Health Of Organisms Research Articles

Blocked conversion of Lactobacillus johnsonii derived acetate to butyrate mediates copper-induced epithelial barrier damage in a pig model

BackgroundHigh-copper diets have been widely used to promote growth performance of pigs, but excess copper supplementation can also produce negative effects on ecosystem stability and organism health. High-copper supplementation can damage the intestinal barrier and disturb the gut microbiome community. However, the specific relationship between high-copper-induced intestinal damage and gut microbiota or its metabolites is unclear.ObjectiveUsing fecal microbiota transplantation and metagenomic sequencing, responses of colonic microbiota to a high-copper diet was profiled. In addition, via comparison of specific bacteria and its metabolites rescue, we investigated a network of bacteria-metabolite interactions involving conversion of specific metabolites as a key mechanism linked to copper-induced damage of the colon.ResultsHigh copper induced colonic damage, Lactobacillus extinction, and reduction of SCFA (acetate and butyrate) concentrations in pigs. LefSe analysis and q-PCR results confirmed the extinction of L. johnsonii. In addition, transplanting copper-rich fecal microbiota to ABX mice reproduced the gut characteristics of the pig donors. Then, L. johnsonii rescue could restore decreased SCFAs (mainly acetate and butyrate) and colonic barrier damage including thinner mucus layer, reduced colon length, and tight junction protein dysfunction. Given that acetate and butyrate concentrations exhibited a positive correlation with L. johnsonii abundance, we investigated how L. johnsonii exerted its effects by supplementing acetate and butyrate. L. johnsonii and butyrate administration but not acetate could correct the damaged colonic barrier. Acetate administration had no effects on butyrate concentration, indicating blocked conversion from acetate to butyrate. Furthermore, L. johnsonii rescue enriched a series of genera with butyrate-producing ability, mainly Lachnospiraceae NK4A136 group.ConclusionsFor the first time, we reveal the microbiota-mediated mechanism of high-copper-induced colonic damage in piglets. A high-copper diet can induce extinction of L. johnsonii which leads to colonic barrier damage and loss of SCFA production. Re-establishment of L. johnsonii normalizes the SCFA-producing pathway and restores colonic barrier function. Mechanistically, Lachnospiraceae NK4A136 group mediated conversion of acetate produced by L. johnsonii to butyrate is indispensable in the protection of colonic barrier function. Collectively, these findings provide a feasible mitigation strategy for gut damage caused by high-copper diets.8Cvt-o5Fp31WwWrGJzuYJnVideo

Selenium alleviates lead-induced CIK cells pyroptosis and inflammation through IRAK1/TAK1/IKK pathway

The toxic heavy metal lead is widely found in rivers and soils as an environmental pollutant, posing a threat to the health of aquatic organisms. Selenium is an essential trace element and a powerful antioxidant that has been shown to have anti-inflammatory and antioxidant properties as well as alleviating heavy metal poisoning. Many studies have shown that lead poisoning produces inflammatory responses and damage to the kidneys of a wide range of animals, but the effects on cellular pyroptosis and immune function and selenium antagonism in CIK cells are not clear. In this study, 500 μM Pb and 20 nM Se were applied to grass carp kidney cells, and the results showed that Pb exposure to CIK cells resulted in oxidative stress, activation of the IRAK1/TAK1/IKK pathway, up-regulation of the expression of cellular pyroptosis markers GSDMD and NLRP3, and cellular pyroptosis of CIK cells, as well as up-regulation of IL-1β and IL-18, and the generation of cellular inflammatory response. In contrast, Se treatment significantly reduced the ROS level, the expression of cellular pyroptosis markers GSDMD, NLRP3 and inflammatory element IL-1β and IL-18. Taken together, Se alleviated cellular pyroptosis and immune dysfunction caused by Pb exposure through oxidative stress and activation of the IRAK1/TAK1/IKK pathway. This study complements the harmful effects of the heavy metal Pb on fish and the real-life application of selenium in the healthy culture of fish as a reference will be provided.

