Lactose malabsorption is a condition of lactase nonpersistence in the cells of the brush border in the small intestine, in consequence of which lactose reaches undigested the colon, where it is actively fermented by resident microorganisms. This fermentation causes unpleasant effects to the host such as abdominal pain, bloating, borborygmi, or laxation. Yogurt lactic acid bacteria and some probiotics are able to evitate the appearance of such discomforts, either releasing lactase or fermenting lactose before it reaches the colon.
IBD (Inflammatory Bowel Disease)
Chronic idiopathic inflammatory bowel diseases (IBD) such as Crohn's disease, ulcerative cholitis, and pouchitis may be caused by a hyper-responsive cell-mediated immune response to intestinal commensal bacteria or microbiota aberrancies in genetically susceptible individuals (Sartor, 2004). IBD is correlated to the breakdown of the normal barrier function given by gut epithelial lining and its mucous. In these cases, the immune response of GI tract seems to be strictly associated with the composition of the microbiota—in particular, the balance of different groups of commensal bacteria may be altered during IBD (ILSI Europe, 2013).
Research on animal models reports probiotics' beneficial effects in the prevention of IBD. Clinical trials in human patients suggest that high number (>5 x 1010 cfu/d) of specific probiotic strains or their combinations can prevent recurrent intestinal inflammation and may possibly treat active IBD, with best results in pouchitis and, to a lesser extent, ulcerative colitis.