Ulcerative colitis (UC) is a chronic inflammatory bowel disease characterized by fine ulcerations on the inner mucosal lining of the colon. The most common symptoms are diarrhea and rectal bleeding. Although there is no cure for UC, there are a number of treatments available, the most common of which are 5-aminosalicylic acid (5-ASA), corticosteroids, immunosuppressive agents, and biologic response modifiers, all with varying degrees of success and risk. Researchers are looking for other potential treatments that have fewer side effects, especially since ulcerative colitis commonly begins in childhood.

Several studies using specific probiotics have shown some promise in treating inflammatory bowel disease. The World Health Organization defines probiotics as “live microorganisms which when administered in adequate amounts confer a health benefit on the host.” Probiotics, such as bacteria and yeasts, work in many possible ways, including:

  • lining the surface of the gastrointestinal tract and stopping harmful organisms from reaching it (competitive exclusion),
  • strengthening the tissue of the bowel wall,
  • acting as antibiotics against other bacteria, and
  • regulating the responses of the immune system, both at the level of the bowel wall and the body as a whole.

A small, prospective, randomized, and placebo-controlled study recently published in Alimentary Pharmacology and Therapeutics1 aimed to see whether a particular strain of the probiotic, Lactobacillus reuteri (L. reuteri), administered through an enema, helps to induce remission in children with active rectal UC. L. reuteri is widely recognized as a natural, beneficial resident of the digestive tract from birth, and it is even found in human breast milk. It is one of very few species of Lactobacillus that is uniquely adapted to reside in the human digestive tract and to interact with us in symbiosis.2

Researchers evaluated 40 children using the Mayo Disease Activity Index, which sets a score for the severity of symptoms, ranging from most severe (12) to no symptoms (0). For 8 weeks, in addition to oral mesalazine (a 5-ASA medication), the children were given an enema before bed containing either L. reuteri ATCC 55730 or a placebo. By the end of the study, 31 children had complied with all of the study’s protocols and the researchers looked only at the results from these children in their final analysis.

When they applied the Mayo Disease Activity Index to the final participants again after 8 weeks, the researchers found that the average score for the children who received the L. reuteri enema dropped drastically, from 8.6 to 3.2, showing a great improvement of symptoms. The children who received the placebo stayed relatively the same, only dropping from 8.7 to 7.1. None of the children who were using the placebo reached clinical remission, whereas 31% of those who were using the L. reuteri enemas did reach remission.

Although researchers aren’t certain how bacteria might affect the development of UC, previous studies have shown differences in microbiota diversity and other factors in ulcerative colitis patients compared to the regular population. Although these results are preliminary and the study sampled only a small number of children, with more research, probiotic treatments might be promising accompaniments to regular therapy for inducing remission of ulcerative colitis in children.

First published in the Inside Tract® newsletter issue 184 – 2012
1. Oliva S et al. Randomised clinical trial: the effectiveness of Lactobacillus reuteri ATCC 55730 rectal enema in children with active distal ulcerative colitis. Alimentary Pharmacology and Therapeutics. 2012;35:327-34.
2. Oh PL, et al. Diversification of the gut symbiont Lactobacillus reuteri as a result of host-driven evolution The ISME Journal. 2010;4:377-387.