scholarly journals Effects of 2,2-dichloroacetamide (DCAcAm), an emerging disinfection by-product in drinking water, on the intestinal microbiota of adult zebrafish

2019 ◽  
Vol 17 (5) ◽  
pp. 683-690 ◽  
Author(s):  
Bin Xue ◽  
Chenyu Li ◽  
Shang Wang ◽  
Chen Zhao ◽  
Kun Dai ◽  
...  
Keyword(s):  
Drinking Water ◽  
Gut Microbiota ◽  
Toxicity Assessment ◽  
Adult Zebrafish ◽  
Opportunistic Pathogens ◽  
Adverse Health Effects ◽  
Complex Interactions ◽  
By Products ◽  
Insight Into ◽  
Gut Microbiota Composition

Abstract The presence of disinfection by-products (DBPs) increases the mutagenicity of water and may pose adverse health effects. Gut microbiota exerts a fundamental role on host physiology, and how extrinsic perturbations influence its composition has been increasingly examined. However, the effect of DBPs on gut microbiota is still poorly understood. In the present study, adult zebrafish were exposed to different concentrations of dichloroacetamide (DCAcAm, an emerging nitrogenous DBP) for 30 days. Sequencing of 16S rRNA amplicons revealed a significant change in the richness and diversity of microbiota in the gut of DCAcAm-exposed zebrafish. At the phylum level, the abundance of Proteobacteria decreased and the abundance of Fusobacteria and Firmicutes increased significantly in the gut after exposure to 100 and 500 μg/L DCAcAm. At the genus level, the abundances of several bacteria which are considered pathogens or opportunistic pathogens in fish and closely related to fish metabolism, disease and inflammation (Aeromonas, Stenotrophomonas, Bacteroides and Ralstonia) increased in the DCAcAm-treated groups. Our results reveal that DBPs in drinking water potentially affect gut microbiota composition, which may contribute to the toxicity assessment of DBPs in future and provide new insight into the complex interactions between the DBPs in drinking water and host health.

scholarly journals The Effect of Different Boiling and Filtering Devices on the Concentration of Disinfection By-Products in Tap Water

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Glòria Carrasco-Turigas ◽  
Cristina M. Villanueva ◽  
Fernando Goñi ◽  
Panu Rantakokko ◽  
Mark J. Nieuwenhuijsen
Keyword(s):  
Drinking Water ◽  
Health Effects ◽  
Reverse Osmosis ◽  
Tap Water ◽  
Epidemiological Studies ◽  
The Other ◽  
Large Decrease ◽  
Adverse Health Effects ◽  
Before And After ◽  
By Products

Disinfection by-products (DBPs) are ubiquitous contaminants in tap drinking water with the potential to produce adverse health effects. Filtering and boiling tap water can lead to changes in the DBP concentrations and modify the exposure through ingestion. Changes in the concentration of 4 individual trihalomethanes (THM4) (chloroform (TCM), bromodichloromethane (BDCM), dibromochloromethane (DBCM), and bromoform (TBM)), MX, and bromate were tested when boiling and filtering high bromine-containing tap water from Barcelona. For filtering, we used a pitcher-type filter and a household reverse osmosis filter; for boiling, an electric kettle, a saucepan, and a microwave were used. Samples were taken before and after each treatment to determine the change in the DBP concentration. pH, conductivity, and free/total chlorine were also measured. A large decrease of THM4 (from 48% to 97%) and MX concentrations was observed for all experiments. Bromine-containing trihalomethanes were mostly eliminated when filtering while chloroform when boiling. There was a large decrease in the concentration of bromate with reverse osmosis, but there was a little effect in the other experiments. These findings suggest that the exposure to THM4 and MX through ingestion is reduced when using these household appliances, while the decrease of bromate is device dependent. This needs to be considered in the exposure assessment of the epidemiological studies.

scholarly journals The microbial colonization of activated carbon block point-of-use (PoU) filters with and without chlorinated phenol disinfection by-products

