Lactobacillus fermentum

Lactobacillus fermentum is a type of rod-shaped, gram-positive bacterium that produces lactic acid as a byproduct of glucose metabolism. These bacteria are commonly found in animal feeds, milk products, and fermented foods like sauerkraut and yogurt.1

Unlike some other Lactobacillus species that are homofermentative (producing primarily lactic acid), L. fermentum is heterofermentative. This means its glucose metabolism results in lactic acid, along with other byproducts such as ethanol, acetic acid, and carbon dioxide.1

Lactobacillus species, including L. fermentum, are often used as probiotics. They are normal inhabitants of the human gastrointestinal tract and can be beneficial for digestion and immune function, especially after antibiotic therapy.12