed.
- https://www.cochrane.org/authors/handbooks-and-manuals/handbook/current/chapter-04 – This source, the Cochrane Handbook, provides guidance on conducting systematic reviews, emphasizing the importance of comprehensive database searches and rigorous methodology. It serves as a reference for assessing the quality and reliability of systematic reviews, supporting the evaluation of the research on lactase.
