Lactose Intolerance: Relieve it with Lactase Enzymes!

In this post, we’re going to talk about lactose, a molecule feared by many as a result of the well-known intolerance.

What is lactose?

Lactose is a disaccharide, the union of two monosaccharides (galactose+glucose) through a glycosidic link β-1,4, that is, it is a sugar present only in mammalian milk and, exceptionally, in reduced quantities in exotic plants that are not part of the environment of developed societies. So:

Lactose is the sugar from the milk.

Chemical structure of galactose and glucose.

What is its function?

Lactose, by itself, has no function, it is simply a component of the milk naturally produced by lactating mammals.

Once its monosaccharides are absorbed, however, it does have a function:

Galactose is a basic substrate necessary for the biosynthesis of various molecules in the body. It is an important constituent of:

Flynn (2016).

How is lactose digested?

Lactose is a disaccharide, and these structures do not have the capacity to cross the barriers of our intestine. To do so, they have to be simplified into the monosaccharides that compose it, in this case glucose+galactose, and we need something that breaks the glucosidic link to release it.

Responsible for this is lactase (β-galactosidase).

Graphic representation of hydrolysis and intestinal absorption of lactose.

Lactase is found in the microvilli of the intestinal brush, especially in the central part of the jejunum, in a lactase/floricin hydrolase complex, which can also hydrolyse other dietary carbohydrates.

Once absorbed, they go into the blood where they can be used for the previously described functions.

Why lactose intolerance?

Lactose has a differentiating characteristic:

Once we’ve passed the lactation phase the ability to digest lactose tends to decrease significantly in many people (with higher or lower prevalence depending on geographical location).

Lactose (in)tolerance phenotypes.

What to do if I’m intolerant?

Taking care of your diet and maintaining a healthy lifestyle.

Lactose intolerance is not a serious condition, nor does it require too much concern.

It can slightly condition your lifestyle by preventing or limiting your intake of dairy foods (especially at social meals), but everything is adaptable, and you have lactase food supplements to help you cope with these occasional moments.

Which foods contain lactose?

Williams (2003).

Foods containing lactose.

Which foods do I need to avoid if I’m intolerant?

Dairy products.

You may even consume dairy products, depending on the degree of hypolactation present, which, as we’ve seen, is normally up to 5g of lactose (the equivalent of 100ml of milk or approximately one yoghurt), which is tolerated by mild-moderate lactose intolerants.

How do I know if I am lactose intolerant?

Symptoms of lactose intolerance

Most of the symptoms of lactose intolerance are limited to the digestive tract, and these include:

However, there are also systemic symptoms associated with lactose consumption in intolerants, of unknown pathogenesis:

There are 4 main clinical tests for detecting lactose intolerance.

Method 1 – Lactose Intolerance Test

Known for being an old method, not very specific and sensitive, with a high possibility of false positives and negatives.

It consisted of administering 50g of lactose, and after 30 minutes making a capillary puncture to measure the glycaemia (blood glucose concentration), which should result in a 20mg/100mL increase with respect to the concentration before the consumption of lactose.

Method 2 – Hydrogen Breath Test

The gold-standard, that is, the test currently with the greatest reliability and validity.

There is a moderate chance of false positives and negatives.

As undigested lactose reaches the colon where it ferments, it generates gases, especially hydrogen; some of this methane is eliminated through breathing (the other part is the source of flatulence).

The amount of hydrogen exhaled after lactose consumption is measured several times, a curve is described, and if it increases significantly it is a sign of lactose intolerance.

Lactose intolerance hydrogen curve, negative (left) and positive (right) .

Method 3 – Genetic Test

By itself it’s not very useful, but it is an excellent complement to determine the (primary/secondary) cause of hypolactation.

Secondary hypolactation can occur due to SIBO, Crohn’s disease, Rotavirus and other infections, consumption of certain antibiotics, etc. If this cause is corrected, the ability to digest lactose usually returns, it’s a “false intolerance”.

When hypolactation is primary (“real”), certain genes are highly specific for the diagnosis of intolerance. Lactose intolerance is “factory-programmed”, if you carry the C/C alleles (wild genotype) of the SNP C/T-13910 (rs4988235), you have been found to suffer from lactose intolerance.

Genotypic configuration of 2 SNPs of the TBI gene with persistence and non-persistence phenotype of lactase.

The mutant C/T and T/T genotypes are phenotypes with persistent lactase activity, and are lactose tolerant.

