fructans of jerusalem artichokes

8/2/2019 Fructans of Jerusalem Artichokes

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AmJC/ in Nuir 1990 ;52 :6 75-81 . P rin ted in USA . 1990 Am erican Soc ie ty fo rC lin ica l N u trition 67 5

F ru c ta n s o f J e ru s a le m a rtic h o k e s : in te s tin a l tra n s p o rt,a b s o rp tio n , fe rm e n ta tio n , a n d in flu e n c e o n b lo o d g lu c o s e ,in s u lin , a n d C -p e p tid e re s p o n s e s in h e a lth y s u b je c ts 1 2Jun Jo han nes R um essen , Su san B ode , O le H am berg , a nd E iv in d G udm an d-H # {2 48}yer

ABSTRAC t F ruc tans a re na tu rally occu rrin g p lan t o lig o -saccharides w ith sw ee ten in g p ro pe rtie s . F ruc tans(FA s) iso la tedfrom Je rusa lem artichok es (H e/ian th us tubero sus) w ere stud iedw ith re sp ec t to in tes tina l h an d ling and in flu en ce on b lood g lu -cose (BG ), in su lin , and C -pep tid e re sp onses in e igh t h ea lthysu b jects . T h e re spon ses w ere com pared w ith those fo r fruc to seing es tio n . Th e e ffect o f FA s ad ded to a w hea t-s ta rch m ea l w asa lso stu d ied . S tanda rd ized b reath -h yd rogen ex cre tion m di-ca ted tha t FA s w ere com p lete ly m a labso rbed and , a fte r a 20 -gd ose , tra ce s o f FA w ere d etec ted in 2 4 -h u rin e co lle c tio ns inon e sub jec t o n ly . O roceca l transit tim es w ere long er fo r FA sth an fo r lac tu lo se and fruc to se. T he B G and insu lin in crem en tsw ere ve ry low afte r FA in gestion , low er th an afte r fru cto se in -gestion , w h ereas h ydrog en p rod uc tion w as m uch h ig he r. A reasu nde r BG curves tend ed to be sm a lle r w hen 1 0 g FA w as add edto a 5 0 -g w hea t-s ta rch m eal, bu t the re w as n o appa ren t in te rfe r-en ce w ith sta rch abso rp tion . A m J C lin N utr l990 ;52 :675-81.

KEY WORD S B rea th te sts , d ieta ry ca rb ohy drate s , d ie taryf ib e r, fruc tan , fru cto se, h yd rog en , inu lin , o ligosaccha rid cs,s tarchIntroduct ion

F ruc tose po lym ers co n ta in in g a sing le g lu co se m oie ty [fru c-tans (FA s )] a re w idesp read in v arious p lan ts , p ar ticu la rly thoseo f th e C om pos itae and G ram in ae fam ilies [eg ,iium sp , ar t i -chok es , a sp aragus, cereals (w h ea t and ry e) , andah lia sp j (1 ,2) . Syn th etic FA s w ith sw ee ten ing p ro pe rtie s an d a low degreeo f po lym eriza tion (ch ain len g th o f th ree to f ive su ga r un its)have been d ev elo ped th ro ugh the use o fiso lated fruc to sy ltrans-fera ses (3 , 4 ). W e stud ied na tu ra lly occu rr ing fruc tans o f lo ng ercha in leng th s, iso la ted and purified from the tu be rs o f J erusa -1 cm a rtic ho ke s (H e /ian th us tu berosu s) by a new ly d eve lopedprocedu re . N a tu ra lly occu rr ing s to rag e po ly saccha ride s fromplan ts , su ch as FA s, m ay sh are p rope rties w ith re sis tan t s ta rchand easily ferm en tab le d ie ta ry f ibe r. S u ch po lysacch a ride scou ld have seve ral po ten tia l n u tr itiona l advan tages a s a d ieta rysup p lem en t and as a sw eeten in g ag en t fo r d iab e tic s .

W e stud ied th e abso rp tio n , tran sit, and fe rm en tatio n o f FA sas w e ll a s th e ir in f luence o n b loo d g lu cose (BG ), in su lin , andC -pep tide re spo nses in h ea lth y sub jec ts . T he p ro pe rtie s o f FA sw ere com pared w ith the ir m onom er fru cto se , w h ich is ve ry o f-

ten in com ple te ly abso rbed (5 , 6 ) and w hich has been prom o tedas an alte rna tive d ieta ry sw ee ten er (7 , 8 ). U nabso rb ab le s to rag eand stru c tu ra l po lysacch a ride s m ay low er BG and in su lin rsp onses to a te st m ea l (9 -12 ) and d ie ta ry f ibe r m ay in c rea sesta rch m a lab so rp tion (I 3 ). W e the re fo re a lso stud ied the effec tso n ab so rp tion and m e tabo lic re sp onses o f th e add ition o f FAto a sta rch m eal.

Sub jects and m eth od sSubjec ts

Eigh t health y sub jec ts ( tw o fem a le , s ix m a le ) aged 2 3-33partic ip a ted . T he sub jec ts w ere of idea l bodye igh t 10 %(m ed ian an d in terqu artile ran ge , 74 kg and 63-76 k g , re spec -tive ly ) and h ad no h isto ry of d iabe tes o r o f g as tro in testina lp u lm ona ry d isease . Th ey w ere no t u nde r an y m ed ica tion , andb lood screen ing te sts w e re no rm a l. T he stud y pro toco l w asp-prov ed by the C openh ag en C oun ty M ed ica l E th ic s C omm ittee .F ruc tan s (fruc tose o /ig osaccha rides)

T he FA s used in th is s tudy w ere unb ranched cha ins o f fruc to -fu ran ose un its in /3 -(2 - l)-g lycosid ic b ind ing [(2 - l)- f3 -D -fruc to -fu ran ose ], con ta in in g a sin g le g lucose m oie ty (2 ). F o r the p u rpo se o fth is s tudy , FA s w ere pu rified from Jerusa lem -artichok etubers in D ecem ber by m eans ofa new ly deve loped procedu re(D an isco A /S , D an ish Sugar C orp , N aksk ov , D enm ark ).

