What Are Probiotics And When Is It Worth Taking A Probiotics Supplement?

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What have you done lately to look after the health of your gut microbiome? To start with, we hope you’re eating enough fibre, and a broad range of fruits and vegetables. The next step might be to dip your toe into the world of fermented food, or you could even consider taking a probiotic supplement in order to ensure the happiness of the good bacteria in your gut.

To find out more about the potential benefits of probiotics, we spoke to Dr Richard Day, medical advisor at probiotics supplement company Bio-Kult.

What are probiotics?

The World Health Organisation defines probiotics as live micro-organisms that, when consumed in adequate amounts, confer a health benefit on the host. Put more simply, these are the bacteria, and a few viruses and fungi, that live in (or on) our bodies and have a positive effect on our overall health.

Each of us has trillions of micro-organisms living in our gastrointestinal tract, and this ecosystem is referred to as the gut microbiome. The particular micro-organisms found in our gut microbiome can affect health outcomes in a huge variety of diagnoses. Every year more and more research is completed implicating the gut microbiome in diagnoses including epilepsy, depression, eczema, diabetes, weight loss and many more.

Do probiotics supplements differ in what they contain?

There is currently a lot of research being conducted into “strain specificity” of probiotics. Bacteria can be categorised based on their species, but then each species can have many different subtypes, known as bacterial strains. One particular strain of a probiotic organism might be found to have a very specific health benefit, while other strains in the same species may lack any health benefit or have a completely different one. Historically, probiotics were thought of as generally good, but now we are starting to realise that strain-specific effects exist, so probiotics are being tailored to specific diagnoses or symptoms.

What are the benefits of taking them?

The benefits of probiotics depend very much on the strains or combinations of strains chosen. Historically, probiotics were used to improve gastrointestinal health. This remains the most researched area of microbiome-related health, and there are hundreds of clinical trials looking into the effects of probiotics on gastroenteritis, irritable bowel syndrome and inflammatory bowel disease, to name just a few diagnoses. But increasingly, research teams around the world are looking at the role of the gut microbiome in other parts of the body.

Will everyone experience the same benefits?

The microbiome is staggeringly complex and we are only just beginning to really understand how these micro-organisms interact with other body systems. Perhaps because of this complexity, there is some variability in whether one person will experience the same health benefits as the next person from a certain probiotic; in much the same way as not every pharmacological treatment works for every person, there is no guarantee that one person will respond to a probiotic in the same way as the next.

How well established are the benefits in terms of scientific research?

There are over 20,000 peer-reviewed scientific publications looking at probiotics. Of course, not all of the studies show positive effects, but this figure helps to illustrate the amount of scientific research that is currently being directed at the human microbiome and probiotics. There are sometimes criticisms of microbiome research: compared with traditional pharmaceutical research, the studies tend to be smaller and less well funded, but this is changing. As the scientific basis for the positive effects of probiotics becomes better understood, so the interest in microbiome research grows, funding becomes more readily available and the quality of the scientific research improves, driving a virtuous cycle.

Can you achieve the same benefits through your diet?

This is a difficult question to answer. Diet greatly affects our gut microbiome and by modifying our diet we can cause quite significant changes in the proportions of different bacteria present. The majority of the scientific evidence to date has focused on taking specific probiotics as a supplement, but this is not to say that diet can’t have a positive effect on our gut microbiome.

Should you take probiotics at all times? Are they especially valuable if you’re taking antibiotics?

Again, this is not an easy question to answer. The short answer is, it depends. First you have to ask: why are you taking a particular probiotic? Is it because of a chronic condition? If it is, then it is likely that you would benefit from taking the probiotic long-term. This is because most microbiome experts agree that taking a probiotic supplement only temporarily alters your gut microbiome. In order to have long-lasting changes to the composition of the gut microbiome, it’s necessary to keep taking the probiotic supplement for a long period.

On the other hand, if you are taking probiotics in the short term, says,with antibiotics, then this would just need to be a short course of probiotics, usually for the duration of the antibiotic course followed by another week or two after stopping. The reason for taking probiotics during a course of antibiotics is because antibiotics can significantly alter the balance of micro-organisms in the gut. This can lead to unwanted side effects – most commonly diarrhoea. There is an established body of evidence that by taking a probiotic during and immediately after a course of antibiotics you can significantly reduce the risk of developing antibiotic-associated diarrhoea.

If antibiotics have a negative effect on your microbiome, should you avoid them?

Prescribing medication is all about weighing up risk versus benefit. The risk of taking antibiotics may be that it could unfavourably alter your gut microbiome, therefore increasing the likelihood of developing gastrointestinal side effects like diarrhoea, nausea or vomiting. But this needs to be weighed up against the benefit of the antibiotics – fighting the bacterial infection and limiting the adverse consequences of a prolonged infection. Always talk to your doctor about the risks and benefits of any treatment before starting and if you do need an antibiotic, then the evidence shows that a probiotic can significantly reduce the likelihood of developing unwanted gastrointestinal side effects.

Nick Harris-Fry
Senior writer

Nick Harris-Fry is a journalist who has been covering health and fitness since 2015. Nick is an avid runner, covering 70-110km a week, which gives him ample opportunity to test a wide range of running shoes and running gear. He is also the chief tester for fitness trackers and running watches, treadmills and exercise bikes, and workout headphones.