Search Results (66)

Cylindrospermopsin (CYN) is a potent cyanotoxin that poses a significant risk to human and animal health. Due to its occurrence in drinking water and food, as well as its ability to bioaccumulate in aquatic organisms and plants irrigated with contaminated water, the oral route is an important exposure pathway. However, data gaps in the current toxicological data for CYN jeopardize the establishment of health guidance values. In this context, mechanistic data and a deeper knowledge of CYN’s mode of action and its adverse outcome pathways are priorities for risk assessment. In recent years, omics techniques have enabled important advances in the comprehensive characterization of the molecular toxicity of CYN. In vitro studies have mainly focused on liver and kidney models, while in vivo studies have mostly used aquatic organisms. These studies have shown effects at both the transcriptional and protein levels on various signaling pathways related to detoxification, DNA damage, apoptosis, cell survival, and lipid metabolism, among others. However, studies using lipidomic, metabolomic, or microbiomic techniques are limited to date. Nevertheless, a recent study suggests that CYN may also induce gut dysbiosis, which would further extend its toxicological profile. This review emphasizes the need to further expand the use of omics approaches to accurately assess the risks associated with the consumption of CYN-contaminated foods. Full article

Drinking water pipe biofilms, comprising viable microorganisms, microbial residues, and organic/inorganic particulates, pose significant risks to water safety by promoting the proliferation of opportunistic pathogens, pipe corrosion, and degradation of water quality. Their formation is strongly influenced by environmental conditions within the piping system. However, there is a lack of systematic research investigating the potential correlations between biofilm microbiota and the oral microbiomes of intensively farmed swine, as well as the age-dependent regulatory mechanisms shaping aquatic microbial communities. This pioneering study conducted a comparative analysis of biofilm microbiota from swine house water pipes and oral microbiomes across three growth stages (30-day BBF, 70-day NBF, and 110-day FBF groups), yielding three key findings. First, the biofilm biomass and dominant bacterial genera (e.g., Brevibacterium in BBF vs. Brevundimonas in FBF) exhibited stage-specific variations associated with swine age. Second, while the oral microbiomes showed no significant taxonomic divergence at the phylum or genus level, they shared characteristic phyla, including Actinobacteria and Bacteroidetes, with pipe biofilms, indicating potential cross-habitat microbial interactions. Third, the antibiotic resistance gene (ARG) adeF was consistently detected at high prevalence across all biofilm groups. These findings offer new insights into microbial transmission dynamics and inform risk mitigation strategies for livestock water supply systems. Full article

Monitoring freshwater resources is crucial to drinking water quality. The Ismailia Canal supplies most freshwater to the Suez Canal area in Egypt. However, information on the freshwater microbiome is limited in this region. A total of 59 freshwater samples were collected. Along with determining the physicochemical properties of the samples, we used conventional methods to identify indicator bacteria. To overcome limitations of conventional culture, we employed high-throughput 16S rRNA gene sequencing, taxonomy profiling, and functional prediction to study uncultivated microbial communities. Total and fecal coliforms prevailed in 100% and 80% of samples, respectively. Predominant contaminants included E. coli, fecal streptococci, Pseudomonas aeruginosa, and Staphylococcus aureus. Taxonomic profiling revealed dominance of Proteobacteria and Actinobacteriota. Proteobacteria showed a positive correlation with Bacteroidetes and a negative correlation with Actinobacteria. Most samples had similar bacterial community structures, despite location-driven variability. Elevated bacterial loads were notable at the Qassasin district, which exhibited the highest relative abundance of genes associated with bacterial infections. This study provides key insights into the impact of freshwater microbiome on public health. Full article

