16 research outputs found
Members of a highly widespread bacteriophage family are hallmarks of metabolic syndrome gut microbiomes
No full textThere is significant interest in altering the course of cardiometabolic disease development via the gut microbiome. Nevertheless, the highly abundant phage members -which impact gut bacteria- of the complex gut ecosystem remain understudied. Here, we characterized gut phageome changes associated with metabolic syndrome (MetS), a highly prevalent clinical condition preceding cardiometabolic disease. MetS gut phageome populations exhibited decreased richness and diversity, but larger inter-individual variation. These populations were enriched in phages infecting Bacteroidaceae and depleted in those infecting Ruminococcaeae. Differential abundance analysis identified eighteen viral clusters (VCs) as significantly associated with either MetS or healthy phageomes. Among these are a MetS-associated Roseburia VC that is related to healthy control-associated Faecalibacterium and Oscillibacter VCs. Further analysis of these VCs revealed the Candidatus Heliusviridae, a highly widespread gut phage lineage found in 90+% of the participants. The identification of the temperate Ca. Heliusviridae provides a novel starting point to a better understanding of the effect that phages have on their bacterial hosts and the role that this plays in MetS
Causality of small and large intestinal microbiota in weight regulation and insulin resistance
No full textObjective<br/><br/>The twin pandemics of obesity and Type 2 diabetes (T2D) are a global challenge for health care systems. Changes in the environment, behavior, diet, and lifestyle during the last decades are considered the major causes. A Western diet, which is rich in saturated fat and simple sugars, may lead to changes in gut microbial composition and physiology, which have recently been linked to the development of metabolic diseases.<br/><br/>Methods<br/><br/>We will discuss evidence that demonstrates the influence of the small and large intestinal microbiota on weight regulation and the development of insulin resistance, based on literature search.<br/><br/>Results<br/><br/>Altered large intestinal microbial composition may promote obesity by increasing energy harvest through specialized gut microbes. In both large and small intestine, microbial alterations may increase gut permeability that facilitates the translocation of whole bacteria or endotoxic bacterial components into metabolic active tissues. Moreover, changed microbial communities may affect the production of satiety-inducing signals. Finally, bacterial metabolic products, such as short chain fatty acids (SCFAs) and their relative ratios, may be causal in disturbed immune and metabolic signaling, notably in the small intestine where the surface is large. The function of these organs (adipose tissue, brain, liver, muscle, pancreas) may be disturbed by the induction of low-grade inflammation, contributing to insulin resistance.<br/><br/>Conclusions<br/><br/>Interventions aimed to restoring gut microbial homeostasis, such as ingestion of specific fibers or therapeutic microbes, are promising strategies to reduce insulin resistance and the related metabolic abnormalities in obesity, metabolic syndrome, and type 2 diabetes. This article is part of a special issue on microbiota.<br/><p>Objective The twin pandemics of obesity and Type 2 diabetes (T2D) are a global challenge for health care systems. Changes in the environment, behavior, diet, and lifestyle during the last decades are considered the major causes. A Western diet, which is rich in saturated fat and simple sugars, may lead to changes in gut microbial composition and physiology, which have recently been linked to the development of metabolic diseases. Methods We will discuss evidence that demonstrates the influence of the small and large intestinal microbiota on weight regulation and the development of insulin resistance, based on literature search. Results Altered large intestinal microbial composition may promote obesity by increasing energy harvest through specialized gut microbes. In both large and small intestine, microbial alterations may increase gut permeability that facilitates the translocation of whole bacteria or endotoxic bacterial components into metabolic active tissues. Moreover, changed microbial communities may affect the production of satiety-inducing signals. Finally, bacterial metabolic products, such as short chain fatty acids (SCFAs) and their relative ratios, may be causal in disturbed immune and metabolic signaling, notably in the small intestine where the surface is large. The function of these organs (adipose tissue, brain, liver, muscle, pancreas) may be disturbed by the induction of low-grade inflammation, contributing to insulin resistance. Conclusions Interventions aimed to restoring gut microbial homeostasis, such as ingestion of specific fibers or therapeutic microbes, are promising strategies to reduce insulin resistance and the related metabolic abnormalities in obesity, metabolic syndrome, and type 2 diabetes. This article is part of a special issue on microbiota.</p
Eremohaplomydas gobabebensis Boschert & Dikow 2022, sp. nov.
