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Journal of Affective Disorders Sep 2024This study uses a two-sample Mendelian randomization (MR) analysis to delineate the causal influence of gut microbiota on the occurrence of irritable bowel syndrome...
OBJECTIVE
This study uses a two-sample Mendelian randomization (MR) analysis to delineate the causal influence of gut microbiota on the occurrence of irritable bowel syndrome (IBS), concurrently assessing the potential mediating function of depression within this framework.
METHODS
Several two-sample MR methods were used to assess the causal repercussions of gut microbiota on the onset of both IBS and depression. Following this, gut microbiota and depression, which demonstrated notable causal associations, were integrated as exposure variables in a multivariable Mendelian randomization (MVMR) framework to construct a model encompassing gut microbiota, depression, and IBS. Mediation effects were assessed by examining the indirect pathway of gut microbiota → depression → IBS.
RESULTS
Two-sample MR analysis unveiled a statistically significant causal association (P < 0.05) between specific bacterial group within the gut microbiota, notably p_Actinobacteria(OR = 0.829225), c_Clostridia(OR = 0.798897), s_Desulfovibrio_piger(OR = 1.163912), g_Streptococcus(OR = 1.132735), c_Actinobacteria(OR = 0.829224), and the onset of IBS. In the MVMR analysis, the relationship between depression and IBS was significant across Model 3, Model 7, Model 8, and Model 13 (P < 0.05). Assessment of mediation effects revealed that c_Clostridia and o_Clostridiales indirectly impacted IBS through depression, with masking effect ratios of 168.46 % and 168.44 %, respectively.
CONCLUSION
These findings underscore a resilient causal association between the composition of gut microbiota and the initiation of IBS. Furthermore, depression serves as a mediator for particular groups of gut bacteria, thereby contributing to the development of IBS. These observations imply that interventions targeting mental health may potentially alleviate the risk of IBS onset attributable to adverse configurations of gut microbiota.
Topics: Irritable Bowel Syndrome; Humans; Gastrointestinal Microbiome; Mendelian Randomization Analysis; Depression
PubMed: 38801922
DOI: 10.1016/j.jad.2024.05.119 -
FEMS Microbiology Ecology Jun 2024Mucin is a glycoprotein secreted throughout the mammalian gastrointestinal tract that can support endogenous microorganisms in the absence of complex polysaccharides....
Mucin is a glycoprotein secreted throughout the mammalian gastrointestinal tract that can support endogenous microorganisms in the absence of complex polysaccharides. While several mucin-degrading bacteria have been identified, the interindividual differences in microbial communities capable of metabolizing this complex polymer are not well described. To determine whether community assembly on mucin is deterministic across individuals or whether taxonomically distinct but functionally similar mucin-degrading communities are selected across fecal inocula, we used a 10-day in vitro sequential batch culture fermentation from three human donors with mucin as the sole carbon source. For each donor, 16S rRNA gene amplicon sequencing was used to characterize microbial community succession, and the short-chain fatty acid profile was determined from the final community. All three communities reached a steady-state by day 7 in which the community composition stabilized. Taxonomic comparisons amongst communities revealed that one of the final communities had Desulfovibrio, another had Akkermansia, and all three shared other members, such as Bacteroides. Metabolic output differences were most notable for one of the donor's communities, with significantly less production of acetate and propionate than the other two communities. These findings demonstrate the feasibility of developing stable mucin-degrading communities with shared and unique taxa. Furthermore, the mechanisms and efficiencies of mucin degradation across individuals are important for understanding how this community-level process impacts human health.
Topics: Humans; Mucins; RNA, Ribosomal, 16S; Feces; Microbial Consortia; Fermentation; Bacteria; Fatty Acids, Volatile; Gastrointestinal Microbiome; Akkermansia; Desulfovibrio; Bacteroides
PubMed: 38794902
DOI: 10.1093/femsec/fiae078 -
Frontiers in Veterinary Science 2024are globally distributed, marine parasitic nematodes that can cause human health problems, including symptoms such as vomiting, acute diarrhea, and allergic reactions....
