Faecal biomarkers in type 1 diabetes with and without diabetic nephropathy

Gastrointestinal dysbiosis is common among persons with type 1 diabetes (T1D), but its potential impact on diabetic nephropathy (DN) remains obscure. We examined whether faecal biomarkers, previously associated with low-grade gastrointestinal inflammation, differ between healthy controls and T1D subjects with and without DN. Faecal samples were analyzed for levels of calprotectin, intestinal alkaline phosphatase (IAP), short-chain fatty acids (SCFA) and immunoglobulins in subjects with T1D (n=159) and healthy controls (NDC; n=50). The subjects with T1D were stratified based on albuminuria: normoalbuminuria (300 mg/g; n=60). aecal calprotectin, IAP and immunoglobulin levels did not differ between the T1D albuminuria groups. However, when subjects were stratified based on faecal calprotectin cut-off level (50 mu g/g), macroalbuminuric T1D subjects exceeded the threshold more frequently than NDC (p=0.02). Concentrations of faecal propionate and butyrate were lower in T1D subjects compared with NDC (p=0.04 and p=0.03, respectively). Among T1D subjects, levels of branched SCFA (BCFA) correlated positively with current albuminuria level (isobutyrate, p=0.03; isovalerate, p=0.005). In our study cohort, fatty acid metabolism seemed to be altered among T1D subjects and those with albuminuria compared to NDC. This may reflect gastrointestinal imbalances associated with T1D and renal complications.Peer reviewe

Rehevöitymisen vaikutus kumppaninvalintaan

The Baltic Sea suffers from eutrophication caused by the increased use of nitrogen- and phosphorus based fertilizers in agriculture. When these nutrients end up in the water ecosystem, they increase the growth of filamentous algae causing turbidity at many locations. The three-spined stickleback (Gasterosteus aculeatus) breeds at the shallow coastal waters of the Baltic Sea, which are often eutrophied. In these locations turbidity of the water may interfere with the mating cues used by the three-spined stickleback, which in turn may lead to decreased fitness of the population. I attempted to find out how turbidity alters the use of visual and olfactory cues in the mate choice of the three-spined stickleback, as well as to see if these changes decrease the viability of the following generation. Female three-spined sticklebacks choose their mates based on visual and olfactory cues. During the reproductive season stickleback males turn bright red and attract females to their nests by a conspicuous courtship dance. Females use males' red colouration, size and courtship intensity as visual cues when choosing an appropriate mating partner. They also pay much attention to olfactory cues. Female sticklebacks are able to smell MHC-encoded peptides which are secreted to the males' skin. The allelic combination of MHC determines which pathogens the individual has resistance for, and this resistance may be inherited by the offspring. I empirically tested the use of olfactory and visual cues in the mate choice of the three-spined stickleback using turbid and clear water as treatments. In mate choice tests a female was made to choose from two males in circumstances where she was allowed to use only one of the cues (visual or olfactory) or both cues simultaneously. The redness and size of the males was measured. Artificial inseminations were performed to produce offspring, whose growth rate was measured to evaluate fitness. Based on the results of these experiments, turbidity alters the use of mating cues of the three-spined stickleback. Visual cues seem to be important in clear water, whereas in turbid water olfactory cues increase in importance in relation to visual cues. The sample size was limited to reliably test offspring fitness effects, but it seems that the alteration in the use of mate choice cues may influence population viability in the long term. However, additional research is needed to determine this.Itämeri on moninpaikoin rehevöitynyt maatalouden lisääntyneen typpi- ja fosforilannoitekäytön seurauksena. Typen ja fosforin rikastuessa vesistössä rihmalevien kasvu kiihtyy ja vesi samenee. Kolmipiikki (Gasterosteus aculeatus) lisääntyy Itämeren matalissa rantavesissä, jotka ovat usein rehevöityneitä. Veden sameneminen voi häiritä kolmipiikin kumppaninvalintaprosessia ja heikentää lajin elinkykyä. Tässä tutkimuksessa pyrin selvittämään kuinka sameus vaikuttaa haju- ja näköaistin käyttöön kolmipiikin kumppaninvalinnassa ja näkyvätkö mahdolliset muutokset seuraavassa sukupolvessa. Kolmipiikkinaaraat valitsevat sopivan koiraan parittelukumppanikseen näkö- ja hajuaistin avulla. Lisääntymiskauden aikana kolmipiikkikoiraat omaksuvat punaisen värityksen ja houkuttelevat naaraita rakentamilleen pesille tyypillisin soidinrituaalein. Naaras valikoi parittelukumppaninsa koiraan punaisen värityksen, koon sekä soidintanssin perusteella. Myös hajuaistilla on suuri merkitys valintaprosessissa, sillä naaraat pystyvät haistamaan koiraan iholle erittyviä MHC-geenien koodaamia peptidejä. MHC-geenien alleelikoostumus määrää mille patogeeneille yksilöllä on vastustuskyky, ja tämä ominaisuus voi periytyä jälkeläisille. Tutkin kokeellisesti haju- ja näköaistin suhteellista merkitystä kolmipiikin kumppaninvalintaan sameassa ja kirkkaassa vedessä. Kumppaninvalintakokeissa naaraan tuli valita kahden koiraan väliltä olosuhteissa, joissa se voi käyttää vain jompaa kumpaa aistia (haju- tai näköaisti), tai molempia aisteja. Koiraan väritys ja koko mitattiin kokeen yhteydessä. Poikasten elinkykyä arvioitiin keinohedelmöityskokeilla, joista saatavien poikasten kasvunopeus mitattiin. Tulosten perusteella sameudella on vaikutusta kolmipiikin kumppaninvalinnassa käyttämiin aisteihin. Näköaisti oli kolmipiikkinaaraille hajuaistia tärkeämpi kirkkaassa vedessä, kun taas sameassa vedessä hajuaistin merkitys kasvoi ja näköaistin merkitys kumppaninvalintaan oli pienempi. Näytekoko oli liian pieni, jotta poikasten elinkykyä oltaisiin voitu arvioida luottamuksella. Näyttää kuitenkin siltä, että kumppaninvalintaprosessin muutoksilla saattaisi olla vaikutusta populaation elinkykyyn. Jotta vaikutuksia voitaisiin arvioida pitkällä tähtäimellä, tarvitaan lisätutkimusta