2017 ◽  
Vol 3 (5) ◽  
pp. 830-843 ◽  
Author(s):  
Chia-Chen Wu ◽  
Sudeshna Ghosh ◽  
Kelly J. Martin ◽  
Ameet J. Pinto ◽  
Vincent J. Denef ◽  
...  
Keyword(s):  
Drinking Water ◽  
Activated Carbon ◽  
Bacterial Community Structure ◽  
Microbial Colonization ◽  
Opportunistic Pathogens ◽  
Absolute Abundance ◽  
Carbon Block ◽  
Point Of Use ◽  
Water Filters ◽  
By Products

Activated carbon based point-of-use drinking water filters change the bacterial community structure and increase the absolute abundance of genera, including those associated with opportunistic pathogens.

scholarly journals Genetic determinants of gut microbiota composition and bile acid profiles in mice

2019 ◽  
Author(s):  
Julia H. Kemis ◽  
Vanessa Linke ◽  
Kelsey L. Barrett ◽  
Frederick J. Boehm ◽  
Lindsay L. Traeger ◽  
...  
Keyword(s):  
Bile Acid ◽  
Gut Microbiota ◽  
Fecal Microbiota ◽  
Microbiota Composition ◽  
Host Genetics ◽  
Host Genetic ◽  
Insight Into ◽  
Gut Microbiota Composition ◽  
Validation Experiments

AbstractThe microbial communities that inhabit the distal gut of humans and other mammals exhibit large inter-individual variation. While host genetics is a known factor that influences gut microbiota composition, the mechanisms underlying this variation remain largely unknown. Bile acids (BAs) are hormones that are produced by the host and chemically modified by gut bacteria. BAs serve as environmental cues and nutrients to microbes, but they can also have antibacterial effects. We hypothesized that host genetic variation in BA metabolism and homeostasis influence gut microbiota composition. To address this, we used the Diversity Outbred (DO) stock, a population of genetically distinct mice derived from eight founder strains. We characterized the fecal microbiota composition and plasma and cecal BA profiles from 400 DO mice maintained on a high-fat high-sucrose diet for ∼22 weeks. Using quantitative trait locus (QTL) analysis, we identified several genomic regions associated with variations in both bacterial and BA profiles. Notably, we found overlapping QTL forTuricibacter sp.and plasma cholic acid, which mapped to a locus containing the gene for the ileal bile acid transporter,Slc10a2. Mediation analysis and subsequent follow-up validation experiments suggest that differences inSlc10a2gene expression associated with the different strains influences levels of both traits and revealed novel interactions betweenTuricibacterand BAs. This work illustrates how systems genetics can be utilized to generate testable hypotheses and provide insight into host-microbe interactions.Author summaryInter-individual variation in the composition of the intestinal microbiota can in part be attributed to host genetics. However, the specific genes and genetic variants underlying differences in the microbiota remain largely unknown. To address this, we profiled the fecal microbiota composition of 400 genetically distinct mice, for which genotypic data is available. We identified many loci of the mouse genome associated with changes in abundance of bacterial taxa. One of these loci is also associated with changes in the abundance of plasma bile acids—metabolites generated by the host that influence both microbiota composition and host physiology. Follow up validation experiments provide mechanistic insights linking host genetic differences, with changes in ileum gene expression, bile acid-bacteria interactions and bile acid homeostasis. Together, this work demonstrates how genetic approaches can be used to generate testable hypothesis to yield novel insight into how host genetics shape gut microbiota composition.

scholarly journals Gut Microbiota in Patients with Different Metabolic Statuses: Moscow Study

2018 ◽  
Vol 6 (4) ◽  
pp. 98 ◽  
Author(s):  
Daria Kashtanova ◽  
Olga Tkacheva ◽  
Ekaterina Doudinskaya ◽  
Irina Strazhesko ◽  
Yulia Kotovskaya ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Alpha Diversity ◽  
Intima Media Thickness ◽  
Strongly Correlated ◽  
Opportunistic Pathogens ◽  
R Programming Language ◽  
Stool Samples ◽  
R Programming ◽  
Gut Microbiota Composition