T he c lean ed tub e rs w ere s liced an d ex trac ted in h o t w a te r.T he cx trax t w as pu rif ied by lim e treatm en t, io n exchan ge , andac tiva ted ch arcoa l. T he p urified ju ice w as concen tratedevapo ra tion , and the f ina l d ry , w h ite p ow der w as p rodu ceda vacuum d rye r (pa ten t ap p lica tio n 1 5 92 /8 8 -K 4 ).

T he ch ain len g ths o f FA s an d the su ga r res idues w ere d ete r-m in ed by h igh -p re ssu re liqu id ch rom a tog raph y (H PLC ) equ ip -m en t (W ate rs M illip o re , Inc , C op en hagen ) w ith tw o co lum ns

C F rom th e Labo ra to ry o f G astroen te ro log y and C lin ica l N u tr ition ,D epartm en t o f In te rna l M edic ine F , and the D epartm en t o f C lin ica lC hem is try , G en to fte H o sp ita l, U n ivers ity o f C openhagen .

2 A ddress rep rin t requests to JJ R um essen , D ep a rtm en t o f M ed icalA na tom y C , P anum In stitu te , U n ive rsity o fC openhagen , B legdam sv e j3 , DK -2200 N , Copenhagen , D enm ark .

R ece ived A ugus t 4 , 1989 .A ccep ted fo r pub lica tio n O ctober 1 1 , 1989 .


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ppm

FA

1

1 2 3 4 5 6 7 8 9 101

67 6 RUM ESSEN E l A L

FI G 1 . M edian increm en ta l b rea th -hyd rogen concen tra tions (hou rly va lu es on ly ) in e ig h t sub jec ts a fte r 1 0 g lac tu -lo se (L , 0 ), 20 g fruc tose (F , 0 ), 5 g fruc tan (FA ,{149}),0 g FA ( i) , an d 20 g fruc tan (Li) m onito red fo r 12 h .

TABLE 1Phy sica l p ro pertie s o f th e fruc tans s tu d ied T ex tu re W hite, am orph ous pow derD ens ity (g Jcm 2) 0 .75W ater so lub ility (g IL ) 200 -300 at 3 0 *C ; 400 a t 50 CSw eeten in g pow er 1 /3 x sucro seM eltin g po in t (C ) 130-180V iscosity (Pa .s) 0 .00 2-0 .004 (a t 100 -300 g /L and at 20 C )Acid stab ility f 1 h 1% , 2 h 3 % , 3 h 4 % , 4 h 6 %

Accord ing to the su pp lier .t A ssessed by an in dependen t tes t pane l (Ju tland Ins titu te o f T ech-

no logy , A rh us, D enm ark).:j: P e rcen t hydro ly sis a t pH 2 .5 (c itr ic ac id ) a t 40 C .

in se ries (B io rad am inex HPX -42C , B ie & B ern tsen , C op enha-g en ). S am ple s w ere d isso lv ed in de ion ized w a te r to 5 g /l00 m Land an aly zed in 1 5 -zL sam p les a t 85 C an d a flow rate o f 0 .3m L /m in . T he frequenc ie s o f d iffe ren t cha in leng ths and re si-d ues in th e p rod uc t w e re as fo llow s: fruc to se 3 .8% ; g lucose5 .1% ; sucrose 14 .5% ; and th ree -sugar un its 10 .6% , four un its10 .2% , f iv e un its 7 .5% , six un its 7 .0% , seven un its 6 .1% , e igh tu n its 5 .3% , and m ore than e igh t un its 29 .9% . Enzym atic d e te r-m ina tion (w ith k its from Boeh rin ger, M annh eim , FRG ) oflu -co se and fruc to se in th e p rod uc t rev ea led th at g lu co se w as 1 .8%and fru cto se, 2 .4% . Th is d isc repancy from the HPLC ana lysisis du e to a s lig h t hydro ly tic activ ity o f the co lum n tow ard theterm in al g lu co se -fru cto se g lycosid ic bo nd , and th e enzym a ticde te rm in atio ns a re con side red m ost accu ra te . O the r p hysica lp ro pe rtie s o f the p rodu c t arc show n in T ab le.Study design

A ll sub jec ts w e re in itia lly ch a llen ged w ith 10 g1 5 m L ) lac tu -lo se [4 -($ -D -g alac topy rano sy l)-D -fruc to se j; SA D , C openh ag en )in 100 m L tap w ate r. T h e lac tu lose so lu tion (SAD ) con ta ined1 10 g ga lacto se and 6 0 m g lacto se /L . A ll su b jects w e re ab le to

genera te a sign ifican t, susta ined rise in hydro gen concen tra tio nin en d-exp ira to ry air o f 0 ppm (14 ). F u rth erm o re , the fo l-low ing cha llenges w ere g iven in ran dom order on a sing le -b lindbasis on d if feren t days separa ted by 72 h , w ith in 1-2 m o: 1)5 g FA (D anisco A/S) in 50 m L tap w ate r; 2) 1 0 g FA in 100m L tap w a te r; 3) 20 g FA in 200 mL tap w a ter ; 4 ) 2 0 g fruc to se(D -fruc topy ran ose , SAD ) in 2 00 m L tap w ate r; 5) 50 g whea tsta rch as b read m ade from glu ten -con ta in in g w hea t f lou r (N a-tion al In stitu te o f A n im al S c ience, C openh ag en ) w ith the folow ing carb ohydrate con ten t (% o f dry w t): FA s 1 .4% , sta rch84 .9% , an d non sta rch p o lysaccha rid cs 3 .9% ; lign in m ade u0 . 1% . Th e b reads w ere baked a t 2 20 C fo r 2 0 mm . N o sabak ing pow der, o r yeast w as u sed in th e process. 6 ) 50 g w heas ta rch in bread m ade as ab ove sup p lem en ted ha lfw ay th rou ghth e m ea l w ith 1 0 g FA in 10 0 m L (as in). A ll m eals w ere ea tenw ith in 15 mm .

