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Biology Mar 2024The present frontrunners in the chemotherapy of infections caused by protozoa are nitro-based prodrugs that are selectively activated by PFOR-mediated redox reactions....
The present frontrunners in the chemotherapy of infections caused by protozoa are nitro-based prodrugs that are selectively activated by PFOR-mediated redox reactions. This study seeks to analyze the distribution of PFOR in selected protozoa and bacteria by applying comparative genomics to test the hypothesis that PFOR in eukaryotes was acquired through horizontal gene transfer (HGT) from bacteria. Furthermore, to identify other putatively acquired genes, proteome-wide and gene enrichment analyses were used. A plausible explanation for the patchy occurrence of PFOR in protozoa is based on the hypothesis that bacteria are potential sources of genes that enhance the adaptation of protozoa in hostile environments. Comparative genomics of and the putative gene donor, , identified eleven candidate genes for HGT involved in intermediary metabolism. If these results can be reproduced in other PFOR-possessing protozoa, it would provide more validated evidence to support the horizontal transfer of from bacteria.
PubMed: 38534448
DOI: 10.3390/biology13030178 -
Molecular Nutrition & Food Research Apr 2024Age-related cognitive decline is primarily attributed to the progressive weakening of synaptic function and loss of synapses, while age-related gut microbial dysbiosis...
Age-related cognitive decline is primarily attributed to the progressive weakening of synaptic function and loss of synapses, while age-related gut microbial dysbiosis is known to impair synaptic plasticity and cognitive behavior by metabolic alterations. To improve the health of the elderly, the protective mechanisms of Oudemansiella raphanipes polysaccharide (ORP-1) against age-related cognitive decline are investigated. The results demonstrate that ORP-1 and its gut microbiota-derived metabolites SCFAs restore a healthy gut microbial population to handle age-related gut microbiota dysbiosis mainly by increasing the abundance of beneficial bacteria Dubosiella, Clostridiales, and Prevotellaceae and reducing the abundance of harmful bacteria Desulfovibrio, strengthen intestinal barrier integrity by abolishing age-related alterations of tight junction (TJ) and mucin 2 (MUC2) proteins expression, diminish age-dependent increase in circulating inflammatory factors, ameliorate cognitive decline by reversing memory- and synaptic plasticity-related proteins levels, and restrain hyperactivation of microglia-mediated synapse engulfment and neuroinflammation. These findings expand the understanding of prebiotic-microbiota-host interactions.
Topics: Humans; Aged; Brain-Gut Axis; Dysbiosis; Prebiotics; Cognitive Dysfunction; Agaricales
PubMed: 38528314
DOI: 10.1002/mnfr.202300739 -
Cardiovascular Research May 2024Probiotics with high bile salt hydrolase (BSH) activity have shown to promote cardiovascular health. However, their mechanism(s) of action remain poorly understood....
AIMS
Probiotics with high bile salt hydrolase (BSH) activity have shown to promote cardiovascular health. However, their mechanism(s) of action remain poorly understood. Here, we performed a pilot exploratory study to investigate effects of a 4-week intervention with escalating doses of a BSH-active formula containing Lactiplantibacillus plantarum strains KABP011, KABP012, and KABP013 on bile acid (BA), lipid profile, and lipoprotein function.
METHODS AND RESULTS
Healthy overweight individuals were included in this study. The probiotic intake was associated with a progressive decrease of conjugated BAs in serum, due to the reduction of tauro- and glyco-conjugated forms. Plasma levels of fibroblast growth factor-19 were significantly reduced and correlated with BA changes. The probiotic induced significant changes in serum lipids, with reduction in non-HDL cholesterol (non-HDLc) and LDL cholesterol (LDLc) levels. The largest decrease was evidenced in the subgroup with higher baseline LDLc levels (LDLc > 130 mg/dL). Fasting levels of circulating apolipoprotein(Apo) B100 and ApoB48 were significantly reduced. Importantly, the decrease in non-HDLc levels was associated with a significant reduction in small LDL particles. Functional testing indicated that LDL particles had a significantly lower susceptibility to oxidation, while HDL particles gained antioxidant capacity after the probiotic intake. The microbiota profile in faeces collected at the end of the study was enriched with members of class Desulfovibrio, a taurine-consuming bacteria, likely because of the increase in free taurine in the gut due to the BSH activity of the probiotic.