The aim of this paper was to study gut microbiota composition in patients with different metabolic statuses. Methods: 92 participants aged 25–76 years (26 of whom were men), with confirmed absence of cardiovascular and other chronic diseases (but with the possible presence of cardiovascular risk factors) were included. Carotid ultrasound examinations, 16S rRNA sequencing of stool samples and diet assessments were performed. Statistical analysis was performed using R programming language, 3.1.0. Results: Enterotyping yielded two clusters differentiated by alpha-diversity. Intima-media thickness was higher in the cluster with lower diversity (adj. p < 0.001). Obesity was associated with higher Serratia (adj. p = 0.003) and Prevotella (adj. p < 0.0003) in relative abundance. Abdominal obesity was associated with higher abundance of Serratia (adj. p = 0.004) and Prevotella (adj. p = 0.0008) and lower levels of Oscillospira (adj. p = 0.0005). Glucose metabolism disturbances were associated with higher Blautia (adj. p = 0.0007) and Serratia (adj. p = 0.003) prevalence. Arterial hypertension was associated with high Blautia levels (adj. p = 0.002). The Blautia genus strongly correlated with low resistant starch consumption (adj. p = 0.007). A combination of high-fat diet and elevated Blautia levels was very common for diabetes mellitus type 2 patients (adj. p = 0.0001). Conclusion: The results show that there is a relationship between metabolic changes and higher representation of opportunistic pathogens and low diversity of gut microbiota even in apparently healthy participants.

The epidemiology and possible mechanisms of disinfection by-products in drinking water

2009 ◽  
Vol 367 (1904) ◽  
pp. 4043-4076 ◽  
Author(s):  
Mark J. Nieuwenhuijsen ◽  
James Grellier ◽  
Rachel Smith ◽  
Nina Iszatt ◽  
James Bennett ◽  
...  
Keyword(s):  
Drinking Water ◽  
Health Effects ◽  
Semen Quality ◽  
Epidemiological Studies ◽  
Small Sample ◽  
Epidemiological Evidence ◽  
Adverse Health Effects ◽  
Adverse Health ◽  
Small Sample Sizes ◽  
By Products

This paper summarizes the epidemiological evidence for adverse health effects associated with disinfection by-products (DBPs) in drinking water and describes the potential mechanism of action. There appears to be good epidemiological evidence for a relationship between exposure to DBPs, as measured by trihalomethanes (THMs), in drinking water and bladder cancer, but the evidence for other cancers including colorectal cancer is inconclusive and inconsistent. There appears to be some evidence for an association between exposure to DBPs, specifically THMs, and little for gestational age/intrauterine growth retardation and, to a lesser extent, pre-term delivery, but evidence for relationships with other outcomes such as low birth weight, stillbirth, congenital anomalies and semen quality is inconclusive and inconsistent. Major limitations in exposure assessment, small sample sizes and potential biases may account for the inconclusive and inconsistent results in epidemiological studies. Moreover, most studies have focused on total THMs as the exposure metric, whereas other DBPs appear to be more toxic than the THMs, albeit generally occurring at lower levels in the water. The mechanisms through which DBPs may cause adverse health effects including cancer and adverse reproductive effects have not been well investigated. Several mechanisms have been suggested, including genotoxicity, oxidative stress, disruption of folate metabolism, disruption of the synthesis and/or secretion of placental syncytiotrophoblast-derived chorionic gonadotropin and lowering of testosterone levels, but further work is required in this area.

scholarly journals Insight into the Possible Use of the Predator Bdellovibrio bacteriovorus as a Probiotic

Nutrients ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2252 ◽  
Author(s):  
Giulia Bonfiglio ◽  
Bruna Neroni ◽  
Giulia Radocchia ◽  
Massimiliano Marazzato ◽  
Fabrizio Pantanella ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Human Organism ◽  
Bdellovibrio Bacteriovorus ◽  
Factors Affecting ◽  
Healthy State ◽  
Mutualistic Relationship ◽  
Principal Factors ◽  
Insight Into ◽  
State Stress ◽  
Gut Microbiota Composition

The gut microbiota is a complex microbial ecosystem that coexists with the human organism in the intestinal tract. The members of this ecosystem live together in a balance between them and the host, contributing to its healthy state. Stress, aging, and antibiotic therapies are the principal factors affecting the gut microbiota composition, breaking the mutualistic relationship among microbes and resulting in the overgrowth of potential pathogens. This condition, called dysbiosis, has been linked to several chronic pathologies. In this review, we propose the use of the predator Bdellovibrio bacteriovorus as a possible probiotic to prevent or counteract dysbiotic outcomes and look at the findings of previous research.