Adverse effects of plastic leachate and its component 2,4-DTBP on the early development of zebrafish embryos

Plastic waste has become a global environmental problem threatening the health of aquatic organisms especially via leachate. In this study, the test of zebrafish embryo showed adverse effects of leachate from some agricultural mulching films after UV light aging for 60 h. A typical phenolic antioxidant 2,4-di-tert-butylphenol (2,4-DTBP) was detected in the leachate and tested further for the zebrafish embryo biotoxicity. The microplastic leachate (6, 8 g/L, mass concentration measured by weight of plastic) increased the death and malformation rates, and reduced the hatching rate, heart rate, and body length of zebrafish larvae in the 96-hour early development period. Similar adverse effects were also caused by the 2,4-DTBP (0.01, 0.1, 1.0 mg/L, corresponding to 0.049, 0.49, and 4.85 μM) to some degree but could not completely explain the significant influences caused by the plastic leachate. Transcriptome analysis of zebrafish embryos exposed to the 2,4-DTBP for 96 h showed that the protein, fat, and carbohydrate digestion and absorption pathways, pancreatic secretion, PPAR signaling pathway, tryptophan metabolism, and adipocytokine signaling pathway were considerably down-regulated, but the cholesterol metabolism pathway was up-regulated in larval zebrafish. The altered transcriptional expression of mRNA at early development stage (96 h post fertilization) of zebrafish suggested that the 2,4-DTBP caused reduction of digestive capacity and pancreatic secretory function, and adversely affected processes associated with energy metabolism and glycolipid metabolism of larval zebrafish. This study helps us further understanding the effects of plastic leachate on the early development of fishes.

Effects of different visible light spectrums on phototaxis and bottom preference behavior of sea cucumber

In recent years, studies have shown that different light wavelengths have varying effects on aquaculture species. This indicates that exposure to light can significantly influence the health and development of aquatic organisms. This study investigated the effects of different visible light spectra on the behavior and physiological responses of sea cucumbers. Under blue LED and white LED illumination, the sea cucumbers exhibited shelter-seeking behavior. A phototaxis experiment found that the blue LED light elicited the strongest negative phototaxis, followed by the white LED. However, the red LED light elicited no obvious response. In the bottom zone preference experiment, blue LED and white LED illumination affected the bottom preference behaviors of some individuals compared to the control group. By measuring the mean photon flux density (MPFD) values at different illumination distances, the individuals in each group tended to stop moving when they were close to a similar MPFD value. Next, this study examined the physiological effects of red LED and blue LED illumination on sea cucumbers. Interestingly, the blue LED group exhibited higher oxygen consumption rates and thinner connective tissue in the respiratory tree during the early stage of the experiment. In contrast, no significant differences in coelomocyte phagocytosis were observed between the blue LED and red LED groups. Our findings suggested that the behaviors and physiological responses elicited by the blue or white LED light are likely caused by the number of photons in a specific time and area received by photoreceptors on the integument of sea cucumbers. Furthermore, neither long- nor short-wavelength spectra caused significant stress or damage to sea cucumbers in this study. The results obtained from this data will be beneficial for lighting usage in aquaculture environments in the future.

Evaluation of quantitative biomarkers of aging in human PBMCs.

Functional decline with age contributes significantly to the burden of disease in developed countries. There is growing interest in the development of therapeutic interventions which slow or even reverse aging. Time and cost constraints prohibit the testing of a large number of interventions for health and lifespan extension in model organisms. Cell-based models of aging could enable high throughput testing of potential interventions. Despite extensive reports in the literature of cell properties that correlate with donor age, few are robustly observed across different laboratories. This casts doubt on the extent that aging signatures are captured in cultured cells. We tested molecular changes previously reported to correlate with donor age in peripheral blood mononuclear cells (PBMCs) and evaluated their suitability for inclusion in a panel of functional aging measures. The tested measures spanned several pathways implicated in aging including epigenetic changes, apoptosis, proteostasis, and intracellular communication. Surprisingly, only two markers correlated with donor age. DNA methylation age accurately predicted donor age confirming this is a robust aging biomarker. Additionally, the apoptotic marker CD95 correlated with donor age but only within subsets of PBMCs. To demonstrate cellular rejuvenation in response to a treatment will require integration of multiple read-outs of cell function. However, building a panel of measures to detect aging in cells is challenging and further research is needed to identify robust predictors of age in humans.

