Gut Feeling: The Buzz Around Probiotics

Over the last few years, probiotics have become increasingly popular as people turn to probiotic-rich foods or dietary supplements to support their digestive health and overall wellbeing. There is some truth to these benefits, but it's important to keep in mind that not all probiotics are created equal, and the results of scientific research exploring their use can vary depending on a number of factors.

Probiotics have been defined as live bacteria that provide the host with health benefits when consumed in adequate amounts. Scientific studies investigating probiotics use specific strains in specific populations. This means that results observed in one population group may not confer the same benefit in others. Therefore, it is important to carefully consider the specific strains used in probiotic foods and dietary supplements, and their intended use in specific populations to ensure their effectiveness and safety. 

It's also worth noting that if a probiotic dietary supplement contains multiple strains, this does not necessarily mean that it will provide greater health benefits. The effects of probiotics depend on various factors such as the type of strain, the dose, the individual's health status, and the interaction between different strains. 

While some studies have shown that probiotics containing multiple strains can have beneficial effects, others have found that the addition of more strains did not result in a significant improvement in health outcomes. The efficacy of a probiotic supplement depends on the specific strains included and their ability to colonise the gut and produce beneficial effects.

Another thing to consider is that everyone's gut microbiome is unique, and what works for one person may not work for another. Probiotics are considered a beneficial way to change the gut's ecosystem and enhance nutritional status and health. However, any new strains of good bacteria introduced into the gut need to reach the gut alive in order for them to be effective. A probiotic supplement should contain at least 1 billion colony-forming units (CFUs) per serving to provide a health benefit and they need to be carefully manufactured and stored to ensure the survival of the beneficial bacteria. 

So, how about fermented foods? Are they probiotics?

For thousands of years, people have consumed fermented foods, which are becoming increasingly popular as a healthy dietary option. However, it's important to note that fermented foods and probiotics are distinct.

Fermented foods are made through changing the food components with enzymes and the growth of microorganisms. The microorganisms determine the properties of the final product. Fermented foods should only be labelled as “contain probiotics” if the strains are clearly defined, well researched to confer a health benefit, and are present in sufficient numbers throughout the product's shelf life.

Foods like yoghurt and kefir can contain enough live bacteria to confer a benefit. Other fermented foods like kimchi, sourdough, sauerkraut and natto, can still contain microbes when they reach the gut but not enough to meet the definition of providing a health benefit, so can’t officially be categorised as ‘probiotics’. More studies are needed to better understand the health effects of fermented foods but they are still considered nourishing for the gut, and beneficial for our overall health. 

So, while probiotics can offer many potential health benefits, it's important to keep in mind that not all strains are created equal. By understanding the difference between probiotics and fermented foods, you can make informed choices about the types of foods and dietary supplements that can help support your gut health. Please reach out to us at [email protected]  if you’d like support to navigate this ever-evolving area of science.

Written by Registered Dietitian, Sharon Sutton

References:

Hill C, Guarner F, Reid G et al. The International Scientific Association for Probiotics and Prebiotics consensus statement on the scope and appropriate use of the term probiotic. 2014. Nature Rev Gastroenterol Hepatol 11: 506–14. 

Marco ML, Heeney D, Binda S et al. Health benefits of fermented foods: microbiota and beyond. 2017. Current Opinion in Biotechnology 44: 94–102

Marco, M.L., Sanders, M.E., Gänzle, M. et al. The International Scientific Association for Probiotics and Prebiotics (ISAPP) consensus statement on fermented foods. 2021. Nat Rev Gastroenterol Hepatol 18, 196–208.

Martinez-Gonzalez, M. A., Gea, A. & Ruiz-Canela, M. The Mediterranean diet and cardiovascular health. 2019. Circ. Res. 124, 779–798.

Ritchie ML & Romanuk TN A meta-analysis of probiotic efficacy for gastrointestinal diseases. 2012. PLoS ONE 7.