Lactase

Nutrient group: Enzymes

Detailed information

Lactose intolerance

Lactose intolerance is the inability to consumer a certain amount of lactose without gastrointestinal complaints. The reason for this is a deficit of the lactose-splitting enzyme lactase. In most cases there is an acquired lactase deficiency. The body's ability to produce lactase decreases with age. Lactase deficiency can also occur due to diseases of the intestinal mucosa and is then usually reversible (1).

Lactase: Enzyme to support lactose digestion

Lactose (milk sugar) is the main carbohydrate of milk. Normally it is split into glucose and galactose in the small intestine by the enzyme lactase. If the lactose enters the large intestine undigested, fermentation processes take place. This produces degradation products that increase osmotic pressure in the colon, which in turn leads to a massive influx of water. Diarrhea and cramps are the consequences (2). In addition, lactose is subject to bacterial degradation to organic acids and gases, which on the one hand stimulates intestinal peristalsis and on the other hand can lead to flatulence. As a result of the disorders of the intestinal tract, further clinical pictures such as food allergies and Leaky-Gut syndrome can develop. Leaky gut syndrome is a barrier disorder caused by swelling and irritation of the intestinal mucosa. Due to the increased permeability of the mucosa, foreign substances such as toxins or incompletely cleaved food components can enter the organism and act as allergens. Many food allergies are caused by a permeability disorder of the intestinal mucosa (3).

Reference values

Substrate	Parameter	Reference value	Description
Blood	Blood sugar	Rise of 20 mg/dl after 2 h without gastrointestinal symptoms	Lactose tolerance test: Blood, 12 hours fasting. First blood is taken fasting, then 50 mg lactose orally with tea or water. Then further blood samples every 30 minutes over a period of 2 hours.
Breath test	Hydrogen content	<20 ppm	H₂-Lactose breath test: 12 h fasting, 6 h nicotine avoidance. First breath test in fasted state, then oral 50 mg lactose with 300 ml water is administrated. Breath samples are taken after 30, 60 and 120 minutes. If lactose enters the large intestine undigested, it is metabolized by bacteria. This produces hydrogen, which diffuses into the blood and is exhaled via the lungs.
Interpretation
Lactose intolerance test No glucose increase		Glucose is produced during digestion of lactose, so that an increase in blood sugar levels is to be expected. The absence of an increase indicates a lactase deficiency.
H₂-Lactose breath test Increased values		Probability of lactose intolerance
Note on the measurement results
Lactose intolerance test: If gastric emptying is delayed or small intestine passage accelerated, false-positive results may occur. H₂-Lactose Breath Test: Antibiotics and laxatives can reduce the intestinal flora in the large intestine and thus lead to false negative results. Smoking increases the hydrogen concentration and can lead to false-positive results.

Deficiency symptoms

Impact on	Symptoms
Stomach and intestines	Flatulance, abdominal cramps, diarrhea

Indications

Effect	Indication	Dosage
Physiological effects at a low intake	For lactose intolerance due to genetic or acquired lactase deficiency	100 - 400 mg/d
	For dyspeptic complaints due to lactase deficiency such as increased peristalsis, diarrhoea, flatulence, intestinal cramps	100 - 400 mg/d
	For secondary lactase deficiency due to inflammatory bowel diseases and bacterial bowel infections	100 - 400 mg/d

Administration

General mode of administration
When	Lactase should be taken before dairy products are consumed. The daily amount can be individually adjusted to milk consumption (100 mg lactase per 5 g milk sugar).
Side effects
No side effects are known to date.
contraindications
No contraindications are known to date.

References

1) Hahn, A. et al. 2006. Ernährung. Physiologische Grundlagen, Prävention, Therapie.
2) Rüffer, A. et al. 2006. Mikroökologie des Darms. In: Martin M (Hrsg): Labormedizin in der Naturheilkunde.
3) Liu, Z. et al. 2005. Tight junctions, leaky intestines, and pediatric diseases. Acta Paediatr. 94(4):386-93

References Interactions
Stargrove, M. B. et al. Herb, Nutrient and Drug Interactions: Clinical Implications and Therapeutic Strategies, 1. Auflage. St. Louis, Missouri: Elsevier Health Sciences, 2008.
Gröber, U. Mikronährstoffe: Metabolic Tuning –Prävention –Therapie, 3. Auflage. Stuttgart: WVG Wissenschaftliche Verlagsgesellschaft Stuttgart, 2011.
Gröber, U. Arzneimittel und Mikronährstoffe: Medikationsorientierte Supplementierung, 3. aktualisierte und erweiterte Auflage. Stuttgart: WVG Wissenschaftliche Verlagsgesellschaft Stuttgart, 2014.