Ecosystem health and malfunctions: an organisational perspective

A recent idea of “ecosystem health” was introduced in the 1970s and 1980s to draws attention to the fact that ecosystems can become ill because of a reduction of properties such as primary productivity, functions and diversity of interactions among system components. Starting from the 1990s, this idea has been deeply criticized by authors who argued that, insofar as ecosystems show many differences with respect to organismic features, these two kinds of systems cannot share a typical organismic property such as health. In recent years, an organisational approach in philosophy of biology and ecology argued that both organisms and ecosystems may share a fundamental characteristic despite their differences, namely, organisational closure. Based on this kind of closure, scholars have also discussed health and malfunctional states in organisms. In this paper, we examine the possibility of expanding such an organisational approach to health and malfunctions to the ecological domain. Firstly, we will see that a malfunction is related to a lower effectiveness in the functional behaviour of some biotic components with respect to other systemic components. We will then show how some introduced species do not satisfactorily interact in an organisational closure with other ecosystem components, thus posing a threat to the self-maintenance of the ecosystem in which they are found. Accordingly, we will argue that an ecosystem can be said to be healthy when it is a vital environment organisationally grounded on its intrinsic capacity to ensure, under favourable conditions, appropriate functional behaviours for ecosystem components and ecosystem self-maintenance.

Assessing the impact of habitat and captivity status on volatilome profiles of the illegally traded shingleback, Tiliqua rugosa

Volatilomics is the study of the total biogenic volatile organic compounds (BVOCs) produced by an organism. This field has been used to assess organism and ecosystem health, as well as determine BVOC biomarkers for forensic purposes, including the detection of human remains, ignitable liquid residues and illicit drugs. For volatilomics to be applied in wildlife-victim casework (e.g. the illegal wildlife trade) a large reference database must be collected across each targeted species range. Adequate sample sizes must be collected from different habitats spanning across the species range of the targeted species to evaluate volatilome variability associated with different environmental and dietary characteristics. This will allow for assessment of chemical diversity and the determination of BVOC biomarkers that are relevant to wildlife forensic cases (e.g. detection, species identification, geographic origin assessment). This study collected the first live animal volatilome database, using the highly trafficked and widely distributed Australian shingleback lizard (Tiliqua rugosa). Optimised thermal desorption and analysis methods were used to examine 127 wild shingleback volatilome samples collected from sites across New South Wales, South Australia and Western Australia and 28 volatilome samples from captive shinglebacks. The results demonstrated that volatilome profiles and chemical diversity differed across each sampling region, potentially related to habitat and diet changes. At least 7 volatilome samples were required to capture chemical diversity in a sampling region. Forty-four tentatively identified BVOCs were shared across all sampling regions and captive animals which may aid in detection purposes. Bioregion-specific BVOCs were also identified, which will also aid in geographic assignment of confiscated individuals. This work demonstrates the importance of sample sizes in capturing chemical diversity within Bioregions prior to downstream volatilome analysis for the establishment of wildlife forensic databases and biomarker selection.

Probiotics: an innovative approach to enhancing aquaculture productivity

Probiotics refer to live beneficial microorganisms introduced into the digestive system via food or water, contributing to overall well-being by promoting a balanced internal microbial environment. These probiotic microorganisms produce a variety of substances, including bacteriocins, siderophores, lysozymes, proteases, and hydrogen peroxide, which effectively inhibit the growth of harmful pathogens. Furthermore, these beneficial bacteria generate a diverse set of enzymes, including amylase enzymes produced by Aeromonas spp., Bacillus subtilis, Bacteroidaceae, Clostridium spp., Lactobacillus plantarum, and Staphylococcus sp., as well as protease and cellulase enzymes produced by B. subtilis, L. plantarum, and Staphylococcus sp. In aquaculture, probiotics have several advantages and play a crucial role in improving fish growth rates, disease resistance, immunity, maintaining health, intestinal epithelial integrity, supporting gut microbiota, and enhancing water quality. Furthermore, the practical application of probiotics in fish diets can reduce the negative impact of antibiotics. The incorporation of these supplements into fish feeds would contribute to improving their productivity and efficient feeds utilization, thereby increasing fish production and safeguarding human health. This article provides an overview of the use of probiotic preparations in aquaculture. It presents information about the composition of the innate microflora in fish, as well as historical facts regarding the development of probiotics in aquaculture. The data analysis indicates that probiotics are effective and environmentally friendly, making them suitable for the entire aquaculture system, including primary and supplementary feeding, as well as water purification. They have a positive impact on the health of aquatic organisms and consumers. Additionally, the article discusses the appropriateness of probiotic use in aquaculture for dynamic and environmentally safe fish farming development, aiming to reduce the spread of antibiotic and chemical resistance and address disease treatment and prevention in fish farms.

