Increased Cadmium Excretion Due to Oral Administration of Lactobacillus plantarum Strains by Regulating Enterohepatic Circulation in Mice

Oat β-glucan prevents high fat diet induced obesity by targeting ileal Farnesoid X receptor-fibroblast growth factor 15 signaling

Oat β-glucan has demonstrated an anti-obesity effect against high fat diet. However, its precise regulatory mechanism remains unclear. The anti-obesity effect was related to the structural characteristics. In this study, different molecular weight oat β-glucans were investigated, and yeast glucan was taken as the positive control. Compared with the low molecular weight oat β-glucan, the higher molecular weight β-glucan presented a superior anti-obesity effect, which might be attributed to its viscosity and fermentability. Oat β-glucan effectively modulated microbiota in both the large and small intestines. Correlation analysis revealed that ileal bacteria played a more critical role in lipid metabolism. Most bile acids are recycled in the distal ileum, and bile acid metabolism influences lipid metabolism. Consequently, the impact of oat β-glucan on bile acid metabolism was assessed. Oat β-glucan intervention reduced the abundance of Faecalibaculum, while increasing the abundance of Lactobacillus and Bifidobacterium. These microbiota alterations contributed to an increase in 7-ketodeoxycholic acid, which was identified as a Farnesoid X receptor (FXR) antagonist in cell experiments. Inactivation of ileal FXR-fibroblast growth factor 15 (FGF15) signaling by 7-ketodeoxycholic acid led to enhanced bile acid synthesis via the alternative pathway. Furthermore, upregulated cytochrome P450 family 27 subfamily A member 1 (CYP27A1) promoted chenodeoxycholic acid production, which subsequently activated hepatic FXR and further accelerated hepatic lipolysis through the peroxisome proliferator-activated receptor α (PPARα)-carnitine palmitoyltransferase 1 A (CPT1A) pathway. These findings provide new evidence that oat β-glucan exerts anti-obesity effects by modulating bile acid metabolism.

Swimming Into View: Zebrafish Uncover Targets, Mechanisms, and Therapies for Cadmium Toxicity

PURPOSE OF REVIEW

Cadmium (Cd) remains a persistent threat to human and environmental health. To better understand causal relationships between genotype and disease phenotypes, a genetically tractable model, zebrafish (Danio rerio) has emerged. We summarize recent empirical evidence on the targets, mechanisms, and potential therapies for Cd toxicity.

RECENT FINDINGS

Recent results show that waterborne Cd exhibits organ specific accumulation including in the eye, brain, heart, and gonads triggering oxidative stress, inflammation, gut dysbiosis, and altered methylation patterns that persist across generations. Novel mechanisms of Cd toxicity include the gut-brain axis, ionic antagonism, the Wnt/β-catenin pathway, and epigenetics, leading to potential therapeutics such as probiotics, selenium, and antioxidants. Based on the reviewed literature, more studies should examine the effects of dietary Cd on zebrafish behavior, brains, and cardiovascular function. Given that humans and wildlife are chronically exposed to Cd, leading to gonadal Cd accumulation, studies should conduct early-life exposures across the zebrafish lifespan and assess endpoints across generations to capture germline and epigenetic effects and mechanisms. The zebrafish's biomedical toolkit, along with high-content screening, should be utilized to develop and refine therapies.

Effect of Feeding Mice Soluble Metals and Heavy Metal Contaminated Soil on Feces Metal Concentrations

The effect of heavy metal availability and interaction in feed on feces heavy metal excretion in mice has rarely been investigated. In this work, feed containing a polluted soil (total Cd = 6.34, total Pb = 387 mg kg-1) amended with phosphate, bentonite and lime, or feed spiked with soluble Pb and Cd were fed to mice for 10 days. Feces were collected on Day 2 and Day 10 and analyzed for Cd, Cu, Mn, Ni, Pb and Zn concentrations. Results indicated that Day 10 samples had 10% greater heavy metal concentrations in some treatments than Day 2. For the Pb and Cd spiked treatments, significant positive correlations were found between Pb and Cd rates and feces Pb and Cd concentrations on both dates. Significantly greater feces Pb and Cd concentrations were found in Day 10 samples than in Day 2 samples. Significant correlations were also found between feed Pb and Cd spiking rates and feces Cu, Mn, Ni and Zn concentrations, indicating mouse metal absorption dynamics and metal interactions. Although the phosphate and lime amended soils had lower DTPA-Pb and Cd than the unamended soil (6.2-17.9%, p < 0.05), no significant difference was found for feces Pb and Cd concentrations between treatments. A marginally negative correlation (p = 0.073) between soil DTPA-Zn and feces Zn concentration for Day 2 samples implied the soil amendment only affected mice absorption of Zn. Overall results imply that mice feces heavy metal concentrations can be used to indicate heavy metal absorption from feed and metal interactions in mice.

Consuming probiotics protects against cadmium exposure from rice consumption while promotes gut health: An assessment based on a mouse model

Cadmium (Cd) in rice constitutes a global health risk. It is crucial to develop strategies that not only reduce the bioavailability of Cd in rice but also confer additional health benefits. One potential approach involves the consumption of probiotics, which can bind Cd in the intestines and enhance gut health. The effects of consuming Akkermansia muciniphila, Bifidobacterium pseudolongum, and Psychrobacter sp. on the bioavailability of Cd in rice and gut health were evaluated using in vivo mouse bioassays and in vitro Cd immobilization assays. In mice fed Cd-contaminated rice without dietary calcium (Ca) and iron (Fe) supplementation (i.e., under conditions of mineral deficiency), the intake of these probiotics insignificantly reduced Cd accumulation in the kidneys and livers, although it did promote Cd excretion via feces. This outcome was primarily due to the competition for Ca and Fe between the probiotics and the host, which led to increased intestinal expression of Ca and Fe transporters under mineral-deficient conditions, thereby mitigating the probiotics' ability to reduce Cd bioavailability. Conversely, in mice fed Cd-contaminated rice with adequate dietary Ca and Fe (i.e., under conditions of mineral adequacy), probiotic intake significantly decreased Cd concentrations in the kidneys by 60.0 %-72.0 % compared to the control group exposed to Cd. Additionally, probiotic consumption fostered the growth of beneficial gut bacteria and strengthened intestinal tight junctions, reducing the inflammatory response in the intestines. These findings suggest that combining probiotics with sufficient Ca and Fe intake can effectively reduce dietary Cd exposure and enhance gut health.

