From feces to data : A metabarcoding method for analyzing consumed and available prey in a bird-insect food web

Diets play a key role in understanding trophic interactions. Knowing the actual structure of food webs contributes greatly to our understanding of biodiversity and ecosystem functioning. The research of prey preferences of different predators requires knowledge not only of the prey consumed, but also of what is available. In this study, we applied DNA metabarcoding to analyze the diet of 4 bird species (willow tits Poecile montanus, Siberian tits Poecile cinctus, great tits Parus major and blue tits Cyanistes caeruleus) by using the feces of nestlings. The availability of their assumed prey (Lepidoptera) was determined from feces of larvae (frass) collected from the main foraging habitat, birch (Betula spp.) canopy. We identified 53 prey species from the nestling feces, of which 11 (21%) were also detected from the frass samples (eight lepidopterans). Approximately 80% of identified prey species in the nestling feces represented lepidopterans, which is in line with the earlier studies on the parids' diet. A subsequent laboratory experiment showed a threshold for fecal sample size and the barcoding success, suggesting that the smallest frass samples do not contain enough larval DNA to be detected by high-throughput sequencing. To summarize, we apply metabarcoding for the first time in a combined approach to identify available prey (through frass) and consumed prey (via nestling feces), expanding the scope and precision for future dietary studies on insectivorous birds.Peer reviewe

Gastrointestinal manifestations after Roux-en-Y gastric bypass surgery in individuals with and without type 2 diabetes

Background: Roux-en-Y gastric bypass (RYGB) surgery is an effective treatment for obesity, which improves cardiovascular health and reduces the risk of premature mortality. However, some reports have suggested that RYGB may predispose patients to adverse health outcomes, such as inflammatory bowel disease (IBD) and colorectal cancer. Objectives: The present prospective study aimed to evaluate the impact of RYGB surgery on cardiovascular risk factors and gastrointestinal inflammation in individuals with and without type 2 diabetes (T2D). Setting: University hospital setting in Finland. Methods: Blood and fecal samples were collected at baseline and 6 months after surgery from 30 individuals, of which 16 had T2D and 14 were nondiabetics. There were also single study visits for 6 healthy reference patients. Changes in cardiovascular risk factors, serum cholesterol, and triglycerides were investigated before and after surgery. Fecal samples were analyzed for calprotectin, anti-Saccharomyces cerevisiae immunoglobulin A antibodies (ASCA), active lipopolysaccharide (LPS) concentration, short-chain fatty acids (SCFAs), intestinal alkaline phosphatase activity, and methylglyoxal-hydro-imidazolone (MG-H1) protein adducts formation. Results: After RYGB, weight decreased on average 221.6% (-27.2 +/- 7.8 kg), excess weight loss averaged 51%, and there were improvements in cardiovascular risk factors. Fecal calprotectin levels (P < .001), active LPS concentration (P < .002), ASCA (P < .02), and MG-H1 (P < .02) values increased significantly, whereas fecal SCFAs, especially acetate (P < .002) and butyrate (P < .03) levels, were significantly lowered. Conclusion: The intestinal homeostasis is altered after RYGB, with several fecal markers suggesting increased inflammation; however, clinical significance of the detected changes is currently uncertain. As chronic inflammation may predispose patients to adverse health effects, our findings may have relevance for the suggested association between RYGB and increased risks of incident IBD and colorectal cancer. (C) 2020 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.Peer reviewe

Total fecal IgA levels increase and natural IgM antibodies decrease after gastric bypass surgery