B reath -h yd rog en tests w e re pe rfo rm ed be fo re and d uring am ea ls af te r a 12 -h o ve rn igh t fa st and a ch lo rhex id in e m ou th -w ash . D up lica te sam ple s w ere taken eve ry 1 5 m m un til o roce -ca l transit tim es w ere de te rm in ed an d ev ery 3 0 m m un til 12a fter in gestion o f the te st m ea l, as p rev iou sly desc rib ed (141 6 ). H ydrogen concen tratio ns w ere ana lyzed on an ex ha led -hy d rogen m on ito r (G as M easu rem en ts L td , R enfrew , S co tl and ) ( 1 4) . S tanda rd ized sym p tom sco res w ere com ple tedth ro ugh ou t a ll te s ts an d com p rised th e occu rrence o f f latulence , d is tension , bo rbo rygm ia , ab dom ina l p a in , an d d ia rrhea.A ll sym ptom s w ere ra ted as no ne (0 ), m ild (1 ) , m ode ra te2) ,o r seve re (3 ) by the su b jec ts at fix ed tim e in terva ls , an d a to tasym p tom sco re fo r each o fthe tests w as ca lcu la ted .

In all s tud ie s , excep t stu dy 1, co ncen tra tion s o f BG , serumin su lin (IR I), an d C -p ep tid e (ICP ) w ere d ete rm ined befo rem ea ls and ev ery 1 5 mm from 0 to 90 m m and eve ry 3 0 mfrom 90 to 1 8 0 mm . A ll sam ple s w ere d raw n from an in dw e ll-in g v enous ca the te r. BG w as ana lyzed by a g lucose dehyd roge-n ase m eth od (M erck , D arm stad t, FRG ). S erum sam ple s fo rIR I and IC P ana lysis w ere sto red at -20 C un til ana ly sis

Hour s1 2


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I N TEST IN A L HA ND L ING OF FRUCTA NS 67 7TA BL E 2Orocecal transi t times (OCTTs) and hydrogen producti on af teri ngestion of l actulose, f ructose, and di f f erent doses of f ructan inei gh t su bj ec ts

OCTTH ydrogen production

Total A UCt SPeak H 2m m ppm.min.102 ppm

1 0 g l ac tu lo se20gfructoseSgfructan

lOgfructan20 g f ru ct an

90 (60- 120)25(15-225)

270(235-300)1 7 5 ( 1 55 - 27 0 )1 4 5 ( 8 5- 1 80 )

7 4 ( 54 -1 05 )15(12-57)48(32-56)

1 0 9 ( 7 7- 1 38 )1 7 7 ( 1 24 - 27 6 )

3 6 ( 27 -4 7)2 1 ( 10 -6 1)29(28-32)5 1 ( 38 -6 4)6 5 ( 36 -7 8)

M edians; i nterquarti l e ranges in parentheses.t Total i ncremental areas under the hydrogen-concentrati on-v s-

time curves f rom OCTTs.:1 :M aximal i ncremental hydrogen concentrati on f rom low est prev i -ous v al ues.

From the four subjects w i th detectable f ructose malabsorpti on.

radioimmunoassay (RIA -gnost, Behringsw erke, M arburg,FRG). A f ter i ngesti on of 2O g FA (study 3) ur ine w as col l ectedf or 24 h and the presence ofFA in urine was analyzed by cnzy -mati c determ inati on of f ructose af ter perchlor i c acid hydrol ysi sof FA (B oehringer M annheim ) (17).D ata analysis

For breath-hydrogen tests orocecal transi t times (OCIT ),peak i ncremental hydrogen concentrati ons (speak H 2, andtotal i ncremental areas under the hydrogen-concentrati on-vs-time curves (A UC) w ere calculated as prev iousl y described (15,1 6). The malabsorbed amounts of f ructose and w heat starchw ere estimated by means of total A UCs of the 10-g lactulosestandards ( 16). I n a few instances hydrogen concentrati on didnot reach basel i ne af ter a 12-h period and the smal l addi ti onalareas w ere determ ined by ex trapolati on.

For BG, IRI , and ICP, f asti ng concentrati ons ( i c, basel i ne),peak incremental values, and areas under the concentrati on-vs-time curves were calculated. A reas were calculated both asposi ti ve incremental areas above basel i ne and net incrementalareas (total areas m inus basel i ne times 180 mm).

N onparametr ic stati sti cs [Pratt s test (1 8) and Friedman stw o-way analy si s of var iance (A NOV A ) w i th mul ti ple-compar-i son pr ocedures ( 19)] w ere used and, consequentl y , al l resul tsare expressed as medians and intcrquarti l e ranges. values< 0.05 w ere considered signi f i cant.

