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Frontiers in Immunology 2022Previous researches have implicated a vital association between gut microbiota (GM) and diabetic retinopathy (DR) based on the association of the "gut-retina" axis. But...
BACKGROUND
Previous researches have implicated a vital association between gut microbiota (GM) and diabetic retinopathy (DR) based on the association of the "gut-retina" axis. But their causal relationship has not been elucidated.
METHODS
Instrumental variables of 211 GM taxa were obtained from genome wide association study (GWAS), and Mendelian randomization study was carried out to estimate their effects on DR risk from FinnGen GWAS (14,584 DR cases and 202,082 controls). Inverse variance weighted (IVW) is the main method to analyze causality, and MR results are verified by several sensitive analyses.
RESULTS
As for 211 GM taxa, IVW results confirmed that family- ( = 1.36×10) and family- ( = 3.13×10) were protective factors for DR. Genus- ( = 4.83×10), genus- ( = 3.44×10) and genus- ( = 4.82×10) were correlated with the risk of DR. At the phylum, class and order levels, we found no GM taxa that were causally related to DR (>0.05). Heterogeneity (>0.05) and pleiotropy (>0.05) analysis confirmed the robustness of MR results.
CONCLUSION
We confirmed that there was a potential causal relationship between some GM taxa and DR, which highlights the association of the "gut-retina" axis and offered new insights into the GM-mediated mechanism of DR. Further explorations of their association are required and will lead to find new biomarkers for targeted prevention strategies of DR.
Topics: Diabetes Mellitus; Diabetic Retinopathy; Gastrointestinal Microbiome; Genome-Wide Association Study; Humans; Mendelian Randomization Analysis; Polymorphism, Single Nucleotide
PubMed: 36159877
DOI: 10.3389/fimmu.2022.930318 -
World Journal of Hepatology Jun 2022Gut dysbiosis and changes in body composition (, a decrease in the proportion of muscle mass and an increase in extracellular fluid) are common in cirrhosis.
BACKGROUND
Gut dysbiosis and changes in body composition (, a decrease in the proportion of muscle mass and an increase in extracellular fluid) are common in cirrhosis.
AIM
To study the relationship between the gut microbiota and body composition in cirrhosis.
METHODS
This observational study included 46 patients with cirrhosis. Stool microbiome was assessed using 16S rRNA gene sequencing. Multifrequency bioelectrical impedance analysis was performed to assess body composition in these patients.
RESULTS
An increase in fat mass and a decrease in body cell mass were noted in 23/46 (50.0%) and 15/46 (32.6%) patients, respectively. Changes in the gut microbiome were not independently associated with the fat mass percentage in cirrhosis. The abundance of ( = 0.041) and ( = 0.001) increased, whereas that of ( = 0.006), ( = 0.021), ( = 0.033), ( = 0.043), ( = 0.028), and ( = 0.015) decreased in the gut microbiome of patients with body cell mass deficiency. The amount of extracellular fluid increased in 22/46 (47.6%) patients. Proteobacteria abundance ( < 0.001) increased, whereas Firmicutes ( = 0.023), Actinobacteria ( = 0.026), Bacilli ( = 0.008), ( = 0.027), ( = 0.038), ( = 0.047), ( = 0.015), ( = 0.003), ( = 0.024), ( = 0.002), ( = 0.030), ( = 0.040), ( = 0.023), ( = 0.008), and ( = 0.024) abundance decreased in these patients. Patients with clinically significant ascites ( = 9) had a higher abundance of Proteobacteria ( = 0.031) and a lower abundance of Actinobacteria ( = 0.019) and Bacteroidetes ( = 0.046) than patients without clinically significant ascites ( = 37).
CONCLUSION
Changes in the amount of body cell mass and extracellular fluid are associated with changes in the gut microbiome in cirrhosis patients.
