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

Its patent-pending bioactive keratin ferment, a blend of lactobacillus, hydrolyzed wool keratin, and honey, fills in the micro-cracks left by chemical or thermal damage, reducing breakage and restoring elasticity after just one use. —Jailynn Taylor, Allure, 31 Dec. 2025

Sourdough Bread Making sourdough with lactobacillus bacteria involves fermentation, which creates ideal conditions for producing postbiotics. —Abby Norman, Verywell Health, 26 Dec. 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. —Jenny Berg, Vogue, 13 Aug. 2025

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