R e s u l t s

The A UCs increased in proporti on to increasing doses of FA(Fig 1, Table 2). T he A UCs of 10 g FA w ere not signi f i cantl ydi f ferent f rom A UCs of 10 g lactulose. H ydrogen producti onaf ter 20 g f ructose w as much low er than af ter 20 g FAP < 0.01,Pratt s test) . Four subjects had detectable malabsorpti on of the20-g-f ructose dose (cal culated amounts 2-5 g). T he OCIT s de-creased w i th increasing doses of FA (Table 2); 10 g FA had a

signi f i cantl y slow er transi t tim e than 10 g lactuloseP < 0.01,Pratt s test) , and 20 g FA had a signi f i cantl y f aster transi t timethan 5 g FA (P < 0.0 1, Pratt s test) (Table 2). A NOV A ofOC -IT s of 10 g lactulose, 5 g FA , 10 g FA , and 20 g FA show edsigni f i cant di f f erence (P < 0.01). M ul ti ple-compari son proce-dures show ed that there w ere signi f i cant di f f erences betw een 1g lactulose and 5 g FAP < 0.01) and betw een 10 g lactuloseand 1O gF A (P< 0.05) .

Fasti ng concentrati ons of BG , IRI , or ICP did not vary sini f i cantl y for the di f ferent substrates (Table). T h e m ax im alincrements in BG were signi f i cantly larger for 20 g f ructosethan for 20 g FA (P < 0.02, Pratt s test). Sim i l arl y , both netareas and posi ti v e incremental areas under the BG-vs-timecurves w ere larger for 20 g f ructose than for 20 g FAP = 0.04and P = 0.08, respecti vel y )(T able 3). Peak incremental IRI w asalso signi f i cantl y l arger f or 20 g f ructose than for 20 g FAP< 0.05, Pratt s test) al though A UCs w ere not di f f erent (Table4) . Peak incremental ICP and A UCs w ere the same20 g f ructose and 20 g FA (Table 4). There w as no detectabledi f ference betw een 10 g and 20 g FA for BG, IRI , or ICPsponses (T ables 3 and 4). W i th 10 g lactulose as a reference,A NOV A show ed that both peak incremental BG and netposi ti ve incremental A UCs ofG w er e sig n if ican t ly lar ger f or20 g f ructose (P < 0.05) but not for 20 g FAP > 0.10)(Table 3).

M alabsorpti on af ter i ngesti on of 50 g wheat starch w as detected in si x subjects (calculated malabsorbed amounts 2-g). For these subjects OCITs w ere 6-8 h (T able 5). A f ter 50 gw heat starch w i th 10 g FA the total hydrogen producti on(A UCs) was not signi f i cantl y di f ferent f rom that fol l ow ing thsum of 50 g w heat starch and 10 g FAP > 0 . 10 , Pratt s test);OCT Is for 50 g w heat starch w i th 10 g FA w ere shorter compared w i th the value f or w heat starch aloneP < 0.05, Pratt stest).

A f ter the addi ti on of 10 g FA to the starch meal , a trendo-w ard lower BG values, cal culated as the posi ti ve or net i ncre-mental areas under the curves, w as apparent (Fig 2, Table)(P = 0. 1 3 and P = 0.04, respecti vel y ; Pratt s test) . There w asno di f ference betw een the magni tude or the tim ing of the peakincremental BG values (Fig 2, T able 6). T here w as no detect-able di f f erence betw een peak incremental v alues or net anposi ti ve incremental areas under the IR I and ICP concentra-ti on curves (Table 7).

T A B L E 3Glycemic responses of di f f erent doses of f ructan compared w i thlactulose and f ructose in eight subjects

PeakBGt N etA UC Posi ti ve A UCm mo//L mm o/. L m m mm o/. L mm

lOglactulose20 g f ructosel0gfructan20 g f ructan

0 (0.OtoO.l)0.8 (0.6 to 1 .0)0 . 2( 0. 1 t o 0. 4 )0.2 (0. 1 to 0.3)

-56(-l l2to -36)-45 (-95 to 34)-14(-52to 18)-38 (-69 to -20)

0(Oto 1)24 (2 to 47)9(Oto 18)2 (0 to 6)

M edians; i nterquarti l e ranges in parentheses.t M ax imal i ncremental ri se ofblood glucose f rom fasti ng values.t Total areas under the blood-glucose-vs-time curves m inus [180mm times fasti ng values] . Posi tiv e incremental areas above fasting values.


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678 R U M ES S EN E l A L

M ed ian s; in te rquartile rang es in paren these s .

T A BL E 4In su lin (IR I) and C -pep tide (IC P) re sp onses to f ruc tan s com pared w ith f ruc to se in e igh t sub jec ts

IR I IC PSPeakI R I t N et A U C Positiv e A U C Peak IC Pt N e t A U C Po sitiv e A U C

pmo//L pmol. L . mm pmol. L . mm pmo//L pmo/. L . mm pmo/. L . mm20 g f ru ct os elOgfructan20 g f ruc tan

29 ( 19-47)22(11-29)1 9 ( 10 -24 )

6 4 6 ( - 94 7 -1 8 94 )-108(-1349-ll33)

6 24 (2 22 - 1019)1 04 0 ( 5 02 - 18 9 4)330(237-703)86 1 ( 4 16- 10 19)

16 7 ( 100-200)100(33-133)1 33 (67 -200 )

4 .3 ( -5 .3 -9 .0 )2.0(-3.6-l2.3)

-0 .3 (-6 .6 -3 .0 )

5 .7 ( 2. 7- 10 .3 )4.3(1.0-12.7)3 .3 (2 .0 -4 .0 )

M ed ian s; in te rquartile rang es in paren theses.t M ax im al in crem ental rise abov e f astin g v alues.

O n ly m ild f latu len ce and bo rbory gm ia w ere repo rted ex cep tf or o ne sub jec t w ho com plained o f m oderate f latu lence af ter1 0 g FA (T able 8). T he d if f erence be tw een 20 g FA and 20 gf ru cto se or b e tw een 50 g w heat starch and 50 g w heat starchp lus 10 g FA w as no t sig n if ican t (P = 0 .0 8 and P = 0. 16, respec-tiv e ly ; Pratts te st). A N O V A rev ealed no sig n if ican t d if f e rencesbe tw een th e sy m ptom scores o f all challeng es. D iarrhea orb-dom inal pain w as no t repo rted .

