The Probiotic Showdown

Following the success of the Fish Oil Showdown we did, here is the Probiotic Showdown. Here I have compared the value and quality of a number of probiotic supplements,...

Following the success of the Fish Oil Showdown we did, here is the Probiotic Showdown. Here I have compared the value and quality of a number of probiotic supplements, and explained the scientific support behind each product – which is the best probiotic?

Most probiotics strengthen/ fortify the digestive system, but a few have some unique benefits, and some have had more research on than others. Each probiotic listed in the products here has a summary of the benefits and research on them at the end of the article (see table of contents on right).


Probiotic Supplement Essentials

Before you read about the different products, there are 2 key aspects to a probiotic supplement which you need to understand:

Spore count – The spore count of probiotics is the count of viable spores at point of manufacture. After manufacture, the spore count will decrease as the spores die, and the rate at which this occurs depends on the storage (warm environments for example will increase the rate of death). A high spore count is important and ensures there are are plenty of probiotics to survive the stomach acid at the time of consumption. The numbers look high (billions), but this is required!

Ideally you want to be consuming a minimum of 1 billion spores of a specific strain of bacteria to ensure effective colonisation of the digestive system40, so be careful if the spore count is not specified for each probiotic.

Diversity – Diversity in the gut microflora population is key to a healthy digestive system, because it makes it more resilient to pathogens and infections. A varied population is a strong population. The probiotics in your gut are your first line of defence against a range of infections, and you can think of them like an army. You wouldn’t want an army to be 100% artillery, or 100% infantry, because there are strengths and weaknesses to each. A strong army is diverse, and this is true for probiotics. Bear this in mind when looking at the probiotics.

Probiotic supplements also often contain prebiotics and its worth knowing the difference between a probiotic and a prebiotic before you read on.


Udo’s Choice Adult’s Blend

udos-probiotics‘Udo’s Choice’ is a brand by Udo Erasmus, who was made famous in his book ‘Fats That Heal, Fats That Kill’, where he goes into great detail about the quality of fats and cold pressing. His early products included the popular ‘Udo’s Oil’, which, as you may have guessed is an exceptional source of healthy cold-pressed fats. He has branched out into other health products, and the Udo’s Choice brand is synonymous with quality – but do his probiotics match the quality of his oil?

  • Price per serving (based on RRP): £0.38
  • 17 Billion spores made up of:
    • Lactobacillus casei: 6 billion spores
    • Lactobacillus rhamnosus: 4.3 billion spores
    • Lactobacillus acidophilus: 3.4 billion spores
    • Lactobacillus plantarum: 1.7 billion spores
    • Bifidobacterium bifidum: 0.9 billion spores
    • Bifidobacterium breve: 0.9 billion spores
  • Potato starch – a prebiotic

This is a thorough probiotic supplement. It has diversity and a large spore count, (particularly for the Lactobacillus casei). This will certainly strengthen your gut!

Special featuresUdo’s choice probiotic supplements are always sold in a fridge. All retailers (certainly bricks and mortar retailers) are provided with an Udo’s choice fridge, and this ensures a high spore count at the time of consumption – which is important! With this in mind, be careful if you want to buy this product online, because you don’t know if it is in a fridge or not!


Natures Best Acidophilus Extra

natures-best-probioticNatures Best are a company which strive to provide affordable health products, but this reduction in cost is often at the expense of quality (as we have seen with their fish oil).

  • Price per serving (based on RRP): £0.24
  • 4 Billion spores made up of:
    • Lactobacillus Acidophilus
    • Bifidobacterium animalis

This supplement provides 2 important probiotics, from 2 different genus – offering minimal diversity. Its spore count is not particularly low (2 billion of each), but it doesn’t contain any prebiotics. This  supplement will support your immune system and digestive system, but isn’t suitable re-populating your digestive system after taking antibiotics. It might be suitable for strengthening an already healthy gut if you are going abroad though. This is a typical ‘budget’ probiotic supplement, and other brands such as Holland & Barretts probiotic are very similar.


Primal Nutrition Primal Flora

primal-flora-probioticPrimal Flora is part of the Primal Blueprint supplement range, which was created by the Paleo guru Mark Sisson.

