Monosodium Glutamate Induces Hloov hauv Hepatic Thiab Raum Metabolic Profiles Thiab Gut Microbiome Ntawm Wistar nas
Feb 22, 2022
Abstract:Kev siv sijhawm luv thiab ntev ntawm monosodium glutamate (MSG) nce pH urinary tab sis cuam tshuam rau txoj hauv kev metabolic hauv daim siab, raum thiab lub plab microbiota tseem tsis paub. Txhawm rau daws qhov teeb meem no, peb tau tshawb xyuas cov neeg laus txiv neej Wistar nas faib kom tau txais cov dej haus nrog lossis tsis muaj 1 g feem pua MSG rau 2 lub lis piam (n=10, txhua). Peb tau ua ib qho Nuclear Magnetic Resonance (NMR) spectroscopy-based metabolomic kawm ntawm jejunum,daim siab, thiablub raum, thaum cov qauv faecal tau sau rau cov kab mob DNA rho tawm los tshawb xyuas lub plab microbiota siv 16S rRNA gene sequencing. Peb tau pom cov kev hloov pauv tseem ceeb hauv covdaim siabntawm MSG-kho nas piv rau kev tswj hauv qib qabzib, pyridoxine, leucine, isoleucine, valine, alanine, kynurenate, thiab nicotinamide. Ntawmraummetabolites, theem ntawm trimethylamine (TMA) tau nce, thiab pyridoxine tau txo qis tom qab MSG-kev kho. Sequencing ntawm 16S rRNA gene qhia tias MSG-kho nas tau nce Firmicutes, cov kab mob plab cuam tshuam nrog TMA metabolism, nrog rau cov kab mob Bifidobacterium tsawg. Peb cov ntaub ntawv txhawb nqa qhov cuam tshuam ntawm MSG noj ntawmdaim siabthiabraummetabolism. Raws li kev hloov pauv hauv plab microbiome, peb kwv yees tias TMA thiab nws cov metabolites xws li trimethylamine-N-oxide (TMAO) tuaj yeem yog tus neeg nruab nrab ntawm cov teebmeem ntawm MSG ntawm lub plab.lub raum noj qab haus huv.
Ntsiab lus:monosodium glutamate; plab microbiota; txoj kev metabolic; metabolomics; microbiome; trimethylamine; Lub raum; Daim siab
Taw qhiaMonosodium glutamate (MSG) feem ntau yog ntxiv rau cov khoom noj kom muaj palatability, tshwj xeeb tshaj yog nyob rau hauv Asian cuisine thiab industrially processed zaub mov [1]. MSG yog suav tias yog cov khoom muaj kev nyab xeeb rau tib neeg noj tsis hais tus nqi los ntawm Food and Drug Administration (FDA) [2] txawm tias cov ntaub ntawv tsis ntev los no qhia tau tias qhov nruab nrab ntawm MSG noj txhua hnub yog 3-4 g thiab txhua gram ntxiv ntawm MSG ua rau muaj kev pheej hmoo. Kev txhim kho metabolic syndrome [3] Kev nce qib ntawm kev noj haus MSG yog txuam nrog rog [4,5] thiab kub siab [6], tab sis cov txiaj ntsig tsis sib xws [7,8].
Kev sim tau ua los qhia txog cov teebmeem ntawm MSG ntawm cov kabmob metabolic ntawm cov tsiaj los ntawm parenteral [9,10] lossis qhov ncauj noj [11,12]. Hauv ib qho ntawm cov kev siv zog los tshawb xyuas qhov cuam tshuam ntawm MSG hauv naslub raum, cov txiaj ntsig tau pom tias ob qho tib si luv- [13] thiab ntev [11] MSG noj ua rau cov zis alkaline hauv nas, txawm hais tias cov txheej txheem ntawm cov zis alkalinization tsis tsim. Metabolomics yog ib txoj hauv kev siv los txheeb xyuas cov kev hloov pauv hauv metabolites los ntawm ntau yam mob [14,15]. Kev noj MSG luv luv ua rau muaj kev hloov pauv hauv cov zis metabolites xws li dimethylamine (DMA) thiab methylamine (MA), uas yog cov metabolites ntawm plab los ntawm trimethylamine (TMA). TMA yog ib qho luv luv-chain aliphatic amine uas muab cov yam ntxwv fifish tsw. Qhov tseeb, cov kab mob plab tsim TMA los ntawm kev noj zaub mov fifish lossis nws tuaj yeem tsim los ntawm lwm cov as-ham xws li choline thiab carnitine, uas muaj ntau hauv qe thiab nqaij liab [16]. Qhov loj ntawm TMA yog enzymatically hloov mus rau cov ntxhiab tsw trimethylamine-N-oxide (TMAO), thiab siab TMAO plasma qib yog txuam nrog cov kab mob plawv (CVD) [17], ntev.mob raum(CKD) [18] thiab ntshav qab zib [19].
