What is Lactobacillus?

Lactobacillus is a large bacterial genus with a number of interesting applications. Bacteria in this genus are generally benign, and some are actually beneficial, leading people to use them in probiotic preparations which are designed to promote health. Some common conventional uses of Lactobacillus bacteria include restoration of normal gut flora after severe infections and treatment of bacterial vaginosis.

Bacteria in this genus are rod shaped, and they may form long chains with each other when they colonize something. They are gram positive, and aerobic, requiring air to survive. Lactobacillus bacteria are among a larger classification of bacteria known as lactic acid bacteria because they produce lactic acid as a byproduct when they feed. In the case of Lactobacillus, the bacteria live on sugars, converting them into lactic acid and an assortment of other compounds.

As the “lacto,” meaning “milk,” would seem to suggest, Lactobacillus bacteria love milk. Some species can cause milk to go sour, while others are used to produce cultured dairy products like cheese and sour cream. Lactobacillus acidophilus is a particularly famous species used to produce various cultured foods. Lactobacillus can also be used in pickles and cultures of other foods and drinks, ranging from beer to sauerkraut. These bacteria are deliberately introduced for the fermentation process.

In addition to being fond of milk, these bacteria also enjoy the lining of the intestines, where they provide a number of benefits to their hosts. Lactobacillus bacteria help people break down food, promoting more efficient digestion and ensuring that people get the nutritional benefits of the foods they eat. These bacteria also appear to be effective in choking out unwanted species, because they create an acidic environment which is undesirable to some other bacteria and organisms like certain yeasts. In other words, they are the good neighbors in the gut.

A great deal is known about Lactobacillus bacteria, because people have been using these bacterial assistants in food production for centuries. Several species have been genetically sequenced, and researchers are constantly uncovering more about these members of the bacterial world. Food scientists study these bacteria to determine how they work and to improve food safety by ensuring that only desirable bacteria are introduced to foods, and members of the medical community are interested in the potential medical applications of Lactobacillus preparations. Microbiologists are fond of saying that there is always more to learn, and this is definitely the case with these bacteria.