No full textEremohaplomydas gobabebensis sp. nov. Figs 10-12, 13-15, 32, 53, 56 Diagnosis. The species is distinguished from congeners by the densely arranged dorso-ventrally flattened setae on legs, the absence of the base of vein M3+M4, the overall golden pubescence, and the restricted distribution in the central Namib Desert. Etymology. This species is named after the Gobabeb Namib Research Institute (www.gobabeb.org) where it was collected for the first time in November 2018. The specific epithet is to be treated as a noun in apposition. Description. Female. unknown. Male. Head : black, facial gibbosity brown, in general golden pubescent, ventrally and posteriorly white pubescent, white setose, laterally compressed setae; width distinctly greater than thorax (at postpronotal lobe), interocular distance on vertex larger than at ventral eye margin; vertex between compound eyes ± horizontally straight, medially only slightly below dorsal eye margin, vertex golden pubescent, white setose; ocellar triangle apubescent; facial gibbosity distinct, well-developed and discernible in lateral view, mystax covering entire facial gibbosity, white; parafacial area approximately as wide as ½ width of central facial gibbosity (at same level); frons not elevated, golden pubescent, white setose; occiput predominantly white pubescent, dorsally golden pubescent, white setose, median occipital sclerite white setose, laterally compressed setae; pocl macrosetae absent; postgena apubescent, long, sparsely white setose; clypeus comprised of inverted U-shaped sclerite, dorsal ½ sclerotized medially to form plate, recessed (concave), ventrally simple, posterior to proboscis, laterally connected to face by sclerotized cuticle; proboscis very short, vestigial, knob-like, yellow; labellum small, as wide as prementum, length indiscernible, sclerotization indiscernible; maxillary palpus laterally compressed (triangular), light brown, slightly longer than proboscis. Antenna: light brown to brown; scape white setose dorsally, asetose ventrally; pedicel white setose dorsally and ventrally; postpedicel cylindrical in proximal 1/5, symmetrically bulbous in distal 4/5, ≥ 5.0 times as long as combined length of scape and pedicel, asetose; apical seta-like sensory element situated apically in cavity on postpedicel. Thorax: brown, scutum golden pubescent, pleura white pubescent; scutum uniformly black, surface entirely smooth, golden pubescent, scutal setation comprised of long white setae with distinct rows of long dorsocentral setae and dense lateral scutal setae; dc setae pre- and postsuturally white, acr setae absent, lateral scutal setae white, npl setae 0, spal setae 0, pal setae 0; proepisternum apubescent, long white setose; proepimeron grey pubescent, asetose; antepronotum antero-medially smooth (without any indentation); lateral postpronotum long white setose; postpronotal lobe light brown, golden to light brown pubescent, long white setose; scutellum golden pubescent, discal scutellar setae absent, apical scutellar setae absent; mesopostnotum golden pubescent, asetose; anatergite golden pubescent, asetose; katatergite white pubescent, long white setose, slightly elevated, smoothly convex; anepisternum white pubescent, anteriorly white setose, posteriorly densely long white setose, scattered long white setose centrally; katepisternum dorsally white pubescent, ventrally apubescent, asetose; anepimeron white pubescent, long white setose; katepimeron white pubescent, asetose; meron white pubescent dorsally, sparsely white pubescent ventrally, asetose; metakatepisternum large; metanepisternum white pubescent, asetose; metepimeron yellow (same color as T1), white pubescent, long white setose, ± flat, infra-halter sclerite absent. Legs: light brown to brown, setation comprised of white laterally compressed setae predominantly covering surface; pro coxa apubescent, sparse white laterally compressed setae; mes coxa apubescent, asetose anteriorly, short white laterally compressed setae posteriorly; met coxa laterally unsclerotized (membrane between coxa and metakatepisternum clearly visible), apubescent, asetose anteriorly, short white laterally compressed setae posteriorly; met trochanter setose medially; pro + mes femur light brown to brown, met femur light brown to brown, distinctly clubbed for nearly entire length, macrosetose, 1 antero-ventral and 1 postero-ventral row of macrosetae, postero-ventrally long white, appressed setose; pro tibia laterally arched; mes tibia laterally arched; met tibia laterally arched, met tibia cylindrical with ventral keel terminating