Background/Objective: Probiotic and vitamin D supplements are widely studied in clinical and animal studies as potential treatments for inflammatory bowel disease. However, their potential synergistic or additive effect in ameliorating colitis development is still poorly understood. The aim of this study was to investigate the potential beneficial enhancement of combining a mixed-strain probiotic with vitamin D supplementation in a colitis animal model. Method: After 5 days of acclimation, C57BL/6 mice received Vivomixx probiotic (at least 1 × 10⁹ Colony-Forming Units) and/or vitamin D (5 IU/g) in drinking water and chow, respectively, for 7 days prior to intracolonic TNBS-induced colitis and until sacrifice. On day 10, animals were sacrificed, and colons were collected to assess colonic damage, cytokine and chemokine expression, total M1 macrophage phenotype, and neutrophil recruitment. Serum and fecal samples were collected to assess vitamin D levels and microbiome composition. Results: Administration of probiotic and vitamin D alone or combined decreased colonic damage and neutrophil recruitment and activity. This effect was associated with an increase in the active form of vitamin D in serum and mucosal barrier integrity. However, administration of probiotics and/or vitamin D did not modulate macrophage infiltration or the M1 pro-inflammatory phenotype. Conclusions: These results suggest that combined probiotic and vitamin D supplementation attenuates TNBS-induced colitis by targeting neutrophil infiltration while enhancing the mucosal barrier. This alternative approach may offer protective potential for IBD management. Full article

Ultrafiltration strips water of bacteria. The common misconception is that the filtrate is thus free of bacteria. This only applies, however, in the case that the filtrate compartment is sterile. In real-world applications, the filtrate is rapidly re-colonized, followed by regrowth. In extreme cases of low water usage, the cell numbers in the filtrate can even exceed those in the feed water, probably due to a combination of the microbial enrichment of the bulk water from surfaces, regrowth in the water body itself, and nutrient enrichment on the filter membrane. Regrowth is made possible because dissolved nutrients can freely pass through the membranes. This explains why the initial decrease in cell numbers in drinking water installation systems with ultrafiltration is often followed by an increase in the periphery of the plumbing system. The extent of actual regrowth hereby depends mostly on water usage behaviours. A shorter frequency of membrane wash cycles is beneficial for reducing cell numbers. Neither frequent wash cycles nor cleaning in place (CIP) in filtration units, however, seem to modulate the maximal regrowth potential. Although the effect of ultrafiltration on cell numbers is not sustainable, it causes profound changes in the bacterial communities, with highly distinct populations in the feed water and the filtrate. The microbiological “reset” is demonstrated using examples both from the fields of drinking water and water reuse. Overall, our results suggest that ultrafiltration has a profound impact on the microbiome, but the cell numbers in filtrates depend mostly on the water usage and operational conditions. Full article

Groundwater, a critical source of drinking water, plays an essential role in global biogeochemical cycles, yet its microbial ecosystems remain insufficiently characterized, particularly in pristine karst aquifers. This study conducted high-resolution profiling of microbial communities and environmental parameters in two representative alpine karst aquifers in Slovenia: Idrijska Bela and Krajcarca. Monthly groundwater samples from the Krajcarca spring and Idrijska Bela borehole over a 14-month period were analyzed using whole-metagenome sequencing (WMS), UV-Vis spectroscopy, inductively coupled plasma mass spectrometry (ICP-MS), and isotopic analysis. The results revealed stable hydrochemical conditions with clear spatial differences driven by bedrock composition and groundwater residence time. Bacterial communities displayed strong correlations with hydrochemical parameters, while archaeal communities exhibited temporal stability. Functional gene profiles mirrored bacterial patterns, emphasizing the influence of environmental gradients on metabolic potential. No significant temporal changes were detected across two sampling campaigns (2016–2023), highlighting the resilience of these aquifers. This work establishes a valuable baseline for understanding pristine groundwater microbiomes and informs future monitoring and water quality management strategies. Full article

Ultrafine bubbles (UFBs) represent an emerging technology with unique physicochemical properties. This study investigated the effects of air-filled UFBs infused in drinking water on gut microbiota composition and the associated health markers in Sprague Dawley rats over a 12-week period. Using a two-phase design, UFB concentration was increased from 1.7 × 10⁶ to 6.5 × 10⁹ UFBs/mL at week 7 to assess dose-dependent effects. Administration of UFBs in drinking water induced significant shifts in gut microbiome populations, characterized by increased Bacteroidetes (+122% weeks 8–12) and decreased Firmicutes (−43% weeks 8–12) compared to controls. These microbial shifts coincided with enhanced short-chain fatty acid production (butyrate +56.0%, p ≤ 0.001; valerate +63.1%, p ≤ 0.01) and reduced inflammatory markers (TNF-α −84.0%, p ≤ 0.05; IL-1β −41.0%, p ≤ 0.05; IL-10 −69.8%, p ≤ 0.05). UFB effects demonstrated systematic concentration-dependent threshold responses, with 85.7% of parameters exhibiting directional reversals between low (1.7 × 10⁶ UFBs/mL) and high (6.5 × 10⁹ UFBs/mL) concentration phases rather than linear dose–response relationships. The systematic nature of these threshold effects, with 71.4% of parameters achieving statistical significance (p ≤ 0.05), indicates concentration-dependent biological mechanisms rather than random effects on gut biology. Despite current metagenomic techniques identifying only 25% of the total gut microbiome, the observed changes in characterized species and metabolites demonstrate UFB technology’s therapeutic potential for conditions requiring microbiome modulation, providing new insights into UFB influence on complex biological systems. Full article

