Probiotic supplements contain live microbes and can come as sachets, capsules or liquids.
Some probiotics have evidence of health benefits, but many don't. If you're unsure, contact the probiotic's manufacturer and ask for their research.
Most people who take probiotic supplements are dealing with a particular gut issue, like irritable bowel syndrome (IBS) or diarrhoea linked with antibiotics.
Probiotics can also help in other ways, such as by warding off colds or supporting women’s health.
If you’re looking for ways to improve your health with probiotics, you’ve come to the right place.
In this article, you’ll learn how probiotics work and which are best for different aspects of health. We’ll also describe how to store these supplements, when to take them and any side effects to watch out for.
How do probiotic supplements work?
Your gut is full of microbes, such as bacteria, viruses and yeasts. Together, they make up your gut microbiome.
The microbes in your gut microbiome support your body in many ways. For example, they:
- aid digestion by breaking down fibre and plant chemicals to make new compounds, like short-chain fatty acids (SCFAs)
- fight off pathogens
- train your immune system
- produce compounds that are important for brain health, including neurotransmitters, such as serotonin, dopamine and GABA
- regulate hormone levels
- protect the health of other organs, including your heart
Some people refer to microbes that do these jobs as ‘friendly’ or ‘good.’
Other microbes in your gut may not be so good for you. Your friendly microbes can crowd out the ‘bad’ ones, tipping the balance of your microbiome in your favour.
And if you nurture your microbes and give them the right environment to thrive, they'll be more likely to support your health.
Probiotic supplements support your ‘good’ microbes. They do this by taking up space and resources, making it harder for harmful viruses, bacteria, fungi and parasites (pathogens) to grow in your gut.
Probiotics can also make enzymes and compounds, like SCFAs, which help your ‘good’ gut microbes. This can lead to a higher number and diversity of friendly microbes in your gut.
Which probiotic supplement is best?
The best probiotic supplement for you will depend on why you’re taking it and your personal preferences, to some extent.
No single probiotic works for everyone and all aspects of health. You may need to try a few until you find what works best for you.
If you’re not keen on capsules, you may prefer sachets or liquids, for example. And dietary considerations can factor in, as well. If you have lactose intolerance, you might opt for a dairy-free product.
Have a think about your preferences and needs, so you can keep these in mind when you’re looking at different supplements.
There should be scientific evidence that the product’s specific microbes provide the health benefit you’re looking for – and that it contains enough microbes to achieve this. If you’re unsure, contact the probiotic's manufacturer and ask for research about their product.
Below, we’ll cover some of the findings about which microbes can help with different aspects of health.
Before we dig in, let’s look at how you can tell which microbes are in a particular supplement and how many microbes it contains.
The answer: check the label. It should tell you the amount and type (or types) of microbes in the product.
The name of a microbial strain is usually a combination of letters and numbers. For example, a probiotic supplement may contain bacteria called Faecalibacterium prausnitzii A2-165. Faecalibacterium is the genus of bacteria, prausnitzii is the species and A2-165 is the specific strain.
The amount is normally displayed in ‘colony-forming units’ – CFUs for short. A higher number of CFUs indicates that there are more microbes in the supplement.
It’s important to note, however, that having more CFUs doesn’t necessarily mean that the supplement is better for you.
Instead, focus on whether there’s evidence that it’s effective – that this particular supplement provides health benefits at the dosage stated on the packaging.
4 ways probiotic supplements can benefit your health
As we mention above, probiotic supplements can support the good microbes in your gut microbiome. This can benefit your gut health by allowing your good microbes to do their jobs.
Many different strains of probiotic microbes are available as supplements. Scientists have focused most of their research so far on strains of Lactobacillus and Bifidobacterium.
Let’s look at four areas of health where probiotics can help.
1. Diarrhoea
Infections with bacteria or viruses cause up to 17 million cases of diarrhoea in the United Kingdom each year.
Diarrhoea is also common during a course of antibiotics.
Research shows that probiotics can help prevent traveller’s diarrhoea, which is due to an infection while travelling abroad.
The specific probiotics highlighted in this research are strains of Lactobacillus and the yeasts Saccharomyces cerevisiae and Saccharomyces boulardii.
Studies also show that Lactobacillus and Bifidobacteria strains may help prevent and treat antibiotic-associated diarrhoea in adults, and that Lacticaseibacillus rhamnosus and Saccharomyces boulardii may help with this issue in children.
You’ll find more information about managing diarrhoea here.
2. IBS
If you have IBS, you’ll be pleased to know that plenty of scientific evidence shows that probiotics can help many people with their IBS symptoms.
Health authorities, including the NHS and National Institute for Health and Care Excellence, confirm that probiotics can be helpful if you have IBS.
Probiotic supplements can ease the following IBS symptoms:
- abdominal pain
- bloating
- constipation
- diarrhoea
- your overall level of symptoms, also called ‘global symptoms’
Much of the research has involved strains of Lactobacillus and Bifidobacterium, but studies have also investigated the yeast Saccharomyces cerevisiae and other microbes.