Peb ntawm no tau coj kom zoo dua ntawm cov cuab yeej metabolomics los tshawb xyuas qhov cuam tshuam ntawm kev siv MSG luv luv ntawm cov metabolome ntawm plasma,daim siab,raumthiab plab hnyuv, thiab txheeb xyuas qhov sib txheeb ntawm cov txiaj ntsig metabolomic thiab kev hloov ntawm plab microbiota. Peb cov ntaub ntawv tuaj yeem muab cov tswv yim tshiab rau kev nkag siab txog qhov cuam tshuam ntawm kev noj haus MSG thaum tseem qhia txog biomarkers ntawm MSG-vim lub cev puas tsuaj.
Cov ntaub ntawv thiab cov txheej txheem
Tsiaj txhuNees nkaum 6-cov txiv neej hnub nyoog ib asthiv Wistar nas (qhov hnyav kwv yees li 200 g) tau txais los ntawm National Laboratory Tsiaj Center (Mahidol University, Salaya, Bangkok, Thaib teb), acclimatized nyob rau hauv ib tug neeg stainless-steel metabolic tawb rau 2 lub lis piam, thiab tom qab ntawd khaws cia nyob rau hauv tus qauv ntsuas kub (23 ± 2 ◦C), av noo (30-60 feem pua) thiab ci ntsa iab (350-400 Lux) ntawm 12 h tsaus ntuj / 12 h lub voj voog. Cov nas tsuag tau muab kev lag luam pelletdiet No. CP 082 (Perfect Companion Group, Bangkok, Thaib teb) thaum kawm. Txhua qhov kev sim tau ua raws li cov lus qhia ntawm Northeast Laboratory Animal Center (NELAC), Khon Kaen University, Thaib teb. Ntxiv mus, txoj kev tshawb fawb tau pom zoo los ntawm Pawg Saib Xyuas Kev Ncaj Ncees Tsiaj ntawm Khon Kaen University, Thaib Teb (AEKKU-NELAC5/2558).
ReagentsCov zaub mov ntshiab (99 feem pua) MSG (Ajinomoto, Tokyo, Nyiv) tau siv los pub tsiaj. Kev lag luam qib methanol thiab chloroform tau yuav los ntawm RCI LABSCAN LIMITED (Bangkok, Thaib teb) rau cov ntaub so ntswg rho tawm, LC-MS-qib dej tau yuav los ntawm Merck (Darmstadt, Lub teb chaws Yelemees), potassium dihydrogen phosphate (KH2PO4) thiab deuterium oxide (D2O) tau yuav. los ntawm Merck (Darmstadt, Switzerland), sodium azide (NaN3) yog tsim los ntawm European Chemicals Agency (ECHA, Helsinki, Finland), sodium trimethylsilyl-[2,2,3,3-2}H4]-propionate (TSP) , tus qauv sab hauv rau NMR tsom xam, tau txais los ntawm Santa Cruz Biotechnology (Santa Cruz CA, USA). Rau huab hwm coj spectrometry, coj mus muag-qib isopropanol (C3H8O) thiab formic acid (CH2O2) tau yuav los ntawm RCI LABSCAN LIMITED (Bangkok, Thaib teb).
Kev sim tsimCov nas tsuag raug muab tso rau kom tau txais cov dej haus nrog (n=10) lossis tsis muaj (n=10) 1 g feem pua ntawm MSG rau 2 lub lis piam. Rov qab osmosis (RO) dej tau siv (chlorine concentration ntawm 3-4 ppm) rau kev kawm tsiaj thaum txhua tus nas muaj kev nkag tau dawb rau zaub mov. Kev haus dej txhua hnub (ml) thiab zaub mov (g) tau sau tseg, nrog rau lub cev hnyav (g). Lub 24 hurinary excretion (ml / nas / hnub) tau sau tseg thoob plaws lub sijhawm kawm. Cov quav quav thiab cov qog ntshav (100 µL ntawm cov ntshav plasma) tau sau tseg ntawm 2 lub lis piam ua ntej kev txi ntawm cov tsiaj uas siv cov pa roj carbon dioxide (CO2) tom qab 12-h yoo mov. Cov ntaub so ntswg, piv txwv li, jejunum,daim siabthiabraum,tau sau thiab snap-khov hauv cov kua nitrogen ua ntej muab khaws cia ntawm t80 ◦C kom txog thaum siv los tshuaj xyuas.
