The lifespan of healthy intestinal epithelia is generally accepted to be about 5 days. These cells, once departed and sloughed off into the fecal stream, are replaced by newer, younger, healthier cells which proceed through the same life-cycle. In the case of inflammatory bowel diseases (IBDs), in addition to inflammation/ulceration/tissue injury, the migration process of these new epithelial cells is stunted. Since the replacement cells have trouble reaching their destination, damage to the intestinal lining is exacerbated.
A recent study -- published in PLoS ONE and open access if anyone wants to take a peek -- investigated the capacity of a nonpathogenic yeast to alleviate this stunted migration of new epithelial cells to the tips of intestinal villi (the fingers of tissue that protrude from the intestinal wall to create surface area for absorption). Saccharomyces boulardii (Sb) is typically used to treat issues such as diarrhea, the idea being that it stimulates growth factors that help restore homeostasis to the gut.
This nigh-rockstar study strikes me because it is targeting a curative mechanism as opposed to a squelching of symptoms. To achieve actual remission in IBDs, one has to pwn both inflammatory and repair dysfunctions. The inflammatory component is predominantly targeted by the entourage of immuno-suppressants with which Crohns are so familiar. Repair is seldom highlighted as it should be -- excepting methods of balancing gut flora.
The team of scientists in France, lead by one Frederic Andre, looked at the beneficial effects of Sb in both mice and an in vitro wound model (this is a strain of cultured epithelial cells which are attacked gently with a toothpick... rather cute).
The first major finding was that mice who were fed Sb for one week doubled new epithelial cell migration. Only one downer for me in this study was that the mice were all healthy, with no in vivo IBD model for comparison. Nonetheless quite encouraging, no?
The second conclusion was that the wounded cell line closed its wound (or, repaired its injury) by roughly 70%. Their video supplement to this end is quite something.
The scientists conclude that Sb improves new epithelial migration both in vivo and in vitro. Interestingly, the study suggests that increased migration is due to increased motility of cells and not to increased proliferation (the generation of new cells). Sb may be stimulating this activity by secreting factors that stimulate a target signaling pathway FAX/paxillin, which leads to several physiological changes in the intestinal epithelial lining that enable motility of new epithelial cells.
The thing about supplement studies such as this one is that they make me want to stop by the grocery and pick some up on my way home...
Canonici A, Siret C, Pellegrino E, Pontier-Bres R, Pouyet L, Montero MP, Colin C, Czerucka D, Rigot V, & André F (2011). Saccharomyces boulardii Improves Intestinal Cell Restitution through Activation of the α2β1 Integrin Collagen Receptor. PloS one, 6 (3) PMID: 21483797