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Frontiers in Endocrinology 2021The intestinal flora of gut microbiota in obese Chinese children and adolescents with and without insulin resistance (IR) was analyzed, as well as associations between...
OBJECTIVE
The intestinal flora of gut microbiota in obese Chinese children and adolescents with and without insulin resistance (IR) was analyzed, as well as associations between the gut microbiota and two serum cytokines related to glucose metabolism, adropin and angiopoietin-like 4 (ANGPTL4).
METHODS
Clinical data, fecal bacterial composition, glucose-related hormones, and serum adipokines (adropin and ANGPTL4) were analyzed in 65 Chinese children with exogenous obesity. The composition of the gut microbiota was determined by 16S rRNA-based metagenomics and IR was calculated using the homeostasis model assessment (HOMA).
RESULTS
The 65 obese subjects were divided into two groups: insulin sensitive (IS) (n=40, 57.5% males) or IR (n=25, 60% males). Principal coordinates analysis revealed that the gut microbiota samples from the IS group clustered together and separated partly from the IR group (p=0.008). By Mann-Whitney -test, at a phylum level, a reduction of and an increase of in the IR subjects was observed. LEfSe analysis revealed that IS subject, when compared to their IR counterparts, harbored members of the order , , and family , that were significantly more abundant. In contrast, the IR subjects had members of family that were significantly more prevalent than the IS subjects (all <0.05). Spearman's correlation analysis revealed that serum ANGPTL4 was positively associated with genus , and , and adropin was positively associated with genus and , and negatively associated with genus (all p<0.05).
CONCLUSION
In obese children, the gut microbiome in IR subjects was significantly discordant from the IS subjects, and the abundance of some metabolism-related bacteria correlated with the serum concentrations of adropin and ANGPTL4. These observations infer that the gut microbiota may be involved in the regulation of glucose metabolism in obesity.
Topics: Adolescent; Angiopoietin-Like Protein 4; Bacteria; Child; China; Cross-Sectional Studies; Cytokines; Diet; Feces; Female; Gastrointestinal Microbiome; Genomics; Glucose; Humans; Insulin Resistance; Male; Metagenome; Pediatric Obesity; Principal Component Analysis; RNA, Ribosomal, 16S
PubMed: 33815293
DOI: 10.3389/fendo.2021.636272 -
Heliyon Oct 2021Microorganisms in clay barriers could affect the long-term performance of waste containers in future deep geological repositories (DGR) for used nuclear fuel through...
Microorganisms in clay barriers could affect the long-term performance of waste containers in future deep geological repositories (DGR) for used nuclear fuel through production of corrosive metabolites ( sulfide), which is why clay materials are highly compacted: to reduce both physical space and access to water for microorganisms to grow. However, the highly compacted nature of clays and the resulting low activity or dormancy of microorganisms complicate the extraction of biomarkers ( PLFA, DNA .) from such barriers for predictive analysis of microbial risks. In order to overcome these challenges, we have combined culture- and 16S rRNA gene amplicon sequencing-based approaches to describe the functional diversity of microorganisms in several commercial clay products, including two different samples of Wyoming type MX-80 bentonite (Batch 1 and Batch 2), the reference clay for a future Canadian DGR, and Avonlea type Canaprill, a clay sample for comparison. Microorganisms from bentonites were enriched in anoxic 10% w/v clay microcosms for three months at ambient temperature with addition of 10% hydrogen along with presumable indigenous organics and sulfate in the clay. High-throughput sequencing of 16S rRNA gene fragments indicated a high abundance of Gram-positive bacteria of the phylum Firmicutes (82%) in MX-80 Batch 1 incubations. Bacterial libraries from microcosms with MX-80 Batch 2 were enriched with Firmicutes (53%) and Chloroflexi (43%). Firmicutes also significantly contributed (<15%) to the bacterial community in Canaprill clay microcosm, which was dominated by Gram-negative Proteobacteria (>70%). Sequence analysis revealed presence of the bacterial families and in MX-80 Batch 1 incubations; along with unidentified bacteria of the phylum Chloroflexi, in MX-80 Batch 2 clay microcosms, and in Canaprill microcosms. Exploration of potential metabolic pathways in the bacterial communities from the clay microcosms suggested variable patterns of sulfur cycling in the different clays with the possible prevalence of bacterial sulfate-reduction in MX-80 bentonite, and probably successive sulfate-reduction/sulfur-oxidation reactions in Canaprill microcosms. Furthermore, analysis of potential metabolic pathways in the bentonite enrichments suggested that bacteria with acid-producing capabilities (, fermenters and acetogens) together with sulfide-producing prokaryotes might perhaps contribute to corrosion risks in clay systems. However, the low activity or dormancy of microorganisms in highly compacted bentonites as a result of severe environmental constraints ( low water activity and high swelling pressure in the confined bentonite) would be expected to largely inhibit bacterial activity in highly compacted clay-based barriers in a future DGR.
