Lactobacillus rhamnosus

Lactobacillus rhamnosus is a bacterium that was originally considered to be a subspecies of L. casei, but later genetic research found it to be a species of its own. Some strains of L. rhamnosus are being used as probiotics. The species is sometimes used in yogurt and other dairy products. Some studies have been done on its in vivo effects. While frequently considered a beneficial organism, L. rhamnosus has been discovered to be pathogenic in certain circumstances.^[1]

Lactobacillus rhamnosus GG (ATCC 53103)

Lactobacillus rhamnosus GG (ATCC 53103) is a strain of L. rhamnosus isolated in 1983 from the intestinal tract of a healthy human being; filed for patent on 17 April 1985, by Sherwood Gorbach and Barry Goldin.^[2] (The 'GG' derives from the first letters of their surnames').^[3] The patent refers to a strain of "L. acidophilus GG" with American Type Culture Collection (ATCC) Accession No. 53103; later reclassified as a strain of L. rhamnosus. The patent claims the L. rhamnosus GG (ATCC 53103) strain is acid– and bile–stable, has a great avidity for human intestinal mucosal cells, and produces lactic acid.

The genome sequence of Lactobacillus rhamnosus GG (ATCC 53103) has been decoded.^[4][5]

Medical research and use

While Lactobacillus rhamnosus GG (ATCC 53103) is able to survive the acid and bile of the stomach and intestine^[6] and is claimed to colonize the digestive tract and to balance intestinal microflora, evidence suggests that Lactobacillus rhamnosus is likely a transient inhabitant, and not autochthonous.^[7] Regardless, it is considered a probiotic useful for treatment of various maladies, as it works on many levels. However, most of the molecular mechanisms are not known.

Diarrhea

Lactobacillus rhamnosus GG has been shown beneficial in the prevention of rotavirus diarrhea in children. The prevention and treatment of various types of diarrhea has been shown both in children and in adults.^{[8][9][10][11]}

Respiratory Tract Infections

L. rhamnosus GG has also been associated with a reduction in the risk of respiratory tract infections in children.^[12][13]

Atopic Dermatitis

Lactobacillus rhamnosus GG has also shown potential in treatment and primary prevention of atopic dermatitis, but the results of intervention trials have been mixed.^[14] A clinical trial with seven-year follow-up shows L. rhamnosus GG is useful in the prevention of atopic dermatitis in children at high risk of allergy.^[15][16]

Urogenital Tract

The clinical health effects of L. rhamnosus GG have been widely studied. Both L. rhamnosus GG and L. rhamnosus GR-1 appear to protect the urogenital tract by excreting biosurfactants to inhibit the adhesion of vaginal and urinary pathogens. ^{[citation needed]}

Intestinal tract permeability

L. rhamnosus has been found to reduce intestinal permeability in children who suffer from irritable bowel syndrome,^[17] and also it has been found to counter alcohol related intestinal permeability.^[18][19]

Gastrointestinal Carriage of VRE

In 2005, L. rhamnosus GG was first successfully used to treat gastrointestinal carriage of vancomycin-resistant enterococcus (VRE) in renal patients.^[20]

Anxiety

Research published in the Proceedings of the National Academy of Sciences on August 29, 2011 reported this bacterium may have an effect on GABA neurotransmitter receptors. Mice that were fed L. rhamnosus had less anxiety and had different levels of a brain-chemical sensor and stress hormones.^[21]

Risks

The use of Lactobacillus rhamnosus GG for probiotic therapy has been linked with very rare cases of sepsis in certain risk groups, primarily those immunocompromised or infants.^[22] Ingestion of L. rhamnosus GG is, nevertheless, considered to be safe, and data from Finland show a significant growth in the consumption of L. rhamnosus GG at the population level has not led to an increase in the number of Lactobacillus bacteraemia cases.^[23]

Use as Commercial Probiotic

In 1990, Finnish company Valio launched Valio Gefilus, a family of products containing Lactobacillus rhamnosus GG (ATCC 53103), for which they also use the trademark LGG.^[24] Valio has licenced rights to LGG to several companies, including Amerifit Brands in the United States (Culturelle), FrieslandCampina in the Netherlands (Vifit),^[25] Oriola in Finland (Gefilus and LGG), and Dukat in Croatia (LGG).^[26]

References

Further reading