Lactase

also: Beta-galactosidase

The enzyme that makes lactose-free milk. It splits milk sugar before you drink it, doing the job your own gut does if you are not lactose intolerant.

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An ingredient list from the yoghurt, milk and dairy aisle

Milk · Reconstituted Lactose Reduced Milk · Lactase Enzyme. Our lactose free products are not suitable for those with a dairy allergy or galactosaemia.

E1106Microbial

Lactase

Lactase is an enzyme that splits lactose, the main sugar in milk, into two simpler sugars, glucose and galactose.

Vegetarian

122

of the 43,325 UK supermarket foods we checked declare E1106 in their ingredients

That is 0.3%, counted by its code or its name.

Only under 0.1% of these labels print “E1106”. Most use the name: look for “lactase”.

Counted by NutraSafe from UK supermarket ingredient lists, September 2026. How we counted

How common it is in UK food, by aisle

Yoghurt, milk and dairy96 products4.2% of 2,273
Cakes, biscuits and desserts7 products0.2% of 3,715
Soft drinks and juices5 products0.2% of 2,627

What lactase is, what it does and where you will see it

What is it?

Lactase is an enzyme that splits lactose, the main sugar in milk, into two simpler sugars, glucose and galactose. The lining of the human small intestine makes it. The lactase used in food is made by fermentation with food-grade yeasts and moulds, mainly Kluyveromyces lactis and Aspergillus oryzae.

What does it do?

Added to milk or dairy, it splits the lactose before the food reaches you, so people who make too little lactase in their own gut can eat it without the usual bloating and discomfort. It works at fridge and room temperature and carries on slowly in the pack. The result tastes slightly sweeter than normal dairy, because glucose and galactose taste sweeter than lactose.

Where you will see it

Lactose-free and reduced-lactose milk, yoghurt, cream, cheese, ice cream and other dairy. Also some infant formula with reduced lactose. It may be listed as lactase, or not listed at all if no active enzyme is left in the finished product. A lactose-free claim usually means it was used.

What the science says

The same enzyme your gut makes

Lactase is the enzyme the lining of the human gut makes to digest milk sugar. People with lactose intolerance make less of it, so undigested lactose reaches the large bowel, where bacteria ferment it and cause bloating and discomfort. Adding the enzyme to food first simply does that digestion in advance.

Lactase is made by cells lining the small intestine and is needed to digest lactose. Its fall after weaning is the cause of lactose intolerance, which affects an estimated 65% of adults worldwide.

2019EstablishedNational Institutes of Health (NIH), Genetics Home Reference: Lactose intolerance

Reviewed as a food enzyme

Under EU and UK rules, food enzymes have to be assessed before they can be used. European reviewers have assessed several lactase preparations and raised no safety issue at the amounts needed to reduce lactose in dairy. They noted that some carry traces of protein from the yeast or mould used to make them, which could in theory trigger a reaction in someone already allergic to that organism.

European reviews of lactase preparations from Kluyveromyces lactis and Aspergillus oryzae raised no safety issue at the proposed use levels in dairy.

Regulator reviewEFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF)

Allergy to the mould or yeast

Lactase is not one of the allergens UK law makes labels declare. Enzymes made by moulds and yeasts can carry trace proteins from them, so people with a known allergy to Aspergillus moulds or Kluyveromyces yeasts could in theory react, though this is not an established risk at food amounts. The enzyme is not made from milk. Allergy to enzyme dust has been recorded in bakery and food workers who breathe it in at far higher levels than anyone eats.

Allergy to enzymes made from fungi, including Aspergillus, has been recorded in bakery and food workers breathing in enzyme dust at levels far above what a consumer eats.

1998ObservationalHouba et al., Occupational and Environmental Medicine

Where it stands with the regulators

Regulated as a food enzyme in the UK and the EU, not as a food additive, so it is not on the Food Standards Agency's list of approved additives. Its use falls under the food enzyme rules (EU Regulation 1332/2008, kept in UK law). The EU's final list of approved enzymes is still being drawn up, and until then established uses carry on under transition rules. The number E1106 appears on some reference lists but is not formally assigned under the additive rules.

Daily limit. None set. Assessed under the food enzyme rules rather than the additive daily-limit system.

Legal basis: EU Regulation 1332/2008 on food enzymes, kept in UK law after Brexit. Not covered by the food additive rules (Regulation 1333/2008).
Permitted foods: Lactose-free and reduced-lactose dairy (milk, yoghurt, cream, ice cream, cheese) · Infant formula with reduced lactose · Other dairy where lactose is reduced
Maximum levels: No set maximum, as long as makers use no more than they need.
History: Lactase has been used in dairy since the 1970s, long before EU enzyme rules. Regulation 1332/2008 required all food enzymes to be assessed by European reviewers before going on a final EU list. Several lactase preparations have been assessed, but the list had not been formally adopted as of 2026, so established uses carry on under transition rules in the EU and UK.

Who should be careful

People with a known allergy to Kluyveromyces yeast or Aspergillus mould may want to know food lactase is often made with them, though traces in finished products are typically very low. Look for lactase in the ingredients of lactose-free dairy.

The honest read

Lactase is the same enzyme the human body uses to digest milk sugar, made by long-established food-grade yeasts and moulds, and used to digest the lactose in dairy before it reaches the shelf. European reviewers have assessed several commercial preparations without raising a consumer issue. The one recorded harm, allergy in workers breathing in enzyme powder at high levels, is a workplace issue rather than a food one.

Common questions about lactase

Is E1106 banned in the UK?

No. Lactase is used legally in UK lactose-free dairy under the food enzyme rules. It is not on the Food Standards Agency's additive list because enzymes are a separate category.

Why is E1106 on some E-number lists but not on the FSA's additive list?

Food enzymes and food additives are covered by different rules in the UK and EU. The FSA's list covers additives, while lactase falls under the enzyme rules. Some E-number reference sites include it as E1106 for completeness, but the number is not formally assigned under the additive rules.

What foods contain E1106?

Mainly lactose-free milk, yoghurt, cream, ice cream and other dairy. Some infant formula uses it too. The label will usually say lactase, or carry a lactose-free claim.

Is E1106 vegan?

The enzyme is almost always made by fermenting a yeast (Kluyveromyces lactis) or a mould (Aspergillus oryzae), so it is not from animals. It is, though, used almost entirely in dairy. If you need to be sure, ask the maker, as methods can vary.