Probiotics and health
Photo by Karly Gomez on Unsplash
Fermented foods and drinks have gained ‘superfood’ status in recent years.
But why are they meant to be so good for us and what exactly are probiotics?
Image by bodymybody from Pixabay
What is our gut microbiome?
A healthy digestive tract (commonly referred to as our gut) contains more than 400 different species of bacteria. These bacteria are what make up our ‘microbiome.’ This equates to approximately 100 trillion microorganisms, weighing together approximately 1.5kg - 2kg. That’s a lot of bacteria!! Most of these bacteria, live in our colon (large intestine) where the environment is less acidic. Just as our fingerprints are unique, so is our gut’s microbiota.
As we evolve and develop over time, so does our microbiome. A baby is born with a sterile gut but as we age, the bacteria in the gut starts to grow and evolve. This delicate balance of bacteria is affected by the food we eat, our age, medications, health conditions, allergies, alcohol and stress.
70% of our body’s immunity is localised in our gut and therefore the healthy balance of bacteria in our microbiome has a direct impact on our overall health and wellbeing. A good balance of bacteria helps to support the absorption of nutrients, elimination waste, our metabolism and our immunity.
What are probiotics?
Fermented foods, such as yoghurt, kimchi, kefir, sauerkraut, and tempeh have been around for thousands of years. Due to the fermentation process, they are easily digested by the body and can provide our gut microbiome with live bacteria. Some of these bacteria are also known as probiotics. While all probiotics are ‘live’ bacteria, not all ‘live’ bacteria have probiotic activity.
Probiotics are defined by the World Health Organisation (WHO) as “live microrganisms which when administered in an adequate amount, confer (provide) a health benefit to the host.” Simply put, probiotics are ‘good’ bugs which help support our health and wellbeing when we take them in the right amount. Different strains of probiotics often offer different health benefits too - they don’t all work in the same way in the body. Therefore, it’s important you choose the right probiotic (and at the right amount) for the job.
Some well-known probiotic strains include:
Lactobacillus acidophilus
Lactobacillus reuteri
Lactobacillus plantarum
Bifidobacterium lactis
Bifidobacterium longum
Bifidobacterium breve
How can probiotics support our health?
All probiotics induce an immune response and many have been proven to have a number of health benefits within the body. There is good scientific evidence to support that some strains of probiotics can help to:
Support and protect our immune system, especially in the critically ill
Destroy toxins or pathogens
Increase nutrient absorption and make vitamins B12 and K
Relieve constipation - specifically strains such as Bifidobacterium lactis DN-173 010, Lactobacillus casei Shirota and Escherichia coli Nissle 1917
Reduce the incidence of traveller’s diarrhoea - specifically strains such as Bifidobacterium infantis, Bifidobacterium breve, Lactobacillus phantarum, Lactobacillus reuteri protectis, L. rhamnosus GG, Lactobacillus casei, Saccharomyces Boulardii
Prevent antibiotic-associated diarrhoea - specifically L. rhamnosus GG, Lactobacillus casei DN-114001, Saccharomyces Boulardii
Reduce symptoms of Irritable Bowel (IBS) - specifically Bifidobacterium lactis DN-173 010, Bifidobacterium infantis 35624, Saccharomyces cerevisiae, Bifidobacterium infantis
Reduce symptoms of Ulcerative Colitis - VSL#3 and other various strains
There is weaker, but emerging evidence to support that some probiotic strains may also be able to:
Reduce the incidence of atopic dermatitis (eczema)
Support our mood and mental health (via the gut - brain axis) - Bifidobacterium longum, Lactobacillus plantarum
What foods contain probiotics?
Probiotics can be found in a range of fermented foods including yogurt, cheese, sauerkraut, pickles, kefir, kimchi, miso, sourdough, or kombucha. These foods either contain probiotics naturally or the probiotics may have been added to the food. However, not all fermented foods contain probiotics.
If products have been pasteurised, or heat-treated, it is also likely that many of the beneficial bugs would have been killed off during the heating process. The good news is that most (but not all) store-bought foods which contain proven probiotics will clearly state so on-pack. You will usually see the probiotic strain (e.g. Lactobacillius acidophilus) listed in the Nutrition Information Panel, along with the product’s corresponding amount of live bacteria, as CFUs (Colony Forming Units). The higher the number of CFU, usually the better. Unfortunately, it is more difficult to determine if your homemade fermented foods or brews have probiotic activity, unless you get them tested.
As with any processed-food, it is also important to read the food labels to find out what other ingredients (such as sugar or salt) have been added to your fermented food. Where possible, aim to choose foods with the least amount of sugar, salt or saturated fat per 100g. In the case of kombucha, it also pays to check the alcohol content - especially if you are giving these products to children or if you are pregnant.
In addition to getting probiotics from the food we eat, we can also purchase probiotic supplements. These often contain higher doses of probiotics and will usually target a specific health area e.g. gut health or immunity. Many of these supplements need to be kept in the fridge, however some shelf-stable varieties are available which do not need to be kept in the fridge. As fermented foods contain a variety of healthful nutrients, in addition to probiotics, a food first approach is usually a good place to start.
As mentioned above, the health benefits of probiotics are dose-dependent. Therefore, if you are after a specific health benefit, not only will you need to choose the right strain of probiotic but you will also need to ensure you take the recommended dose. While there are no specific recommendations round how many probiotics we should include in our diet for general health and wellbeing, given their many health benefits, most experts agree we should try to include fermented foods every day. While some fermented foods may be unappealing due to their taste or smell, because there are so many different fermented foods available, you should be able to find one that suits your preferences.
One benefit of the fermented movement is that it has helped many of us to become more adventurous with our eating, and that is a very good thing indeed! However, the implication that eating a specific food, is going to be a magic bullet and prevent you from getting sick is just plain wrong, and even potentially dangerous. The reality is that for optimal health we need to focus on having a super diet, rather than focusing in on any single superfood or nutrient. By eating a variety of nutritious whole & fermented foods, with plenty of non-starchy vegetables and fruit we will be ensuring that we are getting all the nutrients we need to support our optimal health and wellbeing.
Tips to help you get the most out of your daily probiotics
Include some fermented foods into your diet every day
Choose the right strain for the job
Dose matters - look for products which contain a higher (and ‘proven’) number of CFUs