Nylon microfibers develop a distinct plastisphere but have no apparent effects on the gut microbiome or gut tissue status in the blue mussel, Mytilus edulis.

Ingestion of microplastics (MP) by suspension-feeding bivalves has been well-documented. However, it is unclear whether exposure to MP could damage the stomach and digestive gland (gut) of these animals, causing ramifications for organism and ecosystem health. Here, we show no apparent effects of nylon microfiber (MF) ingestion on the gut microbiome or digestive tissues of the blue mussel, Mytilus edulis. We exposed mussels to two low concentrations (50 and 100 particles/L) of either nylon MF or Spartina spp. particles (dried, ground marsh grass), ca. 250-500 μm in length, or a no particle control laboratory treatment for 21 days. Results showed that nylon MF, when aged in coarsely filtered seawater, developed a different microbial community than Spartina spp. particles and seawater, however, even after exposure to this different community, mussel gut microbial communities resisted disturbance from nylon MF. The microbial communities of experimental mussels clustered together in ordination and were similar in taxonomic composition and measures of alpha diversity. Additionally, there was no evidence of damage to gut tissues after ingestion of nylon MF or Spartina spp. Post-ingestive particle processing likely mediated a short gut retention time of these relatively large particles, contributing to the negligible treatment effects.

Deoxynivalenol upregulates hypoxia-inducible factor-1α to promote an "immune evasion" process by activating STAT3 signaling.

Trichothecene mycotoxin deoxynivalenol (DON) negatively regulates immune response by damaging host immune system and harming the organism's health. We hypothesized that DON can initiate an active immunosuppressive mechanism similar to "immune evasion" to alter the cellular microenvironment and evade immune surveillance. We tested this hypothesis using the RAW264.7 macrophage model. DON rapidly increased the expression of immune checkpoints PD-1 and PD-L1, inflammatory cytokine TGF-β, and key immune evasion factors STAT3, VEGF, and TLR-4, and caused cellular hypoxia. Importantly, hypoxia-inducible factor-1α (HIF-1α) acts as a key regulator of DON-induced immunosuppression. HIF-1α accumulated in the cytoplasm and was gradually transferred to the nucleus following DON treatment. Moreover, DON activated HIF-1α through STAT3 signaling to upregulate downstream signaling, including PD-1/PD-L1. Under DON treatment, immunosuppressive miR-210-3p, lncRNA PVT1, lncRNA H19, and lncRNA HOTAIR were upregulated by the STAT3/HIF-1α axis. Moreover, DON damaged mitochondrial function, causing mitophagy, and suppressed immune defenses. Collectively, DON triggered RAW264.7 intracellular hypoxia and rapidly activated HIF-1α via STAT3 signaling, activating immune evasion signals, miRNAs, and lncRNAs, thereby initiating the key link of immune evasion. This study offers further clues for accurate prevention and treatment of immune diseases caused by mycotoxins.

Multiomics analysis reveals the molecular basis for increased body weight in silkworms (Bombyx mori) exposed to environmental concentrations of polystyrene micro- and nanoplastics

