What does lactobacillus mean?
Lactobacillus is a genus of rod-shaped bacteria that belongs to the lactic acid bacteria. These organisms ferment sugars, especially lactose, and produce lactic acid as a by-product. They are naturally associated with the digestive tracts of humans and other animals and are also important in foods such as yogurt, cheese, kefir, sauerkraut, and kimchi. Selected strains are sold as probiotics, products intended to supply beneficial microorganisms. Although many members of the genus are well regarded, claims about the health benefits of a particular strain cannot be inferred from the name alone. In general writing, the term may refer either to the genus as a whole or informally to one of its bacteria. Its scientific name combines roots referring to milk and a small rod, reflecting both its association with dairy fermentation and its microscopic form.
nounA genus of rod-shaped bacteria that ferment carbohydrates to produce lactic acid. Many species occur naturally in the human and animal digestive tracts and in foods such as yogurt, cheese, and fermented vegetables.
- Any bacterium belonging to the genus Lactobacillus, a group of lactic-acid-producing bacteria.
"Certain strains of lactobacillus are used as probiotics because they can help maintain a healthy balance of intestinal microbes."
"The researcher identified several species of lactobacillus in the fermented milk."
"Supplements containing lactobacillus are marketed as probiotics for digestive health."
Used for multiple bacteria of the genus; also the conventional plural in biological usage.
"Several lactobacilli were detected in the sample."
Lactobacillus turns milk sugar into lactic acid, helping create the tangy flavor of yogurt and many fermented foods.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does lactobacillus come from?
The name is New Latin, formed from Latin lactis, meaning “of milk,” and bacillus, meaning “little rod” or “small staff.” The milk reference reflects the bacteria's association with fermented dairy products, while the rod reference describes their microscopic shape. The name belongs to the same Latin-derived vocabulary as lactic, lactate, and bacillus.
Related word forms
How lactobacillus is actually used
The word is normally used in scientific, medical, food-science, and commercial contexts. In formal writing it often appears in lowercase when used generically, while the genus name is capitalized.
Easily confused with lactobacillus
Bacillus is a genus of rod-shaped bacteria, while lactobacillus is a distinct genus within the lactic acid bacteria.
Lactobacillus is the scientific genus name; the common term lactobacillus is also used informally for individual bacteria belonging to that genus.