The Effectiveness of Probiotics in the Treatment of Inflammatory Bowel Disease (IBD)-A Critical Review

Abstract

Inflammatory bowel disease (IBD), which affects millions of people worldwide, includes two separate diseases: Crohn's disease (CD) and ulcerative colitis (UC). Although the background (chronic inflammatory state) and some of the symptoms of CD and UC are similar, both diseases differ from each other. It is becoming clear that a combination of many factors, in particular genetic background, host immune response and microbial reduced diversity status are associated with IBD. One potential strategy to prevent/treat IBD is gut modulation by probiotics. Over the last twenty years, many publications have focused on the role of probiotics in the course of IBD. The review discusses the utility of different strains of probiotics, especially Bifidobacterium spp., in all factors potentially involved in the etiology of IBD. The probiotic modulatory properties among different study models (cell lines, animal models of colitis, clinical study) are discussed and probiotic usefulness is assessed in relation to the treatment, prevention, and remission of diseases.

Keywords: Bifidobacterium; Crohn’s disease; anti-inflammatory; inflammatory bowel disease; probiotic; treatment; ulcerative colitis.

Figure 1

The key players in inflammatory bowel disease.

Figure 2

The role of the immune response in IBD. In CD, Th1 skewing is observed, but in UD, Th2 skewing is common. The population of Th17 cells is decreased regarding the Th1 or Th2 population. The decreased number of Treg cells and imbalance in Th17 and Treg subpopulation are common in both diseases. The subpopulation disturbance triggers the loss of tolerance for microbiota and the privilege of the proinflammatory processes. In turn, microbiota modulates the Treg population and has an anti-inflammatory effect.