U rine analy ses f or FA s in 24-h co llectio ns af te r a 20-g do sew ere negativ e in sev en sub jects. A con cen tration o fO .2/L cor-resp ond ing to a 24 -h ex cre tion o f I 32 m g FA (< 1% of the load)w as f ound in one sub ject.

DiscussionFA s arc f ru c to -o ligosaccharid es w ith d if f eren t degrees o f po -

ly m eriz ation th at occur in v ary in g pro portion s in d if f e ren tplan t sp ecies and w ith characteristic seasonal v ariation s (2 0).T h e m ost w e ll-described FA is inu lin , w hich has 35 f ruc toseun its (2 1 ). FA s w ith 50 f ruc tose un its h av e been iden tif ied ingarlic (20).

In 1874 inu lin w as fo und not to be degrad ed , hy dro ly z ed ,o r d etec ted in urine o r f eces af ter ing estion in hum ans22 ). Aben ef ic ial e f f ec t o n u rin ary g lu co se ex cre tion in patien ts w ith

T A B L E SO rocecal transit tim es (O CT T s) and h y drogen respon ses af te r 5 0 gwh e a t starch , 10 g f ruc tan , and the com bin ed m eal in e igh t sub jec ts

OCTT

Hydrogen re sponse

T otaIA U C PeakH2mm ppm.min.102 ppm

S O g w heatstarch 425(375-475)t 2 9 (6 -6 0 ) 24 (1 1 -37 )

l0gfructan 175 (155-270) 109 (77-138) 51 (38-64)5 0 g w heat

starch+ lO gf ruc tan 300 (3 00 -32 5 ) 141(70-178) 53(48-60)

M ed ians; in terquartile ranges in paren these s .t From th e six su b jec ts w ith de tectab le m alabsorp tion .

d iab etes m ellitu s w as ob serv ed (22 ). T he in teres ting d ie tary andc lin ical asp ec ts o f FA p rom pted the p roduc tion o f sy n the ticf ruc too ligo saccharides. S tud ie s o f N eosugar (M e iji S e ik a C o ,Japan ), a m ix ture o fFA s con tain ing tw o to fo ur f ru c to se m o le -cu les, suggest that it is n o t h y dro ly z ed by d ig es tiv e en z y m es andin creases f ecal w e igh t and ex cre tion o f v o latile f atty ac idsrats (4 , 23 ). S tud ies in hum ans hav e suggested th at N eosugarcom ple te ly m alabso rb ed (24). It m ay p rom ote b if idobac teriain co lo n ic m ic ro f lo ra and does ot raise B G o r insu lin uponin gestion (25). Y am ash ita e t al (26) found that N eosugar lowered f as ting B G concen tratio ns in non-in su lin -d ep enden t d ia-b e tic s(26 ). T he FA s stu d ied by u s occur natu rally in Jerusalemartich ok es and th ey hav e longer chain leng th s than N eosugar(50% hav e m o re th an fo ur f ru cto se un its) .

T h e standard iz ed h y drog en p roduc tion and the urine analy -ses f o llow in g a 20 -g-FA load , w hich show ed traces o f FA in onp erso n on ly , su ggest com p le te m alabsorp tion o f FA .

T he m uch larger hy d rogen response to FA than to f ruc toseand the fac t that FA induces low er g ly cem ic resp onses and isu lin peak s than does f ruc tose m ay ind icate thatgastric acido r sm all in te stinal hy dro ly sis o f FA to f ru cto se m onom ersin sign if ican t. T h is agrees w ell w ith in v itro stu d ies o f hy d ro ly siso f cereal FA by hum an gastric ju ice27 ). T he v ery m odes trise in B G seen in ou r stud y af ter FA in tak e seem s w ellcoun ted f or by the su crose and m onosaccharide con ten ts o f thproduct.

FA is tran spo rted m o re s low ly in the upp er in testine w hencom pared w ith f ruc tose or the d isaccharide lac tu lo se . T hep-per in testinal tran sit o f FA m ay b e slow er than the tran sitequ iv alen t am ounts o f nonab sorbab le m ono- or d isaccharides

T A B L E 6B lo od g lucose (B C) re spon ses af te r a starch m eal w ith and w ithou taddition o f 10 g f ru c tan in e igh t sub jec ts

S Peak B C N et A U C Pos itiv e A UCmmo//L mmo/. L. mm mmo/. L . mm

SOgwheatstarch 2.4(1.1-3.7) 121(37-177) 134(37-191)5 0 g w heat s tarch

+ lOgfructan 2.3(1.4-3.3) 54(-38-142) 90 (32-155)


5/7

1.

\N : i-1

IN TEST INA L HA ND L ING OF FRUCTA NS 679

M edians; i nterquarti l e ranges in parentheses.

ABGmmol/1

M m.

FIG 2. M edian incremental blood glucose values(BG) in eight sub-j ects af ter i ngestion of 10 g f ructan (0), 50 g w heat starch#{149}),nd thecombined meal (A) moni tored for 180 mm.

because of the larger molecular si ze ofFA and a less prom inentosmoti c ef fect. The OCTTs of N eosugar seem shorter than thetransi t times of the FA studied by us (24).

M alabsorbed FA is v igorousl y f ermented by the coloni cf l ora. Compared w i th equivalent amounts of l actulose, the hy -drogen producti on f ol l ow ing FA w as of sim i l ar magni tude eventhough the contents ofactual f ructose polymers in the productw as not 100% . T he more prolonged OCITs of FA comparedw i th lactulose i s in i tsel f unl i kel y to inf l uence FA -induced hy-drogen producti on (1 5). A larger coloni c bacter i al hydrogenproducti on af ter i ngesti on of the FA substrate compared w i thlactulose theref ore cannot be excluded. Complete or nearl ycomplete f ermentati on of cereal FA and inul i n w as demon-strated in rat hindgut (28).