PubMed: 34703919
DOI: 10.1016/j.heliyon.2021.e08131 -
International Journal of Molecular... Oct 2017Sulfated quercetin derivatives are important authentic standards for metabolic studies. Quercetin-3'--sulfate, quercetin-4'--sulfate, and quercetin-3--sulfate as well as...
Sulfated quercetin derivatives are important authentic standards for metabolic studies. Quercetin-3'--sulfate, quercetin-4'--sulfate, and quercetin-3--sulfate as well as quercetin-di--sulfate mixture (quercetin-7,3'-di--sulfate, quercetin-7,4'-di--sulfate, and quercetin-3',4'-di--sulfate) were synthetized by arylsulfotransferase from . Purified monosulfates and disulfates were fully characterized using MS and NMR and tested for their 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS⁺) and ,dimethyl--phenylenediamine (DMPD) radical scavenging, Folin-Ciocalteau reduction (FCR), ferric reducing antioxidant power (FRAP), and anti-lipoperoxidant activities in rat liver microsomes damaged by -butylhydroperoxide. Although, as expected, the sulfated metabolites were usually less active than quercetin, they remained still effective antiradical and reducing agents. Quercetin-3'--sulfate was more efficient than quercetin-4'--sulfate in DPPH and FCR assays. In contrast, quercetin-4'--sulfate was the best ferric reductant and lipoperoxidation inhibitor. The capacity to scavenge ABTS and DMPD was comparable for all substances, except for disulfates, which were the most efficient. Quantum calculations and molecular dynamics simulations on membrane models supported rationalization of free radical scavenging and lipid peroxidation inhibition. These results clearly showed that individual metabolites of food bioactives can markedly differ in their biological activity. Therefore, a systematic and thorough investigation of all bioavailable metabolites with respect to native compounds is needed when evaluating food health benefits.
Topics: Antioxidants; Arylsulfotransferase; Desulfitobacterium; Quercetin; Structure-Activity Relationship; Sulfates
PubMed: 29068411
DOI: 10.3390/ijms18112231 -
Nutrients Dec 2022Capsaicin, a natural bioactive component, has been reported to improve cognition and ameliorate the pathology of Alzheimer's disease (AD). Studies have linked AD to...
Capsaicin, a natural bioactive component, has been reported to improve cognition and ameliorate the pathology of Alzheimer's disease (AD). Studies have linked AD to alterations in gut microbiota composition and serum metabolites. In the present study, we examined the alterations in serum metabolome and gut microbiome in APPswe/PS1dE9 (APP/PS1) mice treated with capsaicin. Capsaicin treatments resulted in a significant increase in the abundance of , , , and and a significant decrease in the abundance of , , , and . Furthermore, the species () was significantly enriched in capsaicin-treated APP/PS1 mice ( = 0.0002). Serum metabolomic analysis showed that capsaicin-treated APP/PS1 mice had a significant higher level of tryptophan (Trp) metabolism and a significantly lower level of lipid metabolism compared with vehicle-treated mice. Capsaicin altered serum metabolites, including Kynurenine (Kyn), 5-Hydroxy-L-tryptophan (5-HIT), 5-Hydroxyindoleacetic acid (5-HIAA), indoxylsulfuric acid, lysophosphatidyl cholines (LysoPCs), and lysophosphatidyl ethanolamine (LysoPE). Significant correlations were observed between the gut bacteria and serum metabolite. With regard to the increased abundance of and the ensuing rise in tryptophan metabolites, our data show that capsaicin alters both the gut microbiota and blood metabolites. By altering the gut microbiome and serum metabolome, a diet high in capsaicin may reduce the incidence and development of AD.
Topics: Mice; Animals; Gastrointestinal Microbiome; Capsaicin; Tryptophan; Metabolome; Alzheimer Disease; Cognition
PubMed: 36615777
DOI: 10.3390/nu15010118 -
Aging Cell Mar 2024The Methionine restriction (MR) diet has been shown to delay aging and extend lifespan in various model organisms. However, the long-term effects of MR diet on the gut...
