《经济学人》杂志原版英文(整理完整版)

《《经济学人》杂志原版英文(整理完整版)》由会员上传分享，免费在线阅读，更多相关内容在行业资料-天天文库。

1、DigestOfThe.Economist.2006(6-7)HardtodigestAwealthofgeneticinformationistobefoundinthehumangutBACTERIA,likepeople,canbedividedintofriendandfoe.Inspiredbyevidencethatthefriendlysortmayhelpwitharangeofailments,manypeopleconsumebacteriaintheformofyogurtsanddietarysupplements.Suchasmatt

2、eringofartificialadditions,however,representsbutadropintheocean.Thereareatleast800typesofbacterialivinginthehumangut.AndresearchbyStevenGilloftheInstituteforGenomicResearchinRockville,Maryland,andhiscolleagues,publishedinthisweek'sScience,suggeststhatthecollectivegenomeoftheseorgani

3、smsissolargethatitcontains100timesasmanygenesasthehumangenomeitself.DrGillandhisteamwereabletocometothisconclusionbyextractingbacterialDNAfromthefaecesoftwovolunteers.Becauseofthecomplexityofthesamples,theywerenotabletoreconstructtheentiregenomesofeachofthegutbacteria,justtheindivid

4、ualgenes.Butthatallowedthemtomakeanestimateofnumbers.Whatallthesebacteriaaredoingistrickytoidentify—thebacteriathemselvesaredifficulttocultivate.Sotheresearchersguessedatwhattheymightbeuptobycomparingthegenestheydiscoveredwithpublisheddatabasesofgeneswhosefunctionsarealreadyknown.Th

5、iscomparisonhelpedDrGillidentifyforthefirsttimetheprobableenzymaticprocessesbywhichbacteriahelphumanstodigestthecomplexcarbohydratesinplants.Thebacteriaalsocontainaplentifulsupplyofgenesinvolvedinthesynthesisofchemicalsessentialtohumanlife—includingtwoBvitaminsandcertainessentialami

6、noacids—althoughtheteammerelyshowedthatthesemetabolicpathwaysexistratherthanprovingthattheyareused.Nevertheless,thepathwaystheyfoundleavehumanslookingmorelikeruminants:animalssuchasgoatsandsheepthatusebacteriatobreakdownotherwiseindigestiblematterintheplantstheyeat.Thebroaderconclus

7、ionDrGilldrawsisthatpeoplearesuperorganismswhosemetabolismrepresentsanamalgamationofhumanandmicrobialattributes.Thenotionofasuperorganismhasemergedbefore,asresearchersinotherfieldshavecometoviewhumansashavingadiverseinternalecosystem.This,suggestsome,willbecrucialtothesuccessofperso

8、nalisedmedicine,asd