Most important SNPs coding lactase activity in the 2q.21-22 TBI region

Depending on the ethnic group, other more specific polymorphisms should be assessed, the one mentioned above being the one that codes activity in the Caucasian population.

Method 4 – Measurement of lactate activity in the intestinal brush

I won’t go into too much detail as it’s hardly used in the clinic and is more applicable to research.

It consists of doing an intestinal biopsy to extract a piece of enterocyte and directly evaluating the activity of the lactase it expresses.

What if I drink milk and I’m lactose intolerant?

Most lactose intolerant subjects can consume small amounts (around 5g = 100ml of milk) without significant adverse effects, as lactose intolerance is characterised by a deficit of the enzyme lactase (hypolactasia), not by a total absence of it (alactasia).

Stomach pain after drinking milk for someone who is lactose intolerant.

What is lactose-free milk?

Although there are legitimate lactose-free milks, they are scarce and much more expensive.

This is because there are no regulations governing “lactose reduced” / “lactose free” claims, so companies regulate the thresholds for using these designations according to their own interests.

La AECOSAN (Spanish Agency for Food Safety and Nutrition) has established provisional thresholds for the determination of designations relating to the lactose content of foodstuffs:

However, this is a proposal, prior to the drafting of a law that may establish a European Committee directive.

Intolerance, indigestion, malabsorption

These 3 terms are related and are used indistinctly, incorrectly.

The whole development of this pseudo-pathogenic picture starts with the same condition:

Hypolactasia, any deficiency of the enzyme lactase.

This develops because of a non-persistence of lactase, a genetic condition considered a “wild-type” configuration, as most individuals show reduced lactase activity in the apical membrane of the jejunum after cessation of lactation.

In a minority of people, high lactate activity is maintained throughout adulthood (persistence to lactase phenotype, mutant genotype).

Lactose indigestion leads to lactose malabsorption, since lactose cannot be absorbed in its undigested form (Glucose+Galactose).

This leads to the development of lactose intolerance, which is the condition associated with gastrointestinal symptoms due to malabsorption of lactose by bacterial fermentation of sugar in the colon (at the end of the intestinal tract).

em>Intestinal metabolism of lactose in a subject with intolerance.

What is the treatment for lactose intolerance?

There is no cure for lactose intolerance, the only 100% effective treatment is to avoid dairy products.

Other possible strategies thought to be useful are:

em>Lactase activity of different strains of bacteria.

This is why you’ll often hear that Yoghurt is lactose free.

In fact, it does have it, what happens is that thanks to the addition of lactic ferments for its development, it has its own lactic activity, derived from the microorganisms it contains, which contributes to the digestion of its lactose.

em>That’s why fermented dairy products are considered to be well-tolerated, because themselves intolerant to this sugar.

What function does lactase have?

Lactase serves to catalyse (assist) the process of hydrolysis of the glycosidic bond that binds glucose and galactose molecules.

As undigested lactose cannot be absorbed into the intestinal walls, deficiency (hypo-) or absence (a-) of lactase produces the classic symptoms of lactose intolerance.

Where is lactase?

Lactase is an enzyme located in the intestinal microvilli of the small intestine, especially in the jejunal region.

This is where most of the lactose is digested and absorbed, preventing it from reaching the colon, where it produces the symptoms.

Lactase is located in the lactase/floricin hydrolase complex at the intestinal brush border, located in the apical membrane (the one in contact with the intestinal lumen) of enterocytes (intestinal cells).

Produce it naturally

This isn’t possible.

Lactase activity is coded by your own genetic configuration – if you have mutant genotypes of the polymorphisms that determine how your lactate activity involutes from weaning, you can’t generate it by yourself.

An emerging strategy is to use specific strains of probiotics that appear to be able to colonise the gut and express lactate activity, giving the (false) perception of increased self-activity.

When the microorganisms die, we return to the initial condition, but chronic consumption of bacterial ferments with these characteristics is very promising.

How to relieve symptoms of Lactose Intolerance

Don’t believe it?

Be careful, because 19 years later (after many studies showing the efficacy of lactase from this source) Portincasa et al., (2008) designed a very interesting study, using no less than 134 healthy subjects with lactose malabsorption.

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In addition to measuring the hydrogen they expelled, they used several tests to assess the symptoms they presented after consuming half a litre of whole milk without administering lactase; and after administering a reduced dose (6750 Lactase Units) and a standard dose (11250 Lactase Units) from Aspergillus Oryzae.