Qauv Kev Npaj thiab Kev Ntsuam XyuasTxhua cov ntaub so ntswg (100 mg ntub dej) tau siv rau kev tshem tawm cov metabolite raws li cov txheej txheem luam tawm yav dhau los [20]. Ua ntej NMR tau txais, cov theem polar ntawm cov ntaub so ntswg rho tawm tau rov muab ncua rau hauv NMR tsis ntawm 580 µL (100 mM sodium phosphate buffer, pH 7.4, hauv D2O, muaj 0.1 mM TSP thiab 0.2 feem pua NaN3), vortexed ntawm luv luv thiab luv luv. 12, 000 × g rau 5 min ntawm 4 ◦C. Tom qab ntawd, 550 µL ntawm cov sib tov tau raug xa mus rau NMR iav raj (Duran Group, Mainz, Lub teb chaws Yelemees) nrog ib txoj kab uas hla ntawm 5 hli ua ntej NMR tsom xam. Kwv yees li ntawm 250 mg ntawm faeces yog tov nrog 500 µL HPLC-qib dej (Merck, Darmstadt, Lub teb chaws Yelemees) thiab homogenized siv lub vortex tov nrog qhov ceev 2500 rpm rau 15 min ntawm chav tsev kub. Lub faecal ncua kev kawm ntawv yog ces centrifuged ntawm 12, 000 × g rau 15 min ntawm 4 ◦C thiab 540 µL ntawm supernatant raug xa mus rau huv 1.5 mL microtubes, thiab 60 µL ntawm NMR tsis (1.5 M KH2PO4 7.4, pH. , hauv D2O, muaj 2 mM TSP thiab 1 feem pua NaN3) tau ntxiv. Tom ntej no, cov raj tau vortexed luv luv, centrifuged ntawm 12, 000 × g rau 10 min, thiab qhov kawg, 580 µL ntawm cov sib tov tau pauv mus rau 5 hli txheej kab NMR iav raj rau kev tshuaj xyuas.
Cov ntaub so ntswg rho tawm thiab cov qauv faecal tau txheeb xyuas siv 400 MHz NMR spectrom eter (Bruker Biospin, Rheinstetten, USA) ntawm qhov kub ntawm 298.15 K. Cov spectra tau hais txog TSP ncov (δ1H { {14}}.00), phased and baseline corrected using MATLAB (Mathworks, Natrick, MA USA). Lub teeb liab ntawm TSP ncov (δ1H H1.000-0.005) los ntawm tag nrho cov ntaub so ntswg thiab TSP ncov (δ1H H1.20–0.157) los ntawm faeces raug tshem tawm. Tsis tas li ntawd, lub ncov dej tau raug tshem tawm ntawm jejunum (δ1H 4.50 thiab 5.20),daim siab(δ1H 4.68 thiab 5.00),raum(δ1H 4.31 thiab 5.74) thiab faeces (δ1H 4.18 thiab 5.23). Ntxiv mus, nyoos spectra tau raug rau lub ncov sib dhos thiab normalization [21]. Cov ntaub ntawv spectral ntawm tag nrho cov qauv yog anal ysed siv unsupervised principal component analysis (PCA) thiab saib xyuas orthogonal teeb liab kho-projection rau latent structures-discriminant tsom xam (O-PLS-DA). Cov ntaub ntawv yog qhov nruab nrab nruab nrab thiab ntsuas nrog chav ntsuas qhov sib txawv (UV). Cov qauv O-PLS-DA raug soj ntsuam los ntawm R2X, R2Y thiab Q2Y qhov tseem ceeb, sawv cev rau kev ruaj khov, feem ntawm qhov sib txawv ntawm Y matrix, thiab kev kwv yees muaj peev xwm ntawm tus qauv, raws li [22]. Txhawm rau kom tsis txhob muaj teeb meem ntau dhau, 7-fold-validation tau ua rau 500 rov ua dua. Permutation p-value tau siv los qhia qhov qauv siv tau. Cov kev hloov pauv tseem ceeb ntawm txhua tus qauv siv tau raug xaiv los ntawm O-PLS-DA correlation coefficients nrog Benjamini-Hochberg false-discovery rate kho (p <0.05). statistical="" tag="" nrho="" correlation="" spectroscopy="" (stocsy)="" [23],="" in-house="" chemical="" shift="" databases="" and="" the="" human="" metabolome="" database="" (hmdb="" version="" 4,="" usa)="" [24]="" tau="" siv="" rau="" kev="" txheeb="" xyuas="">
Kev txheeb xyuas txoj hauv kev ntxiv kuj tau ua los ntawm MetaboAnalyst (http://www. metaboanalyst.ca/ ( nkag mus rau 14 Lub Xya Hli 2020)) [25]. Cov duab qhia txog kev metabolic tau tsim los ntawm Cytoscape [26]. Kev hloov pauv hauv cov metabolites tau txheeb xyuas los ntawm STOCSY thiab kev tshuaj xyuas tsis sib xws tau ua los ntawm kev tshawb xyuas cov txheeb ze ntawm cov metabolites sib txawv, suav nrog kev sib koom ua ke ntawm spectra peaks. Raws li tus nqi p-value xam los ntawm Tus Tub Kawm Ntawv t-test siv GraphPad Prism 7 (Ver. 7, GraphPad Software, Inc., La Jolla, CA, USA).
Plasma Sample Npaj rau UHPLC-ESI-QTOF-MS Kev Ntsuam XyuasPlasma (50 µL) yog tov nrog 150 µL ntawm isopropanol (IPA), tom qab ntawd los ntawm 24-h incubation ntawm 20 ◦C kom precipitate cov protein. Tag nrho cov qauv raug centrifuged ob zaug ntawm 13, 000 × gat 4 ◦C rau 10 min. Tag nrho ntawm 50 µL tau muab los ntawm txhua tus qauv thiab muab tso rau hauv 1.5 mL microcentrifuge raj rau kev tsim cov qauv tswj kev ua tau zoo (QC) thiab 120 µL ntawm txhua tus qauv sib xyaw tau hloov mus rau HPLC iav ntxig.