into distinct spur, spur not projecting beyond tip of tibia, postero-laterally long white, appressed setose; pro + mes tarsomere 1 approximately as long as individual tarsomeres 2, 3, or 4, met tarsomere 1 as long as individual tarsomeres 2, 3, or 4; pulvillus well-developed, as long as well-developed claw, and as wide as base of claw; setiform empodium absent. Wing: length = 4.2-5.7 mm; hyaline throughout, veins light yellow, microtrichia absent; cells r1, r4, m3, + cua closed, r5 open; C terminating at junction with R1; Sc long, terminating in C proximal to r-m; R4 terminates in R1; R5 terminates in R1 and R4 simultaneously; auxiliary vein (R3) at base of R4 absent; R4 and R5 widest apart medially; r-m distinct, R4+5 and M1 apart, connected by crossvein; M1 curves slightly anteriorly at r-m, M1 (or M1+M2) terminates in C (not reaching wing margin); base of M3+M4 absent, M3+M4 not terminating together in C (not reaching wing margin), M4 and CuA split proximally to m-cu (cell m3 narrow proximally); CuP straight, cell cup wide, CuP and wing margin further apart proximally than distally; alula well-developed; halter light yellow, apubescent, asetose. Abdomen: light brown to brown, setation comprised of dense long white setae, T2-4 parallel-sided and not constricted waist-like, T surface entirely smooth; T1-4 light brown, T5-7 brown; T entirely golden pubescent; T1-7 long white setose; S1-5 brown with white posterior margin, S6-7 dark brown; S apubescent; S1 asetose, S2-7 long white setose; bullae on T2 oval, brown, surface entirely smooth, T2 surface anterior to bullae smooth. ♂ abdomen and terminalia: T1-8 well-developed; T7-8 anteriorly with 2 lateral apodemes; S6 regular, without any special setation postero-medially; S8 simple plate, entire (undivided) ventro-medially, not fused to T8 dorso-laterally; epandrium formed by single sclerite (fused medially ± entirely), distally in dorsal view pointed postero-laterally; subepandrial sclerite without lateral or median protuberances; hypandrium ± flat, divided ventro-medially by unsclerotized area into 2 sclerotized halves, entirely fused with gonocoxite, forming a gonocoxite-hypandrial complex, supra-hypandrial sclerite absent; gonocoxite simple, short, hook-like, without median or lateral protuberance, gonocoxal apodeme absent; 2 functional phallic prongs, short with broad lateral flange, medio-distally connected, parallel or diverging laterally, distally straight or only diverging slightly laterally; phallic epimere absent; lateral ejaculatory process absent; ejaculatory apodeme formed by single dorso-ventrally oriented plate; ventro-median margin of parameral sheath heavily sclerotized (appearing entirely closed); parameral sheath long, sperm sac entirely covered; sperm sac appearing ± heavily sclerotized. Type locality. Namibia: Erongo: Namib-Naukluft National Park, Gobabeb 20 km NW on D1983, Kuiseb riverbed (23°24'56"S, 014°54'43"E, -23.41556, 14.91194). Material examined. Namibia: Erongo: 1♂ Namib-Naukluft National Park, Gobabeb 20 km NW on D1983, Kuiseb riverbed, 23°24'56"S, 014°54'43"E, 317 m, 2018-11-24 collected a.m. (9:00-noon), dry, sandy, partly wooded riverbed, resting on sand, Dikow, T. (USNMENT01518262, Holotype, NMNW); 1♂ Namib-Naukluft National Park, Gobabeb 20 km NW on D1983, Kuiseb riverbed, 23°24'56"S, 014°54'43"E, 317 m, 2018-11-24 collected a.m. (9:00-noon), dry, sandy, partly wooded riverbed, resting on sand, Dikow, T. (USNMENT01518263, Paratype, NMNW); 1♂ Namib-Naukluft National Park, Gobabeb 20 km NW on D1983, Kuiseb riverbed, 23°24'56"S, 014°54'43"E, 317 m, 2018-11-24 collected a.m. (9:00-noon), dry, sandy, partly wooded riverbed, resting on sand, Dikow, T. (USNMENT01518261, Paratype, USNM); 1♂ Namib-Naukluft National Park, Gobabeb 20 km NW on D1983, Kuiseb riverbed, 23°24'56"S, 014°54'43"E, 317 m, 2018-11-24 collected a.m. (9:00-noon), dry, sandy, partly wooded riverbed, resting on sand, Dikow, T. (USNMENT01518260, Paratype, USNM); 1♂ Namib-Naukluft National Park, Gobabeb, dunes W of Kuiseb riverbed, 23°33'48"S, 015°01'58"E, 401 m, 2018-11-21 collected a.m. (9:00-noon), small vegetated dunes, resting on sand, Dikow, T. (USNMENT01518012, Paratype, USNM); 1♂ Namib-Naukluft National Park, Gobabeb, small dunes W of Kuiseb River, 23°33'50"S, 015°01'59"E, 398 m, 2018-11-23 collected p.m. (noon-15:00), partly vegetated dune, resting on sand, Dikow, T. (USNMENT01518339, Paratype, USNM). Distribution, biodiversity hotspots, phenology, and biology. Known only from two localities in the central Namib Desert in Namibia (Fig. 56). A rarely collected species known only from