  • Price per serving (based on UK RRP): £1.00
  • 10 billion spores made up of:
    • Bacillus coagulans (2 billion)
    • Bacillus subtilis (1 billion)
    • Bacillus clausii (1billion)
    • Lactobacillus plantarum (4 billion)
    • B bifidus (Bifidobacterium bifidum) (1 billion)
    • Saccharomyces boulardii (1 billion)
  • 50mg potato starch – a prebiotic

Primal flora has a good spore count (all at least 1 billion), and great diversity in species (6 species across 3 genus!), which are important. Some of the probiotics in this product are not as thoroughly researched as other species, and so the extent of their benefit isn’t well understood. Current research on them does show they are beneficial for the digestive system and whole body, it’s just a little less clear as to how much benefit some offer. Primal flora does have some well researched probiotics in though, which when combined with the not-so-well-researched ones, offers a range of benefits to the body. It is a little more pricey than other similar probiotics (such as Udo’s choice), and this is likely to be due to the superior diversity.

Special feature – Saccharomyces boulardii is rarely found in probiotic blends, and I’m not sure why. Its benefits to the body are both vast and well tested. It’s a great little organism, which protects the gut and adds diversity, and by adding this yeast to the formula has made Primal Flora a great probiotic supplement, rather than just a good one.

In the interest of full disclosure, we do sell Primal Flora (now called Primal Probiotics) in our webstore, but I’m not saying that this probiotic is great because we sell it, we sell it because it is great!


NOW Probiotic-10 50 Billion

  • now-probioticPrice per serving (based on RRP converted from dollars): £0.66
  • 50 Billion spores made up of:
    • Lactobacillus acidophilus
    • Bifidobacterium lactis
    • Lactobacillus plantarum
    • Lactobacillus rhamnosus
    • Strepto. thermophilus
    • Lactobacillus paracasei
    • Bifidobacterium breve
    • Lactobacillus salivarius
    • Lactobacillus casei
  • Fructooligosaccharides (prebiotics)

This probiotic supplement has an insanely high spore count, more than double of the next highest count we have compared here. It is a shame that the spore count for each probiotic is not stated, which means some may be lower than 1billion, but with such a high spore count I would be surprised if this is the case. On top of this, it provides 9 different probiotic species, across 3 different genus which gives great diversity too. It is certainly the most thorough probiotic I’ve seen. If you have been on a course of antibiotics recently, then it might be just the right thing. If you are just looking to strengthen your gut then it might be overkill. Not that overkill is going to do you any harm.


Microbiome Plus+ Gastrointestinal

  • microbiome-probioticPrice per serving (based on RRP): £1.00
  • 3.5 billion spores made up of
    • Lactobacillius reuteri
  • 600mg FOS (prebiotic)

This probiotic offers a good amount of one bacteria, giving no real diversity. The bacteria it provides is a well researched probiotic – but the lack of diversity is a problem, especially when you consider the cost of this supplement. Personally, I would say that this isn’t worth the money.

Special feature – This supplement does have one saving grace, in that it contains 600mg of fructooligosaccharides, which are a great prebiotic. This is the highest amount of prebiotic I’ve seen in a probiotic supplement, and it will benefit any probiotics that are currently in your gut.



  • Price per serving (based on RRP): £0.30
  • 2 Billion spores made up of
    • Bacillus subtilis
    • Bifidobacterium bifidum
    • Bifidobacterium breve
    • Bifidobacterium infantis
    • Bifidobacterium longum
    • Lactobacillus acidophilus
    • Lactobacillus delbrueckii ssp. bulgaricus
    • Lactobacillus casei
    • Lactobacillus plantarum
    • Lactobacillus rhamnosus
    • Lactobacillus helveticus
    • Lactobacillus salivarius
    • Lactococcus lactis ssp. lactis
    • Streptococcus thermophilus

This probiotic contains the greatest diversity with 14 species spread over 3 genus of bacteria. The spore count is quite low for such a large variety of bacteria, which raises the concern that the spore count might be quite low at time of consumption, meaning colonisation of the intestines will be difficult for all species. Ideally, you want a minimum of 1 billion spores of each probiotic, but assuming that all spores are evenly populated, you would only be getting around 0.15 billion spores of each probiotic which is far too low. It is possible that no probiotics will be able to colonise the gut. It would seem that the good diversity of this product has been made at the expense of high spore count, and you need both high diversity and spore count for a good probiotic.