UHPLC-ESI-QTOF-MS AnalysisUHPLC-ESI-QTOF-MS tsom xam tau ua haujlwm ntawm Khon Kaen University International Phenome Laboratory (KKUIPL). Lub aqueous theem rho tawm ntawm cov qauv tau txheeb xyuas ntawm lub thim rov qab-theem platform. Qhov kev sib cais tau ua tiav siv UHPLC system (Bruker, Darmstadt, Lub teb chaws Yelemees) thaum Bruker siv solo HPLC C18 2.1 × 100 mm, 2 µm kem (Bruker, Darmstadt, Lub teb chaws Yelemees) tau siv. Cov kab ntsuas kub tau teem rau ntawm 55 ◦C thiab autosampler kub tau teem rau ntawm 4 ◦C. Mobile theem A yog 10{{20}}} feem pua HPLC qib dej nrog 0.1 feem pua formic acid (FA), thiab theem B mobile yog 10 {{30}} feem pua methanol nrog 0.1 feem pua FA. Tus nqi flflow tau teem rau ntawm 0.4 mL/min thiab qhov elution gradient tau teem li — 99.9 feem pua A (0.{{40}}-2.{{46 }} min, 0.25 mL/min), 99.9–75 feem pua A (2.0–10.0 min, 0. 4 mL/min), 2{{60}} feem pua A (10.0–12.0 min, 0.4 mL/min), 10 feem pua A (12.0–21.0 min, 0.4 mL/ min), 0.1 feem pua A (21.0–23.0 min, 0.4 mL/min), 99.9 feem pua A (24.0–26.0 min, 0.4 mL/min). Ib qho piv txwv txhaj ntim ntawm 4 µL tau siv rau ob qho tib si zoo thiab tsis zoo ionization polarity hom.
Kev soj ntsuam loj spectrometry tau ua los ntawm kev siv ESI-Q-TOF system (Bruker, Darmstadt, Lub teb chaws Yelemees). Sodium formate (HCOONa) uas muaj 2 mM sodium hydroxide, 0.1 feem pua FA thiab 50 feem pua IPA tau raug txhaj ncaj qha raws li kev ntsuas sab nraud nrog flflow tus nqi 0.5 µL / min. Cov xwm txheej hauv qhov zoo ionization polarity hom - huab hwm coj ntau 50-1300 m / z, cone voltage 31 V, capillary voltage 4500 V, qhov kub ntawm 220 ◦C, desolvation kub 220 ◦C, desolvation gas flflow 8 L / min. Cov xwm txheej ntawm qhov tsis zoo ionization polarity hom-m / z ntau: 50-900 m / z, cone voltage 31 V, capillary voltage 4500 V, qhov kub ntawm 220 ◦C, desolvation kub 220 ◦C, desolvation gas flflow 8 L / min.
Lub plab Microbiome AnalysisDNA tau muab rho tawm siv QiAamp® PowerFecal® Pro DNA cov khoom siv (Qiagen, Hilden, Lub teb chaws Yelemees). Extracted DNA tau ntsuas ntawm OD 260/280 siv lub Nanodrop2000c spectrophotometer (Thermo scientifific, Waltham, MA, USA). Tag nrho cov DNA rho tawm tau khaws cia ntawm t20 ◦C kom txog thaum kev soj ntsuam. V3-V4 cheeb tsam ntawm 16S ribosomal RNA (rRNA) noob rau txhua tus qauv tau nthuav dav siv universal forward primer V3 (50-CCTACGGGNGG CWGCAG-30) thiab rov qab primer V4 ({ {11}}GACTACHVGGGGTATCTAATCC-30). PCR cov tshuaj tiv thaiv muaj 2x KAPA HiFi HotStart ReadyMix, 12.5 ng DNA template, thiab 5 µM ntawm txhua primer, nrog thawj denaturation ntawm 95 ◦C rau 3 min ua raws li 25 cycles ntawm denaturation ntawm 95 ◦C rau 30 s, 5 annealing ntawm C rau 30 s, txuas ntxiv ntawm 72 ◦C rau 30 s, thiab qhov kawg txuas ntxiv ntawm 72 ◦C rau 10 feeb. Ib qho Agilent DNA 1000 Chip thiab Agilent 2100 Bioanalyzer (Agilent Technologies, Palo Alto, CA, USA) tau ua ke los ua kom muaj nuj nqis ntawm cov khoom lag luam. PCR amplicons tau purified siv AMPure XP hlaws dai kom huv. Ib nrab ntawm 16S rRNA noob tau ua tiav siv Illumina MiSeq platform (Illumina Inc., San Diego, CA, USA).