IntroductionMicro- and nanoplastics (MNPs) are emerging environmental pollutants that have raised serious concerns about their potential impact on ecosystem and organism health. Despite increasing efforts to investigate the impacts of micro- and nanoplastics (MNPs) on biota little is known about their potential impacts on terrestrial organisms, especially insects, at environmental concentrations. ObjectivesTo address this gap, we used an insect model, silkworm Bombyx mori to examine the potential long-term impacts of different sizes of polystyrene (PS) MNPs at environmentally realistic concentrations (0.25 to 1.0 μg/mL). MethodsAfter exposure to PS-MNPs over most of the larval lifetime (from second to last instar), the endpoints were examined by an integrated physiological (growth and survival) and multiomics approach (metabolomics, 16S rRNA, and transcriptomics). ResultsOur results indicated that dietary exposures to PS-MNPs had no lethal effect on survivorship, but interestingly, increased host body weight. Multiomics analysis revealed that PS-MNPs exposure significantly altered multiple pathways, particularly lipid metabolism, leading to enriched energy reserves. Furthermore, the exposure changed the structure and composition of the gut microbiome and increased the abundance of gut bacteria Acinetobacter and Enterococcus. Notably, the predicted functional profiles and metabolite expressions were significantly correlated with bacterial abundance. Importantly, these observed effects were particle size-dependent and were ranked as PS-S (91.92 nm) > PS-M (5.69 µm) > PS-L (9.7 µm). ConclusionOverall, PS-MNPs at environmentally realistic concentrations exerted stimulatory effects on energy metabolism that subsequently enhanced body weight in silkworms, suggesting that chronic PS-MNPs exposure might trigger weight gain in animals and humans by influencing host energy and microbiota homeostasis.

Regulation of ERK2 activity by dynamic S-acylation

Extracellular signal-regulated kinases (ERK1/2) are key effector proteins of the mitogen-activated protein kinase pathway, choreographing essential processes of cellular physiology. Here, we discover that ERK1/2 are subject to S-acylation, a reversible lipid modification of cysteine residues, at C271/C254. The levels of ERK1/2 S-acylation are modulated by epidermal growth factor (EGF) signaling, mirroring its phosphorylation dynamics, and acylation-deficient ERK2 displays altered phosphorylation patterns. We show that ERK1/2 S-acylation is mediated by "writer" protein acyl transferases (PATs) and "eraser" acyl protein thioesterases (APTs) and that chemical inhibition of either lipid addition or removal alters ERK1/2's EGF-triggered transcriptional program. Finally, in a mouse model of metabolic syndrome, we find that ERK1/2 lipidation levels correlate with alterations in ERK1/2 lipidation writer/eraser expression, solidifying a link between ERK1/2 activity, ERK1/2 lipidation, and organismal health. This study describes how lipidation regulates ERK1/2 and offers insight into the role of dynamic S-acylation in cell signaling more broadly.

Microalgae Technology in Aquaculture Applications: A Comprehensive Literature Review

Microalgae are highly valuable across various industries due to their rich nutritional content and positive environmental impact. In the fast-growing field of aquaculture aimed at meeting global food needs, integrating microalgae technology can be highly beneficial. This literature review explores the diverse roles of microalgae in enhancing aquaculture, focusing on their nutritional benefits, water quality management, larviculture, Integrated Multi-Trophic Aquaculture (IMTA) systems, and bioremediation. Microalgae are excellent natural nutrient sources, offering high protein content, omega-3 fatty acids, vitamins, minerals, and antioxidants, vital for aquatic organism growth and health. Their contributions to water quality maintenance, larval stage nutrition, and waste nutrient uptake are critical. Additionally, microalgae play a pivotal role in IMTA by acting as primary producers and minimizing environmental impact. The review emphasizes challenges like economic constraints and strain optimization, underscoring the need for further research to fully leverage microalgae's potential in aquaculture, promising advancements to revolutionize the industry and enhance global food security.

Molecular Mechanisms of Selenium Mitigating Lead Toxicity in Chickens via Mitochondrial Pathway: Selenoproteins, Oxidative Stress, HSPs, and Apoptosis.

