When it comes to live cultures, it is not a question of 'one-size-fits-all'. At Optibac we specialise entirely in live cultures and use different strains for different groups of people and for different reasons. With our range of specialised live culture supplements, we aim to offer each of our customers a specific supplement to suit their individual needs.
Definition
The term ‘live cultures’ is often used instead of the word ‘probiotics’. Examples of live cultures include microorganisms such as Lactobacillus acidophilus or Bifidobacterium infantis. It seems that there is currently some movement in favour of the term 'live cultures', perhaps due to recent European legislation (the Nutrition & Health Claims regulation) which suggests that the word ‘probiotics’ could be seen as a health claim.
What is a strain?
A strain is just a specific type of bacteria, in the same way that a Golden Retriever is a specific type of dog. Different manufacturers use different strains. Although these may be of the same species and genera; meaning that one acidophilus supplement is not equal to another acidophilus supplement. It is therefore best to choose a friendly bacteria supplement that uses robust, well-researched strains.
The naming of live cultures can take some getting used to, so we've tried to explain it here as simply as possible, as it is so important! The strain name can tell you all about the research and mode of action behind the friendly bacteria. The name Lactobacillus acidophilus Rosell-52 tells you the name of the genus (Lactobacillus), the species (acidophilus) and the strain (Rosell-52) of the live cultures.

Many of our strain names include 'Rosell' as they originated from, and have been rigorously tested by Institut Rosell, one of the leading laboratories in the field. For further clarification, please see the relevant terms in our glossary: genus, species and strain or take a look at the 'The Strain Myth' both of which are in the Probiotics Learning Lab.
Which live culture strains are best?
As well as selecting the optimum live cultures, it is important to consider the viability and efficacy of the strains themselves. Generally, the best strains tend to be the most well-researched, so look out for those with plenty of clinical trials investigating them.
The strains must be alive at the time of consumption and must survive the stomach acidity in order to reach the intestines. Optibac live culture strains undergo numerous in-vitro tests documenting their viability at room temperature and their ability to survive the acidic stomach environment and bile salts.
Live cultures are all individual, and different strains have different modes of action in the body. Therefore, the best live cultures for you might not be the best for somebody else. In general, however, there are a few good ways to tell if a strain is high quality:
- It should be guaranteed to reach the gut alive
- It should be well-researched
- It should have been featured in gold standard human clinical trials and not just in-vitro tests
Are live cultures the same thing as dairy or yoghurt?
Not quite. Yoghurts will always contain live cultures (to different extents, according to various factors including pasteurisation, whether or not live cultures have been added for nutritional value, and so on), and interestingly, it is the live bacterial cultures which help to convert milk into yoghurt in the first place. However live cultures can also be found in other foods such as sauerkraut, and they may be extracted from dairy and cultivated and multiplied to make a live cultures supplement.
Are live cultures always bacterial?
They are often live bacteria, but not always. It is also possible to have active cultures of beneficial yeasts, for example Saccharomyces boulardii.
Optibac live culture strains
At Optibac we specialise entirely in live cultures and all of our products contain various types of live or active cultures. We use different strains for different groups of people and for different reasons. We aim to offer each of our customers a specific supplement to suit their individual needs. When it comes to live cultures, it is not a question of 'one-size-fits-all'! Our range has something for everyone - find which one is right for you.
Bacillus coagulans Unique IS-2
Scientifically researched and shown to survive and reach the guts of children alive. Find this strain in Kids Gummies and Adult Gummies.
Bifidobacterium bifidum Rosell-71
Well-researched and proven to survive to reach the gut alive and adhere to the gut lining. Find this strain in Every Day and One Week Flat.
Bifidobacterium breve M-16V®
Clinically trialled and proven to be safe from birth. Find this strain in Baby Drops and Babies & Children.
Bifidobacterium breve Rosell-70
Well-researched and proven to survive to reach the gut alive and adhere to the gut lining. Find this strain in Every Day.
Bifidobacterium lactis BB-12®
Thought to be the world's most well-researched strain of the entire Bifidobacteria genus. Find this strain in Bifido & Fibre.