CONCLUSION
The intervention with L. plantarum strains induces beneficial effects on BA signature and lipoprotein profile. It reduces ApoB and small LDL levels and LDL susceptibility to oxidation and increases HDL antioxidant capacity. These metabolic profile changes suggest increased protection against atherosclerotic disease.
Topics: Probiotics; Humans; Bile Acids and Salts; Male; Female; Pilot Projects; Middle Aged; Adult; Biomarkers; Cholesterol; Lactobacillus plantarum; Gastrointestinal Microbiome; Time Factors; Apolipoprotein B-100; Amidohydrolases; Apolipoprotein B-48; Treatment Outcome; Cholesterol, LDL; Fibroblast Growth Factors
PubMed: 38525555
DOI: 10.1093/cvr/cvae061 -
The Science of the Total Environment May 2024The disposal of spent nuclear fuel in deep subsurface repositories using multi-barrier systems is considered to be the most promising method for preventing radionuclide...
The disposal of spent nuclear fuel in deep subsurface repositories using multi-barrier systems is considered to be the most promising method for preventing radionuclide leakage. However, the stability of the barriers can be affected by the activities of diverse microbes in subsurface environments. Therefore, this study investigated groundwater geochemistry and microbial populations, activities, and community structures at three potential spent nuclear fuel repository construction sites. The microbial analysis involved a multi-approach including both culture-dependent, culture-independent, and sequence-based methods for a comprehensive understanding of groundwater biogeochemistry. The results from all three sites showed that geochemical properties were closely related to microbial population and activities. Total number of cells estimates were strongly correlated to high dissolved organic carbon; while the ratio of adenosine-triphosphate:total number of cells indicated substantial activities of sulfate reducing bacteria. The 16S rRNA gene sequencing revealed that the microbial communities differed across the three sites, with each featuring microbes performing distinctive functions. In addition, our multi-approach provided some intriguing findings: a site with a low relative abundance of sulfate reducing bacteria based on the 16S rRNA gene sequencing showed high populations during most probable number incubation, implying that despite their low abundance, sulfate reducing bacteria still played an important role in sulfate reduction within the groundwater. Moreover, a redundancy analysis indicated a significant correlation between uranium concentrations and microbial community compositions, which suggests a potential impact of uranium on microbial community. These findings together highlight the importance of multi-methodological assessments in better characterizing groundwater biogeochemical properties for the selection of potential spent nuclear fuel disposal sites.
Topics: Bacteria; Uranium; RNA, Ribosomal, 16S; Prospective Studies; Desulfovibrio; Groundwater; Sulfates
PubMed: 38522553
DOI: 10.1016/j.scitotenv.2024.171918 -
Ecotoxicology and Environmental Safety Apr 2024Iron overload occurs due to excessive iron intake compared to the body's demand, leading to iron deposition and impairment of multiple organ functions. Our previous...
Iron overload occurs due to excessive iron intake compared to the body's demand, leading to iron deposition and impairment of multiple organ functions. Our previous study demonstrated that chronic oral administration of ferric citrate (FC) caused colonic inflammatory injury. However, the precise mechanism underlying this inflammatory response remains unclear. The current study aims to investigate the mechanism by which iron overload induced by FC exposure leads to colonic inflammation. To accomplish this, mice were orally exposed to three different concentrations of FC (71 mg/kg/bw (L), 143 mg/kg/bw (M) and 286 mg/kg/bw (H)) for continuous 16 weeks, with the control group receiving ultrapure water (C). Exposure to FC caused disturbances in the excretory system, altered colonic flora alpha diversity, and enriched pathogenic bacteria, such as Mucispirillum, Helicobacter, Desulfovibrio, and Shigella. These changes led to structural disorders of the colonic flora and an inflammatory response phenotype characterized by inflammatory cells infiltration, atrophy of intestinal glands, and irregular thickening of the intestinal wall. Mechanistic studies revealed that FC-exposure activated the NF-κB signaling pathway by up-regulating TLR4, MyD88, and NF-κB mRNA levels and protein expression. This activation resulted in increased production of pro-inflammatory cytokines, further contributing to the colonic inflammation. Additionally, in vitro experiments in SW480 cells confirmed the activation of NF-κB signaling pathway by FC exposure, consistent with the in vivo findings. The significance of this study lies in its elucidation of the mechanism by which iron overload caused by FC exposure leads to colonic inflammation. By identifying the role of pathogenic bacteria and the NF-κB signaling pathway, this study could potentially offer a crucial theoretical foundation for the research on iron overload, as well as provide valuable insights for clinical iron supplementation.