BACKGROUND
are globally distributed, marine parasitic nematodes that can cause human health problems, including symptoms such as vomiting, acute diarrhea, and allergic reactions. As parasitic nematodes that primarily affect the patient's digestive tract, intestinal helminths can interact directly with the host microbiota through physical contact, chemicals, or nutrient competition. It is widely accepted that the host microbiota plays a crucial role in the regulation of immunity.
MATERIALS AND METHODS
Nematodes collected from the abdominal cavity of marine fish were identified by molecular biology and live worms were artificially infected in rats. Infection was determined by indirect ELISA based on rat serum and worm extraction. Feces were collected for 16S rDNA-based analysis of microbiota diversity.
RESULTS
Molecular biology identification based on ITS sequences identified the collected nematodes as . The success of the artificial infection was determined by indirect ELISA based on serum and worm extraction from artificially infected rats. Microbiota diversity analysis showed that a total of 773 ASVs were generated, and PCoA showed that the infected group was differentiated from the control group. The control group contained five characterized genera ( NK3B31 group, , 1, , ) and the infected group contained nine characterized genera (, , , , , , , , ). Based on the Wilcoxon test, four processes were found to be significant: bacterial secretion system, bacterial invasion of epithelial cells, bacterial chemotaxis, and ABC transporters.
CONCLUSION
This study is the first to analyze the diversity of the intestinal microbiota of rats infected with and to determine the damage and regulation of metabolism and immunity caused by the infection in the rat gut. The findings provide a basis for further research on host-helminth-microbe correlationships.
PubMed: 38784661
DOI: 10.3389/fvets.2024.1403920 -
BMC Microbiology May 2024Mangrove sediment microbes are increasingly attracting scientific attention due to their demonstrated capacity for diverse bioremediation activities, encompassing a wide...
BACKGROUND
Mangrove sediment microbes are increasingly attracting scientific attention due to their demonstrated capacity for diverse bioremediation activities, encompassing a wide range of environmental contaminants.
MATERIALS AND METHODS
The microbial communities of five Avicennia marina mangrove sediment samples collected from Al Rayyis White Head, Red Sea (KSA), were characterized using Illumina amplicon sequencing of the 16S rRNA genes.
RESULTS
Our study investigated the microbial composition and potential for organohalide bioremediation in five mangrove sediments from the Red Sea. While Proteobacteria dominated four microbiomes, Bacteroidetes dominated the fifth. Given the environmental concerns surrounding organohalides, their bioremediation is crucial. Encouragingly, we identified phylogenetically diverse organohalide-respiring bacteria (OHRB) across all samples, including Dehalogenimonas, Dehalococcoides, Anaeromyxobacter, Desulfuromonas, Geobacter, Desulfomonile, Desulfovibrio, Shewanella and Desulfitobacterium. These bacteria are known for their ability to dechlorinate organohalides through reductive dehalogenation. PICRUSt analysis further supported this potential, predicting the presence of functional biomarkers for organohalide respiration (OHR), including reductive dehalogenases targeting tetrachloroethene (PCE) and 3-chloro-4-hydroxyphenylacetate in most sediments. Enrichment cultures studies confirmed this prediction, demonstrating PCE dechlorination by the resident microbial community. PICRUSt also revealed a dominance of anaerobic metabolic processes, suggesting the microbiome's adaptation to the oxygen-limited environment of the sediments.
CONCLUSION
This study provided insights into the bacterial community composition of five mangrove sediments from the Red Sea. Notably, diverse OHRB were detected across all samples, which possess the metabolic potential for organohalide bioremediation through reductive dehalogenation pathways. Furthermore, PICRUSt analysis predicted the presence of functional biomarkers for OHR in most sediments, suggesting potential intrinsic OHR activity by the enclosed microbial community.