The Methionine restriction (MR) diet has been shown to delay aging and extend lifespan in various model organisms. However, the long-term effects of MR diet on the gut microbiome composition remain unclear. To study this, male mice were started on MR and control diet regimens at 6 months and continued until 22 months of age. MR mice have reduced body weight, fat mass percentage, and bone mineral density while having increased lean mass percentage. MR mice also have increased insulin sensitivity along with increasing indirect calorimetry markers such as energy expenditure, oxygen consumption, carbon dioxide production, and glucose oxidation. Fecal samples were collected at 1 week, 18 weeks, and 57 weeks after the diet onset for 16S rRNA amplicon sequencing to study the gut microbiome composition. Alpha and beta diversity metrics detected changes occurring due to the timepoint variable, but no changes were detected due to the diet variable. The results from LEfSe analysis surprisingly showed that more bacterial taxa changes were linked to age rather than diet. Interestingly, we found that the long-term MR diet feeding induced smaller changes compared to short-term feeding. Specific taxa changes due to the diet were observed at the 1 or 18-week time points, including Ileibacterium, Odoribacter, Lachnoclostridium, Marinifilaceae, and Lactobacillaceae. Furthermore, there were consistent aging-associated changes across both groups, with an increase in Ileibacterium and Erysipelotrichaceae with age, while Eubacterium_coprostanoligenes_group, Ruminococcaceae, Peptococcaceae, and Peptococcus decreased with age.
Topics: Male; Mice; Animals; Methionine; Gastrointestinal Microbiome; RNA, Ribosomal, 16S; Diet; Body Weight; Racemethionine
PubMed: 38279509
DOI: 10.1111/acel.14051 -
Microorganisms Apr 2021Sulfate reducing prokaryotes (SRP) are a phylogenetically and physiologically diverse group of microorganisms that use sulfate as an electron acceptor. SRP have long...
Sulfate reducing prokaryotes (SRP) are a phylogenetically and physiologically diverse group of microorganisms that use sulfate as an electron acceptor. SRP have long been recognized as key players of the carbon and sulfur cycles, and more recently, they have been identified to play a relevant role as part of syntrophic and symbiotic relations and the human microbiome. Despite their environmental relevance, there is a poor understanding about the prevalence of prophages and CRISPR arrays and how their distribution and dynamic affect the ecological role of SRP. We addressed this question by analyzing the results of a comprehensive survey of prophages and CRISPR in a total of 91 genomes of SRP with several genotypic, phenotypic, and physiological traits, including genome size, cell volume, minimum doubling time, cell wall, and habitat, among others. Our analysis discovered 81 prophages in 51 strains, representing the 56% of the total evaluated strains. Prophages are non-uniformly distributed across the SRP phylogeny, where prophage-rich lineages belonged to Desulfovibrionaceae and Peptococcaceae. Furthermore, our study found 160 CRISPR arrays in 71 SRP, which is more abundant and widely spread than previously expected. Although there is no correlation between presence and abundance of prophages and CRISPR arrays at the strain level, our analysis showed that there is a directly proportional relation between cellular volumes and number of prophages per cell. This result suggests that there is an additional selective pressure for strains with smaller cells to get rid of foreign DNA, such as prophages, but not CRISPR, due to less availability of cellular resources. Analysis of the prophage genes encoding viral structural proteins reported that 44% of SRP prophages are classified as Myoviridae, and comparative analysis showed high level of homology, but not synteny, among prophages belonging to the Family Desulfovibrionaceae. We further recovered viral-like particles and structures that resemble outer membrane vesicles from str. Hildenborough. The results of this study improved the current understanding of dynamic interactions between prophages and CRISPR with their hosts in both cultured and hitherto-uncultured SRP strains, and how their distribution affects the microbial community dynamics in several sulfidogenic natural and engineered environments.
PubMed: 33925267
DOI: 10.3390/microorganisms9050931 -
Frontiers in Neurology 2024Previous observational studies have provided cumulative data linking gut microbiota to myasthenia gravis (MG). However, the causal link between the two remains...
BACKGROUND
Previous observational studies have provided cumulative data linking gut microbiota to myasthenia gravis (MG). However, the causal link between the two remains unexplored. Hence, the current study was performed to explore the causal link between them.
METHODS
Mendelian randomization (MR) analysis was conducted using the summary statistics of 211 gut microbiota taxa and the largest genome-wide association studies (GWAS) for MG currently available. The inverse variance-weighted (IVW), MR-Egger, weighted median, and weighted mode methods were employed to ascertain the causal influence. Sensitivity studies utilizing several methodologies were then used to assess the robustness of the findings. Lastly, to evaluate reverse causality, a reverse MR analysis was performed.