Background: Early neurovascular unit (NVU) impairment plays a critical role in the pathogenesis of diabetic retinopathy (DR), often preceding clinically detectable changes. Butyrate, a short-chain fatty acid (SCFA) derived from gut microbiota, has shown promising metabolic and anti-inflammatory effects. Methods: This study investigated the protective potential of oral butyrate supplementation in a mouse model of early type 2 diabetes mellitus (T2DM) induced by a high-fat diet and streptozotocin. Mice (C57BL/6J) received sodium butyrate (5 g/L in drinking water) for 12 weeks. Retinal NVU integrity was assessed using widefield swept-source optical coherence tomography angiography (WF SS-OCTA), alongside evaluations of systemic glucose and lipid metabolism, hepatic steatosis, visual function, and gut microbiota composition via 16S rRNA sequencing. Results: Butyrate supplementation significantly reduced body weight, fasting glucose, serum cholesterol, and hepatic lipid accumulation. Microbiome analysis demonstrated a partial reversal of gut dysbiosis, characterized by increased SCFA-producing taxa (Ruminococcaceae, Oscillibacter, Lachnospiraceae) and decreased pro-inflammatory, lipid-metabolism-related genera (Rikenella, Ileibacterium). KEGG pathway analysis further revealed enrichment in microbial lipid metabolism functions (fabG, ABC.CD.A, and transketolase). Retinal vascular and neurodegenerative alterations—including reduced vessel density and retinal thinning—were markedly attenuated by butyrate, as revealed by WF SS-OCTA. OKN testing indicated partial improvement in visual function, despite unchanged ERG amplitudes. Conclusions: Butyrate supplementation mitigates early NVU damage in the diabetic retina by improving glucose and lipid metabolism and partially restoring gut microbial balance. This study also underscores the utility of WF SS-OCTA as a powerful noninvasive tool for detecting early neurovascular changes in DR. Full article

Background and Aims: Non-alcoholic beers (NABs) are gaining popularity as alternatives to alcoholic beverages, yet their metabolic and health effects compared to no consumption of these drinks remain unclear. Material and Methods: The investigator-blinded, single-center, randomized study compares the effects on the metabolism, health, and gut microbiome of the daily consumption of different NABs—pilsener, mixed beer, and wheat beer—on glucose and fat metabolism, body composition, and liver function in 44 healthy young men. The participants consumed 660 mL of one of these beers or water daily for 4 weeks. We measured indicators of glucose and lipid metabolism, liver enzymes, body composition, and the composition of the gut microbiota. Results: The findings revealed that mixed beer increased fasting glucose and triglycerides, and wheat beer increased insulin, C-peptide, and triglycerides. The intake of pilsener and water decreased cholesterol and LDL levels without significantly affecting glucose metabolism. Biomarkers of liver damage such as M30 lowered in water and pilsener, while ALT and AST lowered in mixed beer. The pattern of the gut microbiota also changed, as pilsener lowered Firmicutes and increased Actinobacteria. Conclusions: In summary, consumption of NABs, especially mixed and wheat beers, exerts an unfavorable metabolic impact on glucose and fat, while pilsener and water are more favorable from a metabolic perspective. We concluded that the metabolic alterations seen are probably due to the caloric and sugar content in NABs, rather than polyphenols. The chronic effects of NABs on health should be evaluated in future studies. Full article