Guardians of the Gut: Harnessing the Power of Probiotic Microbiota and Their Exopolysaccharides to Mitigate Heavy Metal Toxicity in Human for Better Health

Heavy metal pollution is a significant global health concern, posing risks to both the environment and human health. Exposure to heavy metals happens through various channels like contaminated water, food, air, and workplaces, resulting in severe health implications. Heavy metals also disrupt the gut's microbial balance, leading to dysbiosis characterized by a decrease in beneficial microorganisms and proliferation in harmful ones, ultimately exacerbating health problems. Probiotic microorganisms have demonstrated their ability to adsorb and sequester heavy metals, while their exopolysaccharides (EPS) exhibit chelating properties, aiding in mitigating heavy metal toxicity. These beneficial microorganisms aid in restoring gut integrity through processes like biosorption, bioaccumulation, and biotransformation of heavy metals. Incorporating probiotic strains with high affinity for heavy metals into functional foods and supplements presents a practical approach to mitigating heavy metal toxicity while enhancing gut health. Utilizing probiotic microbiota and their exopolysaccharides to address heavy metal toxicity offers a novel method for improving human health through modulation of the gut microbiome. By combining probiotics and exopolysaccharides, a distinctive strategy emerges for mitigating heavy metal toxicity, highlighting promising avenues for therapeutic interventions and health improvements. Further exploration in this domain could lead to groundbreaking therapies and preventive measures, underscoring probiotic microbiota and exopolysaccharides as natural and environmentally friendly solutions to heavy metal toxicity. This, in turn, could enhance public health by safeguarding the gut from environmental contaminants.

Metal(loid)-gut microbiota interactions and microbiota-related protective strategies: A review

Human exposure to metal(loid)s has dramatically increased over the past five decades, which has triggered public concern worldwide. Recently, gut microbiota has been considered a target for metal(loid)s, and some literature has reviewed the interactions between gut microbiota and heavy metal(loid)s (HMs) with high toxicity. However, whether there is an interaction between gut microbiota and metal(loid)s with essential roles or some normal functions are far from clear to date. Importantly, in addition to traditional probiotics that have been clarified to alleviate the adverse effect of HMs on the body, some novel probiotics, prebiotics, synbiotics, and postbiotics may also exhibit comparable or even better abilities of metal(loid) remediation. In this review, we mainly outline and discuss recent research findings on the metal(loid)-gut microbiota interactions and microbiota-related protective strategies.

Cadmium in Market Pork Kidneys: A Study on Cadmium Bioavailability and the Health Effects Based on Mouse Models

Edible offal of farmed animals can accumulate cadmium (Cd). However, no studies have investigated Cd bioavailability and its health effects. Here, based on mouse models, market pork kidney samples exhibited high Cd relative bioavailability of 74.5 ± 11.2% (n = 26), close to 83.8 ± 7.80% in Cd-rice (n = 5). This was mainly due to high vitamin D3 content in pork kidney, causing 1.7-2.3-fold up-regulated expression of duodenal Ca transporter genes in mice fed pork kidney compared to mice fed Cd-rice, favoring Cd intestinal absorption via Ca transporters. However, although pork kidney was high in Cd bioavailability, subchronic low-dose (5% in diet) consumption of two pork kidney samples having 0.48 and 0.97 μg Cd g-1 dw over 35 d did not lead to significant Cd accumulation in the tissue of mice fed Cd-free rice but instead remarkably decreased Cd accumulation in the tissue of mice fed Cd-rice (0.48 μg Cd g-1) by ∼50% and increased abundance of gut probiotics (Faecalibaculum and Lactobacillus). Overall, this study contributed to our understanding of the bioavailability and health effects associated with Cd in edible offal, providing mechanistic insights into pork kidney consumption safety based on Cd bioavailability.

Berberine alleviates concanavalin A-induced autoimmune hepatitis in mice by modulating the gut microbiota

BACKGROUND

Autoimmune hepatitis (AIH) is an immune-mediated liver disease of unknown etiology accompanied by intestinal dysbiosis and a damaged intestinal barrier. Berberine (BBR) is a traditional antibacterial medicine that has a variety of pharmacological properties. It has been reported that BBR alleviates AIH, but relevant mechanisms remain to be fully explored.

METHODS

BBR was orally administered at doses of 100 mg⋅kg-1⋅d-1 for 7 days to mice before concanavalin A-induced AIH model establishment. Histopathological, immunohistochemical, immunofluorescence, western blotting, ELISA, 16S rRNA analysis, flow cytometry, real-time quantitative PCR, and fecal microbiota transplantation studies were performed to ascertain BBR effects and mechanisms in AIH mice.

RESULTS

We found that liver necrosis and apoptosis were decreased upon BBR administration; the levels of serum transaminase, serum lipopolysaccharide, liver proinflammatory factors TNF-α, interferon-γ, IL-1β, and IL-17A, and the proportion of Th17 cells in spleen cells were all reduced, while the anti-inflammatory factor IL-10 and regulatory T cell proportions were increased. Moreover, BBR treatment increased beneficial and reduced harmful bacteria in the gut. BBR also strengthened ileal barrier function by increasing the expression of the tight junction proteins zonula occludens-1 and occludin, thereby blocking lipopolysaccharide translocation, preventing lipopolysaccharide/toll-like receptor 4 (TLR4)/ NF-κB pathway activation, and inhibiting inflammatory factor production in the liver. Fecal microbiota transplantation from BBR to model mice also showed that BBR potentially alleviated AIH by altering the gut microbiota.