scholarly journals Clostridium difficileModulates the Gut Microbiota by Inducing the Production of Indole, an Interkingdom Signaling and Antimicrobial Molecule

mSystems ◽  
2019 ◽  
Vol 4 (2) ◽  
Author(s):  
Charles Darkoh ◽  
Kimberly Plants-Paris ◽  
Dayna Bishoff ◽  
Herbert L. DuPont
Keyword(s):  
Gut Microbiota ◽  
Treatment Options ◽  
Intestinal Bacteria ◽  
Chemical Warfare ◽  
Accessory Gene ◽  
Content Type ◽  
Accessory Gene Regulator ◽  
Complex Interactions ◽  
Unique Markers ◽  
Insight Into

ABSTRACTClostridium(Clostridioides)difficileinfection (CDI) is associated with dysbiosis.C. difficilehas a characteristic propensity to persist and recur 1 to 4 weeks after treatment, but the mechanism is unknown. We hypothesized thatC. difficilemay persist by manipulating the intestinal microenvironment, thereby hampering gut microbiota reconstitution following antibiotic-mediated dysbiosis. By screening stools from CDI patients for unique markers, a metabolite identified to be indole by mass spectrometry and Fourier transform infrared spectroscopy was identified. The average fecal indole concentration detected in CDI patients (n= 216; mean, 1,684.0 ± 84.4 µM) was significantly higher than in stools of patients with non-C. difficilediarrhea (n = 204; mean, 762.8 ± 53.8 µM). Certain intestinal bacteria, but notC. difficile, produce indole, a potent antimicrobial antioxidant. Remarkably,C. difficileinduced other indole-producing gut microbes to produce increasing amounts of indole. Furthermore, aC. difficileaccessory gene regulator 1 quorum sensing system mutant cannot induce indole, but complementation of the mutant strain with the wild-type gene restored its ability to induce indole production. Indole tolerance assays indicated that the amount of indole required to inhibit growth of most gut-protective bacteria was within the range detected in the CDI stools. We think that a high indole level limits the growth of beneficial indole-sensitive bacteria in the colon and alters colonization resistance and this might allowC. difficileto proliferate and persist. Together, these results reveal a unique mechanism ofC. difficilepersistence and provide insight into complex interactions and chemical warfare among the gut microbiota.IMPORTANCEClostridiumdifficileinfection is the leading cause of hospital-acquired and antibiotic-associated diarrhea worldwide.C. difficileflourishes in the colon after the diversity of the beneficial and protective gut microbiota have been altered by antibiotic therapy.C. difficiletends to persist, as does dysbiosis, encouraging recurrence a few days to weeks after treatment, and this further complicates treatment options. Here, we show thatC. difficilemight persist by manipulating the indigenous microbiota to produce indole, a bioactive molecule that inhibits the growth and reconstitution of the protective gut microbiota during infection. This discovery may explain a unique strategyC. difficileuses to control other bacteria in the colon and provide insight into the complex interactions and chemical warfare among the gut microbiota.

scholarly journals Organic by-products of Drinking Water Chlorination

2013 ◽  
Vol 1 (3) ◽  
pp. 143-156 ◽  
Keyword(s):  
Drinking Water ◽  
Environmental Fate ◽  
Chemical Properties ◽  
Factors Affecting ◽  
Adverse Health Effects ◽  
Toxicological Studies ◽  
Water Chlorination ◽  
Physical And Chemical ◽  
By Products ◽  
And Chemical Properties

<p>Chlorination of drinking water leads to the formation of a variety of Disinfection By-Products (DBPs) that may have adverse health effects on humans. Research on this subject has been continued and new epidemiological and toxicological studies have been conducted. This review summarizes factors affecting DBP formation and predictive equations proposed for it, physical and chemical properties, environmental fate, actual measurements of these compounds and technologies for controlling them, as well as regulation and currently proposed changes of their Maximum Contaminant Levels (MCLs) after evaluation by EPA of new data available.</p>

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