Everything you need to know about probiotics

Everything you need to know about probiotics

Did you know you’re actually more bacteria than human? Although ratios differ depending on which scientist you ask, the current estimate is that human cells make up only 43% of the body's total cell count, with the rest belonging to bacteria.

We’re full of trillions of microscopic colonists, and that’s a good thing because it would be difficult to survive without them. Microbes inhabit just about every part of the human body - they’re up your nose, on your skin, in your eyes and your saliva. But the greatest and most well-known concentration of bacteria can be found in the gut. 

Housed in the small and large intestines, the gut microbiome is made up of approximately 500 different species. These bacteria function almost like an extra organ - and the health of your body depends on them.

Some bacteria, for example, help the body to digest fibre into short-chain fatty acids, while others help you synthesise vitamin B and vitamin K. With so many important jobs to do, it’s no wonder that dysregulation of the gut flora has been correlated with a whole host of inflammatory and autoimmune conditions[1].

What are Probiotics?

From birth through to adulthood we ‘re exposed to many different forms of bacteria which helps to diversify the gut microbiome. That’s important because the more diverse the gut microbiome becomes, the better it appears to be for human health[2].

Another way to diversify and improve the make-up of your gut microbiome is by eating probiotic foods or supplements. Probiotics are live bacteria (and some specific strains of yeasts) that have been shown to benefit human health, especially our gut health. 

Commonly known as ‘friendly’ or ‘good’ bacteria, they can be found in fermented foods and beverages as well as in gut health supplements. But while today we may think of probiotics as the latest dietary buzzword, our ancestors also had a diet rich in probiotics, with no little bottles of drinking yoghurt required. 

For centuries, cultures around the world from Korea to Peru have fermented foods as a way of preserving fresh vegetables[3], and it wasn’t just good for their gut microbiota. Fermenting also improved the nutritional profile of the produce, with certain vitamins (in particular the B vitamins) proven to be much higher in fermented foods than in their fresh counterparts[4].

Now that fresh produce is available-year round in our supermarkets, our need for fermentation has all but disappeared. Our digestive system’s need for live bacteria, however, has remained the same.

Probiotic or prebiotic?

Probiotics and prebiotics are both great for your gut, which in turn is good for your overall health. But with both words identical apart from a single middle letter, it’s no wonder they are commonly confused.

As we’ve seen, a probiotic food or supplement is something that contains live bacteria thought to be beneficial for our gut health. Eating probiotics regularly gets the beneficial bacteria into your intestines, but once the microbes are there you’ll need to feed them if you want them to thrive. Enter prebiotics. 

Prebiotics can be thought of as fuel for our beneficial gut bacteria. Thankfully, you rarely need a prebiotic supplement if your diet isn’t restricted as they’re found in plentiful supply in most fruits and vegetables. Good examples include soluble fibre (like bananas or sweet potatoes); inulin and oligofructose (found in onions, garlic, leeks and Jerusalem artichoke) and resistant starch (found in cooked and cooled pasta or potatoes, beans and legumes).

All of these foods have a very small portion of the fibre that cannot be broken down by our own digestive systems - our gut bacteria feed on it instead. This provides them with the energy they need to carry out their everyday functions, from regulating our immune system to helping us absorb nutrients from food. 

It’s worth noting, however, that people who suffer with gastrointestinal problems can sometimes have a low tolerance to prebiotics such as FOS and inulin

Probiotic strains and what they are good for

Lactobacillus plantarum LP01. Bifidobacterium infantis BI211. Ever noticed how probiotic strains have such incredibly long names? Probiotics are named according to their genus, species, and strain in that order. 

For example, when looking at Lactobacillus Rhamnosus GG (known as LGG for short), Lactobacillus is the genus, Rhamnosus is the species and GG is the strain. All of the bacteria within a strain carry out the same function within your body.

There are many different types of probiotic strains, and each one has its own speciality. So, if you were taking probiotics hoping for a particular health benefit or to deal with a specific health concern, it’s worth noting that each strain behaves slightly differently.

Here’s a rundown of the probiotic strains you’ll find in the multi-strain Inessa’s Advanced Biotic Complex and the benefits that have been researched and identified.

  • Bifidobacterium breve BR03 - shows benefits for IBS, constipation and diarrhoea
  • Bifidobacterium infantis BI211 - shows benefits for IBS, IBD
  • Lactobacillus rhamnosus GG -most studied species for reducing inflammation in human clinical trials, IBS, encourages other beneficial bacteria to grow
  • Lactobacillus plantarum LP01 - shows benefits in IBD, IBS + diarrhoea, creates microbial balance
  • Bifidobacterium animalis subspecies lactis BS01 - shows benefits for constipation, ulcerative colitis and shown to reduce risk of infection
  • Lactobacillus acidophilus LA02 - shows benefits for IBS, diarrhoea, IBD
  • Saccharomyces Boulardii - reduces diarrhoea in antibiotic associated diarrhoea, rotavirus or traveller’s diarrhoea

Should I take a probiotic?