All probiotics will strengthen the gut, and improve immunity. Some bacteria have unique properties, such as the blood pressure lowering properties of Lactobacillus plantarum, which you may want to seek out if you suffer from high blood pressure but generally speaking, the key to a good probiotic is diversity and spore count.

With this in mind, the best probiotics I’ve looked at here are (in no particular order):

  • Udo’s Choice Adult’s Blend Microbiotics
  • Primal Flora
  • Probiotic-10™ 50 Billion – 50 Veg Capsules

And I would suggest you avoid:

  • Microbiome Plus+ GI – Ultimate Probiotic and Prebiotic Supplement
  • Acidophilus Extra 4 Billion
  • Bio-kult 30 capsules

I hope you found this article useful! If there is any information you would like to add or any questions you would like to ask, please leave them in the comments.


List of Probiotic Bacteria

Lactobacillus casei – This is a well researched and understood probiotic. Being a member of the lactobacillius family it is able to metabolise lactose, which can help with lactose intolerance1, but this is not what it is best known for. Lactobacillus casei is most well known for improving overall bowel health by improving the immune system in the digestive tract2.

Lactobacillus rhamnosus – Another lactobacillius bacteria, meaning it should also be beneficial to those who suffer from lactose intolerance. This probiotic is well researched and has demonstrated an ability to improve immunity and reduce inflammation3, which are extremely important for gut health. This bacteria has also demonstrated some unique benefits to the respiratory system, particularly with regards to upper respiratory infections (URI)4,5. This is quite a unique benefit for a probiotic, and the only other probiotic which has shown similar benefits is Bacillus subtilis (see below).

Lactobacillus acidophilus – Another lactose sugar metaboliser, which is often found in fermented dairy products such as yoghurt. It is possibly the oldest known probiotic, and research has shown it can prevent/ control intestinal infections,  help control serum cholesterol levels, and exerts anticarcinogenic activity6. It is most commonly associated with ‘balancing the gut microflora’, but this may be due to its long history of use as a probiotic, as opposed to any specific antibacterial properties.

Lactobacillus plantarum – This lactose digesting bacteria is extremely interesting. Consumption of this bacteria has been shown to help reduce blood pressure7, and is possibly the only probiotic to have this benefit. This bacteria can also inhibit a number of pathogens and reduce inflammation in the gut8.

Bacillus coagulans – This species is less researched than other strains, and so research is less conclusive. Nonetheless, some small studies have shown that it can protect against symptoms of IBS and bloating9,10, and there is even evidence that it can provide ‘borderline statistically significant improvement’ in rheumatoid arthritis11. The research is promising, but rather limited compared to other probiotics.

Bacillus subtilis – This bacteria is commonly found in both humans and ruminants, but its function as a probiotic is not as well researched as other probiotics. It is known to support the immune system in the digestive system (as many other probiotics do) and can help prevent diarrhoea12. There is concern that this bacteria can actually cause illness in people who have a weakened immune system, but the number of people this will affect is minuscule.

Bacillus clausii – This bacteria has been shown to stimulate the immune system by stimulating the proliferation of a number of immune cells such as T-cells13. There is also research showing that this bacteria can help protect against respiratory infections14, and it could compliment the similar benefits that lactobacillus rhamnosus exerts.(see above).

Lactobacillus paracasei – A well researched bacteria which has been reported to help control blood cholesterol/ blood pressure, maintain a healthy stomach lining, support the immune system, protect against osteoporosis and even inhibit fat tissue accumulation15. While this isn’t a ‘cure-all’ probiotic, it certainly has been shown to benefit a number of systems to some degree.

Lactobacillus delbrueckii ssp. bulgaricus – There is less research on this bacteria than other probiotics, but current research has demonstrated some profound benefits for the immune system by increasing the number of immature T cells and slowing the rate and which some T cells age16.

Lactobacillus salivarius – This is a pretty well researched probiotic, and is associated with improving hosts over-all well-being, and alleviation of intestinal disease17. There is also evidence that this probiotic can reduce the risk of developing colon cancer, but this has only been demonstrated in animal models18.

Lactobacillius reuteri – This bacteria has had a large amount of research done on it. It has been shown to suppress inflammation in the gut19, prevent the growth of common gut pathogens20, and most interesting of all – increase the amount of vitamin D in the host21. This is the only bacteria which has been shown an ability to increase the amount of vitamin D in the host, and is an extremely rare and useful benefit.