CONCLUSIONS

BBR alleviated concanavalin A-induced AIH by modulating the gut microbiota and related immune regulation. These results shed more light on potential BBR therapeutic strategies for AIH.

Could the gut microbiota be capable of making individuals more or less susceptible to environmental toxicants?

Environmental toxicants are chemical substances capable to impair environmental quality and exert adverse effects on humans and other animals. The main routes of exposure to these pollutants are through the respiratory tract, skin, and oral ingestion. When ingested orally, they will encounter trillions of microorganisms that live in a community - the gut microbiota (GM). While pollutants can disrupt the GM balance, GM plays an essential role in the metabolism and bioavailability of these chemical compounds. Under physiological conditions, strategies used by the GM for metabolism and/or excretion of xenobiotics include reductive and hydrolytic transformations, lyase and functional group transfer reactions, and enzyme-mediated functional transformations. Simultaneously, the host performs metabolic processes based mainly on conjugation, oxidation, and hydrolysis reactions. Thus, due to the broad variety of bacterial enzymes present in GM, the repertoire of microbial transformations of chemicals is considered a key component of the machinery involved in the metabolism of pollutants in humans and other mammals. Among pollutants, metals deserve special attention once contamination by metals is a worldwide problem, and their adverse effects can be observed even at very low concentrations due to their toxic properties. In this review, bidirectional interaction between lead, arsenic, cadmium, and mercury and the host organism and its GM will be discussed given the most recent literature, presenting an analysis of the ability of GM to alter the host organism's susceptibility to the toxic effects of heavy metals, as well as evaluating the extent to which interventions targeting the microbiota could be potential initiatives to mitigate the adverse effects resulting from poisoning by heavy metals. This study is the first to highlight the overlap between some of the bacteria found to be altered by metal exposure and the bacteria that also aid the host organism in the metabolism of these metals. This could be a key factor to determine the beneficial species able to minimize the toxicity of metals in future therapeutic approaches.

Exploring substrate-microbe interactions: a metabiotic approach toward developing targeted synbiotic compositions

Gut microbiota is an important modulator of human health and contributes to high inter-individual variation in response to food and pharmaceutical ingredients. The clinical outcomes of interventions with prebiotics, probiotics, and synbiotics have been mixed and often unpredictable, arguing for novel approaches for developing microbiome-targeted therapeutics. Here, we review how the gut microbiota determines the fate of and individual responses to dietary and xenobiotic compounds via its immense metabolic potential. We highlight that microbial metabolites play a crucial role as targetable mediators in the microbiota-host health relationship. With this in mind, we expand the concept of synbiotics beyond prebiotics' role in facilitating growth and engraftment of probiotics, by focusing on microbial metabolism as a vital mode of action thereof. Consequently, we discuss synbiotic compositions that enable the guided metabolism of dietary or co-formulated ingredients by specific microbes leading to target molecules with beneficial functions. A workflow to develop novel synbiotics is presented, including the selection of promising target metabolites (e.g. equol, urolithin A, spermidine, indole-3 derivatives), identification of suitable substrates and producer strains applying bioinformatic tools, gut models, and eventually human trials.In conclusion, we propose that discovering and enabling specific substrate-microbe interactions is a valuable strategy to rationally design synbiotics that could establish a new category of hybrid nutra-/pharmaceuticals.

Blood Cadmium and Abdominal Aortic Calcification in Population with Different Weight Statuses: a Population-Based Study

The aim of our study was to assess the effect of blood cadmium levels (B-Cd) on abdominal aortic calcification (AAC). We used the data from the 2013-2014 NHANES database. A total of 1530 participants were included in our study, with a mean AAC score of 1.40 ± 0.10, and a prevalence of severe AAC of 7.98%. Participants with higher B-Cd quartiles showed a higher prevalence of severe AAC. B-Cd was positively associated with higher AAC scores and increased risk of severe AAC. In the obese population, blood cadmium levels showed a positive association with the risk of severe AAC. There may be a positive correlation between B-Cd levels and AAC scores and risk of severe AAC, and this correlation is more pronounced in the obese population. Therefore, the cadmium load in AAC patients in the obese population should be considered in clinical work.

Cadmium exposure dysregulates purine metabolism and homeostasis across the gut-liver axis in a mouse model

Cadmium (Cd) exposure has been associated with the development of enterohepatic circulation disorders and hyperuricemia, but the possible contribution of chronic low-dose Cd exposure to disease progression is still need to be explored. A mouse model of wild-type mice (WT) and Uox-knockout mice (Uox-KO) to find out the toxic effects of chronic low-dose Cd exposure on liver purine metabolism by liquid chromatography-mass spectrometry (LC-MS) platform and associated intestinal flora. High throughput omics analysis including metabolomics and transcriptomics showed that Cd exposure can cause disruption of purine metabolism and energy metabolism. Cd changes several metabolites associated with purine metabolism (xanthine, hypoxanthine, adenosine, uridine, inosine) and related genes, which are associated with elevated urate levels. Microbiome analysis showed that Cd exposure altered the disturbance of homeostasis in the gut. Uox-KO mice were more susceptible to Cd than WT mice. Our findings extend the understanding of potential toxicological interactions between liver and gut microbiota and shed light on the progression of metabolic diseases caused by Cd exposure.

