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Probiotic supplementation improves survival of D. melanogaster exposed to IMI. (A) CFU enumeration of the ratio of Acetobacter to Lactobacillus. Flies were surface sterilized and plated on MAN agar for Acetobacter spp. and MRS agar for Lactobacillus spp. Data are displayed as mean Acetobacter CFU divided by total bacterial (Acetobacter Lactobacillus) CFU SD (unpaired, two-tailed t tests) from 10 biological replicates (PBS vehicle), 8 biological replicates (PBS with 10 M IMI), 9 biological replicates (LGR-1 vehicle), and 10 biological replicates (LGR-1 with 10 M IMI), each consisting of 3 flies. (B) Duox gene expression displayed as mean fold change (relative to RpLP0) from 7 biological replicates with 5 pooled female flies in each group. Error bars represent mean SD (Mann-Whitney tests). (C) Whole-body H 2 O 2 displayed as mean relative % of H 2 O 2 SD (Mann-Whitney tests) compared to PBS vehicle of 15 biological replicates (PBS vehicle), 14 biological replicates (PBS with 10 M IMI), 13 biological replicates (LGR-1 vehicle), and 14 biological replicates (LGR-1 with 10 M IMI), each consisting of 3 flies. In box plot diagrams, boxes represent first and third quartile values while black lines denote medians. Whiskers encompass maximum and minimum values. *, P 0.05; **, P 0.01; ***, P 0.001; ****, P 0.0001; ns, not significant.
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Sublethal exposure to certain pesticides (e.g., neonicotinoid insecticides) is suspected to contribute to honey bee ( Apis mellifera ) population decline in North America. Neonicotinoids are known to interfere with immune pathways in the gut of insects, but the underlying mechanisms remain elusive. We used a Drosophila melanogaster model to underst...
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... sulfoxide [DMSO]) or 10 M IMI to assess the ability of the bacterium to mitigate the sublethal effects of IMI. When LGR-1-supplemented WT Canton-S flies were exposed to a sublethal concentration (10 M) of IMI, they showed no change in the gut ratio of Acetobacter spp. to Lactobacillus spp. (unpaired, two-tailed t test; t 0.7744, df 17, P 0.4493) (Fig. 5A). The PBS-supplemented flies showed a significant increase in Acetobacter spp. (unpaired, two-tailed t test; t 4.215, df 16, P 0.001) (Fig. 5A). Looking at the Duox pathway, LGR-1-supplemented flies fed sublethal IMI demonstrated no significant difference in Duox expression (Mann-Whitney test; U 20, P 0.5962) (Fig. 5B) and H 2 O 2 ...
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... flies were exposed to a sublethal concentration (10 M) of IMI, they showed no change in the gut ratio of Acetobacter spp. to Lactobacillus spp. (unpaired, two-tailed t test; t 0.7744, df 17, P 0.4493) (Fig. 5A). The PBS-supplemented flies showed a significant increase in Acetobacter spp. (unpaired, two-tailed t test; t 4.215, df 16, P 0.001) (Fig. 5A). Looking at the Duox pathway, LGR-1-supplemented flies fed sublethal IMI demonstrated no significant difference in Duox expression (Mann-Whitney test; U 20, P 0.5962) (Fig. 5B) and H 2 O 2 (Mann-Whitney test; U 68, P 0.2800) (Fig. 5C) compared with LGR-1-supplemented vehicle-exposed flies. As seen with previous experiments, PBS- ...
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... t 0.7744, df 17, P 0.4493) (Fig. 5A). The PBS-supplemented flies showed a significant increase in Acetobacter spp. (unpaired, two-tailed t test; t 4.215, df 16, P 0.001) (Fig. 5A). Looking at the Duox pathway, LGR-1-supplemented flies fed sublethal IMI demonstrated no significant difference in Duox expression (Mann-Whitney test; U 20, P 0.5962) (Fig. 5B) and H 2 O 2 (Mann-Whitney test; U 68, P 0.2800) (Fig. 5C) compared with LGR-1-supplemented vehicle-exposed flies. As seen with previous experiments, PBS- ...
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... flies showed a significant increase in Acetobacter spp. (unpaired, two-tailed t test; t 4.215, df 16, P 0.001) (Fig. 5A). Looking at the Duox pathway, LGR-1-supplemented flies fed sublethal IMI demonstrated no significant difference in Duox expression (Mann-Whitney test; U 20, P 0.5962) (Fig. 5B) and H 2 O 2 (Mann-Whitney test; U 68, P 0.2800) (Fig. 5C) compared with LGR-1-supplemented vehicle-exposed flies. As seen with previous experiments, PBS- ...
Citations
... Prior studies have extensively investigated the negative impacts of sub-lethal doses of neonicotinoid insecticides on honeybees (Blacquiere et al., 2012;Singla et al., 2020), including physiological changes (Catae et al., 2018;Roat et al., 2020;Lv et al., 2023), delayed development (Li et al., 2022), weakened immune response (Chmiel et al., 2019;Annoscia et al., 2020;Zhang et al., 2022), and impaired colony reproduction (Schott, et al., 2021). Specifically, neonicotinoids disturb honeybee behaviors, including waggle dancing (Tison et al., 2020), foraging and homing (Capela et al., 2022), and colony performance (Negi et al., 2022;Reiner et al., 2022). ...