T A B L E 7

FA s have a smal ler gl ycem ic ef f ect than does f ructose, w hichhas been recommended as a sweetening agent in control l ednon-insul i n-dependent diabetes because of i ts smal l gl ycem icef fect (7, 8, 22, 29-34). B ecause of the lack of FA absorpti on,the possible metabol i c di sadvantages of f ructose ingesti on (35could be avoided. L arger doses of FA are necessary , however,to achieve equal sw eetness compared w i th f ructose. M alab-sorpti on of f ructose i s f requent (6, 36) and i t may produceb-dom inal symptoms in susceptible subjects (37). Chronic intakeofN eosugar may give r i se to gas problems (24). Only negl i giblesymptoms w ere provoked by FA in the present study , but thabdom inal symptoms and metabol i c consequences of chroni ci ngestion of FA w i th longer chain lengths need further studyFA may paral l el ef f ects of nonabsorbable starch componentsand certain ty pes of dietary f i ber 13, 38, 39).

FA does not seem to inf l uence w heat-starch absorpti on,w e described prev iousl y f or di f f erent types of dietary f i ber (13)FA may, how ever, modi f y the BG responses to ingested starch.BG values seemed to return to basel i ne earl i er w i th a more atenuated hypoglycem ic phase w hen FA w as given. T his w as noattr i butable to di f f erences in IRI or ICP responses and was pres-ent w el l bef ore the meal reached the cecum . A n ef f ect of FA ogastric empty ing i s possible and may also account f or some othe shortening ofOCIT . The ef f ect may depend on the dietaryf ormulati on, and diabeti cs may respond di f ferentl y f rom non-diabetics.

Complete malabsorpti on of FA reduces the caloriv alue of the product compared w i th that of w el l -absorbedcarbohydrates such as sucrose. This may be relevantnon-insul i n-dependent diabeti cs and obese indi v idual s. M e-tabol i c studies in humans suggest that 50-60% of the theretical energy may be avai lable f rom malabsorbed carbohy-drate af ter complete coloni c bacter ial f ermentati on processes(40-43). The apparent metabol i zable energy of Neosugarrats w as estimated to be tw o-thi rds of the combustion energyor less (44).T he potenti al benef i ts ofFA as a therapy f or diabetes (22, 26need conf i rmation. B ecause of i ts sweetening properti es (athough only one-thi rd as sweet as sucrose), FA may be useda dietary addi ti ve in sw eets, sof t dr i nk s, and food. For diabeti cs,FA could increase palatabi l i ty and compl iance w i th insigni f i -cant gl ycem ic ef fect and possibl y nutri tional ly advantageousef fects. The properties of FA products w i th even longer chainlengths ex tracted f rom other plant species need to be investi -gated. L ong-term studies of FA ingesti on are needed to f urther

I nsul i n (IRI ) and C-pepti de (ICP) responses af ter SO g w heat starch and a combined meal of 10 g f ructan and 50 g w heat starch in eight subjeI RI ICP

SPeak IR I N et A UC Posi ti v e A UC SPeak ICP Net A UC Posi ti ve A UCpm o//L pm o/. L . m in pm ol. L m ipr pm o//L pm o/. L . m m . iO pm o/. L . m m . io

S Og wh e a t s t ar c h50 g w heat starch

+ l Og f r u c t a n

1 9 3 ( 9 0 - 2 74 )

2 0 1 ( 7 3 - 2 6 3 )

1 0 7 ( 5 3 - 1 6 4 )

1 0 9 ( 4 6 - 1 4 5 )

1 0 7 ( 5 3 - 1 6 4 )

1 1 0 ( 4 9 - 1 4 6 )

8 0 0 ( 3 3 3 - 1 1 3 3 )

8 6 7 ( 4 0 0 - 9 6 7 )

5 8 . 3 ( 2 3 - 8 9 . 3 )

4 9 ( 3 8 - 8 1 )

5 8. 3 ( 2 3 - 8 9 . 3 )

4 9 ( 3 8 - 8 1 )


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680 RUM ESSEN E l A LT A BL E 8A bdom inal sy m p tom scores recorded during the te s t pe riod s

Substrate M ed ian score In terquartile rang eS y mp t o m s

N one M ild M oderate S ev ere10 g lac tu lose 6 1-9 2 6 0 0SOg f r u c t a n 2 1 - 1 1 2 6 0 0l 0 g f r u c t a n 2 . 5 0 - 1 1 4 3 1 02 Og f r u c t a n 7 . 5 4 - 1 4 0 8 0 020 g f ruc to se 3 .5 1 -9 2 6 0 050 g w heat starch 0 0 -5 5 3 0 0S O gw heatstarch+ lO g f ruc tan 5 .5 2 -9 1 7 0 0

T o tal sco re s w ere calcu lated as th e sum o f all reg is te red sy m p tom s in w e ll-de f in ed in te rv als durin g the 1 2 -h tes ts.

assess th e phy sio log ical and nu trition al ef f ec ts in health y sub-jec ts and in patien ts w ith d iabe tes m e llitus . B

W e are g rate fu l to G B ischo f f , E B orresen , B Falle sen , L M H an sen ,0 H an sen , L K rogh , and I S taack for techn ical assistance . W e th an k SPe ters and JO R um essen fo r com ments on th e m anuscrip t.