Toxicity of cadmium on dynamic human gut microbiome cultures and the protective effect of cadmium-tolerant bacteria autochthonous to the gut

Cadmium (Cd) is a heavy metal toxic to the gut microbiome. In this study, we cultivated two human gut microbiomes (A and B) in bioreactors with Cd at 0 and 20 ppm for 7 days to investigate effects of Cd on the gut microbiome and to isolate Cd-tolerant bacteria autochthonous to the gut. Cd showed profound toxicity, abolishing butyrate production, depleting microbes in microbiome B, and simplifying microbiome A to a small Cd-tolerant community after 2 d of incubation. When spiked into the Cd-sensitive microbiome B, the Cd-tolerant community from microbiome A and isolates from that community worked synergistically with microbiome B to enhance butyrate production and maintained this synergism at Cd concentrations up to 5 ppm. Bacteria isolated from this Cd-tolerant community included Enterococcus faecium, Enterobacter cloacae, Lactococcus lactis, and Lactobacillus taiwanensis species. This work demonstrates a straightforward method for identifying Cd-tolerant bacteria autochthonous to the human gut that synergize with the microbiome to protect against Cd-related loss of butyrate production.

Cadmium influence on lipid metabolism in Sprague-Dawley rats through linoleic acid and glycerophospholipid metabolism pathways

Cadmium (Cd) is widely distributed in the environment and easy adsorbed by living organisms with adverse effects. Exposure to Cd-contaminated food may disrupt lipid metabolism and increase human health risk. To study the perturbation effect of Cd on lipid metabolism in vivo, 24 male Sprague-Dawley (SD) rats were randomly assigned four groups and treated by Cd chloride solution (0, 1.375 mg/kg, 5.5 mg/kg, 22 mg/kg) for 14 days. The characteristic indexes of serum lipid metabolism were analyzed. Afterwards, untargeted metabolomics analysis was applied to explore the adverse effects of Cd on rats by liquid chromatography coupled with mass spectrometry (LC-MS). The results revealed that Cd exposure obviously decreased the average serum of triglycerides (TG) and low-density lipoprotein cholesterol (LDL-C) and caused an imbalance of endogenous compounds in the 22 mg/kg Cd-exposed group. Compared with the control group, 30 metabolites with significant differences were identified in the serum. Our results indicated that Cd caused lipid metabolic disorders in rats by disrupting linoleic acid and glycerophospholipid metabolism pathways. Furthermore, there were three kinds of remarkable differential metabolites-9Z,12Z-octadecadienoic acid, PC(20:4(8Z,11Z,14Z,17Z)/0:0), and PC(15:0/18:2(9Z,12Z)), which enriched the two significant metabolism pathways and could be the potential biomarkers.

The Effect of Very-Long-Chain n-3 Polyunsaturated Fatty Acids in the Central Nervous System and Their Potential Benefits for Treating Alcohol Use Disorder: Reviewing Pre-Clinical and Clinical Data

Alcohol use poses a significant global health concern, leading to serious physical and socioeconomic issues worldwide. The current treatment options for problematic alcohol consumption are limited, leading to the exploration of alternative approaches, such as nutraceuticals. One promising target is very-long-chain n-3 polyunsaturated fatty acids (VLC n-3 PUFAs). This review aims to compile the most relevant pre-clinical and clinical evidence on the effect of VLC n-3 PUFAs on alcohol use disorders and related outcomes. The findings suggest that VLC n-3 PUFAs may alleviate the physiological changes induced by alcohol consumption, including neuroinflammation and neurotransmitter dysregulation. Additionally, they can reduce withdrawal symptoms, improve mood, and reduce stress level, all of which are closely associated with problematic alcohol consumption. However, more research is required to fully understand the precise mechanisms by which VLC n-3 PUFAs exert their function. Furthermore, PUFAs should not be considered a standalone solution, but as a complement to other therapeutic approaches. Although preliminary evidence supports the potential therapeutic effect of VLC n-3 PUFAs on problematic alcohol consumption, additional research is needed to validate these findings and determine the optimal use of PUFAs as part of a comprehensive approach to the treatment of alcohol use disorders.

Docosahexaenoic Acid Promotes Cd Excretion by Restoring the Abundance of Parabacteroides in Cd-Exposed Mice

As a common harmful pollutant, cadmium (Cd) can easily enter the human body through the food chain, posing a major threat to human health. Gut microbiota play a key role in Cd absorption. Docosahexaenoic acid (DHA) is thought to have a potential role in the treatment of Cd poisoning. This study investigated the therapeutic effect and mechanism of DHA in Cd-exposed mice from the perspective of the gut microbiota. The results showed that DHA significantly increased the Cd content in feces and decreased the Cd accumulation in the organs of mice. The gut microbiota results showed that DHA significantly restored the abundance of Parabacteroides in the gut microbiota of Cd-exposed mice. Parabacteroides distasonis (P. distasonis), a representative strain of the Parabacteroides, also showed Cd- and toxicity-reduction capabilities. P. distasonis significantly restored the gut damage caused by Cd exposure. At the same time, P. distasonis reduced the Cd content in the liver, spleen, lung, kidneys, gut, and blood to varying degrees and significantly increased the Cd content in feces. The succinic acid produced by P. distasonis plays an important role in promoting Cd excretion in Cd-exposed mice. Therefore, these results suggest that P. distasonis may have a potential role in DHA-mediated Cd excretion in Cd-exposed mice.

What happens to gut microorganisms and potential repair mechanisms when meet heavy metal(loid)s

Heavy metal (loid) pollution is a significant threat to human health, as the intake of heavy metal (loid)s can cause disturbances in intestinal microbial ecology and metabolic disorders, leading to intestinal and systemic diseases. Therefore, it is important to understand the effects of heavy metal (loid)s on intestinal microorganisms and the necessary approaches to restore them after damage. This review provides a summary of the effects of common toxic elements, such as lead (Pb), cadmium (Cd), chromium (Cr), and metalloid arsenic (As), on the microbial community and structure, metabolic pathways and metabolites, and intestinal morphology and structure. The effects of heavy metal (loid)s on metabolism are focused on energy, nitrogen, and short-chain fatty acid metabolism. We also discussed the main solutions for recovery of intestinal microorganisms from the effects of heavy metal (loid)s, namely the supplementation of probiotics, recombinant bacteria with metal resistance, and the non-toxic transformation of heavy metal (loid) ions by their own intestinal flora. This article provides insight into the toxic effects of heavy metals and As on gut microorganisms and hosts and provides additional therapeutic options to mitigate the damage caused by these toxic elements.