seven specimens from three collecting events in 2018 (Table 1). The species is not known to occur in any currently recognized biodiversity hotspot. Adult flies are active in November in late spring (Table 2), which is a time at the beginning of a moister period and rising temperatures in this part of the Namib Desert (data for Gobabeb, Namibia, see https://www.worldweatheronline.com/gobabeb-weather/erongo/na.aspx). So far, only males have been collected and they were observed to fly very low above the ground and appeared to inspect the base of single grass plants and dart at high speed across the sand to the next plant. At the Gobabeb locality, the flies were collected flying among Centropodia glauca (Poaceae, Gha Grass, https://www.gbif.org/species/5680035) and at the 20 km N Gobabeb locality the flies darted among Cladoraphis spinosa (Poaceae, Spiny Love Grass, https://www.gbif.org/species/4152290, see habitat photographs with the grasses in the foreground in Figs 1, 2). Both grass species are native and widely distributed in the western parts of southern Africa including the Namib Desert (van Oudtshoorn 2012). The male flies possibly inspected the grasses in search for females resting in the shade although the junior author was not able to observe or collect any females. In general, the flies were very difficult to observe and collect due to their high flight speed, light colouration, and small size. Remarks. Wharton (1982) did not collect this species in his seminal year-long study of Mydidae at Gobabeb.Published as part of Boschert, Claire & Dikow, Torsten, 2022, Taxonomic revision of the mydas-fly genera Eremohaplomydas Bequaert, 1959, Haplomydas Bezzi, 1924, and Lachnocorynus Hesse, 1969 (Insecta, Diptera, Mydidae), pp. 19-75 in African Invertebrates 63 (1) on page 19, DOI: 10.3897/afrinvertebr.63.7630
Yeast cell wall derivatives as a potential strategy for modulating oral microbiota and dental plaque biofilm
No full textIntroduction: Derivatives from Saccharomyces cerevisiae yeast including yeast extracts and yeast cell walls are sustainable sources of valuable nutrients, including dietary fibers and proteins. Previous studies have shown that certain components from these yeast derivatives can inhibit the growth of harmful intestinal bacteria and promote the growth of beneficial bacteria. However, the effects of yeast derivatives on oral health have not yet been investigated. Methods: An in vitro oral biofilm model was employed to examine the impacts of yeast derivatives on the oral microbiota and their potential benefits for maintaining oral homeostasis. The model incorporated dental plaque donor material from both healthy and periodontitis diagnosed individuals. Biofilm formation, density, and microbial composition were quantified. Additionally, the production of short-chain fatty acids in the biofilm supernatants was measured. Results: Yeast extracts had only minor effects on oral biofilm formation. In contrast, yeast cell wall derivatives, which are rich in polysaccharides such as beta-glucans and mannans, significantly reduced the density of the oral biofilms in vitro. This reduction in biofilm density was associated with an overall shift in the bacterial community composition, including an increase in beneficial bacteria and a decrease in the abundance of Tannerella forsythia, an important species involved in bacterial coaggregation and the development and maturation of the oral biofilm. Furthermore, the yeast cell wall derivatives decreased the production of short-chain fatty acids, including acetic and butyric acid. These findings were consistent across both healthy and periodontitis microbiomes. Conclusion: This study has demonstrated the potential of yeast cell wall derivatives to positively impact oral health by significantly reducing biofilm density, modulating the oral microbial composition, and decreasing the production of short-chain fatty acids. The observed effects highlight the promising applications of these yeast-based compounds as an approach to managing oral diseases. Further research is needed to fully elucidate the mechanisms of action and explore the clinical potential of yeast cell wall derivatives in promoting and maintaining oral health.</p
The Interdependence of Determinants for the Strength and Direction of Social Desirability Bias in Racial Attitude Surveys
