Medical nutrition: Are all probiotics the same?

As interest in gut health grows among the general public, GPs can help their patients make informed choices on probiotic supplements and foods to best suit their needs. Here’s what you need to know.

Learn more about this topic in the HealthCert Professional Diploma program in Medical Nutrition Management – online nutrition training for GPs.

What is a probiotic?

Probiotics are defined as live micro-organisms that confer a health benefit on the host when administered in adequate amounts [1]. This definition is based on The International Scientific Association of Probiotics and Prebiotics (ISAPP) consensus that reviewed the term probiotic in 2013.

Probiotics have a three-part name. The first part is the genus, the second is the species, and the third part is the strain. It’s important that the specific strain is classified to see whether it has evidence supporting the specific benefit that’s been looked for. Additionally, the dose needs to be adequate. While more does not necessarily mean better, it’s important to look at the dosage that’s been tested to confer a health benefit and ensure the probiotic contains this amount.

Do fermented foods contain probiotics?

Fermented foods are made through desired microbial growth and enzymatic conversions of food components [2]. Some examples of fermented foods include kimchi, sauerkraut, miso, and kombucha, which are often classified as probiotic foods. However, not all fermented foods contain probiotics. By definition, the food needs to contain live strains that have a scientifically demonstrated beneficial health effect. Fermented foods have mixtures of microbes that are not characterised or have a confirmed benefit. Additionally, some fermented foods go through processing that can kill the live cultures in them.

That said, some fermented foods do meet the criteria to be classified as a probiotic, as they are fermented using a microbe proven to be a probiotic or have them added. Nonetheless, fermented foods still contain live microbes and can be included as part of a healthy balanced diet.

What health benefits do probiotics have?

The US probiotic guide is an evidence-based database that highlights specific probiotic strains found in common supplements and their specific benefits [3]. Examples of evidence-based health benefits of certain probiotic strains include:

• Prevent antibiotic associated diarrhoea
• Improve symptoms of irritable bowel syndrome
• Improve constipation
• Reduce frequency and severity of migraines
• Help treat helicobacter pylori adjunct to standard eradication therapy
• Improve symptoms related to stress and/or anxiety
• Prevent traveller’s diarrhoea
• Reduce LDL and total cholesterol
• Improve functional abdominal pain

General practitioners can help their patients make informed choices on probiotic supplements and foods by choosing probiotic strains that match the benefit they are seeking and in the correct dosage.

Learn more with HealthCert's online Professional Diploma program in Medical Nutrition Management.

– Sarah Marko, Accredited Practising Dietitian

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References

[1]   Hill C, Guarner F, Reid G, Gibson GR, Merenstein DJ, Pot B, et al. Expert consensus document: The international scientific association for probiotics and prebiotics consensus statement on the scope and appropriate use of the term probiotic. Nat Rev Gastroenterol Hepatol 2014. https://doi.org/10.1038/nrgastro.2014.66.
[2]    Marco ML, Sanders ME, Gänzle M, Arrieta MC, Cotter PD, De Vuyst L, et al. The International Scientific Association for Probiotics and Prebiotics (ISAPP) consensus statement on fermented foods. Nat Rev Gastroenterol Hepatol 2021. https://doi.org/10.1038/s41575-020-00390-5.
[3]    D. S-S. Clinical Guide to probiotic products available in USA: 2024 edition. BHSoftInc 2024.