Threonine Facilitates Cd Excretion by Increasing the Abundance of Gut Escherichia coli in Cd-Exposed Mice

Cadmium (Cd) can easily enter the body through the food chain and threaten health since Cd pollution is prevalent in the environment. Gut microbiota is necessary for the reduction of metal ions. To reduce Cd-induced harmful impacts and Cd accumulation in the body, we investigated the effect of amino acids on gut microbiota and Cd excretion in (fecal Cd) Cd-exposed mice. The screening of 20 amino acids showed that threonine (Thr) effectively increased fecal Cd, and reduced Cd-induced intestinal structural damage. The abundance of Escherichia-Shigella genus and KF843036_g significantly increased after the oral administration of Thr. As the type species of the Escherichia-Shigella genus, Escherichia coli exhibited high similarity to KF843036_g species and significantly decreased Cd-induced gut damage. Cd contents in the liver, kidney, and gut of Cd-exposed mice were also significantly (p < 0.05) decreased after E. coli treatment, while the contents in the feces were increased. The results demonstrated the potential roles that gut E. coli might play in Thr-mediated Cd excretion in Cd-exposed mice. The findings may provide important data for better understanding the molecular biological mechanism of Thr in reducing Cd accumulation in the body.

Chronic lead exposure exacerbates hepatic glucolipid metabolism disorder and gut microbiota dysbiosis in high-fat-diet mice

Lead (Pb) and obesity are co-occurring risk factors for metabolic disorders. However, there is still a lack of study on the combined effects of both stressors on metabolism. C57BL/6J mice were exposed to 200 mg/L Pb or/and HFD for 24 weeks and were used to investigate the effects and underlying mechanisms of chronic Pb exposure on obese mice. The results showed that Pb significantly increased body weight, visceral obesity, fasting blood glucose levels, and insulin resistance, and aggravated liver damage, hepatic lipid accumulation and steatosis in HFD-fed mice. Further analysis showed that Pb significantly inhibited insulin signaling pathway PI3K/AKT and fatty acid β-oxidation, and accelerated fatty acid synthesis. Moreover, Pb exacerbated HFD-induced disruption of gut microbiota homeostasis, manifested by increased proportions of pathogenic genera such as Desulfovibrio, Alistipes and Helicobacter, and decreased proportions of beneficial microbes Akkermansia and Barnesiella, which were negatively associated with obesity. These results indicated that Pb exposure exacerbated the disruption of liver glucolipid metabolism in HFD mice possibly by disrupting gut microbiota.

Protective effects of fowl-origin cadmium-tolerant lactobacillus against sub-chronic cadmium-induced toxicity in chickens

Cadmium (Cd) directly endangers poultry health and indirectly causes harm to human health by food chain. Numerous studies have focused on removing Cd using lactic acid bacteria (LAB). However, there is still a lack of in vivo studies to validate whether Cd can be absorbed successfully by LAB to alleviate Cd toxicity. Here, we aimed to isolated and screened poultry-derived Cd-tolerant LAB with the strongest adsorption capacity in vitro and investigate the protective effect of which on sub-chronic Cd toxicity in chickens. First, nine Cd-tolerant LAB strains were selected preliminarily by isolating, screening, and identifying from poultry farms. Next, four strains with the strongest adsorption capacity were used to explore the influence of different physical and chemical factors on the ability of LAB to adsorb Cd as well as its probiotic properties in terms of acid tolerance, bile salt tolerance, drug resistance, and antibacterial effects. Resultantly, the CLF9-1 strain with the best comprehensive ability was selected for further animal protection test. The Cd-tolerant LAB treatment promoted the growth performance of chickens and reduced the Cd-elevated liver and kidney coefficients. Moreover, Cd-induced liver, kidney, and duodenum injuries were alleviated significantly by high-dose LAB treatment. Furthermore, LAB treatment also increased the elimination of Cd in feces and markedly reduced the Cd buildup in the liver and kidney. In summary, these findings determine that screened Cd-tolerant LAB strain exerts a protective effect on chickens against sub-chronic cadmium poisoning, thus providing an essential guideline for the public health and safety of livestock and poultry.

Human supplementation with Pediococcus acidilactici GR-1 decreases heavy metals levels through modifying the gut microbiota and metabolome

Exposure to heavy metals (HMs) is a threat to human health. Although probiotics can detoxify HMs in animals, their effectiveness and mechanism of action in humans have not been studied well. Therefore, we conducted this randomized, double-blind, controlled trial on 152 occupational workers from the metal industry, an at-risk human population, to explore the effectiveness of probiotic yogurt in reducing HM levels. Participants were randomly assigned to two groups: one consumed probiotic yogurt containing the HM-resistant strain Pediococcus acidilactici GR-1 and the other consumed conventional yogurt for 12 weeks. Analysis of metal contents in the blood revealed that the consumption of probiotic yogurt resulted in a higher and faster decrease in copper (34.45%) and nickel (38.34%) levels in the blood than the consumption of conventional yogurt (16.41% and 27.57%, respectively). Metagenomic and metabolomic studies identified a close correlation between gut microbiota (GM) and host metabolism. Significantly enriched members of Blautia and Bifidobacterium correlated positively with the antioxidant capacities of GM and host. Further murine experiments confirmed the essential role of GM and protective effect of GR-1 on the antioxidative role of the intestine against copper. Thus, the use of probiotic yogurt may be an effective and affordable approach for combating toxic metal exposure through the protection of indigenous GM in humans.

