What is Lactobacillus?

If you’ve heard of acidophilus, then chances are you’ve also heard of Lactobacillus. Acidophilus is a species of bacteria from the Lactobacillus family, a widely used type of friendly bacteria often found in probiotics supplements. But let’s go a little bit deeper into the mysterious world of bacteria, to understand exactly what Lactobacillus is.

In this article we look at:

  • What Lactobacillus is
  • Where it is found
  • How Lactobacillus can benefit us
  • Whether there are any side effects
  • How to choose a good Lactobacillus supplement

Lactobacillus taxonomy diagram

What is Lactobacillus?

Lactobacillus is what is known as a genus of bacteria, a large group comprised of different types of lactic-acid-producing bacteria (hence the name Lactobacillus). This genus is the ‘parent’, so to speak, but within this genus, there are numerous well-known probiotic species, including reuteri, rhamnosus, and acidophilus. Lactobacillus bacteria have been featured in countless clinical trials, and the genus boasts a very large number of highly researched strains (types) of live cultures. One such strain is Lactobacillus acidophilus NCFM®, the most extensively researched strain of Lactobacillus acidophilus in the world.

Looking beyond the genus

Whilst all Lactobacilli bacteria share certain qualities, there are many variations between the properties of each species within this genus. These variations are particularly apparent between individual strains within the different species. It is important to avoid the assumption that all Lactobacilli are the same, as each bacterial strain will have its own unique modes of action in the body. Therefore, when considering a probiotic supplement, it is best to compare them at strain level rather than just genus or species. This way you can ensure you are getting the right types of probiotics to suit you.

probiotic capsule

Where is Lactobacillus found?

Lactobacilli are natural residents of the human gut but are also found in a wide variety of environments, including animals, plants and soil. These bacteria are often used commercially in fermentation processes, such as the manufacture of dairy products (cheese, yoghurt, kefir, etc.), the fermentation of vegetables for sauerkraut and kimchi, and also grain fermentation for sourdough bread production.

In addition to these Lactobacillus foods, the bacteria are also used in live cultures supplements in various different formats, including Lactobacillus tablets, capsules, chewable products and liquids.

What is the function of Lactobacillus?

Lactobacilli have multiple effects, some of which are held at genus level, others of which depend on the specific species and strain. People often ask, ‘is Lactobacillus a good bacteria?’, and the answer to this is ‘yes’! These bacteria provide their human ‘hosts’ with many health benefits.

So, what does Lactobacillus do? The two most obvious benefits of Lactobacillus as a genus are their ability to produce acids, including lactic acid, and their ability to colonise the gut and vaginal environments. It is this ability that makes them so popular in live cultures supplements.

Additional benefits include the production of bacteriocins (natural antimicrobial agents), which inhibit the growth of pathogens thereby helping to limit dysbiosis in the gut.

Does Lactobacillus have any side effects?

Taking probiotics in supplement form is considered very safe, and side effects from taking Lactobacillus bacteria are rare. Mild symptoms such as abdominal bloating and/or gas may occasionally be caused as a direct result of the positive ‘shift’ in the microbiota towards a healthier balance of gut microbes.

Any symptoms are generally mild and only last for a few days. If symptoms are of any concern, you can either reduce the amount you are taking or stop taking the supplement and speak to the manufacturer for advice.

How do I find the best type of Lactobacillus for me?

As specified above, it’s much more important to consider the strain rather than just the genus or species of friendly bacteria, so look for Lactobacillus supplements which provide the strain names. This way, you can choose the strains that suit you best.

For example, some strains of Lactobacillus are well researched and known to have benefits for gut health, whereas other strains of Lactobacillus are researched and utilised for the beneficial effects in the vagina. A good example of this can be seen below:

Lactobacillus acidophilus NCFM® - is one of the most researched strains of Lactobacillus acidophilus in the world. This strain has been shown to help occasional bloating and support a healthy digestive system.

Lactobacillus rhamnosus GR1® - is a strain of probiotic bacteria from the Lactobacillus genus that has proven in numerous studies to help with vaginal and urinary tract health. It achieves this by balancing the good bacteria present in the vaginal environment. 

Whilst both of these strains fall under the family ‘umbrella’ or genus of Lactobacillus, their uses differ greatly from each other, and they should not be used interchangeably.

Looking beyond ‘strain specificity’ there are also a few other key points to consider when choosing probiotics, to ensure you are getting a high-quality supplement.

Firstly, the strain should have sufficient scientific evidence to support its safety and survival to the gut. Secondly, don’t be drawn in by huge billion counts. Higher billions do not necessarily equal higher quality – it’s much more important to get the right strains, even if they’re in lower quantities. Lastly, check it has a ‘time of expiry’ guarantee as opposed to a ‘time of manufacture’ guarantee, as this means the contents are guaranteed until the supplement goes out of date, rather than just at the time of manufacture (as numbers can decrease after this point).

Luckily for you, Optibac supplements satisfy all of these criteria!

The following Optibac supplements contain Lactobacillus strains:

Healthcare practitioners might be interested to find out more about Lactobacillus on the Probiotics Database, in Probiotic Professionals. 

Author: Dr Kate Stephens PhD (Food and Microbial Sciences) BSc(Hons) Medical Microbiology