4 reasons your probiotic may contain lactose

Written by: Kari Raman, PharmD, RPh
Published May 7, 2023

As a pharmacist, one of the most common conditions patients tell me they want to try to treat with probiotics is lactose intolerance. But, what many patients don’t realize is that some probiotic supplements contain lactose! Let’s digest some of the major reasons your probiotic may contain lactose. Yes, that was a digestion pun. 

4 reasons some probiotics contain lactose

Some probiotics have lactose as an ingredient for several reasons:

  1. Dairy-based origins: Many probiotics originate from lactic acid bacteria, which are typically found in dairy products – like yogurt. Lactose, the primary sugar found in milk, may be included in the probiotic formulation to maintain the natural growth environment for these bacteria. Since you need the bacteria to be alive when you take the supplement, the lactose is basically food for them while they are in the bottle. And if you get them through yogurt, you are going to get some lactose – unless you opt for a lactose free like Chobani Zero, which I write about here.
  2. Manufacturing process: Lactose can serve as a growth medium for probiotic bacteria when they are being produced in the factory. If you think about how the supplement is made during the manufacturing process, the bacteria need to be fed to multiply. Some of this may not be removed when the pills are packages. 
  3. Stabilizing agent: It can also act as a stabilizing agent in probiotic formulations, helping to maintain the structure and integrity of the final product. It can help with moisture retention, shelf life, keep the pill in a solid form, and the overall texture of the product.
  4. Prebiotic effect: It can also function as a prebiotic, meaning that it helps to feed and support the growth of beneficial bacteria after you’ve taken the supplement (so in your gut). By including lactose in the probiotic supplement, manufacturers aim to enhance the overall effectiveness of the product by giving the bacteria a head start feedstock to make it more likely that they multiply and take up residence in your digestive system.

How can you tell if your probiotic contains lactose?

To determine if your probiotic contains lactose, follow these steps:

  1. Read the label: The product label or packaging should list all ingredients. I sometimes get to educate patients on how to read a supplement or medicine label – well, OK, it’s actually not all that common that someone wants to read a label, but it is an important skill! Drug, and high quality supplement labels have a section called “inactive ingredients. It’s usually below the “active ingredients” section. Look for terms such as “lactose,” “milk sugar,” or “milk-derived” in the inactive ingredients list.
  2. Check for allergen information: Manufacturers are usually required to disclose common allergens on the label. If the probiotic contains lactose, there may be an allergen warning indicating that it contains milk or milk-derived ingredients. The FDA requires food manufacturers to indicate if their product has common allergens. There will be a section labeled “contains” and then it will list the allergens, if the product has any. So look for an indication that milk is contained. 
  3. Visit the manufacturer’s website: If the information on the packaging is unclear or incomplete, check the manufacturer’s website for more details on the product. They may provide additional information about the ingredients and potential allergens. I’ve found that the quality of supplement manufacturers’ websites really varies; not everyone who is good at making supplements is good at making a website, so this step may not help you all that much, but it’s worth taking a look. And if that doesn’t work:
  4. Contact the manufacturer: If you still cannot determine whether the probiotic contains dairy sugar, contact the manufacturer’s customer service for clarification. They should be able to provide you with accurate information about their product. If they can’t answer that question, then pick a different manufacturer.
  5. Look for lactose-free or dairy-free labeling: If you have lactose intolerance or prefer to avoid milk sugar in your probiotics, seek products that specifically indicate they are “lactose-free” or “dairy-free” on the label. To be totally honest, this isn’t all that common in the supplement industry, so finding a product labeled dairy free is going to be hard; it’s just not all that common of a thing.

Remember that not all probiotics contain lactose, and there are plenty of options available for those who require or prefer lactose-free products. Really, the best thing to do – if you are picking a quality supplement manufacturer – is to check out the inactive ingredients section of the label.

What is lactose?

Lactose is a disaccharide sugar, meaning it is composed of two simple sugar molecules, glucose and galactose, linked together. It is the primary carbohydrate found in mammalian milk, including human milk, cow’s milk, and goat’s milk. It usually makes up about 2-8% of milk by weight, depending on the species.

In order for the body to absorb lactose, it must first be broken down into its constituent monosaccharides, glucose and galactose. Monosaccharides are simple sugars – the most basic level of sugar that can’t be broken down into simpler sugars. This process is carried out by an enzyme called lactase, which is produced in the small intestine. Once lactose is broken down, glucose and galactose can be absorbed into the bloodstream and utilized for energy.

Many people have a reduced ability to produce lactase, which leads to lactose intolerance. Lactose intolerance is a common digestive issue where individuals have difficulty digesting lactose, resulting in symptoms such as bloating, gas, abdominal pain, and diarrhea after consuming dairy products – pretty uncomfortable symptoms. This condition can be managed by reducing or eliminating dairy products from the diet or by taking lactase supplements to help with digestion. I usually recommend trying taking a lactase supplement – they are available in pretty much any pharmacy and most big-box retailers like Target. You can get chewable pills and I’ve even seen liquid formulations. 

Can you take lactase with your probiotic?

For an otherwise healthy individual, taking a lactase supplement with a probiotic containing the inactive ingredient lactose shouldn’t be a problem. This is an acceptable strategy for a lactose intolerant individual who really wants to take a specific brand/formulation of probiotics – however, a better strategy might be to find a probiotic that doesn’t contain milk sugar. There are tons of different probiotic formulations available from many quality manufacturers, so this shouldn’t be an issue unless you really want to get a very specific probiotic strain that you can’t get elsewhere. 

However, it is important to note that lactose-containing probiotics may not be suitable for individuals with severe lactose intolerance or a sensitivity to milk products.

Another helpful probiotic tip you might be interested in is learning how long probiotics take to work – it’s not overnight. To help treat some conditions, you may need to take the supplements for weeks before you see real improvements. And you may need to combine them to really get the right set of bacteria going in your gut to see any improvements.

Pharmacist Kari Raman

I’m Kari Raman PharmD, RPh, and I am a licensed, practicing pharmacist. I hold a Doctorate in Pharmacy from The University of the Pacific, and I’ve served patients in retail, compounding and hospital pharmacies.

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