A Lowdown on Probiotics

March 29, 2022

All right, it is time to clarify a hot topic out here: The mysterious world of probiotics. Suddenly people started talking about probiotics non-stop and probiotics appeared in food and beauty products. It can get a bit overwhelming! So why are probiotics everywhere and why are they growing at such high speed?

What are probiotics?

By definition “Probiotics are live microorganisms that, when administered in adequate amounts, confer a health benefit on the host.” There is a common misconception of all bacteria being harmful germs, but let’s think of a probiotic as a supplement/complement in your diet. For example, when we feel tired/sick we might take vitamins; others will take protein shakes when their protein intake is scarce; and others rather take collagen for skin health. In the same way, these good bugs will help you (and your gut, and other systems) boost basic physiological functions.

Why do I need to take probiotics?

As described above, probiotics are live microorganisms which are mainly bacteria. We have bacteria on our skin, in our mouth, in our gut and other parts of the body. Therefore, taking or applying probiotics, will create a synergism in our system. A synergism is when microbes support each other's growth, reinforcing your local/resident bacteria by becoming stronger and therefore providing several benefits to the host (which is you).

However, there are not exclusively “good” bacteria living in our system, we also host pathogens (a.k.a. harmful bacteria). Some studies suggest that specific probiotic strains can counteract the damage or fight against those harmful pathogens.

What is a strain?

A strain is a variant of a type of bacteria, fungi, virus, or other microorganism. For example the most common strains of probiotics are bacteria that belong to a category called Lactobacillus; and Bifidobacterium. However, not only bacteria are used as probiotics, other microorganisms like fungi can be considered probiotics too. A well known type of fungi used as probiotic is a yeast called Saccharomyces.

Different types of probiotics may have different effects. For example, if a specific subtype of Lactobacillus helps to prevent a specific sickness, that doesn’t necessarily mean that another subtype of Lactobacillus or any of the Bifidobacterium probiotics would do the same thing. These differences can also be explained by the different microbiomes between people. A microbiome is the full repertoire of microorganisms in our body, a unique footprint/trademark for every person.

What do probiotics do in my body?

Many of the bacteria in products containing probiotics are the same as, or similar to microorganisms that naturally live in our bodies. Because of this, there are so-called health areas in which specific probiotic strains have demonstrated benefits based on their biology. There are strains that might help you boost your immune system, others will improve/strengthen your gut (yes, less bloating!), and some others can rebalance (support) women’s intimate health.

Recent research has shown that it is not only the bacteria itself that can provide benefits, bacteria can also have the ability to produce natural compounds within our body. Then, our body metabolises and utilises these compounds as beneficial nutrients. And that’s what some people call ‘post-biotics’.

Where can I find probiotics?

You may have seen some yogurt products “with probiotics”. Between you and me, all yogurt types have “probiotics” as they all use millions or billions of bacterial strains as a yogurt starter culture. Although there are some dairy companies indicating the probiotic strain added to their recipe, not all the starter strains have been proven as beneficial to the human consumer. Plus, every company has their own yogurt recipe, and if we consider the definition of a probiotic, it must be proven to confer health benefits. The same principle applies to fermented foods such as Kimchi.

The most effective way of getting your good bugs in, is literally by taking probiotics that usually come in a capsule.

What to look for on a probiotic product/label?

This might be the most important part. Firstly, SAFETY! It’s always a good idea to do some research on a company/brand.

Secondly, pay attention to the taxonomic name. By this I mean the given name and surname of the probiotic. Earlier I gave examples of the most common strains, Lactobacillus and Bifidobacterium, still, it needs to be detailed and very clearly described which type of probiotic you are taking. For example, you might have heard of Lactobacillus casei Shirota, but there is also Lactobacillus rhamnosus GG. Hence the taxonomic name is essential to avoid extrapolation or generalisation of benefits between strains.

Lactobacillus = Given name
Shirota = Surname

Thirdly, the number of bacteria given per capsule/tablet. This is represented by Colonies Forming Units (CFU). All products must mention their CFU on their package since a specific number of CFU is established after being demonstrated to confer a health benefit. Usually the CFU concentration lies between 500 million to 50 billion; however it doesn’t necessarily mean that larger amounts are better.

Remember to always ask a healthcare professional before you start taking probiotics!

To wrap up here are five take home messages from this post:

  1. Probiotics do not treat diseases and they do not replace medicines
  2. There is no age limit to take probiotics (so far!)
  3. The full name of the strains is important
  4. Not all strains act and behave the same in our body
  5. The more doesn’t mean the merrier!

Ps. Personal recommendation based on emerging research: If you decide to start taking probiotics, look for a recognised brand and take them with water and preferably not on an empty stomach. Having had something to eat which is rich in fibre (e.g. some fruit) can help with the probiotics’ survival!

Written by Silvia Lopez

Silvia is a PhD candidate in microbiology with a focus on metabolic health. She is currently screening bacterial strains for their potential effect as probiotics for prevention of Non Alcoholic Fatty Liver Disease. Silvia has an MSc. Nutrition and health with a specialisation on Gut Health and Nutrition by Wageningen University in the Netherlands