Microplastics (MPs) and microfibers (MFs) in stormwater have been poorly investigated. Data on their intra and inter rain events variability over time are still sparse. For the first time, the ...variability of microlitter concentrations in stormwater has been studied. MF and MP concentrations were investigated in stormwater runoff at the outlet of the suburban catchment at Sucy-en-Brie (a suburb of Paris, France), during four rain events. Median MF and MP concentrations were 1.9 and 29 items/L, with an interquartile range of 2.3 and 36 items/L, respectively (N = 18). A different pattern was observed between MFs and MPs. While no relationship or trends were observed for MFs, the highest MP concentrations were observed before the flow rate peak of the rain events. This could indicate a difference in the behaviour between MFs and MPs. We estimated the median MP mass concentration to be 56 μg/L with an interquartile range of 194 μg/L, whereas the mass concentration of macroplastics was estimated to be 31 μg/L with an interquartile range of 22 μg/L at the same sampling site, in a previous study. For this sampling site, MPs and macroplastics have the same order of magnitude. This study may have strong implications on microplastic assessment in urban waters.
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•There is no relationship between stormwater flow rates and microfiber concentrations.•The highest microplastic concentrations were observed before the flow rate peak.•The microplastics and macroplastics were in the same range of mass concentration.
Microfiber (MF) and microplastic (MP) median concentrations in stormwater were 1.9 and 29 items/L. The MP and macroplastics were in the same range of mass concentration.
•Screened materials from stormwater of Paris suburb were collected for one year•Plastic bags or films correspond to the most numerous items found in stormwater•Plastic debris account for 53% of the ...mass of all anthropogenic waste•The mean plastic debris concentration in stormwater is 41 mg/m3•Separate sewer systems of Greater Paris may discharge 8-33 tons of plastic per year
Stormwater possibly represents a significant input for plastic debris in the environment; however, the quantification and composition of plastic debris and other macrolitter in stormwater are not available in literature and the amounts discharged into freshwater have been poorly investigated. To obtain a better understanding, the occurrence, abundance, and composition of the macrolitter in screened materials from stormwater were investigated at a small residential suburban catchment (Sucy-en-Brie, France) in Greater Paris. The macrolitter, particularly the plastic debris, was sorted, weighed, and classified based on the OSPAR methodology. On average, plastics accounted for at least 62% in number and for 53% of the mass of all the anthropogenic waste found in the screened materials. The most common items were plastic bags or films, crisp or sweet packets, cigarette butts, plastic fragments of unknown origin, garbage bags or garbage bag strings, foil wrappers, tampon applicators, plastic cups, and medical items such as bandages. Plastic debris concentrations in runoff water ranged between 7 and 134 mg/m3 (i.e. 0.4–1.7 kg.yr−1.ha−1 or 4.8–18.8 g.yr−1.cap−1). When extrapolated to the Greater Paris area, the estimated amount of plastic debris discarded into the environment through untreated stormwater of separate sewer systems ranges from 8 to 33 tons.yr−1.
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Immunomodulatory properties of 10 dairy propionibacteria, analyzed on human peripheral blood mononuclear cells (PBMCs), revealed a highly strain-dependent induction of anti-inflammatory cytokine ...interleukin 10 (IL-10). Two selected strains of Propionibacterium freudenreichii showed a protective effect against two models of colitis in mice, suggesting a probiotic potential predicted by immune-based selection criteria for these cheese starter bacteria.
The gut microbiota is critical for intestinal homeostasis. Recent studies have revealed the links between different types of dysbiosis and diseases inside and outside the intestine. Environmental ...exposure to pollutants (such as heavy metals) can also impair various physiological functions for good health. Here, we studied the impact of up to 8 weeks of oral lead and cadmium ingestion on the composition of the murine intestinal microbiome.
Pyrosequencing of 16S RNA sequences revealed minor but specific changes in bacterial commensal communities (at both family and genus levels) following oral exposure to the heavy metals, with notably low numbers of Lachnospiraceae and high numbers levels of Lactobacillaceae and Erysipelotrichaceacae (mainly due to changes in Turicibacter spp), relative to control animals.
Non-absorbed heavy metals have a direct impact on the gut microbiota. In turn, this may impact the alimentary tract and overall gut homeostasis. Our results may enable more accurate assessment of the risk of intestinal disease associated with heavy metal ingestion.
•We model chronic ingestion of environmental lead and cadmium in axenic mice.•We addressed the role of the microbiota in heavy-metal dissemination in organs.•We delineate the direct impact of the ...non-absorbed heavy metals on gut homeostasis.•We measure transport- and oxidative-gene expression in intestine.•It enlightens risk assessment of heavy metals in intestinal disease's susceptibility.
Environmental exposure to pollutants such as heavy metal(s) is responsible for various altered physiological functions which are detrimental for health. The gut microbiota is critical for intestinal homeostasis but its role on xenobiotic handling is not fully understood, especially when continuous sub-chronic exposure is addressed. We first confirmed the essential role of the intestinal microbiome to limit heavy metal body burden by using germ-free mice following 6-weeks oral exposure. Significant increases of cadmium and lead absorption and dissemination in blood and target organs were measured in germ-free mice when compared with conventional specific pathogen free (SPF) mice. Besides the “barrier” function of the luminal microbiota, this may involve specific host-genes such as metallothioneins, which are differentially expressed in the gastrointestinal tract of each group of mice. Considering genes relevant for divalent metal transporters and oxidative pathways, significant differences in basal gene expression were measured between control and germ-free mice. Moreover, the magnitude of induction of these genes upon stimulation by heavy metals varied greatly depending on the dose and type of metal as well as the microbial status of the animal. Collectively, these data illustrate the complex host-microbes interplay occurring with environmental pollutants inside the gut.