Lead (Pb), a hazardous heavy metal, can damage the health of organisms. However, it is not clear whether Pb can damage chicken cerebellums and thalami. Selenium (Se), an essential nutrient for organisms, has a palliative effect on Pb poisoning in chickens. In our experiment, a model of chickens treated with Pb and Se alone and in combination was established to investigate the molecular mechanism of Se alleviating Pb-caused damage in both chicken cerebellums and thalami. Our morphological results indicated that Pb caused apoptotic lesions, such as mitochondrial and nuclear damage. Further, the anti-apoptotic gene Bcl-2 decreased; on the contrary, four pro-apoptotic genes (p53, Bax, Cyt c, and Caspase-3) increased under Pb treatment, meaning that Pb caused apoptosis via the p53-Cyt c-Caspase-3 pathway. Furthermore, we further demonstrated that Pb elevated four HSPs (HSP27, HSP40, HSP70, and HSP90), as well as HSP70 took part in the molecular mechanism of Pb-caused apoptosis. In addition, we found that Pb exposure led to oxidative stress via up-regulating the oxidant H2O2 and down-regulating four antioxidants (CAT, SOD, GST, and GPx). Moreover, Pb decreased three Se-containing factors (Txnrd1, Txnrd2, and Txnrd3), further confirming that Pb caused oxidative stress. Interestingly, Se supplementation reversed the above changes caused by Pb and alleviated Pb-induced oxidative stress and apoptosis. A time dependency was demonstrated for Bcl-2, Bax, and Cyt c in the cerebellums, as well as CAT, GPx, and p53 in the thalami of Pb-exposed chickens. HSP70 in cerebellums and HSP27 in thalami were more sensitive than those in thalami and cerebellums, respectively, under Pb exposure. Pb-induced apoptosis of thalami was more severe than cerebellums. In conclusion, after Pb treatment, Txnrds mediated oxidative stress, oxidative stress up-regulated HSPs, and finally, HSP70 triggered apoptosis. Se supplementation antagonized Pb-induced oxidative stress and apoptosis via the mitochondrial pathway and selenoproteins in chicken cerebellums and thalami. This study provides new information for the mechanism of environmental pollutant poisoning and the detoxification of Se on abiotic stress.

Telomeres and telomerase: active but complex players in life-history decisions.

Studies on human telomeres have established that telomeres exert a significant influence on lifespan and health of organisms. However, recent research has indicated that the original idea that telomeres affect lifespan in a universal and central manner across all eukaryotic species is an oversimplification. Indeed, findings from a variety of animal species revealed that the role of telomere biology in aging is more subtle and intricate than previously recognized. Here, we show how telomere biology varies depending on the taxon. We also show how telomere biology corresponds to basic life history traits and affects the life table of a species and investments in growth, body size, reproduction, and lifespan; telomeres are hypothesized to shape evolutionary perspectives for species in an active but complex manner. Our evaluation is based on telomere biology data from many examples from throughout the animal kingdom that vary according to the degree of organismal complexity and life history strategies.

Fast synthesis of Hcy-modified Au nanoclusters under microwave-assisted irradiation and their response to Cu (II) ions

In this work, Cu (II) ion was chosen as an analyte because it is an important trace element in the human body to maintain organism health. AuNCs (gold nanoclusters) with a mean diameter of ∼2 nm were prepared by a microwave-assisted method, using homocysteine (Hcy) as a reducer and stabilizer. The optimal sample showed a red emission peaking at 624 nm with an emission quantum yield of 17.1%, which was assigned as a ligand to metal nanoparticle core charge transfer (LMNCT). This red emission was effectively quenched by Cu (II) but immune to competing metal cations and anions, showing good selectivity. The quenching mechanism was found as the Cu (II) quenching on the LMNCT procedure to AuNCs. The primary advantage of Hcy-modified AuNCs was the easy and quick synthetic procedure, along with acceptable sensing performance, including good selectivity, linear response, and wide working region.

Synergistic influence of iodine and hydrogen peroxide towards the degradation of harmful algal bloom of Microcystis aeruginosa

Cyanobacterial blooming due to the influence of temperature and increased nutrients in ponds/lakes aided by the runoff from agricultural lands, is a serious environmental issue. The presence of cyanotoxins in water may poison the health of aquatic organisms, animals, and humans. In this study, we focus on chemical assisted degradation of Microcystis aeruginosa– an alga that is of special relevance owing to its consistent blooming, especially in tropical regions. The study aims to ascertain the individual iodine (I) and hydrogen peroxide (H2O2) and their combination (hereinafter referred to as IH) effects on the degradation of Microcystis aeruginosa. As expected, the collected pond water revealed the presence of metal ions viz., Ni, Zn, Pb, Cu and Mn, which enriched the blooming of M. aeruginosa. Interestingly, a complete rupture of the cells – pigment loss, biochemical degradation and oxidative damage–was observed by the IH solution after exposure for ∼9 h under ambient conditions. In comparison to control (original water without chemicals), the addition IH completely eliminated the pigments phycocyanin (99.5%) and allophycocyanin (98%), and degraded ∼81% and 91% of carbohydrates and proteins, respectively due to the synergistic action of I and H. Superior degradation of algae through a simple and eco-friendly approach presented in this study could be explored more effectively towards its large-scale applicability.

