All about beneficial bacteria and how to take them 

Until not too long ago, it was thought that all bacteria were bad. That’s because the first bacteria we were able to identify were the ones that made people sick. We now know that almost all bacteria are either completely harmless, or very beneficial to our health. Some of them are absolutely essential to our survival. Only a very small number of bacteria actually pose a pathogenic threat (meaning that they are potentially harmful) to humans. 

Bacteria are sometimes described as “good” or “bad”. Among the “good bacteria”, probiotics stand out as particularly beneficial to human health. 

What are probiotics

The WHO defines probiotics as “live microorganisms that, when administered in adequate amounts, confer a health benefit on the host.” 

Such health benefits may include: 

● Restoring a healthy balance in the gut/digestive system
● Easing diarrhoea
● Improving some mental health conditions
● Supporting cardiovascular health
● Possibly reducing the severity of some allergies and eczema
● Easing tummy discomfort in infants
● Supporting oral health
● Reducing the symptoms of certain digestive disorders
● Supporting bone health
● Boosting the immune system

But how do you know that a probiotic is effective? 

It’s important that the health benefits associated with a probiotic have been proven in clinical trials. But more than that - a probiotic bacteria must be defined and clinically tested on strain level. Products developed as a result of those studies must then contain the exact same strain and the exact same dose as was tested in the clinical trials. 

Approximately 90-95% of these microorganisms can be found in our gastrointestinal tract, or what we commonly call our gut. The gut flora, or microbiota, consists of trillions of bacteria belonging to thousands of different species. 

What is a probiotic strain?

Bacteria are classified into genus, species and strains. Each strain of bacteria has its own genetic composition resulting in different characteristics. A bacteria strain is a population of bacteria that descends from a single individual or pure culture. Bacteria of the same strain have certain characteristics that differentiate them from bacteria of other strains, just as, for example, a Great Dane has different characteristics from a Chihuahua, even though both are dog breeds. 

Different probiotic strains have different effects

Different probiotic products contain different probiotic strains. That’s why it’s not specific enough to talk about for example lactic acid bacteria. It’s important to clarify which strain is being referred to. The fact that a product contains “lactic acid bacteria” or “Limosilactobacillus reuteri” is not enough. Both the species and strain name, for example Limosilactobacillus reuteri DSM 17938, must be specified, in order to know which probiotic is being referred to and what benefits to expect. 

This means that one probiotic product with Limosilactobacillus reuteri (for example L. reuteri NCIMB 30242) is not equal to another probiotic product that contains another strain of Limosilactobacillus reuteri (for example L. reuteri DSM 17938). 

What else should you look for in a probiotic food supplement?

Beside being able to identify the specific strain that the supplement contains and knowing that that strain has been proven in clinical studies, it’s important that the probiotic is proven to reach the gut alive. A probiotic that doesn’t reach the gut alive is of no use to you, no matter how much of it you take. 

A good probiotic also colonises the human gut temporarily - this is what allows a probiotic to help restore a healthy balance of good and bad bacteria in the gut. CFU, or “Colony-Forming Units” is an estimate of how many viable bacteria cells there are in a dose (such as a tablet). 

Even an indigenous bacterium that has the ability to colonise the gut, needs to be taken on a regular basis to reach high enough levels to achieve proper colonisation and have the desired effect. Such colonisation is often transient, which is why daily intake of probiotic supplements is recommended to ensure adequate and stable levels of the probiotic in the gastrointestinal tract. 

What about prebiotics?

Probiotics are live bacteria that are good for you and prebiotics are food for those beneficial bacteria. Prebiotics are carbohydrates, mostly fibres, from fruit and vegetables, that humans can’t digest, but that probiotics love to eat. Eating a varied diet high on fruits and vegetables ensures that you are getting enough prebiotics to support the beneficial bacteria in your gut. 

Are there enough probiotics in a healthy diet to make a supplement unnecessary?

Since it’s not possible to know how much beneficial bacteria is in your diet, it’s impossible to know if you are getting enough. For example, one way of increasing the amount of beneficial bacteria in your diet is eating fermented foods, which contain a higher concentration of bacteria. But it’s not possible to know which strains of bacteria you are getting or in which amounts. 

Probiotic supplements therefore have some advantages: 

● You know exactly which strains are present and in which amounts 
● The concentration and viability of the bacteria is ensured throughout the product life
● The effects are clinically proven

BioGaia’s L. reuteri research and products

BioGaia’s probiotic products with Limosilactobacillus reuteri (formerly known as Lactobacillus reuteri) are among the most scientifically well-documented probiotics in the world. To date the efficacy and safety of BioGaia’s different strains of L. reuteri have been documented in 246 clinical studies in around 20,000 people of all ages (Dec 2021). 

BioGaia’s strains of L. reuteri has been tested in 120 studies in children, from newborns up to 18 years old, and in 126 studies in adults. 

Probiotics research

Research on bacteria and their significance for our health has exploded in the past decade. At BioGaia, we’ve spent the last 30 years doing clinical research on Limosilactobacillus reuteri


Read more about our research here.