Bifidobacterium lactis Bl-04®
Extensively researched and often trialled with B. lactis Bi-07® and L. acidophilus NCFM®. Find this strain in Every Day EXTRA and Every Day MAX.
Bifidobacterium lactis Bi-07®
Clinically researched and proven to survive and reach the gut alive, alone or in combination. Find this strain in Every Day EXTRA.
Bifidobacterium lactis HN019
From the incredibly well-researched Bifidobacterium genus, HN019 was originally isolated from a yoghurt source. Find this strain in Every Day MAX and Pregnancy.
Bifidobacterium lactis Lafti B94
This strain is well researched to reach the gut alive even alongside taking antibiotics. Find this strain in For Those On Antibiotics.
Bifidobacterium longum Rosell-175
Well-researched and proven to survive to reach the gut alive and adhere to the gut lining. Find this strain in Every Day and Travel Abroad.
Lactobacillus acidophilus NCFM®
The most well-researched strain of L. acidophilus in the world. Find this strain in Every Day EXTRA and Every Day MAX.
Lactobacillus acidophilus Rosell-52
Often trialled with L. rhamnosus Rosell-11, this strain is well-researched and proven to reach the gut alive even during antibiotics. Find this strain in Every Day, Travel Abroad, One Week Flat and For Those On Antibiotics.
Lactobacillus rhamnosus HN001
Clinically trialled and shown to survive and reach the guts of children alive. Highly researched in pregnant women, and shown to safely reach the gut and vagina alive. Find this strain in Babies & Children and Pregnancy.
Lactobacillus rhamnosus GG
The most scientifically studied strain in the world. Find this strain in Babies & Children.
Lactobacillus casei Rosell-215
Well-researched and proven to survive to reach the gut alive and adhere to the gut lining. Find this strain in One Week Flat.
Lactobacillus paracasei CASEI 431®
One of the most well-researched strains of Lactobacillus; described in over 80 scientific publications, and tested on thousands of people in over 20 clinical trials. Find this strain in Immune Support.
Lactobacillus paracasei Lpc-37®
Well-researched and proven to survive to reach the gut alive and adhere to the gut lining. Find this strain in Every Day EXTRA.
Lactobacillus paracasei F-19®
Clinically trialled to support intimate health. Find this strain in For Women.
Lactobacillus reuteri RC-14®and Lactobacillus rhamnosus GR-1®
Extensively researched and proven to reach the intimate area; mostly trialled as a pair, in 26 trials and in over 2,500 women. Find this strain in For Women.
Lactobacillus rhamnosus Rosell-11
This strain has been trialled with L. acidophilus Rosell-52 alongside antibiotics. Find this strain in Every Day, Travel Abroad and For Those On Antibiotics.
Lactococcus lactis Rosell-1058
Well-researched and proven to survive to reach the gut alive and adhere to the gut lining. Find this strain in Every Day and One Week Flat.
Saccharomyces boulardii
Actually a transient yeast, S. boulardii boasts international acclaim and was introduced to the UK and Ireland by Optibac. This strain is found in Travel Abroad and Saccharomyces Boulardii.
In conclusion, it is very important to look at live bacteria and yeasts on a strain-specific level, rather than only the genus and species of the microorganism in question.
Where do live cultures come from?
Every friendly bacteria strain is unique, and this is also true of their origins. Saccharomyces boulardii, for example, is actually a yeast, and was originally derived from the lychee fruit. Bifidobacterium lactis HN019, on the other hand, was first extracted from a yoghurt source. Many strains of friendly bacteria are known as 'human strains', this means they were initially isolated from healthy digestive tracts of humans and are natural residents of the gut! This doesn't, however, mean they are extracted from humans for commercial use or that live cultures you may take are directly taken from that source. In fact, the original strains are stored in microbiology 'banks' and future generations are cultured by scientists in laboratories.
To find out more about the Optibac range, visit our live cultures shop or take a look at our 'Why Optibac?' article.
You may also like to read: Which is the best friendly bacteria supplement
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