Topics: Geologic Sediments; RNA, Ribosomal, 16S; Biodegradation, Environmental; Phylogeny; Microbiota; Bacteria; Indian Ocean; Metagenomics; DNA, Bacterial; Wetlands; Metagenome
PubMed: 38778276
DOI: 10.1186/s12866-024-03291-8 -
Journal of Agricultural and Food... Jun 2024Anthocyanin-rich edible berries protect against diet-induced obesity in animal models. Prevention is mediated through the bidirectional relationship with the fecal...
Anthocyanin-rich edible berries protect against diet-induced obesity in animal models. Prevention is mediated through the bidirectional relationship with the fecal microbiome, and gut-derived phenolic metabolite absorption increases with physical activity, which may influence bioactivity. The objective of this study was to test elderberry juice powder on the development of diet-induced obesity and its influence on the fecal microbiome alone or in combination with physical activity. Male C57BL/6J mice were assigned to one of four treatments, including (1) high-fat diet without wheel access; (2) high-fat diet with unlimited wheel access; (3) high-fat diet supplemented with 10% elderberry juice powder without wheel access; and (4) high-fat diet supplemented with 10% elderberry juice powder with unlimited wheel access. Body weight gain, fat pads, and whole-body fat content in mice fed elderberry juice were significantly less than in mice fed the control diet independent of wheel access. At the end of the study, active mice fed elderberry juice ate significantly more than active mice fed a control diet. There was no difference in the physical activity between active groups. Elderberry juice increased, promoted and , and prevented the growth of . Elderberry juice is a potent inhibitor of diet-induced obesity with action mediated by the gut microbiota.
Topics: Animals; Mice, Inbred C57BL; Male; Obesity; Mice; Feces; Diet, High-Fat; Gastrointestinal Microbiome; Fruit and Vegetable Juices; Bacteria; Fruit; Humans; Sambucus nigra; Plant Extracts; Powders
PubMed: 38776153
DOI: 10.1021/acs.jafc.4c01211 -
Bioelectrochemistry (Amsterdam,... Oct 2024Carbon steel microbiologically influenced corrosion (MIC) by sulfate reducing bacteria (SRB) is known to occur via extracellular electron transfer (EET). A higher...
Carbon steel microbiologically influenced corrosion (MIC) by sulfate reducing bacteria (SRB) is known to occur via extracellular electron transfer (EET). A higher biofilm sessile cell count leads to more electrons being harvested for sulfate reduction by SRB in energy production. Metal surface roughness can impact the severity of MIC by SRB because of varied biofilm attachment. C1018 carbon steel coupons (1.2 cm top working surface) polished to 36 grit (4.06 μm roughness which is relatively rough) and 600 grit (0.13 μm) were incubated in enriched artificial seawater inoculated with highly corrosive Desulfovibrio ferrophilus IS5 at 28 ℃ for 7 d and 30 d. It was found that after 7 d of SRB incubation, 36 grit coupons had a 11% higher sessile cell count at (2.0 ± 0.17) × 10 cells/cm, 52% higher weight loss at 22.4 ± 5.9 mg/cm (1.48 ± 0.39 mm/a uniform corrosion rate), and 18% higher maximum pit depth at 53 μm compared with 600 grit coupons. However, after 30 d, the differences diminished. Electrochemical tests with transient information supported the weight loss data trends. This work suggests that a rougher surface facilitates initial biofilm establishment but provides no long-term advantage for increased biofilm growth.
Topics: Biofilms; Corrosion; Steel; Surface Properties; Desulfovibrio; Carbon; Electrons; Electron Transport; Sulfates
PubMed: 38759479
DOI: 10.1016/j.bioelechem.2024.108731 -
Microbiological Research Aug 2024Soil nitrogen (N) fixation, driven by microbial reactions, is critical to support the entrance of nitrogen in nutrient poor and pioneer ecosystems. However, how and why...