RESULTS
Seven suggestive causal associations between the gastrointestinal microbiota and MG were identified based on the outcomes of the MR analysis. Specifically, phylum Actinobacteria (OR: 0.602, 95% CI: 0.405-0.896, = 0.012), class Gammaproteobacteria (OR: 0.587, 95% CI: 0.357-0.968, = 0.037), and families (OR: 0.695, 95% CI: 0.485-0.996, = 0.047), (OR: 0.614, 95% CI: 0.412-0.916, = 0.017), and (OR: 0.698, 95% CI: 0.505-0.964, = 0.029) had suggestive protective effects on MG, while order Mollicutes RF9 (OR: 1.424, 95% CI: 1.015-1.998, = 0.041) and genus (OR: 1.763, 95% CI: 1.220-2.547, = 0.003) were suggestive risk factors for MG. The outcomes indicate that neither heterogeneity nor horizontal pleiotropy had any discernible impact. Nevertheless, this reverse analysis did not reveal any apparent effect of MG on the gut microbiota composition.
CONCLUSION
The MR investigation has substantiated the suggestive causal connection between gut microbiota and MG, which may provide helpful insights for innovative therapeutic and preventative approaches for MG. Further randomized controlled trials are needed to elucidate the gut microbiota's precise role and therapeutic potential in the pathogenesis of MG.
PubMed: 38333605
DOI: 10.3389/fneur.2024.1309530 -
Frontiers in Microbiology 2023Studies demonstrate that time-restricted feeding (TRF) can regulate gut microbiota composition. However, it is unclear whether TRF could affect the gut microbial...
INTRODUCTION
Studies demonstrate that time-restricted feeding (TRF) can regulate gut microbiota composition. However, it is unclear whether TRF could affect the gut microbial rhythmicity in growing pigs. Therefore, the present study aimed to explore the effects of TRF on the dynamic fluctuation of the gut microbiota.
METHODS
A total of 10 healthy growing pigs equipped with T cannula were employed. Pigs were randomly allotted to the free access (FA) and the TRF groups with 5 replicates (1 pig/replicates). Pigs in the FA group were fed free access during the whole experimental period, whereas pigs in the TRF group were fed free access three times per day within limited times (7:00-8:00, 12:00-13:00, 17:00-18:00). The experiment lasted for 15 days, at 06:00 a.m. of the day 16, colonic digesta were collected at a 6-h interval for consecutive 24 h marked as T06 (06:00), T12 (12:00), T18 (18:00), T24 (24:00), T30 (06:00), respectively.
RESULTS
Results showed that TRF altered the distribution of feed intake without changing the total feed intake within a day ( = 0.870). TRF decreased the overall concentration of colonic cellulose and altered their oscillating patterns. All alpha-diversity indexes of different time points showed significant differences regardless of feeding pattern with a trough at T18 or T24. TRF shifted the trough of the alpha-diversity index Simpson and Invsimpson. TRF lost the rhythmicity of , , _S24-7_group, and and gained the rhythmicity of , _1, , and . Also, TRF altered the interaction pattern by increasing the microbes involved in the co-occurrence network and their crosstalk, especially at T24. Interestingly, the microbial variation at T24 could largely explained by colonic substrates starch (R = 0.369; = 0.001), cellulose (R = 0.235; = 0.009) and NH4-N (R = 0.489; = 0.001).
CONCLUSION
In conclusion, TRF has changed the concentrates of cellulose and the relative abundance of specific microbes and certain microbial metabolites. In addition, TRF has more powerful effects on the fluctuation modes of these nutrient substrates, microbes, and metabolites by shifting their peaks or troughs. This knowledge facilitates the development of precision regulation targeting gut microbial rhythmicity.
PubMed: 37275162
DOI: 10.3389/fmicb.2023.1162482 -
Frontiers in Microbiology 2021Previous work demonstrated that microbial Fe(III)-reduction contributes to void formation, and potentially cave formation within Fe(III)-rich rocks, such as banded iron...
Hydrologic Alteration and Enhanced Microbial Reductive Dissolution of Fe(III) (hydr)oxides Under Flow Conditions in Fe(III)-Rich Rocks: Contribution to Cave-Forming Processes.