No full textEmpirical evidence suggests that the respondents� approval motive, their desirability beliefs and the privacy of the response situation affects respondents� susceptibility to social desirability bias. Previous research has analyzed the explanatory power of these factors separately and has not taken their possible interdependence as determinants for social desirability bias into account. This article tests the prediction from rational-choice theory that a strong approval motive, clear differences in the perceived desirability of response options and a lack of privacy are all necessary but not sufficient conditions for social desirability bias. According to the empirical results from our first study a three-way interaction between the analyzed factors predicts respondents� racial attitude reports. However, since attitude answers and desirability beliefs were collected in the same interview, the observed associations may be an artifact due to subjects� sensitization for social desirability concerns. This possibility is tested in a second study, where only racial attitude answers were collected under conditions of varying response privacy. Aggregated response differences between the utilized attitude items and respondents� social group affiliation were matched with equivalent differences in the desirability beliefs found in the first study. The results from the main study were replicated with this independent sample of respondents.
Faecal Microbiota transplantation affects liver DNA methylation in Non-alcoholic fatty liver disease: a multi-omics approach
No full textABSTRACTIndividuals with nonalcoholic fatty liver disease (NAFLD) have an altered gut microbiota composition. Moreover, hepatic DNA methylation may be altered in the state of NAFLD. Using a fecal microbiota transplantation (FMT) intervention, we aimed to investigate whether a change in gut microbiota composition relates to altered liver DNA methylation in NAFLD. Moreover, we assessed whether plasma metabolite profiles altered by FMT relate to changes in liver DNA methylation. Twenty-one individuals with NAFLD underwent three 8-weekly vegan allogenic donor (n = 10) or autologous (n = 11) FMTs. We obtained hepatic DNA methylation profiles from paired liver biopsies of study participants before and after FMTs. We applied a multi-omics machine learning approach to identify changes in the gut microbiome, peripheral blood metabolome and liver DNA methylome, and analyzed cross-omics correlations. Vegan allogenic donor FMT compared to autologous FMT induced distinct differential changes in I) gut microbiota profiles, including increased abundance of Eubacterium siraeum and potential probiotic Blautia wexlerae; II) plasma metabolites, including altered levels of phenylacetylcarnitine (PAC) and phenylacetylglutamine (PAG) both from gut-derived phenylacetic acid, and of several choline-derived long-chain acylcholines; and III) hepatic DNA methylation profiles, most importantly in Threonyl-TRNA Synthetase 1 (TARS) and Zinc finger protein 57 (ZFP57). Multi-omics analysis showed that Gemmiger formicillis and Firmicutes bacterium_CAG_170 positively correlated with both PAC and PAG. E siraeum negatively correlated with DNA methylation of cg16885113 in ZFP57. Alterations in gut microbiota composition by FMT caused widespread changes in plasma metabolites (e.g. PAC, PAG, and choline-derived metabolites) and liver DNA methylation profiles in individuals with NAFLD. These results indicate that FMTs might induce metaorganismal pathway changes, from the gut bacteria to the liver
The SIB Swiss Institute of Bioinformatics' resources: focus on curated databases
No full textThe SIB Swiss Institute of Bioinformatics (www.isb-sib.ch) provides world-class bioinformatics databases, software tools, services and training to the international life science community in academia and industry. These solutions allow life scientists to turn the exponentially growing amount of data into knowledge. Here, we provide an overview of SIB's resources and competence areas, with a strong focus on curated databases and SIB's most popular and widely used resources. In particular, SIB's Bioinformatics resource portal ExPASy features over 150 resources, including UniProtKB/Swiss-Prot, ENZYME, PROSITE, neXtProt, STRING, UniCarbKB, SugarBindDB, SwissRegulon, EPD, arrayMap, Bgee, SWISS-MODEL Repository, OMA, OrthoDB and other databases, which are briefly described in this article
Gut-derived bacterial flagellin induces beta-cell inflammation and dysfunction