ClinicalTrials.gov identifier: ChiCTR2100053222

Effects of exposure to cadmium (Cd) and selenium-enriched Lactobacillus plantarum in Luciobarbus capito: Bioaccumulation, antioxidant responses and intestinal microflora

Cadmium (Cd) is a dangerous pollutant with multiple toxic effects on aquatic animals, and it exists widely in the environment. Selenium (Se) is a biologically essential trace element. Interactions between heavy metals and selenium can significantly affect their biological toxicity, although little is known about the mechanism of this antagonism. Lactobacillus is one of the dominant probiotics, given that a certain dose promotes host health. In this study, we evaluated the protective effect of a dietary probiotic supplementation, Se-enriched Lactobacillus plantarum (L. plantarum), on the bioaccumulation, oxidative stress and gut microflora of Luciobarbus capito exposed to waterborne Cd. Fish were exposed for 28 days to waterborne Cd at 0.05 mg/L and/or dietary Se-enriched L. plantarum. Exposure to Cd in water leads to Cd accumulation in tissues, oxidative stress and significant changes in gut microflora composition. Adding Se-enriched L. plantarum to the diet can reduce the accumulation of Cd in tissues, enhance the activity of antioxidant enzymes, and reverse changes in intestinal microbial composition after Cd exposure. The results obtained indicate that Se-enriched L. plantarum provides significant protection against the toxicity of Cd by inhibiting bioaccumulation. Selenium reduced oxidative stress by increasing the activity of glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX) and malondialdehyde (MDA). Se-enriched L. plantarum can reduce the increase in the number of pathogenic Aeromonas caviae bacteria in the intestine caused by Cd stress and increase the number of Gemmobacter to regulate the microbial population. The results of this study show that Se-enriched L. plantarum dietary supplements can effectively protect Luciobarbus capito against Cd toxicity at subchronic levels.

Rice hull insoluble dietary fiber alleviated experimental colitis induced by low dose of dextran sulfate sodium in cadmium-exposed mice

Cadmium (Cd), an important toxic environmental pollutant, can invade the gastrointestinal tract and induce the occurrence of gastrointestinal diseases. This study aimed to investigate the protective effect of rice hull insoluble dietary fiber (RHF) on Cd-promoted colitis induced by low dose of dextran sulfate sodium. Administration of RHF attenuated inflammation by limiting Cd accumulation and regulating intestinal immune homeostasis in colitis mice with Cd exposure. RHF could maintain the structure of the gut barrier by increasing mucin secretion and intestinal tight connectivity in mice. Subsequently, RHF repressed the colonic inflammation mediated by the TLR4/MyD88/NF-κB pathway, and inhibited the transcription regulation of inflammatory cytokines. Furthermore, RHF showed an enhancement of a variety of probiotics, such as Eubacterium and Faecalibaculum. RHF also inhibited the growth of pathogenic bacteria, including Erysipelatoclostridium, Helicobacter and Bacteroides. The growth of beneficial bacteria was also accompanied by reversing the decline in short-chain fatty acids, supporting the initial potentiality of RHF as a prebiotic in cases of damage by Cd exposure in colitis mice. Importantly, RHF also remained resistant to Cd toxicity in colitis mice when the gut microbiota was depleted by antibiotics. We suggest that RHF could be used as a novel dietary supplement strategy against Cd-exacerbated colitis.

A Multifunctional Microspheric Soil Conditioner Based on Chitosan-Grafted Poly(acrylamide-co-acrylic acid)/Biochar

A multifunctional microspheric soil conditioner based on chitosan-grafted poly(acrylamide-co-acrylic acid)/biochar [CS-g-P(AM-co-AA)/BC] was prepared. First, the P(AM-co-AA) was synthesized and successfully grafted onto CS, and the three-dimensional network structure of microspheres was formed with N,N-methylenebis(acrylamide) as the cross-linking agent according to the inverse suspension polymerization method. Meanwhile, BC and urea were encapsulated into the body of microspheres during the polymerization. The structure of the microspheres was analyzed by Fourier transform infrared spectroscopy, polarized optical microscopy, and scanning electron microscopy, and the mechanism of adsorption of Cu²⁺ on the microspheres was investigated by X-ray photoelectron spectroscopy. Furthermore, the experimental results demonstrated the excellent water absorption and retention capabilities of microspheres, and the release rate of urea was dramatically reduced. Importantly, the introduction of BC significantly enhanced the adsorption performance of the microspheres with respect to heavy metal ions. Consequently, the multifunctional soil conditioner held promise for use in soil improvement and agricultural production.

Metabolomics analysis of the effects of quercetin on Cd-induced hepatotoxicityin rats

Cadmium(Cd) is known to cause damage to the liver. In this study, metabolomics technology was used to investigate the effect of quercetin(QE) on Cd-induced hepatotoxicity. A total of 60 male SD rats were randomly divided into the following 6 groups: control group (C), low and high dose QE group (Q1: 10 mg/kg·bw, Q2: 50 mg/kg·bw), Cd group (D), low and high dose QE and Cd combined intervention group (DQ1, DQ2). The rats were given Cd chloride (CdCl₂) at a concentration of 40 mg/L through free drinking water. After 12 weeks of treatment, liver samples of rats were collected for metabonomic analysis. A total of 12 metabolites were identified, the intensities of PC(18:0/14:1(9Z)) and Arachidonate acid were decreased in the Cd-treated group (p < 0.01), whereas the intensities of Chenodeoxyglycocholic acid, Cholic acid, Taurochenodesoxycholic acid, Glycocholic acid, Prostaglandin D2, 15-Deoxy-d-12,14-PGJ2, Oxidized glutathione, Cholesterol, Protoporphyrin IX, Bilirubinwere increased significantly in the Cd-treated group compared with group C(p < 0.01). When rats were given high doses of QE and Cd at the same time, the intensity of the above metabolites was significantly restored in group DQ2. Results suggest that The protective effect of QE on Cd-induced liver injury is associated with antioxidant activity of QE, as well as QE can regulates hepatic bile acid metabolism by affecting FXR and BSEP, and regulates AA metabolism by inhibiting Cd-induced activities of COX-2 and PLA2.