Obesity is associated with low-grade inflammation and increased systemic oxidative stress. Roux-en-Y gastric bypass (RYGB) surgery is known to ameliorate the obesity-induced metabolic dysfunctions. We aimed to study the levels of natural antibodies in feces, before and 6 months after RYGB surgery in obese individuals with and without type 2 diabetes (T2D). Sixteen individuals with T2D and 14 non-diabetic (ND) individuals were operated. Total IgA, IgG and IgM antibody levels and specific antibodies to oxidized low-density lipoprotein (oxLDL), malondialdehyde-acetaldehyde adducts (MAA adducts), Porphyromonas gingivalis gingipain A hemagglutinin domain (Rgp44) and phosphocholine (PCho) were measured using chemiluminescence immunoassay. Total fecal IgA was elevated, while total IgM and IgG were not affected by the surgery. Fecal natural IgM specific to oxLDL decreased significantly in both T2D and ND individuals, while fecal IgM to Rgp44 and PCho decreased significantly in T2D individuals. A decrease in IgG to MAA-LDL, Rgp44 and PCho was detected. RYGB surgery increases the levels of total fecal IgA and decreases fecal natural IgG and IgM antibodies specific to oxLDL. Natural antibodies and IgA are important in maintaining the normal gut homeostasis and first-line defense against microbes, and their production is markedly altered with RYGB surgery.Peer reviewe

Assessing Interventional Components in a Weight Loss App

Many mHealth interventions for health behavior change are considered effective for improving health outcomes. However, there is a limited understanding of the role of the components in an intervention on its effectiveness. Insights into intervention components such as content and software features are needed to design efficient and effective interventions. In this study, we conducted an exploratory analysis of objective data from the usage of a weight management app to understand the role of intervention components in weight loss. We identified a positive correlation between weight loss and the use of the intervention. We also found differences in the app feature use among those who lost weight. To lose weight, users needed to comply with the intervention by completing a combination of tasks. They needed to complete 70% of some tasks and up to a maximum of 30% of other tasks. In the future, we hope to use other types of collected data (logged and survey data) to gain more nuanced insights into how interventions are used. With the help of data analytics, we may find optimal paths of use and determine a satisfactory level of compliance to achieve desired goals. This can deepen our understanding of what works in an intervention

Activation of pregnane X receptor induces atherogenic lipids and PCSK9 by a SREBP2-mediated mechanism

Background and Purpose Many drugs and environmental contaminants induce hypercholesterolemia and promote the risk of atherosclerotic cardiovascular disease. We tested the hypothesis that pregnane X receptor (PXR), a xenobiotic-sensing nuclear receptor, regulates the level of circulating atherogenic lipids in humans and utilized mouse experiments to identify the mechanisms involved.Experimental Approach We performed serum NMR metabolomics in healthy volunteers administered rifampicin, a prototypical human PXR ligand or placebo in a crossover setting. We used high-fat diet fed wild-type and PXR knockout mice to investigate the mechanisms mediating the PXR-induced alterations in cholesterol homeostasis.Key Results Activation of PXR induced cholesterogenesis both in pre-clinical and clinical settings. In human volunteers, rifampicin increased intermediate-density lipoprotein (IDL), low-density lipoprotein (LDL) and total cholesterol and lathosterol-cholesterol ratio, a marker of cholesterol synthesis, suggesting increased cholesterol synthesis. Experiments in mice indicated that PXR activation causes widespread induction of the cholesterol synthesis genes including the rate-limiting Hmgcr and upregulates the intermediates in the Kandutsch-Russell cholesterol synthesis pathway in the liver. Additionally, PXR activation induced plasma proprotein convertase subtilisin/kexin type 9 (PCSK9), a negative regulator of hepatic LDL uptake, in both mice and humans. We propose that these effects were mediated through increased proteolytic activation of sterol regulatory element-binding protein 2 (SREBP2) in response to PXR activation.Conclusion and Implications PXR activation induces cholesterol synthesis, elevating LDL and total cholesterol in humans. The PXR-SREBP2 pathway is a novel regulator of the cholesterol and PCSK9 synthesis and a molecular mechanism for drug- and chemical-induced hypercholesterolemia

Analysis of the SYSDIET Healthy Nordic Diet randomized trial based on metabolic profiling reveal beneficial effects on glucose metabolism and blood lipids