PubMed: 35978666
DOI: 10.4254/wjh.v14.i6.1210 -
Diagnostics (Basel, Switzerland) Apr 2022Through a multitude of studies, the gut microbiota has been recognized as a significant influencer of both homeostasis and pathophysiology. Certain microbial taxa can...
Through a multitude of studies, the gut microbiota has been recognized as a significant influencer of both homeostasis and pathophysiology. Certain microbial taxa can even affect treatments such as cancer immunotherapies, including the immune checkpoint blockade. These taxa can impact such processes both individually as well as collectively through mechanisms from quorum sensing to metabolite production. Due to this overarching presence of the gut microbiota in many physiological processes distal to the GI tract, we hypothesized that mice bearing tumors at extraintestinal sites would display a distinct intestinal microbial signature from non-tumor-bearing mice, and that such a signature would involve taxa that collectively shift with tumor presence. Microbial OTUs were determined from 16S rRNA genes isolated from the fecal samples of C57BL/6 mice challenged with either B16-F10 melanoma cells or PBS control and analyzed using QIIME. Relative proportions of bacteria were determined for each mouse and, using machine-learning approaches, significantly altered taxa and co-occurrence patterns between tumor- and non-tumor-bearing mice were found. Mice with a tumor had elevated proportions of , .g_rc4.4, and as well as significant information gains and ReliefF weights for , , , and . , , and were also implicated through shifting co-occurrences and PCA values. Using these seven taxa as a melanoma signature, a neural network reached an 80% tumor detection accuracy in a 10-fold stratified random sampling validation. These results indicated gut microbial proportions as a biosensor for tumor detection, and that shifting co-occurrences could be used to reveal relevant taxa.
PubMed: 35454006
DOI: 10.3390/diagnostics12040958 -
The Science of the Total Environment Aug 2022Polylactic acid (PLA), an alternative to petroleum-based plastics, has been widely used in food packaging and disposable tableware for biodegradable properties. As a...
Fate of polylactic acid microplastics during anaerobic digestion of kitchen waste: Insights on property changes, released dissolved organic matters, and biofilm formation.
Polylactic acid (PLA), an alternative to petroleum-based plastics, has been widely used in food packaging and disposable tableware for biodegradable properties. As a result, PLA fragments were often mixed with kitchen waste (KW) and disposed of together. This study aimed to assess the fate of polylactic acid microplastics (PMP) when co-digested with KW. The spiked PMP did not increase the methane yield of KW but had deformation and fragmentation at mesophilic and thermophilic conditions, respectively. Identification of physicochemical properties and leachates showed that the anaerobic digestion of the KW process caused the aging and fragmentation of PMP, including the generation of irregular cracking and tiny daughter particles, the increase of oxygen-containing functional groups, and the releasing of dissolved organic matters (DOM). The thermophilic anaerobic digestion with KW enhanced the aging and fragmentation of PMP to the highest degree, which was attributed to the high temperature and enriched microorganisms (Peptococcaceae, Tepidimicrobium, and Clostridium_sensu_stricto_7) in the biofilm. Clostridium_sensu_stricto_7 was only found in the anaerobic digestion with KW, which meant the KW anaerobic digestion could contribute to the enrichment of microorganisms that promoted the PMP degradation.
Topics: Anaerobiosis; Biofilms; Bioreactors; Dissolved Organic Matter; Methane; Microplastics; Plastics; Polyesters; Sewage
PubMed: 35398128
DOI: 10.1016/j.scitotenv.2022.155108 -
Food & Function Apr 2022A high fat and cholesterol diet (HFCD) can modulate the gut microbiota, which is closely related with hypercholesterolemia. This study aimed to explore the...