Faecal biomarkers in type 1 diabetes with and without diabetic nephropathy

Abstract Gastrointestinal dysbiosis is common among persons with type 1 diabetes (T1D), but its potential impact on diabetic nephropathy (DN) remains obscure. We examined whether faecal biomarkers, previously associated with low-grade gastrointestinal inflammation, differ between healthy controls and T1D subjects with and without DN. Faecal samples were analyzed for levels of calprotectin, intestinal alkaline phosphatase (IAP), short-chain fatty acids (SCFA) and immunoglobulins in subjects with T1D (n = 159) and healthy controls (NDC; n = 50). The subjects with T1D were stratified based on albuminuria: normoalbuminuria (< 30 mg/g; n = 49), microalbuminuria (30–299 mg/g; n = 50) and macroalbuminuria (≥ 300 mg/g; n = 60). aecal calprotectin, IAP and immunoglobulin levels did not differ between the T1D albuminuria groups. However, when subjects were stratified based on faecal calprotectin cut-off level (50 µg/g), macroalbuminuric T1D subjects exceeded the threshold more frequently than NDC (p = 0.02). Concentrations of faecal propionate and butyrate were lower in T1D subjects compared with NDC (p = 0.04 and p = 0.03, respectively). Among T1D subjects, levels of branched SCFA (BCFA) correlated positively with current albuminuria level (isobutyrate, p = 0.03; isovalerate, p = 0.005). In our study cohort, fatty acid metabolism seemed to be altered among T1D subjects and those with albuminuria compared to NDC. This may reflect gastrointestinal imbalances associated with T1D and renal complications