Previous work demonstrated that microbial Fe(III)-reduction contributes to void formation, and potentially cave formation within Fe(III)-rich rocks, such as banded iron formation (BIF), iron ore and canga (a surficial duricrust), based on field observations and static batch cultures. Microbiological Fe(III) reduction is often limited when biogenic Fe(II) passivates further Fe(III) reduction, although subsurface groundwater flow and the export of biogenic Fe(II) could alleviate this passivation process, and thus accelerate cave formation. Given that static batch cultures are unlikely to reflect the dynamics of groundwater flow conditions , we carried out comparative batch and column experiments to extend our understanding of the mass transport of iron and other solutes under flow conditions, and its effect on community structure dynamics and Fe(III)-reduction. A solution with chemistry approximating cave-associated porewater was amended with 5.0 mM lactate as a carbon source and added to columns packed with canga and inoculated with an assemblage of microorganisms associated with the interior of cave walls. Under anaerobic conditions, microbial Fe(III) reduction was enhanced in flow-through column incubations, compared to static batch incubations. During incubation, the microbial community profile in both batch culture and columns shifted from a Proteobacterial dominance to the Firmicutes, including Clostridiaceae, Peptococcaceae, and Veillonellaceae, the latter of which has not previously been shown to reduce Fe(III). The bacterial Fe(III) reduction altered the advective properties of canga-packed columns and enhanced permeability. Our results demonstrate that removing inhibitory Fe(II) via mimicking hydrologic flow of groundwater increases reduction rates and overall Fe-oxide dissolution, which in turn alters the hydrology of the Fe(III)-rich rocks. Our results also suggest that reductive weathering of Fe(III)-rich rocks such as canga, BIF, and iron ores may be more substantial than previously understood.
PubMed: 34335526
DOI: 10.3389/fmicb.2021.696534 -
Microbiology Spectrum Mar 2023Undernutrition may change cecal microbiota-epithelium interactions to influence cecal feed fermentation, nutrient absorption and metabolism, and immune function. Sixteen...
Undernutrition may change cecal microbiota-epithelium interactions to influence cecal feed fermentation, nutrient absorption and metabolism, and immune function. Sixteen late-gestation Hu-sheep were randomly divided into control (normal feeding) and treatment (feed restriction) groups to establish an undernourished sheep model. Cecal digesta and epithelium were collected to analyze microbiota-host interactions based on 16S rRNA gene and transcriptome sequencing. Results showed that cecal weight and pH were decreased, volatile fatty acids and microbial proteins concentrations were increased, and epithelial morphology was changed upon undernutrition. Undernutrition reduced the diversity, richness, and evenness of cecal microbiota. The relative abundances of cecal genera involved in acetate production ( dgA-11 gut group, RC9 gut group, and ) and negatively correlated with butyrate proportion ( vadinBB60 group_norank) were decreased, while genera related to butyrate (_uncultured and _uncultured) and valerate (_uncultured) production were increased in undernourished ewes. These findings were consistent with the decreased molar proportion of acetate and the increased molar proportions of butyrate and valerate. Undernutrition changed the overall transcriptional profile and substance transport and metabolism in cecal epithelium. Undernutrition suppressed extracellular matrix-receptor interaction and intracellular phosphatidyl inositol 3-kinase (PI3K) signaling pathway then disrupted biological processes in cecal epithelium. Moreover, undernutrition repressed phagosome antigen processing and presentation, cytokine-cytokine receptor interaction, and intestinal immune network. In conclusion, undernutrition affected cecal microbial diversity and composition and fermentation parameters, inhibited extracellular matrix-receptor interaction and the PI3K signaling pathway, and then disrupted epithelial proliferation and renewal and intestinal immune functions. Our findings exposed cecal microbiota-host interactions upon undernutrition and contribute to their further exploration. Undernutrition is commonly encountered in ruminant production, especially during pregnancy and lactation in females. Undernutrition not only induces metabolic diseases and threatens pregnant mothers' health, but also inhibits fetal growth and development, leading to weakness or even death of fetuses. Cecum works importantly in hindgut fermentation, providing volatile fatty acids and microbial proteins to the organism. Intestinal epithelial tissue plays a role in nutrient absorption and transport, barrier function, and immune function. However, little is known about cecal microbiota and epithelium interactions upon undernutrition. Our findings showed that undernutrition affected bacterial structures and functions, which changed fermentation parameters and energy regimens, and therefore affected the substance transport and metabolism in cecal epithelium. Extracellular matrix-receptor interactions were inhibited, which repressed cecal epithelial morphology and cecal weight via the PI3K signaling pathway and lowered immune response function upon undernutrition. These findings will help in further exploring microbe-host interactions.
PubMed: 36976022
DOI: 10.1128/spectrum.05320-22