A high fat and cholesterol diet (HFCD) can modulate the gut microbiota, which is closely related with hypercholesterolemia. This study aimed to explore the anti-hypercholesterolemia effect of oryzanol, and investigate whether the function of oryzanol is associated with the gut microbiota and related metabolites. 16S rRNA and ultrahigh-performance liquid chromatography-quadrupole time-of-flight mass spectrometry were applied for the gut microbiota and untargeted metabolomics, respectively. The results showed that HFCD significantly upregulated body fat accumulation and serum lipids, including triglyceride, total cholesterol, low density lipoprotein cholesterol (LDL-c), high density lipoprotein cholesterol (HDL-c), and ratio of LDL-c/HDL-c, which induced hypercholesterolemia. Oryzanol supplementation decreased body fat accumulation and serum lipids, especially the LDL-c concentration and LDL-c/HDL-c ratio. In addition, the abundances of , , , , , , , and were increased and the abundance of was decreased in HFCD-induced hyperlipidemia hamsters. Metabolites were changed after HFCD treatment and 9 differential metabolites belonged to bile acids and 8 differential metabolites belonged to amino acids. Those genera and metabolites were significantly associated with serum lipids. HFCD also disrupted the intestinal barrier. Oryzanol supplementation reversed the changes of the gut microbiota and metabolites, and intestinal barrier injury was also partly relieved. This suggests that oryzanol supplementation modulating the gut microbiota contributes to its anti-hyperlipidemia function, especially anti-hypercholesterolemia.
Topics: Animals; Cholesterol; Cholesterol, HDL; Cholesterol, LDL; Cricetinae; Diet, High-Fat; Gastrointestinal Microbiome; Hypercholesterolemia; Hyperlipidemias; Phenylpropionates; RNA, Ribosomal, 16S
PubMed: 35348138
DOI: 10.1039/d1fo03464b -
Microbiological Research May 2022Malaria, caused by Plasmodium, is a global life-threatening infectious disease. However, the dynamic interactions between intestinal microbiota and host immunity during...
Malaria, caused by Plasmodium, is a global life-threatening infectious disease. However, the dynamic interactions between intestinal microbiota and host immunity during the infections are still unclear. Here, we investigated the change of intestinal microbiome and transcriptome during Plasmodium yoelii infection in mice. The mice were infected with P. yoelii through the intraperitoneal injection. The intestinal contents and tissues were collected at different time points along with the malaria procession and they were subjected to the microbiome and transcriptome sequencing and analysis respectively. The dynamic landscape of parasitemia-dependent intestinal microbiota and related host immunity were identified: (1) The diversity and composition of the intestinal microbiota represented a significant correlation with the Plasmodium infection; (2) Up-regulated genes from the intestinal transcriptome were mainly enriched in immune cell differentiation pathways, especially, naive CD4+ T cell differentiation to Th1/2 cells in the early immune response and Th17 cells in the later immune stage, T cell receptor (TCR) and B cell receptor (BCR) activation in the whole host immunity; (3) Host immune cells presented parasitemia phase-specific characteristics against P. yoelii infection; (4) There were significant associations between the parasitemia phase-specific microbiotas and the host immune response. Th1 cell differentiation was positively correlated with genera Moryella and specie Erysipelotrichaceae bacterium canine oral taxon 255, while negatively correlated with genera Ruminiclostridium. Th17 cell differentiation was related to the colonization of family Peptococcaceae, genera Lachnospiraceae FCS020 group, and specie Eubacterium plexicaudatum ASF492 and the reduction of family Bacteroidales BS11 gut group, genera Sutterella, and specie Parabacteroides distasonis str. 3776 D15 I. BCRs and TCRs were highly related with the family Bacteroidales BS11 gut group, genera Moryella, and specie Erysipelotrichaceae bacterium canine oral taxon 255, but negatively related with the genera Ruminiclostridium. Our results indicated a remarkable dynamic landscape and correlation of the parasitemia-dependent shifting of intestinal microbiota and immunity, suggesting the essential roles of intestinal microbiome on the modulation of host immunity against Plasmodium infection.