Lub tsev qiv ntawv 16S rRNA sequencing tau npaj siv genomic DNA (gDNA), thiab kev sib koom ua ke ua ke-kawg tau sib koom ua ke siv FLASH (http://ccb.jhu.edu/software/ FLASH/ ( nkag mus rau 29 Lub Rau Hli 2020)) [27] . Kev lim dej zoo tshem tawm cov kab ke uas muaj cov ntawv nyeem tsis zoo thiab tau ua tiav siv CD-HIT-OTU (http://weizhong-lab.ucsd.edu/ cd-hit-otu ( nkag mus rau 29 Lub Rau Hli 2020)) [28] thiab rDnaTools pob. OTUs (Operational taxonomic units) tau muab faib ua 97 feem pua ntawm tus kheej siv UCLUST algorithm raws li 100 feem pua zoo sib xws. Kev sib koom ua ke Ntau dua lossis sib npaug rau 97 feem pua zoo sib xws tau muab rau tib OTU. Cov neeg sawv cev OTU cov kab ke tau ua raws thiab tau muab faib ua pawg raws li kev siv Ribosomal Database Project (RDP) thiab tau muab piv nrog cov ntaub ntawv siv NCBI databases. Kev faib tawm yog ua raws li Green genes database (http://greengenes.lbl. gov/ ( nkag mus rau 29 Lub Rau Hli 2020)). Cov txiaj ntsig ntawm kev faib tawm ntawm kev nyeem ntawm ntau qib taxonomic - lub nceeg vaj, phylum, chav kawm, kev txiav txim, tsev neeg, genus, thiab hom siv Quantitative Insights Into Microbial Ecology (QIIME) [29].
Kev txheeb caisKev txheeb xyuas cov khoom noj thiab dej kom tsawg, cov zis ntim zis thiab lub cev hnyav tau tshaj tawm raws li qhov txhais tau tias ±SD rau ib pawg tsiaj thiab qhov sib txawv ntawm pawg tau muab piv rau qhov tseem ceeb ntawm Cov Tub Ntxhais Kawm T-test nrog p-value < {{2} }.05 suav tias yog qhov tseem ceeb.
Cov txiaj ntsig
Kev cuam tshuam ntawm MSG ntawm kev noj zaub mov thiab dej, lub cev hnyav thiab tso zis tso zisMSG-kho thiab tswj nas muaj cov khoom noj zoo sib xws (17.44 ± 1.94 thiab 18.46 ± 1.37 g / nas / hnub, raws li) (Daim duab 1A) thiab lub cev hnyav (333.58 ± 17.23 thiab 333.80 ± 15.50 g / rat). (Daim duab 1B). Txawm li cas los xij, kev haus dej tau nce siab dua hauv MSG-kho nas (52.38 ± 18.36 mL / hnub) piv rau kev tswj hwm (38.38 ± 8.39 mL / hnub) (Daim duab 1C). Nyob rau hauv ob qho tib si MSG-kho thiab tswj pawg, cov zis tso tawm yuav nce ntxiv nrog lub sijhawm, txawm hais tias qhov nce tseem ceeb tau pom tsuas yog hauv MSG kho nas (15.42 ± 3.92 mL / nas / hnub ntawm kev kho mob ua ntej thiab 29.09 ± 8.78 mL / nas /. hnub tom qab kev kho mob). Tsis tas li, txawm hais tias tsis muaj qhov tseem ceeb, cov zis tso zis ntawm MSG-kho nas (29.09 ± 8.78 mL / nas / hnub) tau pom meej siab dua li ntawm kev tswj hwm (23.15 ± 10.55 mL / nas / hnub) (Daim duab 1D).
Kev hloov pauv hauv cov metabolism hauv lub cev tseem ceebNMR spectra ntawm cov ntaub so ntswg uas tau muab tshuaj xyuas tom qab ob lub lis piam ntawm kev kho MSG. PCA ntawm NMR spectral cov ntaub ntawv tau pib ua los saib xyuas txhua qhov pom tseeb ntawm pawg thiab outliers (Daim duab 2). Kev sib cais meej thiab kev sib cais tiav tau pom nyob rau hauv hepatic metabolite profifiles ntawm kev tswj thiab MSG-kho pab pawg nrog permutation p-tus nqi ntawm 0.002, R2X ntawm 58 feem pua, Q2Y ntawm 0.84, thiab R2Y ntawm 0.93 qhia hauv PCA thiab O-PLS-DA cov qhab nia (Daim duab 2A, B). Ib tus neeg sawv cev OPLS-coefficient loading plot nrog metabolite assignment yog nyob rau hauv daim duab 3 nrog qhov tseem ceebdaim siabcov qauv qhia hauv daim duab 3A; Tag nrho cov kev hloov pauv tseem ceeb hauv cov metabolites tau sau tseg hauv Table 1. Hauv daim siab, qib siab ntawm rau cov metabolites nrog rau cov piam thaj, pyridoxine, 2-deoxyuridine, inosine, tsis paub 1 thiab 2 tau pom nyob rau hauv pawg MSG-kho, whereas kaum ib metabolites. , xws li leucine, isoleucine, valine, alanine, N-acetylglycoprotein, acetone, 1,3 dimethylurate, histamine, xanthine, kynurenate thiab nicotinamide, tau muaj txiaj ntsig ntau dua hauv pawg tswj hwm. PCA cov qhab nia raws li qhovlub raummetabolites (Daim duab 2C) qhia tias tsis muaj kev sib cais meej ntawm ob pawg, thiab O-PLS-DA qauv yog qhov tseem ceeb nrog rau kev hloov pauv p-tus nqi ntawm 0.018, R2X ntawm 56 feem pua, Q2Y ntawm 0.29, thiab R2Y ntawm 0.74 (Daim duab 2D). Ob qhov hloov pauv metabolites tau pom hauvcov ntaub so ntswgnrog rau qib trimethy lamine ntau dua thiab tseem ceeb txo qis pyridoxine hauv pawg MSG-kho tau piv rau kev tswj hwm (Daim duab 3B). Hauv qhov sib piv, cov txiaj ntsig ntawm jejunum (Daim duab 2E, F), faeces thiab ntshav (Daim duab 2 thiab daim duab S1) qhia tsis muaj kev sib koom ua ke ntawm cov kev kho mob thiab kev tswj cov pab pawg tau piav qhia hauv PCA thiab O-PLS-DA cov qhab nia.
