lactobacillus

noun

lac·​to·​ba·​cil·​lus ˌlak-tō-bə-ˈsi-ləs 

: any of a genus (Lactobacillus) of bacteria that produce lactic acid

Examples of lactobacillus in a Sentence

Recent Examples on the Web

Identifying higher levels of healthy lactobacillus in the guts of people engaging in good anti-stress behaviors. —John Werner, Forbes.com, 13 June 2025

The true star ingredient of this formula is lactobacillus—a probiotic extract that helps repair the microbiome to rapidly calm redness and irritation. —Conçetta Ciarlo, Vogue, 13 June 2025

While these intensive ingredients get to work, lactobacillus ferment, a probiotic, soothes skin to offset any sensitivity. —Jennifer Hussein, Allure, 25 Feb. 2025

The elixir pairs ingredients like vitamin E, niacinamide, lactobacillus extract complex, and even SPF 17 to protect against UV rays and improve skin tone, texture, and moisture levels. —Kiana Murden, Vogue, 31 Jan. 2025

Word History

Etymology

New Latin

First Known Use

1924, in the meaning defined above

Rhymes for lactobacillus

• amaryllis
• haemophilus
• bacillus
• utilise
• hilus
• villous
• villus
• willis

Medical Definition

lactobacillus

noun

lac·​to·​ba·​cil·​lus ˌlak-tō-bə-ˈsil-əs 

1

capitalized : a genus of gram-positive nonmotile lactic-acid-forming bacteria of the family Lactobacillaceae including various commercially important lactic acid bacteria

2

plural lactobacilli

-ˌī also -ˌē

: any bacterium of the genus Lactobacillus