Written by James McIntosh
Reviewed by Sammie Gill
Live, friendly bacteria are microbes that can benefit your health. They’re a type of probiotic, and there’s evidence that some can improve your gut health.
Your gut is home to trillions of bacteria and other microbes, including yeasts, viruses and fungi. Together, they make up your gut microbiome.
Many are important for your health. They’re sometimes called ‘good’ or ‘friendly’ microbes, as there can also be microbes in your gut which aren’t so good for your health.
Probiotics can tip the balance of your microbiome in favour of the ‘friendly’ microbes.
In this article, you’ll discover more about probiotics and how they can improve your gut health.
You’ll also learn about the possible side effects, how to tell if your probiotics are working and other strategies for better gut health.
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What are probiotics?
While some foods, like certain yoghurts, contain probiotics, most probiotics come as supplements. These might be sachets, capsules or liquids.
A probiotic has to contain live microbes that, when taken in the right amounts, provide a health benefit.
A supplement’s packaging should explain how and when to take the product. It should also list the exact type and amount of microbes involved.
For example, a supplement may contain Faecalibacterium prausnitzii A2-165. In this case, Faecalibacterium is the genus of bacteria, prausnitzii is the species and A2-165 is the specific strain.
The name of a microbial strain is usually a combination of letters and numbers.
There are many different strains of live, friendly bacteria. The most common ones that scientists have studied are strains of Lactobacillus and Bifidobacterium.
How can probiotics benefit your gut health?
In general, probiotics can have several health benefits.
How well a probiotic supplement will work for you depends on the specific microbial strains, your gut microbiome and your overall health.
Here are four ways that probiotics may improve your gut health.
1. Gut microbiome
There’s a lot of evidence that probiotics can improve the health of the gut microbiome by creating a favourable environment.
Specifically, probiotics can make it harder for pathogens – like harmful bacteria, viruses, fungi and parasites – to grow in your gut.
They do this by competing with these pathogens for space and resources. Taking probiotics also promotes a higher number and diversity of friendly microbes.
In addition, probiotics produce beneficial compounds and enzymes that can help your friendly bacteria.
2. Diarrhoea
Diarrhoea is incredibly common. There are different types, depending on how long it lasts and what the cause is, such as an infection or a chronic health condition.
Probiotics may help with diarrhoea caused by infections. Certain probiotics may help prevent traveller’s diarrhoea, which results from an infection while travelling.
Certain probiotics may also help prevent diarrhoea after an infection with Clostridium difficile bacteria.
Some people who take antibiotics are more susceptible to C. diff infections, which can cause very severe diarrhoea.
3. Bloating
Most research on probiotics and bloating involves people with irritable bowel syndrome (IBS).
A large review of studies found that certain probiotics can help with bloating if you have IBS.
Remember that some products work for certain people but not others because of the differences among individual bodies and gut microbiomes.
If you don’t have IBS, there isn’t a lot of good-quality evidence that probiotics will help with bloating. There haven’t been many relevant studies.
It can be confusing because studies often report different results. This is due to many factors, including the:
- type and dose of microbes in the probiotic preparation
- study design, including how long the testing phase lasted
- specific people included in the study
For this reason, if you're considering taking a probiotic, contact the manufacturer and ask for research that covers the health condition or symptoms you're hoping to treat.
Probiotics might reduce bloating for people without IBS. But more research is needed to know for sure.
For other ways to reduce bloating, check out this article.
4. IBS
IBS is a condition that affects the digestive system. There are different types, and the symptoms can include bloating, constipation, diarrhoea and stomach cramps.
As we note above, some people with IBS find that certain probiotics help ease bloating.
Beyond this, there's evidence that probiotics can help with the symptoms of IBS overall, particularly abdominal pain.
This was particularly the case for probiotics that contained Lactobacillus and Bifidobacterium strains.
Further research has found that probiotics can improve the quality of life for people with IBS.
What are the side effects of probiotics?
Probiotics are safe for the vast majority of people. They shouldn’t cause any serious side effects.
But your gut may take some time to adjust to the new microbes. So, you might experience mild side effects for a few days after you start taking a probiotic.
The effects can include wind, bloating and mild abdominal cramps. All should disappear within a few days or weeks.
If you have concerns about side effects, it’s best to speak with a pharmacist about the product you’re taking and your options.
Recovery after antibiotics
Antibiotics are life-saving medicines that most of us will likely take at some point.
You may have heard that antibiotics are bad for your gut microbiome and that probiotics can help.
It’s true that antibiotics can kill the friendly bacteria in your gut and cause a temporary imbalance between friendly and unfriendly bacteria.
Most research suggests that probiotics may help prevent and treat antibiotic-associated diarrhoea in adults and children.
However, more recent research indicates that taking probiotics may actually slow down recovery in some cases.
In some cases, a doctor may recommend a specific probiotic while you’re taking antibiotics. Be sure to check with your doctor if you’re thinking of trying a probiotic supplement during antibiotic treatment.
How to tell if probiotics are working
If probiotics are working, you should notice a positive change. The specific change will depend on your reason for taking the supplement.
For example, if you were experiencing bloating, you’ll likely notice that the bloating isn’t as frequent or severe.
It can take several weeks before you notice changes. It might be worth tracking your symptoms in a diary while you’re trying a probiotic to check for any improvements.
If you’re taking probiotics to help with IBS, medical guidelines recommend taking these supplements for at least 4–12 weeks at the dosage that the manufacturer recommends.
If things aren’t improving by this point, the supplement likely isn’t working. You could give a different product a try or take a different approach.
Other ways to improve gut health
Probiotics aren’t the only way to improve your gut health. There are many other strategies to try.
You can make your diet more gut-friendly by:
- Eating more plant foods: This gives your gut more fibre and other plant chemicals (like polyphenols) which act as fuel for your friendly bacteria.
- Trying fermented foods: These foods can contain live bacteria, some of which may be probiotic and help support your gut microbiome.
- Cutting down on ultra-processed foods: Their additives may promote the growth of unfriendly bacteria and limit the growth of friendly ones in your gut.
There’s also evidence that prioritising your sleep can help with gut health.
Scientists aren’t yet sure why, but they know that poor sleep is linked with worse gut health – and a less diverse gut microbiome is linked with poorer sleep.
It’s important to note that a more diverse gut microbiome is considered a healthier gut microbiome.
Exactly how much sleep is ideal varies from person to person, but keeping your sleep pattern regular and aiming for around 7–8 hours are good ways to start.
Other ways to boost your gut health include getting physical activity, like walking, doing yoga and swimming, and managing your stress levels.
You can learn more about how to improve your sleep in this article.
Summary
Probiotics are live, friendly bacteria and other microbes that have a health benefit.
Many probiotics are available, and certain types work for some people who have particular health concerns.
No single probiotic will work for everyone – it's typically best to try a probiotic for between 4 and 12 weeks to see if it improves your gut symptoms.
Scientific research shows that probiotic supplements can support your gut health, boosting the health of your gut microbiome. Some products can also help with types of diarrhoea, bloating and IBS.
It can take a little time for your gut to adjust to a new probiotic. While side effects are unlikely, some bloating and wind are possible.
If a probiotic is working for you, your symptoms should improve, though it may take several weeks.
If you want to try other approaches to improve your gut health, you can start by adjusting your diet to make it more gut-friendly.
It’s also a good idea to prioritise sleep, incorporate regular movement into your days and look after your stress levels.
To learn more about gut health and similar topics, visit Symprove’s Gut Hub.
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