Symptom relationship between groups that were not given lactase (placebo), that were given a reduced dose (Tilactase 6750); and that were given a standard dose (Tilactase 11250). On the left ‘bloating’ and on the right ‘abdominal pain’; above test ratings (in the dotted diagram), and below (area under the curve of the reports in the bar chart). (Portincasa et al., 2008)

The results were dramatic…

Obviously there was a quasi-perfect significance (confidence level) (P {;0.001) in the reduction of hydrogen production between the placebo group (which was not given lactase) and the experimental group (which was given lactase).

How long does it take for the symptoms to disappear?

As soon as the consumption of dairy is stopped, the symptoms disappear, as the manifestations of discomfort are acute, if lactose is not consumed, there is no discomfort.

The time required to see a significant effect through consumption of bacterial ferments has not yet been clearly determined in humans, but it is expected to take around 3-4 weeks of use of effective doses of the particular strain that has lactose activity to colonise the gut.

Its effects gradually diminish until it disappears if no longer used.

Lactase Supplementation

There are functional differences between the endogenous lactase that we synthesise in mammals and that which we obtain from yeasts, fungi and bacteria such as Saccharomyces lactis, Kluyveromyces fragilis, Aspergillus Niger or Aspergillus Oryzae.

Why Aspergillus Oryzae?

Because it’s a great source for obtaining lactase, demonstrating great effectiveness.

This is reflected in a wide variety of clinical trials and does not compromise the properties of milk as Saccharomyces Lactis or Aspergillus Niger do, which strongly alter the sweetness of the product and require maceration of at least 24 hours on average in order to hydrolyse the lactose (DiPalma & Collins, 1989).

These authors used 10 healthy subjects suffering from lactose malabsorption to see how much hydrogen they expelled (when tested).

In the trial they administered:

The amount of hydrogen expelled by subjects in a test intended to be measured after a first test without lactase (B-1), a second test days later (B-2) and two tests administering 250mg lactase (L-250) and 500mg lactase (L-500) (Dipalma & Collins, 1989)

The conclusions were clear: the amount of hydrogen emitted by subjects with lactose malabsorption after administration of 250mg lactase from Aspergillus Oryzae was significantly lower.

And when they were administered 500mg, even less. What does this mean?

That the lactose was better digested, the absorption rate increased exponentially, decreasing the fermentation of the sugars of the milk in the large intestine and decreasing all the symptoms of discomfort it generated.

How are lactase pills taken?

It depends on the source it’s obtained from.

In general, follow the instructions for use recommended on the product label:

Currently, practically all lactase food supplements marketed have an acute effect (lasting approximately 1h) and do not require prior maceration in the medium (milk or derivatives).

Protein for lactose digestion

You’ll find all the benefits of this enzyme in products of dairy origin, such as

Conclusions

Lactose is the sugar in milk and its derivatives.

Milk, like any other food, is not compulsory (except in breastfeeding, where there are also substitutes), although it is a complete food of high nutritional interest.

If we are like this, it’s because we have evolved and adapted to environmental exposure, including post-lactation dairy consumption.

Tolerance, intolerance and mixed expression in intolerant subjects and in singular or divided doses.

Bibliographic references

1. Corgneau, M., Scher, J., Ritie-Pertusa, L., Le, D. t. l., Petit, J., Nikolova, Y., … Gaiani, C. (2017). Recent advances on lactose intolerance: Tolerance thresholds and currently available answers. Critical Reviews in Food Science and Nutrition, 57(15), 3344–3356.
2. Fassio, F., Facioni, M. S., & Guagnini, F. (2018). Lactose maldigestion, malabsorption, and intolerance: a comprehensive review with a focus on current management and future perspectives. Nutrients, 10(11).
3. Flynn, A. (2016). Nutrition and Health: Galactosemia. In Reference Module in Food Science.
4. Ghoshal, U. C. (2016). Overview of hydrogen breath tests in gastroenterology practice. In Evaluation of Gastrointestinal Motility and its Disorders (pp. 87–94).
5. Szilagyi, A., & Ishayek, N. (2018). Lactose intolerance, dairy avoidance, and treatment options. Nutrients, 10(12).
6. Ugidos-Rodríguez, S., Matallana-González, M. C., & Sánchez-Mata, M. C. (2018). Lactose malabsorption and intolerance: a review. Food and Function, 9(8), 4056–4068.
7. Williams, C. A. (2003). Encyclopedia of food sciences and nutrition. In B. Caballero (Ed.), Encyclopedia of Food Sciences and Nutrition (Second Edition, pp. 2843–2846).

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