47 research outputs found

    The human gut microbiota and glucose metabolism: a scoping review of key bacteria and the potential role of SCFAs

    Get PDF
    The gut microbiota plays a fundamental role in human nutrition and metabolism and may have direct implications for type 2 diabetes and associated preconditions. An improved understanding of relations between human gut microbiota and glucose metabolism could lead to novel opportunities for type 2 diabetes prevention, but human observational studies reporting on such findings have not been extensively reviewed. Here, we review the literature on associations between gut microbiota and markers and stages of glucose dysregulation and insulin resistance in healthy adults and in adults with metabolic disease and risk factors. We present the current evidence for identified key bacteria and their potential roles in glucose metabolism independent of overweight, obesity, and metabolic drugs. We provide support for SCFAs mediating such effects and discuss the role of diet, as well as metabolites derived from diet and gut microbiota interactions. From 5983 initially identified PubMed records, 45 original studies were eligible and reviewed. alpha Diversity and 45 bacterial taxa were associated with selected outcomes. Six taxa were most frequently associated with glucose metabolism: Akkermansia muciniphila, Bifidobacterium longum, Clostridium leptum group, Faecalibacterium prausnitzii, and Faecalibacterium (inversely associated) and Dorea (directly associated). For Dorea and A. muciniphila, associations were independent of metabolic drugs and body measures. For A. muciniphila and F. prausnitzii, limited evidence supported SCFA mediation of potential effects on glucose metabolism. We conclude that observational studies applying metagenomics sequencing to identify species-level relations are warranted, as are studies accounting for confounding factors and investigating SCFA and postprandial glucose metabolism. Such advances in the field will, together with mechanistic and prospective studies and investigations into diet-gut microbiota interactions, have the potential to bring critical insight into roles of gut microbiota and microbial metabolites in human glucose metabolism and to contribute toward the development of novel prevention strategies for type 2 diabetes, including precision nutrition

    The human gut microbiota and glucose metabolism: a scoping review of key bacteria and the potential role of SCFAs

    Get PDF
    The gut microbiota plays a fundamental role in human nutrition and metabolism and may have direct implications for type 2 diabetes and associated preconditions. An improved understanding of relations between human gut microbiota and glucose metabolism could lead to novel opportunities for type 2 diabetes prevention, but human observational studies reporting on such findings have not been extensively reviewed. Here, we review the literature on associations between gut microbiota and markers and stages of glucose dysregulation and insulin resistance in healthy adults and in adults with metabolic disease and risk factors. We present the current evidence for identified key bacteria and their potential roles in glucose metabolism independent of overweight, obesity, and metabolic drugs. We provide support for SCFAs mediating such effects and discuss the role of diet, as well as metabolites derived from diet and gut microbiota interactions. From 5983 initially identified PubMed records, 45 original studies were eligible and reviewed. alpha Diversity and 45 bacterial taxa were associated with selected outcomes. Six taxa were most frequently associated with glucose metabolism: Akkermansia muciniphila, Bifidobacterium longum, Clostridium leptum group, Faecalibacterium prausnitzii, and Faecalibacterium (inversely associated) and Dorea (directly associated). For Dorea and A. muciniphila, associations were independent of metabolic drugs and body measures. For A. muciniphila and F. prausnitzii, limited evidence supported SCFA mediation of potential effects on glucose metabolism. We conclude that observational studies applying metagenomics sequencing to identify species-level relations are warranted, as are studies accounting for confounding factors and investigating SCFA and postprandial glucose metabolism. Such advances in the field will, together with mechanistic and prospective studies and investigations into diet-gut microbiota interactions, have the potential to bring critical insight into roles of gut microbiota and microbial metabolites in human glucose metabolism and to contribute toward the development of novel prevention strategies for type 2 diabetes, including precision nutrition