Engineered Bacteria EcN-MT Alleviate Liver Injury in Cadmium-Exposed Mice via its Probiotics Characteristics and Expressing of Metallothionein

Cadmium (Cd) exposure is a widespread problem in many parts of the world, but effective means to treat Cd exposure is still lacking. Hence, an engineered strain expressing metallothionein (MT) named Escherichia coli Nissle 1917 (EcN)-MT was constructed, and its potential in the treatment of Cd exposure was evaluated. The in vitro studies showed that metallothionein expressed by EcN-MT could significantly bind Cd. Further, the in vivo results indicated that EcN-MT strain could reduce 26.3% Cd in the liver and increase 24.7% Cd in the feces, which greatly decreased malondialdehyde (MDA) levels and increased catalase (CAT), glutathione (GSH), and superoxide dismutase (SOD) levels in liver, and reduced the expression of toll-like receptor4 (TLR4), nuclear factor-κB (NF-κB), the myeloid differentiation factor 88 (Myd88) andincreased B-cell lymphoma 2 (Bcl-2)/Bcl-2-Associated X (Bax). Moreover, high throughput sequencing results indicated that EcN-MT strain greatly enhanced the beneficial bacteria of Ruminococcaceae, Lactobacillaceae, Akkermansia, Muribaculaceae, Lachnospiraceae, Dubosiella and restored the disturbed microbial ecology to the normal level. Therefore, the high Cd binding capacity of the expressed metallothionein, together with the beneficial characteristics of the host bacteria EcN, makes EcN-MT a sound reagent for the treatment of subchronic Cd exposure-induced liver injury.

The influence of preferred habitat and daily range of the European hare on its contamination by heavy metals: a case study from the West Carpathians

The Spišská Magura mountain range, located in the Middle Spiš, is one of the regions in Slovakia most contaminated by heavy metals resulting from mining and smelting activities. Heavy metals and other potentially toxic elements have accumulated in mountain areas via atmospheric transport. The influence of the daily range size of the European hare on its contamination by heavy metals was investigated in three habitat types (forest, woodland edge, meadow) in the Spišská Magura mountain range in the West Carpathians. Individual hares (n = 21) were traced and located by GPS following snowfall. Pair samples of their faeces (n = 64) and food (n = 64) were collected from feeding sites. The maps created were used for determination of the size of the daily range as being small or large. All hares that have a small daily range avoid meadows and open spaces due to the higher predation risk. However, individuals with a large daily range feed in all habitats, including meadows. Hares with a small daily range in a forest habitat ingested higher amounts of bio-elements Ca, Cr, S, and Mn as well as higher amounts of heavy metals Ba and Pb than hares with a large daily range. Moreover, dominant hares with a small daily range, with access to abundant food sources in a forest habitat, may gradually take on higher levels of bio-elements including heavy metals that are present in their food source. In contrast, in the woodland edge, hares with a small daily range had a smaller concentration of Ca, Cr, Mn, S, Ba, and Pb compared to hares with a large daily range. Caecotrophy plays a very significant role as far as the intake of nutrients and other elements is concerned. We found significant dependence between concentrations of the elements Cr, S, Ba, Pb, and Cd in the food of European hares and in their faeces.

Reducing the reproductive toxicity activity of Lactiplantibacillus plantarum: a review of mechanisms and prospects

Food pollution can cause a variety of negative effects on human health, especially reproductive toxicity. Common food contaminants include biological contaminants, chemical contaminants, and physical contaminants, among which endocrine disruptors, pesticides, and heavy metals have the greatest reproductive toxicity in chemical contaminants. Humans mainly solve food pollution through three aspects: decreasing the pollution of food raw materials, lowering the pollution in food processing, and reducing the harm to the human body after food pollutants enter the human body. With more and more research on probiotics, not only beneficial effects, but also the ability to reduce the toxicity of food contaminants is found. Thus, microbial treatment has been proved to be a more effective way to deal with food pollution. Recent research shows that several strains of Lactiplantibacillus plantarum can adsorb or degrade some chemical pollutants and relieve inflammation and oxidative stress caused by them. This review summarized the research to explore the possible role of Lactiplantibacillus plantarum in protecting human reproductive ability and maintaining food safety.

A review on Cadmium Exposure in the Population and Intervention Strategies Against Cadmium Toxicity

The rapid industrial development has led to serious cadmium (Cd) pollution. Cd is a toxic heavy metal placing severe health threat to human. Cd can enter the body through the atmosphere, water, soil and food, and has a long half-life (10-30 years), it largely accumulates in kidneys, liver, bone and other organs and causes irreversible damage to the target organs. Cd pollution has also further caused certain carcinogenic and non-carcinogenic health risk. This study summarizes the current situation of Cd pollution, the toxicity of specific target organs, carcinogenic risk and non-carcinogenic risk in the general population, as well as dietary supplements to prevent and mitigate Cd toxication, which aims to focus on the adverse effects of Cd to human from both individual and population perspectives, hoping that not only the health risk of Cd poisoning can be reduced, but also the accurate prevention and control of Cd poisoning can be achieved in the future.