Background & aims Intake assessment in multicenter trials is challenging, yet important for accurate outcome evaluation. The present study aimed to characterize a multicenter randomized controlled trial with a healthy Nordic diet (HND) compared to a Control diet (CD) by plasma and urine metabolic profiles and to associate them with cardiometabolic markers. MethodsDuring 18-24 weeks of intervention, 200 participants with metabolic syndrome were advised at six centres to eat either HND (e.g. whole-grain products, berries, rapeseed oil, fish and low-fat dairy) or CD while being weight stable. Of these 166/159 completers delivered blood/urine samples. Metabolic profiles of fasting plasma and 24 h pooled urine were analysed to identify characteristic diet-related patterns. Principal components analysis (PCA) scores (i.e. PC1 and PC2 scores) were used to test their combined effect on blood glucose response (primary endpoint), serum lipoproteins, triglycerides, and inflammatory markers. ResultsThe profiles distinguished HND and CD with AUC of 0.96 ± 0.03 and 0.93 ± 0.02 for plasma and urine, respectively, with limited heterogeneity between centers, reflecting markers of key foods. Markers of fish, whole grain and polyunsaturated lipids characterized HND, while CD was reflected by lipids containing palmitoleic acid. The PC1 scores of plasma metabolites characterizing the intervention is associated with HDL (β = 0.05; 95% CI: 0.02, 0.08; P = 0.001) and triglycerides (β = -0.06; 95% CI: -0.09, -0.03; P ConclusionsPlasma and urine metabolite profiles from SYSDIET reflected good compliance with dietary recommendations across the region. The scores of metabolites characterizing the diets associated with outcomes related with cardio-metabolic risk. Our analysis therefore offers a novel way to approach a per protocol analysis with a balanced compliance assessment in larger multicentre dietary trials.The study was registered at clinicaltrials.gov with NCT00992641.</p

Lääkkeellinen painonhallinta

Tiivistelmä Lihavuuden lääkehoitoa harkitaan elintapahoidon tueksi, kun painoindeksi on ≥ 30 kg/m². Jos potilaalla on lihavuuden liitännäissairauksia, voidaan lääkitystä harkita, kun indeksi on yli 27 kg/m². Lääkevaihtoehtoja ovat orlistaatti, liraglutidi sekä naltreksonin ja bupropionin yhdistelmävalmiste. Myös semaglutidin vaikutuksesta on vahvaa näyttöä. Lääkityksen teho on yksilöllistä. Tehoton lääkitys (paino vähenee &lt; 5 %) tulee lopettaa. Merkittävä painonnousu on tyypillinen ongelma lääkehoidon lopettamisen jälkeen. Lääkehoito pitäisi suunnitella riittävän pitkäaikaiseksi.Summary Pharmacological therapy for obesity and overweight as an adjunct to lifestyle intervention can be considered when the body mass index is ≥ 30 kg/m², or ≥ 27 kg/m² with obesity-related comorbidities. The history of anti-obesity medications is long and often problematic as several medications have been withdrawn due to cardiovascular hazards and mood disorders. There are currently three options for pharmacotherapy in Finland: orlistat, naltrexone–bupropion, and liraglutide. In addition, the diabetes medication semaglutide is currently under evaluation by the European Medicines Agency as a treatment for obesity. The most efficient drugs for weight loss are the GLP-1 agonists liraglutide and especially semaglutide. Orlistat has the most extensive accumulated long term clinical experience of safety, but its efficacy is only modest. Naltrexone–bupropion has moderate efficacy, but several contraindications and drug-drug interactions complicate its use. Cardiovascular safety is established for liraglutide and semaglutide but only in the treatment of diabetes at lower doses than indicated in obesity therapy. The challenges in pharmacotherapy for obesity include the high treatment discontinuation rates, interindividual differences in response to medications, the tendency to regain weight after the drug treatment, and high costs for the patient due to lack of reimbursement. However, liraglutide was recently granted reimbursement for patients with body mass index ≥ 35 kg/m² and prediabetes, with the additional prerequisite of drug treatment for hypertension or dyslipidaemia. Utilization of the current more efficient anti-obesity medications and better access to therapy should lead to improved long-term outcomes, especially when pharmacotherapy is combined with effective lifestyle interventions

OTU table

Reads assigned for each OTU in each sample. Contains the metadata information of the samples

OTUS

Otus as fasta format file. See Otutable.xls to link sample names to data