Probiotics: What GPs should know

With probiotics gaining considerable attention in the media for their role in managing conditions like irritable bowel syndrome and diarrhoea, or for supporting general gut health, it’s important for general practitioners to understand how to navigate the growing body of evidence surrounding them.

What are probiotics?

Probiotics are live micro-organisms that, when consumed in adequate amounts, confer health benefits to the host by positively influencing the gut microbiota [1]. These microorganisms are named using a three-part naming system: genus, species, and strain. The three-part name helps identify the exact strain, which is important as different strains may have varying effects on health and have their own potential therapeutic benefits.

The US Probiotic Guide is a resource for healthcare professionals seeking guidance on the most well-researched probiotic strains [2]. It outlines which strains have demonstrated efficacy for specific conditions, allowing GPs to make informed decisions based on robust clinical evidence.

It’s important to remember that more probiotic strains are not necessarily better, but what matters is the correct strain at the right dosage for the specific condition.

When to recommend probiotics

Probiotics have shown promising potential in managing specific gastrointestinal conditions. Here are some key clinical indications for their use [2]:

Irritable bowel syndrome (IBS)

Certain probiotic strains, such as B. longum 35624 have demonstrated efficacy in alleviating IBS symptoms, including bloating, abdominal discomfort, and changes in bowel movements.

Antibiotic-Associated Diarrhoea (AAD)

Probiotics have been shown to reduce the incidence of antibiotic-associated diarrhoea.

Clostridium Difficile Associated Diarrhoea – Prevention (CDAD)

Some probiotics may be helpful in preventing clostridium difficile associated diarrhoea.

There are additional clinically relevant conditions that probiotics can be useful for.

General gut health: Beyond probiotics

While probiotics can play a role in managing specific gut health conditions, they are not a universal solution. A healthy gut microbiota can often be supported through lifestyle and dietary changes alone. The diversity of the gut microbiota is strongly influenced by diet. Research has shown that individuals who consume 30 or more plant-based foods (such as whole grains, vegetables, fruits, legumes, nuts and seeds) per week tend to have more diverse gut microbiotas, which is associated with better overall gut health [3]. Encouraging patients to aim for a wide variety of plant foods can enhance microbial diversity and hence support gut health.

Patients can also be encouraged to increase fibre intake, 25g per day for women and 30g per day for men, and to include prebiotic-rich foods like garlic, onions, and bananas to help support gut health [4]. Lifestyle factors, such as quality sleep, regular physical activity, and stress management, also contribute to supporting a healthy gut microbiota.

A final word

Probiotics can be an effective tool for managing specific gut health conditions, but their use should be guided by clinical evidence and patient-specific needs. As a GP, understanding the strains of probiotics that are most effective for specific symptoms allows for more informed and targeted recommendations.

For maintaining overall gut health, a balanced approach that includes a fibre-rich diet, prebiotics, and healthy lifestyle habits is key to fostering a thriving gut microbiome. By staying informed on the latest evidence and resources, such as the US Probiotic Guide, GPs can continue to offer their patients the best possible guidance for optimising gut health.

– Sarah Marko, Accredited Practising Dietitian

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References

1.    Salminen, S., Collado, M. C., Endo, A., Hill, C., Lebeer, S., Quigley, E. M. M., Sanders, M. E., Shamir, R., Swann, J. R., Szajewska, H., & Vinderola, G. (2021). The International Scientific Association of Probiotics and Prebiotics (ISAPP) consensus statement on the definition and scope of postbiotics. In Nature Reviews Gastroenterology and Hepatology. https://doi.org/10.1038/s41575-021-00440-6
2.    The US Probiotic Guide (2025). Retrieved from http://www.usprobioticguide.com
3.    McDonald, D., Hyde, E., Debelius, J. W., et al. (2018). American Gut: An Open Platform for Citizen Science Microbiome Research. mSystems, 3(3), e00031-18. https://doi.org/10.1128/mSystems.00031-18
4.    National Health and Medical Research Council. (2013). Australian Guidelines Dietary Eat For Health. In Australian Dietary Guidelines.