Relief of Cadmium-Induced Intestinal Motility Disorder in Mice by Lactobacillus plantarum CCFM8610

Cadmium (Cd) is a toxic metal inducing a range of adverse effects on organs including liver and kidneys. However, the underlying molecular mechanisms of Cd-induced intestinal toxicity through dietary intake is poorly studied. This study evaluated the toxic effects of Cd on intestinal physiology and confirmed the effectiveness of the protective mechanism of the probiotic Lactobacillus plantarum CCFM8610 against chronic Cd toxicity. After treatment with Cd, the HT-29 cell line was subjected to iTRAQ analysis, which revealed that changes in the proteomic profiles after Cd exposure were related to pathways involved in the stress response and carbohydrate metabolism. The results of an animal trial also indicated that 10 weeks of Cd exposure decreased the fecal water content and contractile response of colonic muscle strips in mice, and delayed the excretion time of the first black feces. L. plantarum CCFM8610 treatment provided protective effects against these Cd-induced intestinal motility dysfunctions by recovering the levels of neurotransmitters, including substance P, acetyl cholinesterase, vasoactive intestinal peptide, 5-hydroxytryptamine, calcitonin gene-related peptide, and nitric oxide, and suppressing the cellular stress response in mice (e.g., the inhibition of mitogen-activated protein kinase pathways). The administration of this probiotic was also observed to reduce Cd levels in the tissues and blood of the mice. Our results suggest a newly identified protective mechanism of probiotics against Cd toxicity that involves the recovery of intestinal motility and increase in fecal cadmium excretion.

Lead exposure results in defective behavior as well as alteration of gut microbiota composition in flies and their offsprings

BACKGROUND

Lead (Pb) has become one of the most dangerous metals to human health, especially to the nervous system as its persistent accumulation and high toxicity. However, how the gut microbiota influence the Pb-related neurotoxicity remains unclear. The aim of our study was to explore the link among Pb exposure, behavior changes, and gut microbiota.

METHODS

Using Drosophila melanogaster as model, climbing assay, social avoidance, social space, and short-term memory analysis were preformed to study the behavioral changes in flies exposed to Pb and their offspring. 16S rRNA sequencing was used to explore the changes in the gut microbiota of the flies with/without Pb-exposure.

RESULTS

The crawling ability, memory, and social interactions of Pb-exposed parent flies decreased significantly. For the offspring, behaviors were more significantly affected in male offspring whose male parent was exposed to Pb. The alpha diversity and the beta diversity of gut microbiota were significantly different between the Pb-exposed flies and the controls, as well as between the male offspring and the controls. Two genera, Lactobacillus and Bifidobacterium were found significantly decreased in the Pb-exposed flies when compared to the controls and significantly correlated with the learning and memory. Four genera, Bilophila, Coprococcus, Desulfovibrio, and Ruminococcus were found depleted in the female offspring of the Pb-exposed flies.

CONCLUSIONS

Lead exposure resulted in defective behavior and alteration of gut microbiota composition in flies and their offspring, alteration in gut microbiota might be the link between behavioral changes induced by Pb-exposure.

Lactobacillus plantarum LP33 attenuates Pb-induced hepatic injury in rats by reducing oxidative stress and inflammation and promoting Pb excretion

Lead (Pb) is one of the most common heavy metals and is harmful to human health. The liver is considered as a major target organ for Pb poisoning. Although probiotics have been shown to alleviate liver injury, the protective effect of Lactobacillus plantarum LP33 (LP33) against Pb-induced hepatotoxicity remains unclear. In order to explore the hepatoprotective effect of LP33, LP33 was administered to Pb-intoxicated Sprague-Dawley rats once daily by oral gavage for 8 weeks. The present results showed that LP33 supplementation alleviated liver injury, and inhibited oxidative stress and inflammation in Pb-exposed rats. Treatment with LP33 also promoted the phosphorylation of adenosine monophosphate-activated protein kinase and protein kinase B, activated nuclear factor erythroid 2-related factor 2 signaling and inhibited the activation of nuclear factor-κB signaling in liver tissues of rats exposed to Pb. Additionally, LP33 exhibited adequate Pb-binding capacity and satisfactory survival under simulated gastrointestinal conditions in vitro, and promoted Pb excretion via enterohepatic circulation of bile acids. This study demonstrated that LP33 reduced Pb-induced oxidative stress and inflammation and promoted Pb excretion, thereby attenuating the Pb-induced hepatic injury. Our findings suggest that LP33 supplementation may be a potential strategy for the treatment of Pb-induced hepatic toxicity.

Recombinant invasive Lactobacillus plantarum expressing the Eimeria tenella fusion gene TA4 and AMA1 induces protection against coccidiosis in chickens

Coccidiosis is an intestinal parasitic disease that is caused by Eimeria tenella and other species, and it seriously restricts the economic development of the broiler breeding industry. In this study, a recombinant Lactobacillus plantarum with an invasive effect was constructed, and it expressed the TA4-AMA1 protein of E. tenella. After oral immunization with recombinant L. plantarum, specific humoral and mucosal immune levels were measured by indirect ELISA, and the differentiation of T cells was analysed by flow cytometry. After challenge with sporulated oocysts, the body weight, oocyst shedding and cecum lesions of the chicken were evaluated. The results indicated that chickens immunized with recombinant invasive L. plantarum produced higher levels of specific antibodies in the serum than did the non-immunized controls, and the secretory IgA (sIgA) levels were increased in the intestinal washes compared to those of the controls (P < 0.05). Flow cytometry showed that recombinant invasive L. plantarum significantly stimulated T cell differentiation compared to the PBS group (P < 0.01, P < 0.001), and a higher proportion of CD4⁺ and CD8⁺ T cells were detected in peripheral blood. Moreover, the lesion scores and histopathological caecum sections showed that immunizing chickens with recombinant invasive L. plantarum can significantly relieve pathological damage in the cecum (P < 0.01), and the relative body weight gain was 89.64 %, which was higher than the 79.83 % gain in the chickens immunized with non-invasive L. plantarum. After the challenge, faeces from ten chickens in each group were collected between 4 and 7 days, and the oocysts per gram (OPG) was determined by the McMaster technique. The data indicated that oocysts in the faeces of chickens immunized with the recombinant invasive L. plantarum were significantly lower than those of the controls (P < 0.01). The results suggest that recombinant invasive L. plantarum effectively activated immune responses against E. tenella infection and can be used as a candidate vaccine against E. tenella infection.