Learn more about the evidence and which specific microbes can help in this article.
3. Respiratory infections
The common cold, tonsillitis and laryngitis are all common acute upper respiratory infections. Probiotics can help with these by supporting your immune system.
A large review of studies found that when people take probiotics, they have, on average, fewer upper respiratory tract infections. And when people who take probiotics do get sick, they recover more quickly.
In their review, the researchers looked at data from 23 clinical trials which had tested many different probiotics, including strains of Lactobacillus, Bifidobacterium and Streptococcus.
4. Women’s health
Taking probiotic supplements can support several aspects of female health, including:
- bone health
- menopause
- mental health
- urinary tract infections
- vaginal health
You can learn about the science and specific strains in our article on probiotics for women’s health.
How to store probiotic supplements
The right way to store probiotics depends on whether they’ve been dried – and put in sachets or capsules – or whether they’re in a liquid.
You can usually store supplements with dried microbes in a dry, cool place, like a cupboard.
The drying process makes the microbes ‘dormant.’ It’s similar to hibernation – the microbes are alive, but their activity levels are very low. This means that they don’t have metabolic activity and won’t grow or multiply.
Once you consume the probiotic and it reaches your gut, the microbes rehydrate and become active. That’s because your gut is the right temperature and provides optimal conditions and nutrients.
But not all probiotics are created equal – some probiotics are evidence-based, though many are not.
Liquid probiotics fare best in the fridge, as the cool temperature helps keep the microbes alive.
Make sure to check the supplement’s packaging, which will describe the best way to store it.
How to take probiotic supplements
It’s a good idea to follow the manufacturer’s advice about taking the probiotic supplement. The label should state how much to take and how often – for example, daily.
Some products are best on an empty stomach. For most people, this means taking probiotics first thing in the morning.
It might be worth waiting a short time before eating or drinking anything else. This gives the microbes a head start on their journey to your gut.
Other probiotic supplements can be taken at any time.
Probiotic supplement side effects
According to the NHS, probiotics are safe for the vast majority of us.
It can take your gut a little while to get used to the new microbes, but there shouldn’t be any serious side effects.
As your gut adjusts, you might notice mild effects, which could include bloating, wind and mild abdominal cramps. If you experience any of these, they should go away within a few days or weeks.
Speak to a pharmacist if you have concerns about a specific product. They can discuss your options and offer advice.
Anyone with a chronic health condition or a weakened immune system should talk to a doctor before trying probiotics.
Summary
Probiotic supplements contain live microbes that can support your health if you consume adequate amounts.
The label should tell you how much to take, when to take the supplement and how to store it.
There are many types of probiotic supplements, and they can come in sachets, liquids or capsules. The best option for you will depend on your reason for taking them, your preferences and any dietary requirements.
When you’re considering a product, make sure there’s scientific evidence to show that it can improve the aspect of health that you’re focusing on.
Due to strict regulations, a supplement’s packaging or website shouldn’t list any health benefits. This can make it challenging for people to tell whether a probiotic product might work for them. We recommend contacting the manufacturer directly and asking for their published research.
There’s good evidence that probiotic supplements can improve gut health and help with many symptoms of IBS.
They can also support your immune system, lowering your risk of respiratory infections. Plus, probiotic supplements can help with many aspects of female health.
These supplements are safe for most people, but it’s best to check with a pharmacist or a doctor if you have any concerns or a chronic health condition.
To learn more about gut health and other topics, visit Symprove’s Gut Hub.
Sources
A review on enzyme-producing Lactobacilli associated with the human digestive process: From metabolism to application. Enzyme and Microbial Technology. (2021). Link.
Diarrhoea – adult’s assessment: How common is it? (2023). Link.
Effect of probiotics on common cold, influenza, and influenza-like illness. (2023). Link.
Efficacy and safety of probiotics in irritable bowel syndrome: A systematic review and meta-analysis. Clinical Nutrition ESPEN. (2024). Link.
How do probiotics stay alive until they are consumed? (2020). Link.
Investigating the influence of probiotics in preventing traveler's diarrhea: Meta-analysis based systematic review. Travel Medicine and Infectious Disease. (2024). Link.
Irritable bowel syndrome in adults: Diagnosis and management. (2017). Link.
Overview of systematic reviews of probiotics in the prevention and treatment of antibiotic-associated diarrhea in children. Frontiers in Pharmacology. (2023). Link.
Probiotic checklist: Making a smart selection. (2018). Link.
Probiotics. (2022). Link.
Probiotics for preventing acute upper respiratory tract infections. Cochrane Database of Systematic Reviews. (2022). Link.
Probiotics for the prevention of antibiotic-associated diarrhoea: A systematic review and meta-analysis. BMJ Open. (2020). Link.
The International Scientific Association for Probiotics and Prebiotics consensus statement on the scope and appropriate use of the term probiotic. Nature Reviews Gastroenterology & Hepatology. (2014). Link.
What is IBS? (2021). Link.