Cov kev sib raug zoo ntawm cov metabolites tseem ceeb hauv covdaim siabthiabcov ntaub so ntswgtau tshawb xyuas siv KEGG IDs thiab tsim los ntawm Cytoscape software. Cov metabolites tau pom los txuas rau lub network metabolic. Thaum cov txiaj ntsig no tau ua ke los kos ib daim ntawv qhia kev metabolic txhawm rau qhia txog kev sib raug zoo dua, cov metabolites tau qhia tias feem ntau cuam tshuam nrog cov txheej txheem metabolic, xws li hepatic gluconeogenesis, branched-chain amino acids, vitamin B6, thiab trimethylamine metabolism ( Daim duab S3).
MSG Consumption Alters Gut MicrobiomeCov txiaj ntsig ntawm kev txheeb xyuas cov kab mob faecal tau qhia txog xya phyla, 15 chav kawm, 19 xaj, 46 tsev neeg, 127 genera thiab 220 hom los ntawm txhua pawg tsiaj. Sab saum toj 7-10 hom tau raug xaiv thiab feem pua ntawm cov neeg muaj kab mob ntau ntawm cov phylum, chav kawm, kev txiav txim, tsev neeg, genus thiab hom qib tau tsim tawm (Daim duab 4). Nyob rau theem phylum, plaub sab saum toj kawg nkaus phyla muaj nyob rau hauv qhov kev txiav txim hauv qab no - Firmicutes > Bacteroidetes > Proteobacteria > Actinobacteria hauv txhua tus tsiaj (Daim duab 4A). Qhov kev nplua nuj ntawm Actinobacteria tau qis dua hauv MSG-kho nas (0.30 feem pua) dua li cov nas tswj (1.32 feem pua) (Daim duab 5A).
Hauv chav kawm, cov microbiota ntau tshaj plaws yog Bacilli > Clostridia > Bacteroidia > Erysipelotrichia hauv txhua tus tsiaj (Daim duab 4B). Cov pab pawg kho mob MSG tau muaj txiaj ntsig ntau dua Clostridia (31.59 feem pua) dua li pawg tswj hwm (19.25 feem pua). Txawm li cas los xij, cov nas uas tau kho MSG tau qis dua Actinobacteria (0.15 feem pua) dua li cov nas tswj (1.09 feem pua) (Daim duab 4B). Thaum txhais ntawm qib kev txiav txim, Lactobacillales, Clostridiales, Bacteroidales, Erysipelotrichales muaj ntau nyob rau hauv tag nrho cov tsiaj (Daim duab 4C). Clostridiales tau muaj txiaj ntsig ntau dua hauv MSG kho nas (31.59 feem pua) dua li cov nas tswj (19.25 feem pua), thaum Bifidobacteriales tau qis dua hauv MSG-kho nas (0.06 feem pua) piv rau cov nas tswj (1.06 feem pua).
Plaub tsev neeg uas muaj ntau tshaj plaws uas pom nyob rau hauv tag nrho cov tsiaj sim yog nyob rau hauv kev txiav txim hauv qab no - Lactobacillaceae > Erysipelotrichaceae > Clostridiaceae > Prevotellaceae (Daim duab 4D). Hauv tsev neeg, Bifidobacteriaceae tau qis dua, tab sis Clostridiales tsis pom muaj qhov tseem ceeb hauv MSG-kho nas piv rau cov nas tswj. Cov txheeb ze ntau ntawm plaub genera saum toj kawg nkaus pom nyob rau hauv tag nrho cov tsiaj yog nyob rau hauv cov nram qab no kev txiav txim - Lactobacillus > Turicibacter > Prevotella < clostridium="" (daim="" duab="" 4e).="" daim="" ntawv="" qhia="" tshav="" kub="" ntawm="" cov="" txheeb="" ze="" ntau="" ntawm="" cov="" genus="" theem="" pom="" tias="" qis="" dua="" ntawm="" lactobacillus="" thiab="" ntau="" dua="" ntawm="" clostridium="" hauv="" msg-kho="" nas="" (daim="" duab="" 5b).="" ntxiv="" mus,="" qhov="" qis="" dua="" ntawm="" bifidobacterium="" kuj="" tau="" pom="" hauv="" msg-kho="" nas="" (0.06%)="" piv="" rau="" cov="" nas="" tswj="">
Nyob rau theem hom, plaub hom kab mob plab tshaj plaws uas muaj nyob hauv txhua tus nas yog Lacto bacillus plab hnyuv, Turicibacter sanguinis, Clostridium saudiense, thiab Muribaculum plab hnyuv hauv kev txiav txim (Daim duab 4F). Hauv pawg MSG-kho, Flintibacter butyricus tseem ceeb ntau dua li hauv pawg tswj hwm, whereas Faecalibaculum rodentium thiab Bifidobacterium pseudolongum muaj qhov tseem ceeb tsawg dua.