This study was undertaken to determine the effect of bird age and administering either Lactococcus lactis ssp. lactis 1 (LL) or Limosilactobacillus fermentum 1 (LF) in the drinking water on the prevalence of antimicrobial resistance by phenotypic test, multilocus sequence typing (MLST) and virulence genes of Escherichia coli (E. coli) isolated from broiler caeca by whole-genome sequencing (WGS) analysis. Male (Ross 308) day-old chicks (240) were reared for 28 days. Water was provided either untreated (CON) or with LL (10⁷/mL) or LF (10⁷/mL) via a nipple drinker on three days each week during the starter phase (days 1, 3, 5, 7, 9 and 11 d) in eight replicate pens per treatment, with initially ten chicks per pen. One chick from each pen was sacrificed when LL or LF was added to the water, and again on d 14 and 28. There was no evidence that LL and LF had any effect on the prevalence of antimicrobial resistance and virulence genes in E. coli isolates. The population density of Lactobacillus sp. and coliforms decreased with age (p < 0.001). The high resistance of E. coli to ampicillin and tetracycline was maintained throughout the life of the broilers. The prevalence of virulence genes was greatest during the starter phase but declined when birds were 28 days of age (p < 0.05). In birds < 14 d of age, E. coli MLST 457, 1640, 1485 and 155 were dominant, and these carried iucD, irp2, astA, iutA and iroN genes. When birds were 28 d of age, MLST 1286, 1112 and 973 predominated, and these carried few virulence genes. This suggests that young birds were more susceptible to putative pathogenic E. coli than older birds. Supporting the development of a healthy microbiome that might control the proliferation of potentially pathogenic E. coli is an area of future research. Full article

Background/Objectives: Esomeprazole, a proton pump inhibitor (PPI), is commonly prescribed for gastric-acid-related disorders but has been associated with impaired gastrointestinal (GI) motility with long-term use. However, the effect of concurrent antibiotic administration on this dysfunction remains unclear. Therefore, this study aimed to investigate the effects of antibiotics on esomeprazole-induced GI motility dysfunction and explore the underlying mechanisms in a mouse model. Methods: Male C57BL/6 mice were orally administered esomeprazole (160 mg/kg) five times per week for 4 weeks. Three days before initiating esomeprazole treatment, a broad-spectrum antibiotic cocktail (ABX) consisting of ampicillin (1 g/kg), neomycin (1 g/kg), metronidazole (1 g/kg), and vancomycin (0.5 g/kg) was provided in drinking water and maintained throughout the experimental period. Mosapride (3 mg/kg), a prokinetic agent, was used as a positive control. Results: Neither esomeprazole alone nor in combination with ABX affected body weight or food intake. Compared to normal controls, esomeprazole treatment significantly delayed both intestinal transit and gastric emptying. However, ABX co-administration further pronounced intestinal transit time and improved gastric motility. The potential mechanisms may involve interactions among gastric H⁺/K⁺-ATPase, CYP3A11, gastrointestinal hormones (secretin and motilin), and the gut microbiome. Conclusions: Long-term esomeprazole use can impair both gastric and intestinal motility, and ABX co-treatment further exacerbates intestinal transit delay while paradoxically enhancing gastric emptying. These findings highlight the critical role of the gut microbiota in esomeprazole-induced GI motility dysfunction and suggest that antibiotic use should be approached with caution, particularly when combined with PPI therapy. Full article

Childhood and adolescent obesity and its associated morbidities are increasing in part due to the ingestion of diets high in fat (HFD). Changes in the gastrointestinal microbiome have been associated with these morbidities, including insulin resistance, cardiovascular disease, and inflammatory states. The use of dietary probiotics may mitigate these microbiome-associated morbidities and improve health during maturation. Using our established model of obesity in rats consuming an HFD from weaning, we examined the gut microbiome with a single-strain probiotic in the drinking water [Lactiplantibacillus plantarum 299v (Lp299v, LP299V^®)] of adolescent and adult rats. Our main finding was a differential effect of HFD and probiotic on the gut microbiome that was associated with maturation (adolescence vs. adulthood). Specifically, probiotic treatment of adolescent rats on an HFD led to alterations in the enrichment of the gut microbiome, which were associated with the morbidities of obesity, while adult rats under the same conditions exhibited minimal changes, demonstrating differences in plasticity associated with maturation. Of particular relevance in this regard is the fact that Oscillospiraceae and Lachnospiraceae, associated with beneficial short-chain fatty acid production, were enriched in adolescent rats on an HFD and treated with Lp299v. Our data suggest that the use of probiotics in childhood and adolescence may improve health in adulthood by potentially affecting the developing gastrointestinal microbiome. Full article