References1 . A rchbo ld H K . Fruc to san s in th e m onoco ty ledons. A rev iew . N ew

P h y t o l l 9 4 0 ; 3 9 : 1 8 2 1 9 .2 . E de lm an J, Je f f o rd T G . T he m echan ism s o f f ru cto san m e tabo lism

in h ig her p lan ts as ex em plif ied ine /ia nihus tube ro sus . N ew Phy -t o l l 9 6 8; 6 7 : 5 l 7 - 3 l .

3 . S h iom i N , Iz aw a M . Purif icatio n and charac teriz atio n o f sucro se:sucro se- 1 -f ru tosy ltransf erase f rom the roo ts o f asparagu sAspara-g us o ffi ci na li s L. ) . A g r ic B io l C hem I980 ;44:6 03-l4 .

4 . O k u T , T ok unaga T , H o soy a N . N ondig estib ility o f a new sw ee t-ener, N eo sugar, in th erat. J N utr 1 984 ; 1 1 4:1574 -81 .

5 . R av ich W i, B ay le ss T M , T hom as M . Fruc to se: incom ple te in te sti-nal absor p t ion i n hum ans. G astr oen ter ology l983;84:26-9.

6. Rume s s e n ii , G ud mand-H #{ 248} yer E . A b sorp tion capac ity o f f ru cto sein health y adu lts. C om parison w ith sucro se and its cons titu en tmo n o s a c c h a r i d e s . Gu t 1 9 86 ; 2 7 : 1 1 6 1 - 8.

7 . C rap o PA , K o lterm an n 00 , O le f sk y JM . E f f ec ts o f o ral f ruc to se innorm al, d iab etic and im paired g luco se to lerance sub jects . D iab etesCare 1980;3:575-82 .

8 . C rapo PA , K olte rm ann 00 , H en ry R R . M etabo lic con sequenceo f tw o-w eek f ruc to se f eed in g in d iabe tic sub jec ts. D iabe tes C arel9 86;9 :1 11-9 .

9 . Jenk ins D JA , L e e d s A R , Gassu l l M A , Coch et B , A lberti K G M M .D ecrease in pos tp rand ial in su lin and g lucose con cen tration s b yguarand p ec tin . A nn In tern M ed l977 ;86:2 0-3 .

1 0 . Jenk in s D JA , W o lev er T M S , L eed s R , e t al. D ietary f ibres, f ibreanalog ues, and g lucose to leran ce : im po rtan ce o f v isco sity . B r M edJ l 97 8; l :l 39 2- 4.

1 1 . H agander B , A sp N -G , E f end i# { 233}. N ilsso n-E hle P. L undqu ist I ,S chers t# { 233 } n . R edu ced g ly cem ic re spo nses to bee tib re m eal in non-in su lin -dependen t d iabe tic s and its relation to p lasm a lev e ls o f pan -creatic and gastro in testinal h orm ones. D iabe tes R es 1986 ; 3:91 -6 .

1 2 . H am berg 0 , R um essen ii, G udm and-H # { 248} y er E . R educed b loodg lucose re sponse to pea f iber. C om pariso ns w ith sugar-b ee t f iberand w heat b ran . A m J C lin N utr 1989; 50:324-8 .

1 3 . H am berg 0 , R um essen ii, G udm and-H y er E . In h ib itio n o fs tarc h ab so rp tio n by d ie tary f ibre. A com parativ e s tudy o f w heatbran, sugar-beet f ibre , and p ea f ibre. S cand J G astro en tero ll9 89;2 4: 1 03-9 .

14 . R um essen ii, K ok ho lm G , G udm an d -H #{ 2 48} y er E . M etho do log ical

a spec ts ofb reath h y drog en (H 2) analy sis E v aluation o f a H2 -m oni-to r and in terp re tatio n o f the H 2 b reath test. S cand J C linab Inves tl987 ;47 :555 -60 .

15 . R um essen ii, H am berg 0 , G udm and -H ey er E . In f lu ence o f o rocaecal transit tim e on h y drog en ex cretio n af te r carbohy d rate m al-absorption. G ut 198 9;3O :8 l 1 -4 .

16 . R um essen JJ, H am b erg 0 , G udm an d -H y er E . In te rv al sam p lingo f end -ex p irato ry hy drogen (H ,) concen tratio n s to quan titate carb ohy d rate m alabsorp tion by m eans o f lac tu lo se s tand ards. G ul 9 9 0 ; 3 l : 3 7 - 4 2 .

17 . B eu tle r H -O . Inu lin . In : B ergm ey er H U , ed . M e th ods o f en z y m aticanaly sis . 3 rd ed . B ase l: V erlagC hem ie, W einh eim , 1984:41-5 .

18 . R ahe A J. T ab les o f critical v alu es f or th e Pratt m atch ed pair sign edran k statistic . J A m S tatA s so c l 97 4;6 9:3 68 -7 3.

19 . S ieg el S , C aste llan N J Jr. N onparam etric s tatistic s f or th e behav -ioral sc ien ces. 2 nd ed . N ew Y ork : M cG raw -H ill, 19 88 .

2 0 . D arby sh ire B , H enry R i. D if f eren ces in f ruc tan con ten t and sythesis in som e allium sp ec ies. N ew Phy to l 198 l;87:2 49-56 .

21 . B acon JS D , E de lm an J. T he carboh y drate s o f the Jeru salem artchok e and o ther C om positae . B io chem J 1951;48 :l 14-26 .

22 . K #{ 252} lz. O n the p atho lo gy and th erapy o f d iabe tes m e llitus. M ar-burg : N G E lw erts V erlag , 1 874 (in G erm an ) .23 . T ok unag a T , O k u T , H osoy a N . In f lu ence o f ch ron ic in tak e o f nesw ee tener f ru cto o ligo sacchaiide (N eosugar) on g row th and gastro in -te s tin al f u nc tio n o f the rat. N utr S d V itam ino l l986;3 2:l 1 1 -2 1 .

