CH391L/S13/Probiotics

Probiotics

A probiotic (from the Latin, pro-, "in favor, for" and the Greek , biōtikós, "pertaining to life")refers to live microorganism that provides a benefit to the host, either directly or indirectly, by via interactions with the hosts cells or the host's microbiota. Such microorganism will interact by producing bioactives, biological compounds and macromolecules, that will produce such benefit.Although the concept of a probiotic has evolved since the the last century and the the first years of the current century that it acquired the current definition and we can see the health benefits humans can gain from he understanding of such interactions. Some research currently ongoing include the Human Microbiome Project[], and the use on single organisms to prevent disease. For example, the use of fecal transplantation for antibiotic-associated diarrea[].

iGEM 2009: Stanford's Approach to Probiotics

The 2009 Stanford iGEM Team project centered on probiotics and Inflammatory Bowel Disease (IBD). IBD, as explained, is caused by an imbalance of two types of T-cells, Treg cells that immunosuppres the Th17 cells that cause the inflammation seen in patients. They suggest that an novel theraputic mechanism can be achieved by in vivo regulation of these cells. Their approach focuses in constructing two different Escherichia coli(E.coli) strains, each that would contain a distinct input/output cassette , each that is referred as a device. The first device would detect as input Nitric Oxide(NO), a byproduct of inflammation and Th17 proliferation, produces retinoic acid, that blocks further CD4+ T-cells differentiation into Th17 cells. The second device detects 5-Methyl tryptophan (5MT) as an input and produces Interleukin-6 to regulate Treg proliferation to regulate their immunosuppression response. Ideally depending on the balance between these two markers, if too much NO is sensed by Device 1 it would prevent inflammation. The opposite would also be true if the second device sences to much 5MT that would immunosuppress Th17 cell by blocking their differentiation.

Probiotics and the Media links

The Media perspective on Probiotics

• http://www.npr.org/2011/09/02/140146780/probiotic-bacteria-chill-out-anxious-mice
• http://www.telegraph.co.uk/health/healthnews/8261808/Designer-probiotic-yogurts-could-help-people-lose-weight.html

References

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8. Leemhuis H, Kelly RM, Dijkhuizen L. Directed evolution of enzymes: library screening strategies. IUBMB Life, 2009.