Topics: Animals; Dogs; Gastrointestinal Microbiome; Malaria; Mice; Parasitemia; Plasmodium yoelii; Transcriptome
PubMed: 35220138
DOI: 10.1016/j.micres.2022.126994 -
Genes Feb 2022Polycystic ovary syndrome (PCOS) is a very common endocrine condition in women in India. Gut microbiome alterations were shown to be involved in PCOS, yet it is...
Polycystic ovary syndrome (PCOS) is a very common endocrine condition in women in India. Gut microbiome alterations were shown to be involved in PCOS, yet it is remarkably understudied in Indian women who have a higher incidence of PCOS as compared to other ethnic populations. During the regional PCOS screening program among young women, we recruited 19 drug naive women with PCOS and 20 control women at the Sher-i-Kashmir Institute of Medical Sciences, Kashmir, North India. We profiled the gut microbiome in faecal samples by 16S rRNA sequencing and included 40/58 operational taxonomic units (OTUs) detected in at least 1/3 of the subjects with relative abundance (RA) ≥ 0.1%. We compared the RAs at a family/genus level in PCOS/non-PCOS groups and their correlation with 33 metabolic and hormonal factors, and corrected for multiple testing, while taking the variation in day of menstrual cycle at sample collection, age and BMI into account. Five genera were significantly enriched in PCOS cases: , , and previously reported for PCOS , and confirmed by different statistical models. At the family level, the relative abundance of was enriched, whereas was decreased among cases. We observed increased relative abundance of and with higher fasting blood glucose levels, and and with larger hip, waist circumference, weight, and with lower prolactin levels. We also detected a novel association between and follicle-stimulating hormone levels and between and alkaline phosphatase, independently of the BMI of the participants. Our report supports that there is a relationship between gut microbiome composition and PCOS with links to specific reproductive health metabolic and hormonal predictors in Indian women.
Topics: Bacteroidetes; Bifidobacterium; Feces; Female; Gastrointestinal Microbiome; Humans; Polycystic Ovary Syndrome; RNA, Ribosomal, 16S
PubMed: 35205422
DOI: 10.3390/genes13020379 -
Chemosphere Jun 2022Two thermophilic trickle bed reactors (TBRs) were packed with different packing densities with polyurethane foam (PUF) and their performance under different retention...
Two thermophilic trickle bed reactors (TBRs) were packed with different packing densities with polyurethane foam (PUF) and their performance under different retention times were evaluated during ex-situ biogas upgrading process. The results showed that the TBR more tightly packed i.e. containing more layers of PUF achieved higher H utilization efficiency (>99%) and thus, higher methane content (>95%) in the output gas. The tightly packed micro-porous PUF enhanced biofilm immobilization, gas-liquid mass transfer and biomethanation efficiency. Moreover, applying a continuous high-rate nutrient trickling could lead to liquid overflow resulting in formation of non-homogenous biofilm and severe deduction of biomethanation efficiency. High-throughput 16S rRNA gene sequencing revealed that the liquid media were predominated by hydrogenotrophic methanogens. Moreover, members of Peptococcaceae family and uncultured members of Clostridia class were identified as the most abundant species in the biofilm. The proliferation of hydrogenotrophic methanogens together with syntrophic bacteria showed that H addition resulted in altering the microbial community in biogas upgrading process.
Topics: Anaerobiosis; Biofuels; Bioreactors; Hydrogen; Methane; Porosity; RNA, Ribosomal, 16S
PubMed: 35176296
DOI: 10.1016/j.chemosphere.2022.133987 -
Food & Function Feb 2022Regulating host energy metabolism and re-shaping gut microbiota are effective strategies against high-fat diet (HFD)-induced obesity and related metabolic disorders. A...
Proanthocyanidins from Chinese bayberry leaves reduce obesity and associated metabolic disorders in high-fat diet-induced obese mice through a combination of AMPK activation and an alteration in gut microbiota.