Kev sib tham
Ntau cov ntaub ntawv pov thawj tau txuas mus txuas ntxiv MSG kev noj qab haus huv rau tib neeg kev noj qab haus huv, xws li kev mob hnyav dua ntawm metabolic syndrome [3], rog dhau [4,5] thiab arterial hypertension [6]. Txawm li cas los xij, cov ntaub ntawv tau tsis sib haum xeeb hauv qee qhov xwm txheej thiab cov txheej txheem hauv qab tseem tsis meej. Txhawm rau daws qhov teeb meem no, peb tau tshawb xyuas cov ntaub so ntswg metabolic alterations thiab lub plab microbial hloov induced los ntawm MSG noj. Raws li pom nyob rau hauv daim duab schematic nyob rau hauv daim duab 6, MSG noj altered cov metabolites txuam nrog hepatic gluconeogenesis, branched-chain amino acid (BCAA) metabolism, vitamin B6 thiab trimethylamine metabolism. Ntxiv mus, lub sij hawm luv luv MSG noj tau txwv tsis pub muaj cov txheeb ze ntawm Bifidobacterium, uas tau pom tias tsim cov kab mob muaj txiaj ntsig, thiab Clostridium ntsig txog TMA thiab TMAO ntau lawm [30].
Hauv daim siab, cov metabolites xws li qabzib, pyridoxine (B6), 2-deoxyuridine, inosine, tsis paub 1 thiab 2 yog qhov tseem ceeb hauv MSG-kho tsiaj ntau dua li hauv kev tswj, thaum kaum ib metabolites (ie, leucine, isoleucine, valine. , alanine, N-acetylglycoprotein, acetone, 1, 3-dimethylurate, histamine, xanthine, kynurenate, thiab nicotinamide) tau qis dua. Ua ntej, cov piam thaj ntau dua yuav qhia tau tias muaj kev nce siab ntawm cov piam thaj hauv siab cuam tshuam nrog MSG, uas tau pom zoo nrog yav dhau los tau tshaj tawm cov ntshav qabzib siab hauv cov menyuam yug tshiab uas tau txais MSG supplementation (1 g / kg lub cev hnyav) [31]. Qhov thib ob, qhov txo qis ntawm alanine thiab peb BCAAs, suav nrog valine, leucine thiab isoleucine, tuaj yeem cuam tshuam nrog amino acid catabolism thiab lub zog metabolism hauv uas lawv cov pob txha pob txha tuaj yeem siv ua ntej rau gluconeogenesis (alanine, valine thiab isoleucine li glucogenic amino acids) thiab lub zog tsim tawm ntawm lub voj voog tricarboxylic acid (TCA). Raws li kev pom zoo nrog tsab ntawv tshaj tawm dhau los, peb pom tias cov khoom degradation ntawm leucine thiab lysine, beta-hydroxyisovalerate thiab 5-aminovalerate, feem, yog qhov tseem ceeb hauv cov zis ntawm MSG-kho nas [13]. Thib peb, nce pyridoxine hauv covdaim siabthiab txo qis pyridoxine hauv covraumntawm MSG-kho nas pom tias hloov pauv ntawm cov vitamin B6 metabolism. Peb kuj pom qhov txo qis ntawm histamine, kynurenate, thiab nicotinamide hauv covdaim siabntawm MSG-kho nas, uas yog cov khoom ntawm B6-dependent enzymes hauv histidine thiab tryptophan metabolism. Kev sib txuas ntawm MSG kom tsawg thiab cov metabolism ntawm vitamin B6, histidine thiab tryptophan yuav tsum tau tshawb xyuas ntxiv. Plaub, MSG-kho nas muaj ntau dua ntawm trimethylamine (TMA) hauv covraum. TMA yog tsim los ntawm cov khoom noj khoom haus, suav nrog choline, L-carnitine thiab betaine los ntawm kev ua ntawm microbial enzymes [16]. TMA yog absorbed loj nyob rau hauv ib tug passive txoj kev mus rau hauv lub portal ncig, thiab mas oxidized rau trimethylamine-N-oxide (TMAO) los ntawm hepatic flflavin-muaj monooxygenases (FMOs). Ib feem me me ntawm TMA yog oxidized rau dimethylamine (DMA) thiab methylamine (MA), thiab kawg tawm mus rau hauv cov zis [32,33]. Cov qib siab ntawm DMA thiab MA hauv cov zis ntawm MSG-kho nas tau tshaj tawm yav dhau los [13]. Ntau qhov kev tshawb fawb tau pom tias qhov siab TMA precursors, choline, lossis nws cov metabolites, TMAO, tuaj yeem ua rau muaj kev vam meej.lub raumtubulointerstitial fifibrosis, kab mob plawv, thiab mob ntevmob raum[34–36]. Yog li ntawd, theem siab ntawm TMA nyob rau hauv lubraumtuaj yeem tsim qhov sib txuas ntawm MSG tau txais thiablub raum puas.