Do food ecosystems feed gut ecosystems? And if so… fuel the immune system? Recent developments in metagenomics have provided researchers tools to open the “black box” of microbiome science. These ...novel technologies have enabled the establishment of correlations between dysbiotic microbial communities and many diseases. The complex interaction of the commensal microbiota with the immune system is a topic of substantial interest due to its relevance to health. The human gastrointestinal tract is composed of an immense number of resident and transient microorganisms. Both may play a direct and vital role in the maintenance of human health and well-being. An understanding of the interactions and mechanisms through which commensal and food-derived microbes shape host immunity and metabolism may yield new insights into the pathogenesis of many immune-mediated diseases. Consequently, by manipulating the contribution of food microbiota to the functionality of the gut ecosystem, there is great hope for development of new prophylactic and therapeutic interventions. This paper presents some insights and comments on the possible impact of exogenous fermented food microbes on the gut homeostasis. We shed light on the similar features shared by both fermented food microbes and probiotics. In particular, the key role of microbial strains as part of food ecosystems for health and diseases is discussed through the prism of fermented dairy products and gut inflammation.
Although the heavy metals cadmium (Cd) and lead (Pb) are known environmental health concerns, their long-term impacts on gut ecology and susceptibility to gastrointestinal autoimmune diseases have ...not been extensively investigated. We sought to determine whether subchronic oral exposure to Cd or Pb is a risk factor for the development and progression of inflammatory bowel disease (IBD). Mice were exposed to various doses of CdCl2 or PbCl2 in drinking water for 1, 4 or 6 weeks prior to infection with Salmonella, the induction of colitis with dextran sodium sulfate (DSS) or trinitrobenzene sulfonic acid (TNBS). In human cell-based models, exposure to Cd and Pb is associated with reduced transepithelial electric resistance and changes in bacteria-induced cytokine responses. Although 1- and 6-week exposures did not have clear effects on the response to Salmonella infectious challenges, 1-week short-term treatments with CdCl2 tended to enhance intestinal inflammation in mice. Unexpectedly, subchronic exposure to Cd and (to a lesser extent) Pb significantly mitigated some of the symptoms of DSS-induced colitis and reduced the severity of TNBS colitis in a dose-dependent manner. The possible adaptive and immunosuppressive mechanisms by which heavy metals might reduce intestinal inflammation are explored and discussed.
Scope: Inflammatory bowel disease (IBD) constitutes a growing public health concern in western countries. Bacteria with anti‐inflammatory properties are lacking in the dysbiosis accompanying IBD. ...Selected strains of probiotic bacteria with anti‐inflammatory properties accordingly alleviate symptoms and enhance treatment of ulcerative colitis in clinical trials. Such properties are also found in selected strains of dairy starters such as Propionibacterium freudenreichii and Lactobacillus delbrueckii (Ld). We thus investigated the possibility to develop a fermented dairy product, combining both starter and probiotic abilities of both lactic acid and propionic acid bacteria, designed to extend remissions in IBD patients.
Methods and results: We developed a single‐strain Ld‐fermented milk and a two‐strain P. freudenreichii and Ld‐fermented experimental pressed cheese using strains previously selected for their anti‐inflammatory properties. Consumption of these experimental fermented dairy products protected mice against trinitrobenzenesulfonic acid induced colitis, alleviating severity of symptoms, modulating local and systemic inflammation, as well as colonic oxidative stress and epithelial cell damages. As a control, the corresponding sterile dairy matrix failed to afford such protection.
Conclusion: This work reveals the probiotic potential of this bacterial mixture, in the context of fermented dairy products. It opens new perspectives for the reverse engineering development of anti‐inflammatory fermented foods designed for target populations with IBD, and has provided evidences leading to an ongoing pilot clinical study in ulcerative colitis patients.
We have selected two promising anti‐inflammatory bacteria from traditional dairy products: a lactobacillus used to make yogurt and a propionibacterium used to make Swiss‐type cheese. We designed a prototype cheese with milk and both bacteria. Following 5 days consumption of this cheese, mice were protected toward experimental inflammatory intestinal disease. Consumption limited weight loss, intestine attack, and alleviated the overall inflammation and stress, depicted by transcriptional signatures. This opens perspectives for clinical studies on intestinal diseases.
Chronic ingestion of environmental heavy metals such as lead (Pb) and cadmium (Cd) causes various well-documented pathologies in specific target organs following their intestinal absorption and ...subsequent accumulation. However, little is known about the direct impact of the non-absorbed heavy metals on the small intestine and the colon homeostasis. The aim of our study was to compare the specific bioaccumulation and retention of Cd and Pb and their effect on the essential metal balance in primary organs, with those occurring specifically in the gastrointestinal tract of mice. Various doses of Cd (5, 20 and 100 mg l
−1
) and Pb (100 and 500 mg l
−1
) chloride salts were provided in drinking water for subchronic to chronic exposures (4, 8 and 12 weeks). In contrast to a clear dose- and time-dependent accumulation in target organs, results showed that intestines are poor accumulators for Cd and Pb. Notwithstanding, changes in gene expression of representative intestinal markers revealed that the transport-, oxidative- and inflammatory status of the gut epithelium of the duodenum, ileum and colon were specifically affected by both heavy metal species. Additionally, in vivo comet assay used to evaluate the impact of heavy metals on DNA damage showed clear genotoxic activities of Cd, on both the upper and distal parts of the gastrointestinal tract. Altogether, these results outline the resilience of the gut which balances the various effects of chronic Cd and Pb in the intestinal mucosa. Collectively, it provides useful information for the risk assessment of heavy metals in gut homeostasis and further disease’s susceptibility.
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