Soil nitrogen (N) fixation, driven by microbial reactions, is critical to support the entrance of nitrogen in nutrient poor and pioneer ecosystems. However, how and why N fixation and soil diazotrophs evolve as forests develop remain poorly understood. Here, we used a 60-year forest rewilding chronosequence and found that soil N fixation activity gradually decreased with increasing forest age, experiencing dramatic drops of 64.8% in intermediate stages and 93.0% in the oldest forests. Further analyses revealed loses in diazotrophic diversity and a significant reduction in the abundance of important diazotrophs (e.g., Desulfovibrio and Pseudomonas) as forest develops. This reduction in N fixation, and associated shifts in soil microbes, was driven by acidification and increases in N content during forest succession. Our results provide new insights on the life history of one of the most important groups of soil organisms in terrestrial ecosystems, with consequences for understanding the buildup of nutrients as forest soil develops.
Topics: Nitrogen Fixation; Forests; Soil Microbiology; Soil; Nitrogen; Ecosystem; Bacteria; Tropical Climate; Biodiversity; Trees
PubMed: 38759379
DOI: 10.1016/j.micres.2024.127757 -
Frontiers in Microbiology 2024Cryopreservation of semen can give full play to the reproductive advantages of male animals. However, in actual production, due to the poor frost resistance of sheep...
INTRODUCTION
Cryopreservation of semen can give full play to the reproductive advantages of male animals. However, in actual production, due to the poor frost resistance of sheep semen and the low conception rate, the promotion of sheep frozen semen is greatly hindered. Therefore, it is urgent to improve the frost resistance of semen to improve the quality of frozen semen. At present, most studies on improving the quality of frozen semen are based on the improvement of semen dilutions, and few studies on improving the freezing resistance of ram semen by feeding functional amino acids.
METHODS
Therefore, 24 Turpan black rams were divided into high antifreeze group (HF) and a low antifreeze group (LF) Each of these groups was further randomly divided into control and experimental subgroups. The control subgroup was fed a basal diet, while the experimental subgroup received an additional 12 g/d of -Cit supplementation based on the control group for a duration of 90 days.
RESULTS
The results showed that Following -Cit supplementation, the experimental group demonstrated significantly elevated sperm density and VSL (Velocity of straight line), T-AOC, GSH-Px, and NO levels in fresh semen compared to the control group ( < 0.01). After thawing, the experimental group exhibited significantly higher levels of T-AOC, GSH-Px, and NO compared to the control group ( < 0.01). Additionally, the HFT group, after thawing frozen semen, displayed significantly higher HK1 protein expression compared to the control group. The number of spermatogonia, spermatocytes, and sperm cells in the HFT group was significantly higher than that in the HFC group. Moreover, 16S rRNA sequence analysis showed that , and were significantly enriched in the rumen of the HFT group, while was significantly enriched in the HFC group. In the duodenum, , and were significantly enriched in the HFT group, whereas and were significantly enriched in the HFC group.
DISCUSSION
Under the conditions employed in this study, -Cit supplementation was found to enhance the intestinal flora composition in rams, thereby improving semen quality, enhancing the antifreeze performance of semen, and promoting the development of testicular spermatogenic cells.
PubMed: 38756735
DOI: 10.3389/fmicb.2024.1396796 -
Animal Bioscience May 2024This study investigated the impact of Aspergillus niger lysing polysaccharide monooxygenase (AnLPMO) on in vitro rumen microbial fermentation of rice straw.
OBJECTIVE
This study investigated the impact of Aspergillus niger lysing polysaccharide monooxygenase (AnLPMO) on in vitro rumen microbial fermentation of rice straw.