Glycolysis characteristics of intracellular polysaccharides from Agaricus bitorquis (Quél.) sacc. Chaidam and its effects on intestinal flora from different altitudes of mice in vitro fermentation

The glycolysis characteristics and effects on intestinal flora of polysaccharides from Agaricus bitorquis (Quél.) Sacc. Chaidam (ABIPs) in vitro fermentation by different altitudes of mice feces was examined, including low, medium, and high altitudes groups (LG, MG, and HG). In vitro, fermentation of ABIPs forty-eight hours resulted in a remarkable decrease in total sugar content and improvement of short-chain fatty acids (SCFAs) (mainly acetate, propionate, and butyrate), which simultaneously induced the composition of monose and uronic acids and SCFAs continuously change. Besides, ABIPs influenced the abundance and composition of the intestinal flora, generally increasing the abundance of probiotic bacteria (such as Bifidobacterium and Faecalibacterium) and decreasing the abundance of harmful bacteria (such as Phenylobacterium and Streptococcus) in all groups, with the highland biology core genus Blautia significantly enriched in LG and MG groups. It was also found that ABIPs enhanced pathways associated with biosynthesis and metabolism. In addition, correlation analysis speculated that the metabolism of SCFAs by ABIPs may be associated with genera such as Anaerostipes, Roseburia, and Weissella. ABIPs may protect organismal health by regulating hypoxic intestinal flora composition and metabolic function, and more superior fermentation performance was observed in MG compared to other groups.

Investigating the influence of diet diversity on infection outcomes in a bumble bee (Bombus impatiens) and microsporidian (Nosema bombi) host-pathogen system.

Diet can have an array of both direct and indirect effects on an organism's health and fitness, which can influence the outcomes of host-pathogen interactions. Land use changes, which could impact diet quantity and quality, have imposed foraging stress on important natural and agricultural pollinators. Diet related stress could exacerbate existing negative impacts of pathogen infection. Accounting for most of its nutritional intake in terms of protein and many micronutrients, pollen can influence bee health through changes in immunity, infection, and various aspects of individual and colony fitness. We investigate how adult pollen consumption, pollen type, and pollen diversity influence bumble bee Bombus impatiens survival and infection outcomes for a microsporidian pathogen Nosema (Vairimorpha) bombi. Experimental pathogen exposures of larvae occurred in microcolonies and newly emerged adult workers were given one of three predominantly monofloral, polyfloral, or no pollen diets. Workers were assessed for size, pollen consumption, infection 8-days following adult-eclosion, survival, and the presence of extracellular microsporidian spores at death. Pollen diet treatment, specifically absence of pollen, and infection independently reduced survival, but we saw no effects of pollen, pollen type, or pollen diet diversity on infection outcomes. The latter suggests infection outcomes were likely already set, prior to differential diets. Although infection outcomes were not altered by pollen diet in our study, it highlights both pathogen infection and pollen availability as important for bumble bee health, and these factors may interact at different stages of bumble bee development, at the colony level, or under different dietary regimes.

Understanding the diversity and dynamics of in vivo efferocytosis: Insights from the fly embryo.

The clearance of dead and dying cells, termed efferocytosis, is a rapid and efficient process and one that is critical for organismal health. The extraordinary speed and efficiency with which dead cells are detected and engulfed by immune cells within tissues presents a challenge to researchers who wish to unravel this fascinating process, since these fleeting moments of uptake are almost impossible to catch in vivo. In recent years, the fruit fly (Drosophila melanogaster) embryo has emerged as a powerful model to circumvent this problem. With its abundance of dying cells, specialist phagocytes and relative ease of live imaging, the humble fly embryo provides a unique opportunity to catch and study the moment of cell engulfment in real-time within a living animal. In this review, we explore the recent advances that have come from studies in the fly, and how live imaging and genetics have revealed a previously unappreciated level of diversity in the efferocytic program. A variety of efferocytic strategies across the phagocytic cell population ensure efficient and rapid clearance of corpses wherever death is encountered within the varied and complex setting of a multicellular living organism.