Topics: Mice; Animals; NF-kappa B; Inflammation; Iron Overload; Iron; Ferric Compounds
PubMed: 38522287
DOI: 10.1016/j.ecoenv.2024.116241 -
Journal of Ethnopharmacology Jun 2024Gastrodia elata Blume is a traditional Chinese medicine with the effects of improving the deficiency of the body and maintaining health, and polysaccharide (GEP) is one...
ETHNOPHARMACOLOGICAL RELEVANCE
Gastrodia elata Blume is a traditional Chinese medicine with the effects of improving the deficiency of the body and maintaining health, and polysaccharide (GEP) is one of the effective ingredients to play these activities of G. elata. Traditionally, G. elata is orally administered, so the activities of GEP are associated with digestive and intestinal metabolism. However, the digestive behavior of GEP and its effects on the human gut microbiota are unclear and need to be fully studied.
AIM OF THE STUDY
This study aimed to investigate the changes in structural characteristics of GEP during digestion and the related impacts of its digestive product on gut microbiota in human fecal fermentation, and to explain the beneficial mechanism of GEP on human health from the perspective of digestive characteristics and "gut" axis.
MATERIALS AND METHODS
The changes of reducing sugars, free monosaccharides and physicochemical properties of GEP during digestion were investigated by GPC, HPLC, FT-IR, CD, NMR, SEM, and TGA. Moreover, polysaccharide consumption, pH value changes, SCFAs production, and changes in gut microbiota during fermentation were also discussed.
RESULTS
During digestion of GEP, glucose was partially released causing a decrease in molecular weight, and a change in monosaccharide composition. In addition, the characteristics of GEP before and after digestion, including configuration, morphology, and stability, were different. The digestive product of GEP was polysaccharide (GEP-I), which actively participated in the fecal fermentation process. As the fermentation time increased, the utilization of GEP-I by the microbiota gradually increased. The abundance of probiotics such as Bifidobacterium, Collinsella, Prevotella, and Faecalibacterium was significantly increased, and the abundance of pathogenic Shigella, Dorea, Desulfovibrio, and Blautia was significantly inhibited, thereby suggesting that GEP has the potential to maintain human health through the "gut" axis. In addition, the beneficial health effects of GEP-I have also been observed in the influence of microbial metabolites. During the fermentation of GEP-I, the pH value gradually decreased, and the contents of beneficial metabolites such as acetic acid, propionic acid, and caproic acid significantly increased.
CONCLUSION
The structure of GEP changed significantly during digestion, and its digestive product had the potential to maintain human health by regulating gut microbiota, which may be one of the active mechanisms of GEP.
Topics: Humans; Gastrointestinal Microbiome; Gastrodia; Spectroscopy, Fourier Transform Infrared; Plant Extracts; Polysaccharides; Fermentation; Digestion
PubMed: 38521425
DOI: 10.1016/j.jep.2024.118064 -
Environmental Research Jun 2024The high organic matter in river sediment primarily induces black and odorous rebound. Traditional humic-reducing bacteria demonstrate relatively single metabolic...