24 . S tone -D orsh ow T , L ev itt M D . G aseous re spon se to ing es tion o fp oo rly ab so rb ed f ru cto -o lig os ac ch arid e sw ee tener. A m J C lin N utrl9 87;4 6:6 1-5 .

25 . H idak a H , E ida T , T ak iz aw a T , T ok u naga T , T ash iro Y . E f f ec tsfructooligosaccharides on in testin al f lora and hum an health . B if i-d o b a c t M i cro l 98 6;5 :3 7- 50 .

26 . Y am ash ita K , K aw ai K , Itak u ra M . E f f ec ts o f f ruc to -o lig o saccha-rides on b lood g luco se and serum lip ids in d iabe tic sub jec ts. N u trR e s 1 9 84 ;4 :9 6l -6 .

27 . N ils so n U , O ste R , J# { 22 8} gers tadM , B irk hed D . C ereal f ruc tan s:v itro and in v iv o stud ie s o n av ailab ility inats and hum an s. J N utr1 9 88 ; 1 1 8:1 3 2S - 30 .28 . N ilsson U , B j# { 246} rck. A v ailab ility o f ce real f ruc tan s and inu lin ithe rat in testin al trac t. J N utr 1988; 1 1 8:1482-6 .

29 . A kg# { 252 } n, E rte l N H . A com pariso n o f carb ohy drate m e tab o lismaf te r su crose , sorb ito l, an d f ruc tose m eals in norm al and d iabe ticsub jec ts. D iab ete s C are 19 80 ; 3 :582 -5 .

30 . Crapo PA , S carle tt JA , K olte rm ann 00 . C om pariso n o f th e m ets-b o lic re spo nses to f ruc to se an d sucro se sw ee ten ed f ood s. A m J C linN utr 198 2; 36 :256 -6 1.

3 1. A k g#{ 252 }n, E rte l N H. T h e e f f ec ts o f sucro se, f ruc tose and h igh-f ruc -tose corn sy rup m eals o n p lasm a g lucose and insu lin in non insu lin -dependen t d iabe tic sub jec ts . D iabe te s C are l985 ;8 :27 9 -83 .


7/7

I N T EST I NA L H A NDL I NG O F FRUCT A NS 68132 . B an tle JP, D aw n C , L am e R D . T hom as JW . M e tabo lic e f f e c ts o f

d ie tary f ruc to se and sucro se in ty pes I and II d iabe tic sub jec ts.JA M A l9 86 ;2 56 :3 24 l-6 .

33 . O se i K , Falk o J, B osse tti B M , H o lland G C . M e tabo lic ef f e cts o ff ruc tose as a natu ral sw ee ten er in the p hy sio lo g ic m eals o f am bu la-to ry obese patien ts w ith t y p e I I diabetes. A m J M ed l987;83 :249 -5 5 .

3 4 . G rig oresco C , R iz k all S W , H alf o n P, e t al. L ack o f de tec tab le dd e-terious e f f ec ts o n m etabo lic con tro l o fdaily f ruc to se ingestio n f or2 m o in N ID D M patien ts . D iabe te s C are 19 88 ; 1 1 :546 -50 .

3 5 . S es to f t L . Fru cto se and the d ie tary th erapy o f d iabe te s m e llitu s .Di a b e t o l o g i a 1 97 9; 1 7: 1 - 3 .

3 6 . R um essen JJ, G udm and -H y er E . M alabsorp tion o f f ru cto se -so r-b ito l m ix tu re s. In te rac tion s cau sing ab dom inal d is tre s s. S can d JG astroen te ro l l987 ;2 2 :43 1 -6 .

3 7 . R um essen JJ, G udm an d -H #{ 24 8} y er E . Fu nc tion al bow e l d isease : m al-absorption and abdom inal d istress af ter ingestio n o f f ruc tose , so r-b ito l and f ruc tose-sorb ito l m ix tures. G astroen tero log y I988 ;95:6 9 4 - 7 0 0 .

3 8 . S he tty PS , K urpad A V . Increasing starch in tak e in the h um an d iein creases f ecal bulk ing . A m J C lin N utr l986 ;43:2 l0 -2 .

39 . Lev i t t M D , Hirsch P. Fetz e r C A , S heahan M , L ev in e A S . H 2 ex cre -tio n af te r inges tio n o f com p lex carbohy drates . G as troen te ro logy1987;92:383-9 .

40 . T hi# { 233} baud, Jaco t E ,S chw itz H , S peng le r M , Fe lb er JP . Compara -tiv e stu dy o f isom alt and sucrose by m eans o fcon tinuous ind irectcalo rim etry . M etabo lism l98 4;33 :808 -l 3 .

41 . V an E s A JH , D e G root L ,og t JE . Energy balances o f e igh t v o lu n-teers f ed on d ie ts supp lem ented w ith eith er lac tito l or saccharose .B rJ N utr I986 ;56:5 45-54 .

42 . G rim ble GH , Patil DH , S ilk D B A . A ssim ilatio n o f L ac tito l, anu nabso rbed d isaccharide in th e no rm al h um an co lon . G ul988 ;29: 1666-7 1 .

43 . M cB urn ey M I, T hom p son L U , Jen k ins D JA . C olo n ic f e rm en ts-tion o f som e breads and it s im plication f or energy av ailab ility inm an . N utrR es l9 87;7 :l229 -4 l.

44 . T ok unaga T , O k u T , H osoy a N . U tiliz ation and ex cre tion o f a n ewsw ee tener, f ruc too ligosaccharid e (N eosugar) , inats. J Nu tr1 98 9 ; 1 1 9 : 5 5 3 - 9 .

fructans of jerusalem artichokes

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