Lactobacillus helveticus – This is a relatively well understood probiotic, and its benefits to the host include supporting the immune system, improving bioavailablilty of nutrients, and removing allergens from the gut22.

Lactococcus lactis ssp. lactis – This bacteria has been shown to combat ulcerative colitis in animal studies23, but research on humans is limited, and it is not as well researched as other lactobacillius spp.

Bifidobacterium bifidum – This bacterium is well researched, and is a common bacteria found in probiotic supplements. It has been shown to be able to fight infections in the digestive tract, inhibit the growth of pathogenic yeast and reduce the severity of non-digestive tract related illnesses (such as the common cold)24.

Bifidobacterium breve – This bacterium is often though to help ‘balance the gut’, and plays a role in regulating bowl movement and general gut health25. There is also some interesting research showing that supplementing your diet with this probiotic can help protect against skin damage from the sun26. Whilst this is interesting, it has only been demonstrated in animals models, and is not a reason to stop using sun-cream!

Bifidobacterium animalis – This bacteria can be found in fermented foods such as yoghurt. It is known for its ability to improve the immune function in the digestive system27, and there is emerging evidence that it may be able to curb weight gain in obese people28. However, this has only been demonstrated in animal models.

Bifidobacterium lactis – This is a well understood probiotic. It is noted for its ability to ‘settle’ the stomach, and has been reported to reduce bloating and general stomach discomfort29,30. What is particularly interesting about this probiotic is that is has been shown to inhibit the toxic effects induced by wheat gliadin31, which makes this probiotic very interesting. With wheat such a debatable topic, yet a staple to many, this bacteria could help minimise some of the negative effects of gluten.

Bifidobacterium infantis – This bacteria has been show to reduce the symptoms of IBS32 and reduce inflammation33. It has been noted that its ability to reduce inflammation is not limited to the digestive system, and has been shown to combat inflammation throughout the body.

Bifidobacterium longum – This probiotic is most noted for its ability to support the immune system of the gut34, but it has also been shown to have some anti-inflammatory effects35. There is some evidence that it may be able to help combat symptoms of hey-fever36, which is thought to be due to its immuno-supportive properties, but there is limited research on this.

Streptococcus thermophilus – This bacteria is used in yoghurt production, but its benefits as a probiotic are debated as it may not survive the high acidity of the stomach. As such, the research is quite limited, but there is evidence that it can help strengthen the digestive system and protect against various causes of diarrhoea, including travellers37 diarrhoea and AAD38 when taken alongside other probiotics. How much of this benefit is from the other probiotics is uncertain though.

Saccharomyces boulardii – This is not a bacteria but a yeast, and a rather well researched yeast I might add. A number of clinical trials on this yeast have been reviewed and it has shown an ability to protect against a number of digestive tract ailments such as antibiotic associated diarrhoea (AAD), Clostridium difficile infection, IBS, ulcerative colitis, Chron’s disease and various parasite infections39. It is not the most thoroughly researched probiotic, but the current research has shown some very real benefits.




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2. Justyna Sutula. (2013). The effect of a commercial probiotic drink containing Lactobacillus casei strain Shirota on oral health in healthy dentate people. Microb Ecol Health Disease. 24 (0), ISSN 1651-2235.

3. Lee SK. (2012). Anti-inflammatory mechanism of Lactobacillus rhamnosus GG in lipopolysaccharide- stimulated HT-29 cell. Korean J Gastroenterol. 60 (2), 86-93.

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21. Jones ML. (2013). Oral supplementation with probiotic L. reuteri NCIMB 30242 increases mean circulating 25-hydroxyvitamin D: a post hoc analysis of a randomized controlled trial. J Clin Endocrinol Metab. 98 (7), 2944-51.

22. Valentina Taverniti. (2012). Health-Promoting Properties of Lactobacillus helveticus. Front Microbiol. 392 (3), page not stated.

23. Akemi Imaoka. (2008). Anti-inflammatory activity of probiotic Bifidobacterium: Enhancement of IL-10 production in peripheral blood mononuclear cells from ulcerative colitis patients and inhibition of IL-8 secretion in HT-2. World J Gastroenterol. 14 (16), 2511-2516.

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