Select Probiotic Strains Help Inflammatory Bowel Disease
Probiotics—sometimes referred to as good or friendly bacteria—may help people who suffer with inflammatory bowel disease (IBD). Not all good bacteria are the same, however, and a new study shows that select probiotic strains that possess a specific protein are the ones that may offer the benefits for IBD.
Prevalence of inflammatory bowel disease is rising
Inflammatory bowel disease is a condition that is believed to be autoimmune in nature, meaning the body attacks its own healthy tissues. The two main types of IBD are Crohn disease and ulcerative colitis: Crohn disease can affect any part of the gastrointestinal tract from the mouth to the anus, while ulcerative colitis is limited to the colon.
Treatment of inflammatory bowel disease focuses on relieving symptoms and includes antidiarrhea agents, antispasmodics, acid suppressants, and bile acid-binding agents. Probiotics are also used by some patients, but as a recent study from King’s College London reported, patients frequently choose probiotic strains without evidence that they are effective for IBD.
This new study, led by researchers from the Institut Pasteur de Lille in France, tested the anti-inflammatory powers of two Lactobacillus strains, L. salivarius Ls33 and L. acidophilus NCFM, in a mouse model of colitis. Previous studies have indicated that the former strain is helpful for IBD while the latter strain is not.
Some of the mice were genetically engineered to lack receptors called NOD2, which are known to react with a protein called peptidoglycan (PGN), which is found on the surface of certain probiotic strains. A second group of mice used in the study had NOD2.
When the researchers exposed both groups of mice to the two bacterial strains, they found that an anti-inflammatory compound (interleukin 10) was produced in mice that had NOD2 when exposed to L. salivarius Ls33. However, L. acidophilus NCFM did not produce the same effect.
Therefore, the investigators noted “that PGN purified from the protective L. salivarius Ls33 strain exhibited anti-inflammatory potential, while PGN derived from a non-protective strain [L. acidophilus NCFM] did not.” In other words, the ability of select probiotic strains to provide anti-inflammatory benefits depends on the presence and ability of NOD2 receptors to recognize specific PGN.
An estimated 1 to 2 million people in the United States have one of the two forms of IBD. The incidence of IBD among whites is about four times that of other races, and individuals among the American Jewish population have prevalence rates 4 to 5 times that of the general population. Incidence rates among black, Hispanic, and non-Jewish populations are rising.
The investigators concluded that the “insights gained through these findings will thus improve strain selection procedures and hopefully provide highly positive results in future clinical trials with probiotics” in patients who have inflammatory bowel disease.
Fernandez EM et al. Gut 2011; 60: 1050-59; doi: 10.1136/gut.2010.232918
Hedin CR et al. Inflammatory Bowel Disease 2010 Dec 16(12): 2099-108