The microbiota is thought to have an impact on our whole body health – including our immune system – as well as having been linked to a vast range of diseases.

In healthy humans, there is a balance of good to ‘bad’ microbes, but when this equilibrium is not naturally present or disturbed (through illness, poor diet or use of certain medications, for example) long term digestive or systemic health issues can arise. 

Consuming probiotics through fermented food and drink as well as supplements can be beneficial, as can eating plenty of fibre-rich foods such as fruit, vegetables and whole grains as fibre has been shown to encourage a healthy microbiota.

Probiotics and your immune system

Thought your gut was just for digesting food? It’s actually a major player in keeping you healthy, with some 75-80% of the body's immune cells found within its walls. Probiotics help your gut with its immune-boosting work in a number of ways.

  • Probiotics help maintain a healthy gut lining
  • Your gut lining isn't just a passive barrier. It's an active checkpoint, patrolled by immune cells like lymphocytes and macrophages. They scan for invaders, like bacteria and viruses, and trigger an inflammatory response to neutralise them before they can damage your body. Probiotics help maintain normal function of the gut lining, and can strengthen the junctions between gut cells. Like tiny mortar filling cracks in the wall, this sturdy barrier prevents  harmful bacteria and toxins from sneaking through[5].

  • Probiotics stimulate immune cells
  • The friendly bacteria in your gut aren't just bystanders, they're active allies. They produce compounds that stimulate immune cell development. In other words, they help train immune cells to recognise and fight off pathogens effectively[6].

  • Probiotics compete with bad bacteria
  • Encourage good bacteria into your gut microbiome and they’ll take up resources and space, making it harder for harmful bacteria to thrive[7].

  • Probiotics regulate inflammation
  • Good bacteria produce anti-inflammatory molecules that keep the immune response in check, preventing excessive inflammation that can damage tissues[8].

    Probiotics and the digestive system

    Whether it’s a one-off bout of traveller’s diarrhoea, a tummy upset after a course of antibiotics, or a chronic condition like IBS, digestive problems can affect anyone at any time. So can probiotics help soothe the discomfort? 

    Probiotics have been widely researched for their benefits on digestive health. More than a dietary fad, they are used in NHS trusts across the country to reduce the risk of the bowel infection Clostridium difficile in patients taking antibiotics, for example[9].

    Here are a few ways that probiotics have been shown to help the digestive system.

    Diarrhoea & GI Infections

    Some probiotic strains, such as LGG, have been shown to help prevent and treat gastrointestinal infections and diarrhoea.

    Antibiotic-associated diarrhoea

    Along with disease-causing bacteria, antibiotics can kill healthy bacteria in the gut and as a result, people have symptoms such as diarrhoea. Probiotics have been found to prevent antibiotic-associated diarrhoea (AAD) by the normalisation of an unbalanced gastrointestinal flora[10].


    Gas is produced as a normal part of the digestive process, and bloating is essentially a build-up of this gas. Probiotics have been found to reduce symptoms of bloating, with Lactobacillus strains shown to be particularly effective[11]. 


    Certain Lactobacillus, Bifidobacterium, and Saccharomyces strains of probiotics can help with the stomach pain and cramps experienced by patients with irregular bowel syndrome (IBS), greatly increasing quality of life[12].

    Impact on weight loss

    Could looking after your gut bacteria be an alternative to intermittent fasting or low carbing? While it’s unlikely that taking probiotics will make you slim down, there are links between the health of our gut microbiome and our weight - for example, people with obesity have different gut bacteria to those who do not[13]. 

    In one study, 26 participants went on a lower-calorie diet high in fruit and vegetables. Some didn’t lose as much weight as others and analysis of their gut bacteria found they had different levels of two particular types of bacteria, and one, Dialister, that hindered weight loss[14]. This bacteria was able to break down carbohydrates more effectively, extracting even more calories from them.

    Why might one person have more ‘bad’ bacteria than others? It seems to stem from our diets. Eating a high-sugar, low-fibre diet is thought to promote harmful bacteria, while starving the most beneficial species[15].

    Do I need a probiotic?

    There are some who argue that taking a probiotic daily can be helpful for maintaining a healthy immune system, however at Inessa, we feel only those with temporary and long-term digestive disturbances and chronic health problems (some strains have been shown to be beneficial in inflammatory skin conditions such as eczema, others in inflammatory bowel disease, or even reducing allergy risk), need to take probiotic supplements, such as our Inessa Advanced Daily Biotic, regularly.

