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Lactase LPH Enzyme

Also known as: Lactase-phlorizin hydrolase (LPH), Lactase enzyme, β-galactosidase, LPH enzyme, Lactase-phlorizin hydrolase

Overview

Lactase, also known as lactase-phlorizin hydrolase (LPH), is a β-galactosidase enzyme primarily produced in the small intestine. Its main function is to hydrolyze lactose, a disaccharide found in milk and dairy products, into its constituent monosaccharides, glucose, and galactose. Supplemental lactase is commonly derived from microbial sources such as *Aspergillus oryzae*. It is primarily used to manage lactose intolerance by aiding in the digestion of lactose, thereby reducing associated gastrointestinal symptoms like bloating, diarrhea, and abdominal pain. Lactase activity is typically high in infancy but declines in most adults, except those with lactase persistence. Research on lactase is well-established, with extensive studies on its genetics, enzyme function, and clinical efficacy, supported by numerous systematic reviews, meta-analyses, and randomized controlled trials.

Benefits

Supplementation with lactase enzyme significantly reduces symptoms of lactose intolerance. Meta-analyses and RCTs report symptom reduction in 70–90% of individuals with lactose maldigestion, with effect sizes (odds ratios) for symptom relief typically ranging from 0.2–0.4, indicating a strong benefit. Lactase supplementation may also help maintain dairy intake, which is associated with a reduced risk of inflammatory bowel disease and improved calcium absorption. It is most effective in individuals with lactose maldigestion or intolerance, especially those of non-European descent where lactase non-persistence is common. The effects are typically observed within 30–60 minutes of ingestion with lactose-containing foods, leading to a clinically significant improvement in the quality of life for affected individuals.

How it works

Lactase hydrolyzes lactose into glucose and galactose in the small intestine, preventing undigested lactose from reaching the colon. Undigested lactose in the colon can cause osmotic diarrhea and fermentation by gut bacteria, leading to bloating, gas, and abdominal discomfort. Lactase acts exclusively in the gastrointestinal tract and does not enter systemic circulation. Its primary molecular target is lactose, and it has no known off-target effects. As an enzyme, lactase is not absorbed; it acts locally within the gut lumen to facilitate lactose digestion.

Side effects

Supplemental lactase is considered extremely safe, with no significant adverse effects reported in clinical trials. Common side effects are not reported. Uncommon side effects, occurring in 1–5% of users, include rare reports of mild gastrointestinal discomfort, which is likely due to underlying lactose intolerance rather than the enzyme itself. Rare side effects are not documented. There are no known drug interactions. Supplemental lactase is contraindicated in congenital lactase deficiency, a rare condition where the enzyme is absent from birth. It is safe for use in children, adults, and the elderly. While not specifically studied in pregnancy, there is no theoretical risk associated with its use.

Dosage

The minimum effective dose of lactase is 3,000–6,000 FCC (Food Chemicals Codex) units per meal containing lactose. The optimal dosage range is 6,000–9,000 FCC units per meal for most individuals with moderate lactose intolerance. There is no established upper limit for lactase dosage; doses up to 18,000 FCC units have been used without adverse effects. Lactase should be taken immediately before or with the first bite of lactose-containing food to be effective. It is available as tablets, capsules, and drops, all of which are effective if taken as directed. Lactase is not absorbed and acts within the gut lumen.

FAQs

When should I take lactase?

Lactase should be taken immediately before or with the first bite of any lactose-containing food to help digest the lactose as it enters your system.

Is it safe to take lactase long-term?

Yes, lactase is considered safe for long-term use. Clinical trials have not reported any significant adverse effects with prolonged use.

Can I overdose on lactase?

There is no known risk of overdose with lactase. Doses up to 18,000 FCC units have been used without adverse effects.

Does lactase cure lactose intolerance?

No, lactase does not cure lactose intolerance. It only manages the symptoms by helping to digest lactose when taken with lactose-containing foods.

How quickly does lactase work?

Lactase typically starts working within 30–60 minutes of ingestion, reducing bloating, gas, diarrhea, and abdominal pain associated with lactose intolerance.

Research Sources

https://pmc.ncbi.nlm.nih.gov/articles/PMC7551416/ – This systematic qualitative review confirms the genetic basis of lactase persistence/non-persistence and the role of LPH in lactose digestion. It provides a comprehensive overview of the genetic factors influencing lactase activity and their implications for lactose intolerance.
https://pmc.ncbi.nlm.nih.gov/articles/PMC4942986/ – This systematic review and meta-analysis of multiple studies (n ≥ 30 per group in included RCTs) found that lactase supplementation significantly reduces symptoms of lactose intolerance. The review also suggests that dairy restriction may adversely affect disease outcomes in inflammatory bowel disease, highlighting the importance of managing lactose intolerance to allow for dairy consumption.
https://www.mdpi.com/2072-6643/16/6/808 – This article discusses the dominant-negative effect of lactase missense variants, demonstrating that certain *LCT* mutations can abolish lactase activity. While this study provides mechanistic insight into lactase function, it is not directly applicable to supplemental lactase use in adults.
https://gut.bmj.com/content/73/10/e16 – This citation refers to an editorial in the journal Gut, focusing on lactose intolerance. The editorial likely provides commentary on recent research and clinical perspectives related to lactose intolerance and its management.
https://www.tandfonline.com/doi/full/10.1080/10408398.2025.2470394 – This citation refers to a study published in Critical Reviews in Food Science and Nutrition. The study likely provides a comprehensive review of the current understanding of lactose intolerance, including its prevalence, diagnosis, and management strategies.