The bacteria kingdom - understanding classification

When selecting a probiotic strain for your product, you must know how to differentiate between bacteria. Bacteria are classified into different groups according to traits. The bacteria family tree has several hierarchical levels, starting with Kingdom (Bacteria) followed by Phylum, where bacteria are ordered into 24 divisions. The most common divisions for probiotic bacteria are “Firmicutes” (for example, Lactobacilli) or “Actinobacteria” (such as Bifidobacteria), whereas many typically pathogenic bacteria belong to the phylum of “Proteobacteria” (like, Salmonella).

The further down the family tree, the higher the similarity between bacteria. The last three parts of the hierarchy, Genus – Species – Strains, are most often the ones discussed for probiotic strains.

Lactobacillus is a genus composed of many different species including Lactiplantibacillus plantarum*. Each species contains several strains. For example, Lactiplantibacillus plantarum 299v and Lactiplantibacillus plantarum HEAL9 are different strains of the same species (and genus). Some proprietary strains also have a trademark, such as LP299V^®. An individual bacterial strain is defined as genetically identical cells, sharing the same traits.

The origin of probiotic strains

Another important aspect when selecting the right probiotic strain is to know the strain’s origin. Probiotic bacteria can originate from many different places, including plants, vegetables, food products and animal or human microbiota. Human origin is often viewed as important for possible colonization in the gastrointestinal tract of that particular strain after consumption. This can however not be guaranteed without performing clinical studies investigating colonization and persistence within the gut.

There are several different criteria to be considered when producing a probiotic product. Probi has more than 30 years of experience working in the field of probiotics. Contact us to learn more about how we can support your company all the way from strain selection to finished product.

_{Image: A microscopic picture of Lactiplantibacillus plantarum 299v (LP299V®).}

Bacteria can have three different shapes; Spheres (as Streptococci), Rods (as LP299V® in the picture) and Spirals (as Helicobacter).

_{* changed from Lactobacillus plantarum in the 2020 taxonomy-changes.}