Tsiv los ntawm cov kev hloov pauv hauv TMAs, peb tau tshawb xyuas lub plab microbiota ntawm MSG-kho nas thiab ua kom pom kev hloov pauv ntawm ob lub phyla loj, Firmicutes thiab Bacteroidetes. Qhov ntau dua ntawm Firmicutes, tab sis qis dua ntawm Bacteroidetes, tau pom hauv MSG-kho nas. Nyob rau theem genus, MSG-kho nas muaj ntau dua abun seev cev ntawm Clostridium, thiab qis dua ntawm Lactobacillus thiab Bifidobacterium. Lub genus Clostridium suav nrog ib pawg ntawm cov kab mob uas muaj nyob hauv phylum Firmicutes. Qee qhov Clostridium spp. yog txuam nrog TMA metabolism los ntawm kev tsim cov enzymes los hloov choline lossis cov khoom noj khoom haus rau TMA [33,37,38]. Qhov nce TMA-ua cov kab mob plab, piv txwv li, Clostridium spp., txhawb nqa qhov nce ntawm TMA metabolites hauvraumthiab tso zis ntawm MSG-kho nas. Ntxiv mus, MSG noj txo cov Bifidobacterium pejxeem, ib tug kab mob probiotic uas plays lub luag hauj lwm tseem ceeb hauv plab homeostasis thiab noj qab haus huv [39]. Yooj yim thiab digestible carbohydrates xws li lactose thiab sucrose yog metabo liized nyob rau hauv lub plab hnyuv siab raum (GI) ib ntsuj av tau los ntawm tus tswv tsev thiab cov kab mob xws li lactobacilli. Txawm li cas los xij, cov carbohydrates uas tsis yog digestible, piv txwv li, kev noj haus fifibre, yog metabolized nyob rau hauv qis GI ib ntsuj av los ntawm cov tswv cuab ntawm plab microbiota, suav nrog Bifidobacterium. Kev noj zaub mov nrog cov ntsiab lus siab ntawm cov roj saturated thiab cov suab thaj yooj yim tab sis depleted ntawm cov khoom noj fifibre xws li kev noj zaub mov sab hnub poob tuaj yeem ua rau muaj cov kab mob tsawg dua [40]. Qhov txo qis ntawm Bifidobacterium, cov kab mob zoo, tau tshaj tawm hauv cov kab mob ua rau mob ntev xws li rog rog [41], kab mob siab B [42], thiab ntshav qab zib [43,44]. Cov txiaj ntsig ntawm MSG noj ntawm lub plab microbiota hauv tib neeg tau tshaj tawm ua ntej tsis muaj kev hloov pauv tseem ceeb hauv cov kab mob microbial piv rau cov hauv paus [45]. Qhov cuam tshuam tsawg ntawm MSG ntawm lub plab microbiota hauv txoj kev tshawb no tej zaum yuav yog vim qhov tsawg ntawm MSG supplementation (2 g / hnub), vim qhov nruab nrab txhua hnub MSG tau txais hauv peb qhov kev soj ntsuam yog 4 g / hnub [3]. Peb pom tias txhua 1 g ntawm MSG noj txhua hnub ua rau muaj kev pheej hmoo ntawm metabolic syndrome. Txawm hais tias lub mecha nism ntawm MSG noj ua rau cov kab mob metabolic tsis tau tsim, qhov txo qis ntawm Bifidobacterium hauv MSG-kho tsiaj tej zaum yuav yog ib qho laj thawj. Piv txwv li, qhov txo qis Bifidobacterium hauv MSG-kho nas pom nyob rau hauv txoj kev tshawb no zoo ib yam li cov nas uas muaj vitamin B6 defificiency [46]. Kev tshawb fawb hnyav ntawm MSG txo cov kab mob zoo li cas thiab hloov cov vitamin B6 raws li txoj cai xav tau kev tshawb nrhiav ntxiv.
Peb tau pom tias MSG noj induced hepatic thiablub raumKev hloov pauv hauv metabolic koom nrog hauv gluconeogenesis thiab branched-chain amino acid, vitamin B6 thiab TMA metabolism, nrog rau lub plab microbiota compositional hloov. Cov kev soj ntsuam no qhia tau hais tias cov kev hloov pauv hauv cov txheej txheem metabolic tuaj yeem cuam tshuam nrog kev cuam tshuam tsis zoo ntawm kev siv MSG mus ntev, tshwj xeeb tshaj yog nyob rau hauvdaim siabthiabraum.