No full textHyperglycemia and type 2 diabetes (T2D) are caused by failure of pancreatic beta cells. The role of the gut microbiota in T2D has been studied, but causal links remain enigmatic. Obese individuals with or without T2D were included from two independent Dutch cohorts. Human data were translated in vitro and in vivo by using pancreatic islets from C57BL6/J mice and by injecting flagellin into obese mice. Flagellin is part of the bacterial locomotor appendage flagellum, present in gut bacteria including Enterobacteriaceae, which we show to be more abundant in the gut of individuals with T2D. Subsequently, flagellin induces a pro-inflammatory response in pancreatic islets mediated by the Toll-like receptor (TLR)-5 expressed on resident islet macrophages. This inflammatory response is associated with beta-cell dysfunction, characterized by reduced insulin gene expression, impaired proinsulin processing and stress-induced insulin hypersecretion in vitro and in vivo in mice. We postulate that increased systemically disseminated flagellin in T2D is a contributing factor to beta-cell failure in time and represents a novel therapeutic target
Imaging of mice and men; adventures in multispectral imaging
No full textCancer of the brain and CNS account for only 2% of new cancer cases in the UK however it is responsible for 7% of cancer deaths of those aged under 70 years of age. Although surgery falls short of a cure it is the primary method of treatment. Two of the key problems in tumour surgery in the brain are a) that many tumours are visually indistinguishable from normal tissue even for experienced surgeons and b) that the risk of post-surgical neurological deficit is related to the proximity of functional (or 'eloquent') neurological tissue. In collaboration with surgeons at the Southampton University NHS Hospitals Trust we seek to address both of these problems. Firstly there is literature evidence that normal and neoplastic tissue have different spectral characteristics in the visible and near-infrared region. We investigate whether these can be practically imaged intraoperatively to establish disease state. Secondly the redox state of haemoglobin is known to affect it's visible and near-infrared spectral characteristics. This project investigates whether it is possible to identify the haemodynamic response associated with functional activity intraoperatively in the human brain. Prion diseases are fatal chronic neurodegenerative diseases of animals and man. They have gained notoriety due to recent outbreaks of Bovine Spongiform Encephalopathy (BSE) and the evidence that they can be transmitted between species, including to man. Exposure to BSE infected material has been shown to cause variant Creutzfeldt-Jacob disease in man. Prion disease is also used as a model of other neurodegenerative diseases, such as Alzheimers disease. Remarkably little is known about this class of disease including the specific cause of the neurodegeneration. Prions are a mis-folded protein which have a different conformation than the normal protein. Certain spectral features in the mid infrared region are associated with protein conformation. In collaboration with neuro-biologists within the university and using a synchrotron light source we investigate the application of multispectral imaging in early stage prion disease. By analysis of the protein conformation sensitivity of the mid infrared spectra (with particular interest in the Amide I band) we seek to identify structurally relevant markers in a mouse model before clinical symptoms of the disease are evident. This may lead to better understanding of the disease progression and the neurotoxic element
Measurement of differential production cross-sections and forward-backward ratio in p+Pb collisions with the ATLAS detector
No full textSee paper for full list of authors - 13 pages plus author list + cover pages (26 pages total), 8 figures, 8 tables, submitted to Phys. Rev. C. All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2013-07/International audienceMeasurements of differential cross-sections for production in p+Pb collisions at = 5.02 TeV at the LHC with the ATLAS detector are presented. The data set used corresponds to an integrated luminosity of 28.1 nb. The mesons are reconstructed in the dimuon decay channel over the transverse momentum range GeV and over the center-of-mass rapidity range . Prompt are separated from resulting from -hadron decays through an analysis of the distance between the decay vertex and the event primary vertex. The differential cross-section for production of nonprompt is compared to a FONLL calculation that does not include nuclear effects. Forward-backward production ratios are presented and compared to theoretical predictions. These results constrain the kinematic dependence of nuclear modifications of charmonium and -quark production in p+Pb collisions
