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Lactobacillus acidophilus (New Latin 'acid-loving milk-bacillus') is a species of gram positive bacteria in the genus Lactobacillus. L. acidophilus is a homofermentative, microaerophilic species, fermenting sugars into lactic acid, and grows readily at rather low pH values (below pH 5.0) and has an optimum growth temperature of around 37 °C (99 °F).[1] L. acidophilus occurs naturally in the human and animal gastrointestinal tract and mouth.[2] Some strains of L. acidophilus may be considered to have probiotic characteristics.[3] These strains are commercially used in many dairy products, sometimes together with Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus in the production of acidophilus-type yogurt, or acidophiline. Its genome has been sequenced.[4]

Lactobacillus acidophilus
"Lactobacillus acidophilus", Numbered ticks are 11 μm (micrometers)
Lactobacillus acidophilus, Numbered ticks are 11 μm
Scientific classification edit
Domain: Bacteria
Phylum: Firmicutes
Class: Bacilli
Order: Lactobacillales
Family: Lactobacillaceae
Genus: Lactobacillus
L. acidophilus
Binomial name
Lactobacillus acidophilus
(Moro 1900) Hansen & Mocquot 1970
Lactobacillus acidophilus, electron micrograph

L. acidophilus was found to lower serum cholesterol and raise cholesterol in fecal matter when fed to pigs.[5] These pigs were fed the same amount of food, with the same nutritional content, but one group received saline solution with L. acidophilus while the other group received just the saline. The group given the saline with the bacteria had lowered serum cholesterol compared to the control group. Pigs were chosen because their digestive system is similar to that of humans.

L. acidophilus is also correlated with antagonistic actions upon growth for Staphylococcus aureus, Escherichia coli, Salmonella typhimurium, and Clostridium perfergens[6]. The S. aureus, out of the four organisms, was the most affected by L. acidophilus. However, along with S. aureus , the other gram positive bacteria C. perfergnes, was affected more by L. acidophilus, than the two other bacteria that are gram negative.

L. acidophilus is found to also reduce oral plaque formation by Streptococcus mutans[7]. Although some research has been done, more needs to be done to determine how strong the effect is on S. mutans, what the effect is, and how exactly the effect is executed on L. acidophilus. The research was performed in the lab, and not on animals.

Vaginal microbiotaEdit

Lactobacillus acidophilus is part of the vaginal microbiota along with other species in the genus including Lactobacillus crispatus, Lactobacillus gasseri, Lactobacillus jensenii, and Lactobacillus iners.[4][8][9][10] In lab experiments, L. acidophilus seemed to decrease Candida albicans’ ability to adhere to vaginal epithelial cells; however, L. acidophilus’ role in preventing yeast infections is unclear because this species of Lactobacilli has also been found not to have a very strong ability to adhere to (and thereby colonize) the vaginal cells.[11]

Side effectsEdit

Although probiotics are generally safe, when they are used by oral administration there is a small risk of passage of viable bacteria from the gastrointestinal tract to the blood stream (bacteremia), which can cause adverse health consequences.[12] Some people, such as those with a compromised immune system, short bowel syndrome, central venous catheters, cardiac valve disease and premature infants, may be at higher risk for adverse events.[13] In children with lowered immune systems or who are already critically ill, consumption of probiotics may rarely cause bacteremia or fungemia, leading to sepsis, which is a potentially fatal disease.[14] Scant complaints of mild gastrointestinal discomfort or gas have been noted.[15]

Therapeutic applicationsEdit

Lactobacillus acidophilus is a constituent in VSL#3. This proprietary, standardized, formulation of live bacteria may be used in combination with conventional therapies to treat ulcerative colitis.[16]

