Characteristics of Lactobacillus
The genus Lactobacillus is the largest and most diverse group among the lactic acid producing bacteria (LAB), comprising approximately 120 species or more! They are generally gram-positive, rod-shaped and non-spore-forming. This genus of bacteria is aero tolerant – meaning they can survive in both aerobic and anaerobic conditions.
Lactobacillus and Fermentation
These bacteria are natural inhabitants of the gastrointestinal tract and genitourinary tract. They derive their energy from fermenting lactose, glucose and other sugars, and converting these to lactate, lactic acid, or alcohol as a metabolic by-product. The amount of lactic acid they produce varies from one type of Lactobacilli to the other, and is a distinguishing factor between them. Different species may produce different types of lactic acid: either L-lactate, D-lactate or a combination of both. We can therefore further differentiate Lactobacillus at species level, and sub-divide them into groups according to how they process carbohydrates and the end product of this.
Lactobacilli play a significant role in controlling intestinal pH through the production of these acids, which decrease the intestinal pH (making it more acidic), restricting the growth of many potentially pathogenic and putrefactive bacteria and favouring the growth of further Lactobacilli as they prefer to live in a lower ph. This helps to maintain a balanced intestinal flora, protect from unwanted intruders and protects against leaky gut. This low pH also helps with mineral absorption such as Calcium, Copper, Magnesium and Iron. Only a small number of Lactobacilli species produce a small amount of acetic acid.
The Uses of Lactobacillus Bacteria
Lactobacillus bacteria are naturally abundant in both plant and animal environments (such as yoghurt and cheese). This is why experts suggest that eating a variety of foods may help support a wide diversity of gut microflora, which are vital to the health of your digestive system. Lactobacillus bacteria are commonly used as part of the fermentation process in yoghurt, cider, wine, sauerkraut, pickles, cheese, chocolate, and other fermented foods.
Taxonomic changes to the Lactobacillus genus
In April 2020 taxonomic changes to the genus Lactobacillus were published (Zheng J et al., 2020). Genetic analysis shows that not all the species previously grouped under Lactobacillus could accurately remain. Microbiology experts have therefore reclassified the genus into 23 new genera. For example, Lactobacillus rhamnosus has become Lacticaseibacillus rhamnosus. Because the name Lactobacillus is so recognisable and widely-used commercially, scientists have tried to keep the new species as close to Lactobacillus in name as possible, and many still begin with an ‘L’. These pages have been updated as much as possible to reflect the changes.
As some properties & benefits of probiotics may be strain-specific, this database provides even more detailed information at strain level. Read more about the strains that we have included from this genus below.
Lactobacillus acidophilus strains: Lactobacillus acidophilus LA-05, Lactobacillus acidophilus NCFM®, Lactobacillus acidophilus Rosell-52.
Lactobacillus casei strains: Lactobacillus casei Shirota, Lactobacillus casei DN-114001.
Lactobacillus plantarum strains: Lactobacillus plantarum LP299v.
Lactobacillus reuteri strains: Lactobacillus reuteri Protectis and Lactobacillus reuteri RC-14®.
Lactobacillus rhamnosus strains: Lactobacillus rhamnosus LGG®, Lactobacillus rhamnosus HN001, Lactobacillus rhamnosus GR-1® and Lactobacillus rhamnosus Rosell-11.
Lactobacillus paracasei strains: Lactobacillus paracasei CASEI 431®.
For more insights and professional updates on probiotics, please visit the Probiotic Professionals pages.
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