    Provning och utvÀrdering av nya typer av artificiellt ljus i hönsstallar

    Get PDF
    Ljusmiljön i hönshus Ă€r avgörande för vĂ€rphönorna och deras Ă€gglĂ€ggning. FĂ„glar har, till skillnad frĂ„n mĂ€nniskor en fjĂ€rde typ av kon i ögats nĂ€thinna som gör att hönorna kan uppfatta Ă€ven elektromagnetisk strĂ„lning (ljus) med en vĂ„glĂ€ngd kortare Ă€n 400 nm. FĂ„glar har ocksĂ„ en större spektral kĂ€nslighet Ă€n mĂ€nniskor och en hög kritisk flimmerfrekvensen, 100 Hz, vilket innebĂ€r att de kan reagera annorlunda pĂ„ ljusmiljön. Enligt Svensk djurskyddslag ska alla byggnader för husdjur har fönster eller andra öppningar för dagsljus. Det finns dock inga riktlinjer för hur dessa dagsljusinslĂ€pp skall vara utformade eller placerade. OlĂ€mplig belysning eller olĂ€mpligt utformade dagsljusinslĂ€pp kan öka risken för beteendeproblem, t.ex. kannibalism och fjĂ€derplockning. Glödljus har tills nyligen varit den vanligaste typen av belysning i svenska hönshus. PĂ„ grund av ett förbud mot glödlampor inom EU finns emellertid behov av att ersĂ€tta denna glödljusbelysning. Det finns Ă€ven behov av alternativa belysningstyper i hönshus med olĂ€mpligt utformade dagsljusinslĂ€pp samt riktlinjer för hur dagsljusinslĂ€pp skall utformas i nybyggda vĂ€rphönsstallar. Syftet med detta projekt var att utvĂ€rdera ett belysningsalternativ till vĂ€rphönsstallar, med olĂ€mpligt utformade dagsljusinslĂ€pp, samt utvĂ€rdera ett belysningsalternativ till glödlampan. Baserat pĂ„ en litteraturstudie samt en fĂ€ltstudie i svenska vĂ€rphönsstallar har ocksĂ„ riktlinjer för utformning och placering av dagsljusinlĂ€pp tagits fram. En ny typ av belysningssystem (HATOÂź Agricultural Lighting) har importerats till Sverige, och detta system uppges, av tillverkarna, vara mer lik naturligt ljus eftersom det har jĂ€mnare vĂ„glĂ€ngdsfördelning mellan 400 och 700 nm, och högre andel av ultraviolett A ljus (UVA). För att bli godkĂ€nd som ett alternativ till dagsljusinslĂ€pp mĂ„ste det visas att lampan inte orsakar sjukdom och onödigt lidande hos djuren. En fĂ€ltstudie genomfördes pĂ„ tvĂ„ gĂ„rdar med vĂ€rphöns i system för frigĂ„ende höns och i inredda burar och en uppfödning (frigĂ„ende), som redan Ă€r utrustade med HATOÂź-belysning. Studien genomfördes under en produktionsomgĂ„ng i samtliga flockar. Som ett belysningsalternativ till glödlampan har LED (Light Emitting Diode) utvĂ€rderats i ett vĂ€rphönsstall, ocksĂ„ det under en produktionsomgĂ„ng. Belysningsmiljö registrerades avseende ljusintensitet och spektralfördelning, i gĂ„ngarna, vid fodertrĂ„g och i redena. PĂ„ varje gĂ„rd genomfördes kliniska undersökningar pĂ„ ett slumpmĂ€ssigt urval av 100 fĂ„glar; dessutom gjordes kvalitativa beteendestudier. Unghönsen inspekterades vid 1, 10 och 14 veckors Ă„lder, och produktionsflockar inspekterades vid 35, 55 och 70 veckors Ă„lder. I Stallarna utrustade med HATO belysning var ljusintensiteten 12-70 lux i uppfödningen, frĂ„n 2,5 till 26 lux i stallet med inredda burar och frĂ„n 7,6 till 26 lux i systemet för frigĂ„ende höns. I vĂ€rphönsstallet med LED ljus var ljusintensiteten 0,7-11 lux. Äggproduktionen var normal jĂ€mfört med den förvĂ€ntade. Det var lĂ„g förekomst av beteenden negativa för djurvĂ€lfĂ€rden sĂ„som att hönorna var spĂ€nda eller nervösa. Hönorna var vi normal hull och förekomsten av kamskador var lĂ„g. FjĂ€derplockning observerades i grupperna, men en tydlig koppling till huset eller ljus system kunde inte göras. FjĂ€derplockning har Ă€ven rapporterats frĂ„n hönor som har möjlighet att gĂ„ ute. NĂ€r dagsljusinlĂ€pp anvĂ€nds Ă€r det viktigt att fördelningen av ljuset Ă€r jĂ€mn samt att dagsljusinslĂ€ppet Ă€r kordinerat med det befintliga ljusprogrammet i stallet

    Impedance of SOFC electrodes: A review and a comprehensive case study on the impedance of LSM:YSZ cathodes

    Get PDF
    AbstractIt was shown through a comprehensive impedance spectroscopy study that the impedance of the classic composite LSM:YSZ (lanthanum strontium manganite and yttria stabilized zirconia) solid oxide fuel cell (SOFC) cathode can be described well with porous electrode theory. Furthermore, it was illustrated through a literature review on SOFC electrodes that porous electrode theory not only describes the classic LSM:YSZ SOFC cathode well, but SOFC electrodes in general. The extensive impedance spectroscopy study of LSM:YSZ cathodes consisted of measurements on cathodes with three different sintering temperatures and hence different microstructures and varying degrees of LSM/YSZ solid state interactions. LSM based composite cathodes, where YSZ was replaced with CGO was also studied in order to acquire further knowledge on the chemical compatibility between LSM and YSZ. All impedance measurements were acquired in the very broad temperature range of 200–900°C for complete elucidation of the impedance. All impedance spectra were analyzed in terms of porous electrode theory. Physical materials parameters were extracted from the analysis, which were in excellent accordance with literature values. Valuable insight about the dissolution of Mn in the cathode composite material YSZ during preparation was furthermore provided along with valuable engineering characteristics such as the electrochemical utilization thickness. From the combined impedance study and literature review, it is clear, that porous electrode theory is the most suitable framework for any type of porous composite SOFC electrode evaluation

    Global scaling of the heat transport in fusion plasmas

    Get PDF

    Att spela utan att tÀnka eller vÀrdera

    Get PDF
    Detta arbete gĂ„r ut pĂ„ att jag, i ett antal improvisationer, undersöker möjligheten att spela utan att tĂ€nka pĂ„, reflektera över eller vĂ€rdera det jag spelar. De frĂ„gor och funderingar jag kommer att utgĂ„ ifrĂ„n Ă€r: * Kan jag spela utan att reflektera över detta jag spelar? * Kan jag spela utan att vĂ€rdera det jag spelar? * Hur pĂ„verkar dessa försök och förhĂ„llningssĂ€tt mitt musicerande i olika spelsituationer? Dessa frĂ„gor försöker jag besvara genom att med olika ramar och utgĂ„ngspunkter göra undersökningar genom att improvisera och samtidigt dokumentera detta. Efter varje improvisation noterar jag hur jag upplevde situationen och jĂ€mför sedan detta med hur det lĂ€t och sĂ„g ut. Jag kommer att knyta an detta till Kenny Werners bok “Effortless Mastery” och Stephen Nachmanovitchs bok “Free play”
    corecore