The value of probiotics became clear at the beginning of the 20th century when Nobel prize winner, Dr Elie Metchnikoff studied peasants who lived longer. He noted that their diets included natural probiotics foods like fermented yoghurt.
He found there was a link between longevity and the natural probiotic bacteria found in yoghurt. In studying the yoghurt, he discovered the first probiotic strain: Lactobacillus bulgaris.
Probiotics bacteria attach to the lining of your gut. Many produce lactic acid, which helps promote a mildly acidic environment in the gut – the ideal conditions for gut health. Our digestive and urogenital system is home to trillions of beneficial bacteria, working to promote better immune, digestive and mental health.
Each probiotic strain offers its own unique benefits – but do you know your friendly bacteria?
Probiotics and prebiotics
So, what’s the difference between probiotics and prebiotics?
Prebiotics offer nutrition for good bacteria, aka probiotics. They’re found in plant fibres from foods like onions, greens, bananas, artichokes, garlic, leeks and oats.
Probiotics are the live, good bacteria living in your gut.
Colonising vs transient probiotics
Probiotics can be split up into two main groups – those that colonise, and transient strains.
Colonising strains linger in the gut, reproducing and establishing populations. They protect the lining of our gut, supporting our health. These bacteria are usually wiped out by antibiotics.
Transient strains nourish the gut, producing by-products which support the establishment of colonising strains. The original strain discovered by Dr Elie (lactobacillus bulgaris) is a transient strain.
The key players
There are more than 500 probiotic species, all of which offer individual benefits. Two of the core species are lactobacillus and bifidobacterium.
A common benefit is that these species produce lactic acid, which enhances the digestion of lactose – products that contain dairy.
Lactic acid creates an acidic environment in the gut which defends against toxins. These conditions are also anaerobic, which supports better colonisation of bifidobacteria while inhibiting the growth of bad bacteria. This maximises gut health and the other areas of wellbeing that our gut governs.
Another benefit shared by lactobacillus and bifidobacterium species named below is that they help produce B vitamins and vitamin K, which help nourish our immune system.
Lactobacillus
Well known in the probiotic world, lactobacillus species are a hallmark for a healthy gut. All three of these species aid in the production of vitamins and enzymes that help us absorb nutrients.
Lactobacillus acidophilus
By nourishing your gut, where 70% of your immune system resides, acidophilus can upregulate your immune system. [1]
Named as a psychobiotic, a probiotic supportive to mental health, L. acidophilus supports better moods and sleep.
Acidophilus is particularly useful when it comes to cardiovascular health, and scientists have proven that it can reduce cholesterol levels.
- acidophilus has been shown to relieve symptoms of allergies like a runny or blocked nose. Research shows that the children of women who supplement during pregnancy and the first few months of life, reduce their children’s chances of having eczema by 22%.
Lactobacillus acidophilus eases digestive discomfort like abdominal pain, bloating, constipation, diarrhoea and gas.
Lactobacillus rhamnosus and lactobacillus casei
- rhamnosus and casei are the most researched probiotics when it comes to immunity. Rhamnosus boosts white blood cell activity, produces immunoglobulins (antibodies) and activates macrophages, all of which play a key role in immune function.
Casei helps regulate and activate our immune function, also helping boost levels of antibodies.
- rhamnosus has been shown to be particularly beneficial for urogenital health.
Studies show that L. casei eases digestive pain and diarrhoea.
Bifidobacterium bifidum
Bifidobacterium bifidum is one of the first probiotics which is established in the GI tract of babies. It’s the strain most commonly found in the stool of breastfed infants.
Research shows that B bifidum can replenish levels of good bacteria after medical interventions that wipe out good bacteria as well as the bad – like courses of antibiotics, or chemotherapy.
B bifidum can alleviate digestive pain, constipation and acute diarrhoea.
Bifidobacterium longum
B longum is the gut’s key producer of lactic, acetic and formic acid which balance the acidity of the small and large intestines, helping good bacteria thrive while inhibiting growth of bad bacteria and ammonia production.
Studies show that B longum can help increase athletic performance.
It’s also good for urogenital health.
Streptococcus thermophilus
S thermophilus is often found in probiotic yoghurts and produces lactase. It’s a transient strain that produces the natural antioxidant SOD – superoxide dismutase.
Saccharomyces boulardii
S boulardii is a travel essential, protecting immunity and easing upset stomachs.
Birth and breastfeeding
Babies that were born via caesarean have a very different GI tract compared to babies born vaginally. Those born via caesarean have a less diverse gut microbiome, with fewer lactobacillus, Escherichia and Bacteroides bacteria.
Women may choose to bottle feed over breastfeeding for a multitude of reasons – for their mental health, physical health and more. Though necessary, this can impact your baby’s gut microbiome, resulting in less diversity.
For babies, seek out formulas that contain bifidobacterium infantis, bifidobacteria breve and bifidobacterium longum. These three strains are the most common strains found in the GI tract of healthy breastfed newborns and infants. L rhamnosus is another strain which is beneficial to infants.
[1] P van Baarlen, Human mucosal in vivo transcriptome responses to three lactobacilli indicate how probiotics may modules human cellular pathways, 2010