Regulating host energy metabolism and re-shaping gut microbiota are effective strategies against high-fat diet (HFD)-induced obesity and related metabolic disorders. A special type of proanthocyanidin extracted from Chinese bayberry leaves (BLPs) was studied for its effects and mechanisms in preventing HFD-induced obesity in mice. BLPs significantly reduced body weight, ameliorated inflammation and regulated gut dysbiosis in HFD-fed mice. BLPs activated AMP-activated protein kinase (AMPK) in the liver and white adipose tissue (WAT), which led to the downregulation of genes related to lipogenesis (ACC, FAS and SREBP-1c), and the upregulation of genes related to β-oxidation. Furthermore, BLPs improved HFD-induced gut dysbiosis by sharply decreasing the percentage of an endotoxin-producing bacteria - , and enabling some distinct bacteria, such as , and . BLPs also reduced the circulated endotoxin and maintained the gut barrier's integrity. Further antibiotic treatment revealed that depleting the gut microbiota abrogated the anti-obesogenic effects of BLPs, yet did not affect AMPK activation. Collectively, these results suggest that BLPs reduce obesity and associated metabolic disorders in HFD-fed mice through a combination of AMPK activation and an alteration in gut microbiota.
Topics: AMP-Activated Protein Kinases; Adipose Tissue, White; Animals; Diet, High-Fat; Disease Models, Animal; Functional Food; Gastrointestinal Microbiome; Liver; Male; Mice; Mice, Inbred C57BL; Myrica; Plant Extracts; Plant Leaves; Proanthocyanidins
PubMed: 35142317
DOI: 10.1039/d1fo04147a -
Frontiers in Immunology 2021Levels of type 2 cytokines are elevated in the blood and intestinal tissues of ulcerative colitis (UC) patients in the active phase; this phenomenon indicates the...
Levels of type 2 cytokines are elevated in the blood and intestinal tissues of ulcerative colitis (UC) patients in the active phase; this phenomenon indicates the participation of type 2 immune response in UC progression. The beneficial effects of melatonin in dextran sodium sulfate (DSS) and 2,4,6-trinitrobenzene sulfonic acid (TNBS) colitis models have been illustrated, but its role in the oxazolone (Oxa)-induced colitis model (driven by type 2 immune response) remains relatively unknown. We investigated the relationship between melatonin concentration and the severity of UC, revealing a significantly negative correlation. Subsequently, we investigated the effects of melatonin in Oxa-induced colitis mice and the potential underlying mechanisms. Administration of melatonin significantly counteracted body weight loss, colon shortening, and neutrophil infiltration in Oxa-induced colitis mice. Melatonin treatment mitigated Oxa-induced colitis by suppressing type 2 immune response. In addition, melatonin attenuated intestinal permeability by enhancing the expression of ZO-1 and occludin in colitis mice. Interestingly, the protective effect of melatonin was abolished when the mice were co-housed, indicating that the regulation of gut microbiota by melatonin was critical in alleviating Oxa-induced colitis. Subsequently, 16S rRNA sequencing was performed to explore the microbiota composition. Decreased richness and diversity of intestinal microbiota at the operational taxonomic unit (OTU) level resulted from melatonin treatment. Melatonin also elevated the abundance of , a well-known probiotic, and reduced proportions of several harmful bacterial genera, such as , Peptococcaceae, and Lachnospiraceae. Fecal microbiota transplantation (FMT) was used to explore the role of microbiota in the function of melatonin in Oxa-induced colitis. Microbiota transplantation from melatonin-treated mice alleviated Oxa-induced colitis, suggesting that the microbiome participates in the relief of Oxa-induced colitis by melatonin. Our findings demonstrate that melatonin ameliorates Oxa-induced colitis in a microbiota-dependent manner, suggesting the therapeutic potential of melatonin in treating type 2 immunity-associated UC.
Topics: Animals; Colitis, Ulcerative; Colon; Fecal Microbiota Transplantation; Gastrointestinal Microbiome; Humans; Melatonin; Mice; Oxazolone
PubMed: 35116024
DOI: 10.3389/fimmu.2021.783806