    However, healthy individuals who are travelling abroad, taking certain medications such as antibiotics, or suffer a tummy bug can benefit from a course of probiotics taken for a couple of weeks before and after. Particularly beneficial species in these cases include the non-pathogenic probiotic yeast Saccharomyces boulardii and Lactobacillus rhamnosus GG.

    How do I choose the right one for me?

    There are many different types of probiotics – and what works brilliantly for one person may not work well for another. For example, those with specific health concerns may do brilliantly on a single-strain probiotic, like Inessa's Advanced Daily Biotic, and others may require a multi-strain product such as Inessa's Advanced Biotic Complex. Our advice is to use a product that includes a well-researched strain with evidence for use for your specific needs.

    Be aware that dosing can be important too. Our founder, Aliza, personally takes higher doses of probiotics because she has inflammatory bowel disease, but for those who are taking them to relieve mild gastrointestinal symptoms, a lower dose product could be sufficient.

    For individuals who don’t have any particular health concerns and don’t necessarily require supplemental support, we’d recommend regularly eating a wide variety of plant foods and including fermented foods naturally rich in probiotics such as live yoghurt, sauerkraut, pickles or kombucha.

    Are there any side effects?

    Most people are able to take probiotics without any side effects, however, in the case of high-dose products, we recommend that those who have never tried live bacteria products before start off slowly to avoid any adverse effects such as temporary bloating, by opening up the capsule and taking ¼ or ½ the contents mixed in a cold drink or yoghurt for a couple of weeks before increasing the dose.

    Probiotic products are deemed safe for most individuals but those who are immunocompromised or on certain types of immunosuppressant drugs may suffer adverse effects and should always check with their doctor before use.

    What are your tips for taking probiotic supplements?

    Opinion differs on the best time to take probiotics with some suggesting that before bed may be best. At Inessa, we’re firmly in the traditional camp that believes that it’s best to take live bacteria products in the morning with a cold beverage before breakfast. Taking bacteria late at night could cause bloating which may disturb sleep, but if it works for you, go for it.

    Inessa’s probiotics come encapsulated in ‘delayed release’ capsules as these bypass stomach acid and bile – both of which can destroy probiotics – to deliver the good bugs to your gut where they can be most effective.

    Heat damages probiotics, so always check that your product is heat stable and safe to keep at room temperature if you’re planning to do so, and in the event of a heatwave or if travelling to a hot country make sure you keep it in the fridge to avoid damaging the live bacteria. For the same reason, it’s recommended that you take probiotic products with cold liquids rather than hot.

    The Inessa Insight

    Maintaining a healthy gut is about more than taking a probiotic supplement, with a healthy diet and regular exercise just as important. However, probiotic supplements may offer a wide range of benefits and are particularly useful when treating one-off digestive complaints or chronic conditions such as IBS.

    Be sure to use a reputable product, start slowly, and if you’re not sure whether they’re right for you it’s always best to speak to a healthcare professional. 

    If you enjoyed this post, you may like to read Health benefits of Lactobacillus Rhamnosus GG.


    1. <p>https://pubmed.ncbi.nlm.nih.gov/33086688/#</p>
    2. <p><span style="font-weight: 400;">https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6351938/</span></p>
    3. <p><span style="font-weight: 400;"> https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9227559/</span></p>
    4. <p><span style="font-weight: 400;">https://www.sciencedirect.com/science/article/abs/pii/B9780128023099000078</span></p>
    5. <p><span style="font-weight: 400;">https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3864899/#</span></p>
    6. <p><span style="font-weight: 400;">https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4006993/#</span></p>
    7. <p><span style="font-weight: 400;">https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4402713/#:</span></p>
    8. <p><span style="font-weight: 400;">https://www.gutmicrobiotaforhealth.com/can-probiotics-have-anti-inflammatory-effects-worth-considering-in-chronic-intestinal-diseases/#</span></p>
    9. <p><span style="font-weight: 400;">https://www.iow.nhs.uk/Downloads/Patient_Information_Leaflets/Probiotics%20for%20preventing%20Cdiff.pdf</span></p>
    10. <p><span style="font-weight: 400;"> https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5745464/#:</span></p>
    11. <p><span style="font-weight: 400;"> https://pubmed.ncbi.nlm.nih.gov/21436726/</span></p>
    12. <p><span style="font-weight: 400;">https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9116469/#:</span></p>
    13. <p><span style="font-weight: 400;">https://www.mayoclinicproceedings.org/article/S0025-6196(11)60702-7/fulltext#:</span></p>
    14. <p><span style="font-weight: 400;">https://www.mayoclinicproceedings.org/article/S0025-6196(18)30148-4/fulltext</span></p>
    15. <p><span style="font-weight: 400;">https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-017-1175-y</span></p>

    Post author

    Aliza Marogy

    Nutritional Therapist, ND & Founder of Inessa

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