The high organic matter in river sediment primarily induces black and odorous rebound. Traditional humic-reducing bacteria demonstrate relatively single metabolic functions and restrain the remediation within complex sediment environments. In addition, Ca(NO) is commonly utilized in synergistic with bioremediation to improve the reducing environment of sediments. In this study, a multifunctional bacterial community with humic reduction-denitrification coupled bacteria was domesticated by the step-feeding strategy in an anaerobic baffle reactor (ABR). The performance, remediation effect, and metabolic mechanisms were analyzed. The results indicated that humic-reducing bacteria (HRB) and denitrifying-humic-reducing bacteria (DF/HRB) have quinone-reduction and denitrification capabilities. The synergistic effect of DF/HRBs and Ca(NO) was superior to HRBs and Ca(NO) on the removal of total organic matter(TOM). Microbial community structure analysis revealed an enhanced relative abundance of denitrification and humic-reducing bacteria (e.g., Thauera, Pseudomonas, Sulfurospirillum, Desulfovibrio, Geobacter) in the DF/HRB, resulting in a superior synergistic effect of DF/HRBs with Ca(NO). This work helps to present an innovative approach to domesticate humic-reducing bacteria suited for the remediation environment effectively. It also expands the application of humic-reducing bacteria for in-situ anaerobic remediation of river sediments.
Topics: Geologic Sediments; Humic Substances; Denitrification; Bacteria; Biodegradation, Environmental; Oxidation-Reduction; Bioreactors
PubMed: 38518914
DOI: 10.1016/j.envres.2024.118761 -
Journal of Agricultural and Food... Apr 2024Microplastics derived from plastic waste have emerged as a pervasive environmental pollutant with potential transfer and accumulation through the food chain, thus posing...
Modulation of Gut Microbial Metabolism by Cyanidin-3--Glucoside in Mitigating Polystyrene-Induced Colonic Inflammation: Insights from 16S rRNA Sequencing and Metabolomics.
Microplastics derived from plastic waste have emerged as a pervasive environmental pollutant with potential transfer and accumulation through the food chain, thus posing risks to both ecosystems and human health. The gut microbiota, tightly intertwined with metabolic processes, exert substantial influences on host physiology by utilizing dietary compounds and generating bacterial metabolites such as tryptophan and bile acid. Our previous studies have demonstrated that exposure to microplastic polystyrene (PS) disrupts the gut microbiota and induces colonic inflammation. Meanwhile, intervention with cyanidin-3--glucoside (C3G), a natural anthocyanin derived from red bayberry, could mitigate colonic inflammation by reshaping the gut bacterial composition. Despite these findings, the specific influence of gut bacteria and their metabolites on alleviating colonic inflammation through C3G intervention remains incompletely elucidated. Therefore, employing a C57BL/6 mouse model, this study aims to investigate the mechanisms underlying how C3G modulates gut bacteria and their metabolites to alleviate colonic inflammation. Notably, our findings demonstrated the efficacy of C3G in reversing the elevated levels of pro-inflammatory cytokines (IL-6, IL-1β, and TNF-α) and the upregulation of mRNA expression (, , and ) induced by PS exposure. Meanwhile, C3G effectively inhibited the reduction in levels (IL-22, IL-10, and IL-4) and the downregulation of mRNA expression (, , and ) of anti-inflammatory cytokines induced by PS exposure. Moreover, PS-induced phosphorylation of the transcription factor NF-κB in the nucleus, as well as the increased level of protein expression of iNOS and COX-2 in the colon, were inhibited by C3G. Metabolisms of gut bacterial tryptophan and bile acids have been extensively implicated in the regulation of inflammatory processes. The 16S rRNA high-throughput sequencing disclosed that PS treatment significantly increased the abundance of pro-inflammatory bacteria (, , , and ) while decreasing the abundance of anti-inflammatory bacteria (, , and ). Intriguingly, C3G intervention reversed these pro-inflammatory changes in bacterial abundances and augmented the enrichment of bacterial genes involved in tryptophan and bile acid metabolism pathways. Furthermore, untargeted metabolomic analysis revealed the notable upregulation of metabolites associated with tryptophan metabolism (shikimate, l-tryptophan, indole-3-lactic acid, and -acetylserotonin) and bile acid metabolism (3b-hydroxy-5-cholenoic acid, chenodeoxycholate, taurine, and lithocholic acid) following C3G administration. Collectively, these findings shed new light on the protective effects of dietary C3G against PS exposure and underscore the involvement of specific gut bacterial metabolites in the amelioration of colonic inflammation.