METHODS
AnLPMO was heterologously expressed in Escherichia coli. Fourier transform infrared spectrometry and X-ray photoelectron spectroscopy analyzed the surface structure of rice straw after AnLPMO treatment. Two in vitro experiments, coupled with 16S high-throughput sequencing and qRT-PCR techniques, assessed the influence of AnLPMO on rumen microbial fermentation of rice straw.
RESULTS
AnLPMO exhibited peak activity at 40 °C and pH 6.5, with a preference for rice straw xylan hydrolysis, followed by Avicel. AnLPMO application led to the fractional removal of cellulose and hemicelluloses and a notable reduction in the levels of carbon elements and C-C groups present on the surface of rice straw. Compared to the control (no AnLPMO), supplementing AnLPMO at 1.1 U-2.0 U significantly enhanced in vitro digestibility of dry matter (IVDMD, P < 0.01), total gas production (P < 0.01), and concentrations of total volatile fatty acids (VFA, P < 0.01), acetate (P < 0.01), and ammonia-N (P < 0.01). Particularly, the 1.4 U AnLPMO group showed a 14.8% increase in IVDMD. In the second experiment, compared to deactivated AnLPMO (1.4 U), supplementing bioactive AnLPMO at 1.4 U increased IVDMD (P = 0.01), total gas production (P = 0.04), and concentrations of total VFA (P < 0.01), propionate (P < 0.01), and ammonia-N (P < 0.01), with a limited 9.6% increase in IVDMD. Supplementing AnLPMO stimulated the growth of ruminal bacterial taxa facilitating fiber degradation, including Proteobacteria, Spirochaetes, Succinivibrio, Rikenellaceae_RC9_Gut_Group, Prevotelaceae_UCG-003, Desulfovibrio, Fibrobacter succinogenes, Ruminococcus albus, R. flavefaciens, Prevotella bryantii, P. ruminicola, and Treponema bryantii.
CONCLUSION
These findings highlight AnLPMO's potential as a feed additive for improving rice straw utilization in ruminant production.
PubMed: 38754847
DOI: 10.5713/ab.24.0026 -
Journal of Agricultural and Food... May 2024Oolong tea polyphenols (OTP) have attracted wide attention due to their ability to reduce inflammatory response, regulate gut microbiota, and improve cognitive function....
Oolong tea polyphenols (OTP) have attracted wide attention due to their ability to reduce inflammatory response, regulate gut microbiota, and improve cognitive function. However, exactly how the gut microbiota modulates nervous system activity is still an open question. We previously expounded that supplementing with OTP alleviated neuroinflammation in circadian rhythm disorder (CRD) mice. Here, we showed that OTP can relieve microglia activation by reducing harmful microbial metabolites lipopolysaccharide (LPS) that alleviate CRD-induced cognitive decline. Mechanistically, OTP suppressed the inflammation response by regulating the gut microbiota composition, including upregulating the relative abundance of and and downregulating , promoting the production of short-chain fatty acids (SCFAs). Moreover, the use of OTP alleviated intestinal barrier damage and decreased the LPS transport to the serum. These results further inhibited the activation of microglia, thus alleviating cognitive impairment by inhibiting neuroinflammation, neuron damage, and neurotoxicity metabolite glutamate elevation. Meanwhile, OTP upregulated the expression of synaptic plasticity-related protein postsynaptic density protein 95 (PSD-95) and synaptophysin (SYN) by elevating the brain-derived neurotrophic factor (BDNF) level. Taken together, our findings suggest that the OTP has the potential to prevent CRD-induced cognition decline by modulating gut microbiota and microbial metabolites.
Topics: Gastrointestinal Microbiome; Animals; Polyphenols; Mice; Cognitive Dysfunction; Male; Tea; Mice, Inbred C57BL; Camellia sinensis; Neuroprotective Agents; Chronobiology Disorders; Humans; Bacteria; Brain-Derived Neurotrophic Factor; Microglia; Plant Extracts
PubMed: 38745351
DOI: 10.1021/acs.jafc.4c01922