Inflammatory bowel disease is a risk factor for brain dysfunction; however, the underlying mechanisms remain largely unknown. In this study, we aimed to explore the potential molecular mechanisms through which intestinal inflammation affects brain function and to verify these mechanisms. Mice were treated with multiple cycles of 1% w/v dextran sulfate sodium (DSS) in drinking water to establish a chronic colitis model. Behavioral tests were conducted using the open field test (OFT), tail suspension test (TST), forced swimming test (FST), and Morris water maze test (MWM). Brain metabolomics, transcriptomics, and proteomics analyses were performed, and key target proteins were verified using qPCR and immunofluorescence. Four cycles of DSS administration induced colitis, anxiety, depression, and spatial memory impairment. The integrated multi-omics characterization of colitis revealed decreased brain chenodeoxycholic acid (CDCA) levels as well as reduced stearoyl-CoA desaturase (Scd1) gene and protein expression. Transplantation of the colitis microbiome resulted in anxiety, depression, impaired spatial memory, reduced CDCA content, decreased Scd1 gene and protein expression, and lower concentrations of monounsaturated fatty acids (MUFAs), palmitoleate (C16:1), and oleate (C18:1) in the brain. In addition, CDCA supplementation improved DSS-induced colitis, alleviated depression and spatial memory impairment, and increased Scd1 gene and protein expression as well as MUFA levels in the brain. The gut microbiome induced by colitis contributes to neurological dysfunction, possibly through the CDCA–Scd1 signaling axis. CDCA supplementation alleviates colitis and depressive behavior, likely by increasing Scd1 expression in the brain. Full article

Background/Objectives: The role of the gut microbiome in the development and progression of many diseases has received increased attention in recent years. Boron, a trace mineral found in dietary sources, has attracted interest due to its unique electron depletion and coordination characteristics in chemistry, as well as its potential role in modulating the gut microbiota. This study investigates the effects of inorganic boron derivatives on the gut microbiota of mice. Methods: For three weeks, boric acid (BA), sodium pentaborate pentahydrate (NaB), and sodium perborate tetrahydrate (SPT) were dissolved (200 mg/kg each) in drinking water and administered to wild-type BALB/c mice. The composition of the gut microbiota was analyzed to determine the impact of these treatments. Results: The administration of BA significantly altered the composition of the gut microbiota, resulting in a rise in advantageous species such as Barnesiella and Alistipes. Additionally, there was a decrease in some taxa associated with inflammation and illness, such as Clostridium XIVb and Bilophila. Notable increases in genera like Treponema and Catellicoccus were observed, suggesting the potential of boron compounds to enrich microbial communities with unique metabolic functions. Conclusions: These findings indicate that boron compounds may have the potential to influence gut microbiota composition positively, offering potential prebiotic effects. Further research with additional analyses is necessary to fully understand the interaction between boron and microbiota and to explore the possibility of their use as prebiotic agents in clinical settings. Full article

A maternal diet rich in dietary fiber, such as β-glucan, plays a crucial role in the offspring’s acquisition of gut microbiota and the subsequent shaping of its microbiome profile and metabolome. This in turn has been shown to aid in neurodevelopmental processes, including early microglial maturation and immunomodulation via metabolites like short chain fatty acids (SCFAs). This study aimed to investigate the effects of oat β-glucan supplementation, solubilized by citric acid hydrolysis, from gestation to adulthood. Female C57BL/6J mice were orally supplemented with soluble oat β-glucan (ObG) or carboxymethyl cellulose (CMC) via drinking water at 200 mg/kg body weight during breeding while the control group received 50 mg/kg body weight of carboxymethyl cellulose. ObG supplementation increased butyrate production in the guts of both dams and 4-week-old pups, attributing to alterations in the gut microbiota profile. One-week-old pups from the ObG group showed increased neurodevelopmental markers similar to four-week-old pups that also exhibited alterations in serum markers of metabolism and anti-inflammatory cytokines. Notably, at 8 weeks, ObG-supplemented pups exhibited the highest levels of spatial memory and cognition compared to the control and CMC groups. These findings suggest a potential enhancement of neonatal neurodevelopment via shaping of early-life gut microbiome profile, and the subsequent increased later-life cognitive function. Full article