Topics: Mice; Animals; Humans; Interleukin-10; Anthocyanins; RNA, Ribosomal, 16S; Tumor Necrosis Factor-alpha; Plastics; Polystyrenes; Interleukin-6; Gastrointestinal Microbiome; Interleukin-4; Ecosystem; Tryptophan; Mice, Inbred C57BL; Cytokines; Inflammation; Anti-Inflammatory Agents; Glucosides; Bile Acids and Salts; RNA, Messenger
PubMed: 38518253
DOI: 10.1021/acs.jafc.3c08454 -
Food & Function Apr 2024Given the limited efficacy and adverse effects associated with conventional drugs, probiotics are emerging as a promising therapeutic strategy for mitigating the chronic...
Given the limited efficacy and adverse effects associated with conventional drugs, probiotics are emerging as a promising therapeutic strategy for mitigating the chronic nature of ulcerative colitis (UC) and its consequential secondary liver injury (SLI). HF06 and HF05 are strains we screened with excellent anti-inflammatory and probiotic properties . In this study, the intervention of HF06 and HF05 in combination (MIXL) was found to be more effective in alleviating intestinal inflammation and secondary liver injury in UC mice compared to supplementing with the two strains individually. Results demonstrated that MIXL effectively attenuated colon shortening and weight loss, downregulated the expression of pro-inflammatory cytokines TNF-α, IL-1β, and IL-6 mRNA in the intestines, mitigated SLI, and augmented the enzymatic activities of SOD, CAT, and GSH-Px in the liver. MIXL enhances the intestinal barrier in UC mice, regulates the structure and composition of the gut microbiota, promotes the abundance of , and suppresses the abundance of bacteria associated with inflammation and liver injury, including , , and . This study demonstrated the synergistic effect of HF06 and HF05, providing a reliable foundation for the alleviation of UC.
Topics: Animals; Mice; Colitis, Ulcerative; Anti-Inflammatory Agents; Inflammation; Colon; Liver; Probiotics; Dextran Sulfate; Disease Models, Animal; Colitis; Mice, Inbred C57BL
PubMed: 38506656
DOI: 10.1039/d3fo04419j -
Heliyon Mar 2024/aims: Atherosclerosis (AS) is the common pathological basis of a variety of cardiovascular diseases (CVD), and has become the main cause of human death worldwide, and...
BACKGROUND
/aims: Atherosclerosis (AS) is the common pathological basis of a variety of cardiovascular diseases (CVD), and has become the main cause of human death worldwide, and the incidence is increasing and younger trend. Ginsenoside Rb1 (Rb1), an important monomer component of the traditional Chinese herb ginseng, known for its ability to improve blood lipid disorders and anti-inflammatory. In addition, Rb1 was proved to be an effective treatment for AS. However, the effect of Rb1 on AS remains to be elucidated. The aim of this study was to investigate the mechanisms of Rb1 in ameliorating AS induced by high-fat diet (HFD).
MATERIALS AND METHODS
In this study, we developed an experimental AS model in Sprague-Dawley rats by feeding HFD with intraperitoneal injection of vitamin D3. The potential therapeutic mechanism of Rb1 in AS rats was investigated by detecting the expression of inflammatory factors, microbiome 16S rRNA gene sequencing, short-chain fatty acids (SCFAs) targeted metabolomics and untargeted metabolomics.
RESULTS
Rb1 could effectively alleviate the symptoms of AS and suppress the overexpression of inflammation-related factors. Meanwhile, Rb1 altered gut microbial composition and concentration of SCFAs characterized by Bacteroidetes, Actinobacteria, Lactobacillus, Prevotella, Oscillospira enrichment and Desulfovibrio depletion, accompanied by increased production of acetic acid and propionic acid. Moreover, untargeted metabolomics showed that Rb1 considerably improved faecal metabolite profiles, particularly arachidonic acid metabolism and primary bile acid biosynthesis.
CONCLUSION
Rb1 ameliorated the HFD-induced AS, and the mechanism is related to improving intestinal metabolic homeostasis and inhibiting systemic inflammation by regulating gut microbiota.
PubMed: 38500998
DOI: 10.1016/j.heliyon.2024.e27597