See alsoEdit


  1. ^ Bâati, L. ̈L.; Fabre-Gea, C.; Auriol, D.; Blanc, P. J. (2000). "Study of the cryotolerance of Lactobacillus acidophilus: Effect of culture and freezing conditions on the viability and cellular protein levels". International Journal of Food Microbiology. 59 (3): 241–247. doi:10.1016/S0168-1605(00)00361-5. PMID 11020044.
  2. ^ "Bacteria Genomes – Lactobacillus acidophilus". European Bioinformatics Institute. Retrieved 2007-08-22.
  3. ^ Ljungh A, Wadström T (2006). "Lactic acid bacteria as probiotics". Curr Issues Intest Microbiol. 7 (2): 73–89. PMID 16875422.
  4. ^ a b Fijan, Sabina (2014). "Microorganisms with Claimed Probiotic Properties: An Overview of Recent Literature". International Journal of Environmental Research and Public Health. 11 (5): 4745–4767. doi:10.3390/ijerph110504745. ISSN 1660-4601. PMC 4053917. PMID 24859749.
  5. ^ Maxwell, C.; Nelson, C. R.; Gilliland, S. E. (1985-02-01). "Assimilation of cholesterol by Lactobacillus acidophilus". Applied and Environmental Microbiology. 49 (2): 377–381. ISSN 0099-2240. PMC 238411. PMID 3920964.
  6. ^ GILLILAND, S. E.; SPECK, M. L. (December 1977). "Antagonistic Action of Lactobacillus acidophilus Toward Intestinal and Foodborne Pathogens in Associative Cultures". Journal of Food Protection. 40 (12): 820–823. doi:10.4315/0362-028x-40.12.820. ISSN 0362-028X. PMID 30736216.
  7. ^ Tahmourespour, Arezoo; Kermanshahi, Rooha Kasra (February 2011). "The effect of a probiotic strain (Lactobacillus acidophilus) on the plaque formation of oral Streptococci". Bosnian Journal of Basic Medical Sciences. 11 (1): 37–40. doi:10.17305/bjbms.2011.2621. ISSN 1512-8601. PMC 4362563. PMID 21342140.
  8. ^ Ratner, Adam J.; Aagaard, Kjersti; Riehle, Kevin; Ma, Jun; Segata, Nicola; Mistretta, Toni-Ann; Coarfa, Cristian; Raza, Sabeen; Rosenbaum, Sean; Van den Veyver, Ignatia; Milosavljevic, Aleksandar; Gevers, Dirk; Huttenhower, Curtis; Petrosino, Joseph; Versalovic, James (2012). "A Metagenomic Approach to Characterization of the Vaginal Microbiome Signature in Pregnancy". PLoS ONE. 7 (6): e36466. Bibcode:2012PLoSO...736466A. doi:10.1371/journal.pone.0036466. ISSN 1932-6203. PMC 3374618. PMID 22719832.
  9. ^ Senok, Abiola C; Verstraelen, Hans; Temmerman, Marleen; Botta, Giuseppe A; Senok, Abiola C (2009). "Probiotics for the treatment of bacterial vaginosis". Cochrane Database Syst Rev (4): CD006289. doi:10.1002/14651858.CD006289.pub2. PMID 19821358.
  10. ^ Nardis, C.; Mastromarino, P.; Mosca, L. (September–October 2013). "Vaginal microbiota and viral sexually transmitted diseases". Annali di Igiene. 25 (5): 443–56. doi:10.7416/ai.2013.1946. PMID 24048183.
  11. ^ Can Yogurt Prevent Yeast Infections?. Planned Parenthood Advocates of Arizona. 28 February 2012. Retrieved 28 February 2012.
  12. ^ Durchschein F, Petritsch W, Hammer HF (2016). "Diet therapy for inflammatory bowel diseases: The established and the new". World J Gastroenterol (Review). 22 (7): 2179–94. doi:10.3748/wjg.v22.i7.2179. PMC 4734995. PMID 26900283.
  13. ^ Doron S, Snydman DR (2015). "Risk and safety of probiotics". Clin Infect Dis (Review). 60 Suppl 2: S129–34. doi:10.1093/cid/civ085. PMC 4490230. PMID 25922398.
  14. ^ Singhi SC, Kumar S (2016). "Probiotics in critically ill children". F1000Res (Review). 5: 407. doi:10.12688/f1000research.7630.1. PMC 4813632. PMID 27081478.
  15. ^ "Lactobacillus acidophilus". Natural Medicines Comprehensive Database, Consumer Version. Medline Plus. Retrieved April 20, 2012.
  16. ^ Ghouri, Yezaz A; Richards, David M; Rahimi, Erik F; Krill, Joseph T; Jelinek, Katherine A; DuPont, Andrew W (9 December 2014). "Systematic review of randomized controlled trials of probiotics, prebiotics, and synbiotics in inflammatory bowel disease". Clin Exp Gastroenterol. 7: 473–487. doi:10.2147/CEG.S27530. PMC 4266241. PMID 25525379.

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