The use of agricultural neonicotinoid insecticides has sub-lethal chronic effects on bees that are more prevalent than acute toxicity. Among these insecticides, thiacloprid, a commonly used compound with low toxicity, has attracted significant attention due to its potential impact on the olfactory and learning abilities of honeybees. The effect of sub-lethal larval exposure to thiacloprid on the antennal activity of adult honeybees ( Apis mellifera L.) is not yet fully understood. To address this knowledge gap, laboratory-based experiments were conducted in which honeybee larvae were administered thiacloprid (0.5 mg/L and 1.0 mg/L). Using electroantennography (EAG), the impacts of thiacloprid exposure on the antennal selectivity to common floral volatiles were evaluated. Additionally, the effects of sub-lethal exposure on odor-related learning and memory were also assessed. The results of this study reveal, for the first time, that sub-lethal larval exposure to thiacloprid decreased honeybee antenna EAG responses to floral scents, leading to increased olfactory selectivity in the high-dose (1.0 mg/L) group compared to the control group (0 mg/L vs . 1.0 mg/L: p = 0.042). The results also suggest that thiacloprid negatively affected odor-associated paired learning acquisition, as well as medium-term (1 h) (0 mg/L vs . 1.0 mg/L: p = 0.019) and long-term memory (24 h) (0 mg/L vs . 1.0 mg/L: p = 0.037) in adult honeybees. EAG amplitudes were dramatically reduced following R-linalool paired olfactory training (0 mg/L vs . 1.0 mg/L: p = 0.001; 0 mg/L vs . 0.5 mg/L: p = 0.027), while antennal activities only differed significantly in the control between paired and unpaired groups. Our results indicated that exposure to sub-lethal concentrations of thiacloprid may affect olfactory perception and learning and memory behaviors in honeybees. These findings have important implications for the safe use of agrochemicals in the environment.
... There have been limited studies on the positive effects of probiotics against neonicotinoid pesticides' toxic effects. All of these studies include different organs and systems, such as the liver, kidney and immune system; however, there have been no data concerning probiotics' effects on the reproductive system against neonicotinoids toxicity [28,[48][49][50]. This is the first study to evaluate and report the positive effects of probiotic S.boulardii supplementation against imidacloprid and acetamiprid toxicity in male rat reproductive organs. ...
The potential health-promoting effects of probiotics against intoxication by pesticides is a topic of increasing commercial interest with limited scientific evidence. In this study, we aimed to investigate the positive effects of probiotic Saccharomyces boulardii on the male reproductive system under low dose neonicotinoid pesticide exposure conditions. We observed that acetamiprid and imidacloprid caused a degeneration and necrosis of the spermatocytes in the tubular wall, a severe edema of the intertubular region and a hyperemia. This was concomittant to increased levels of 8-hydroxy-2′-deoxyguanosine reflecting oxidative stress, and an increase in caspase 3 expression, reflecting apoptosis. According to our results, Saccharomyces boulardii supplementation mitigates these toxic effects. Further in vivo and clinical studies are needed to clarify the molecular mechanisms of protection. Altogether, our study reinforces the burden of evidence from emerging studies linking the composition of the gut microbiome to the function of the reproductive system.
... Neonicotinoids were found to increase hydrogen peroxide production, leading to oxidative stress and DNA damage in the Dipteran aquatic insect Chironomus dilutus through mitochondrial Ca + flux [33]. Interestingly, imidacloprid was found to reduce hydrogen peroxide production in honeybees, bumblebees [34], and Drosophila [35]. Variation in the immune response to pesticide exposure between and within different orders necessitates the assessment of species-specific immune responses. ...
... Along with A. mellifera hemocytes, we included the Schneider-2 cell line established from Drosophila melanogaster (Diptera) hemocytes. Drosophila was previously used as a model organism to study interactions with neonicotinoids and pathogens [35,[38][39][40]. We also included the MB-L2 cell line established from larvae of the cabbage moth (Mamestra brassicae) as a model for hemocytes of Lepidopteran insects such as the wax moth. ...
Invertebrates have a diverse immune system that responds differently to stressors such as pesticides and pathogens, which leads to different degrees of susceptibility. Honeybees are facing a phenomenon called colony collapse disorder which is attributed to several factors including pesticides and pathogens. We applied an in vitro approach to assess the response of immune-activated hemocytes from Apis mellifera, Drosophila melanogaster and Mamestra brassicae after exposure to imidacloprid and amitraz. Hemocytes were exposed to the pesticides in single and co-exposures using zymosan A for immune activation. We measured the effect of these exposures on cell viability, nitric oxide (NO) production from 15 to 120 min and on extracellular hydrogen peroxide (H2O2) production after 3 h to assess potential alterations in the oxidative response. Our results indicate that NO and H2O2 production is more altered in honeybee hemocytes compared to D. melanogaster and M. brassicae cell lines. There is also a differential production at different time points after pesticide exposure between these insect species as contrasting effects were evident with the oxidative responses in hemocytes. The results imply that imidacloprid and amitraz act differently on the immune response among insect orders and may render honeybee colonies more susceptible to infection and pests.
... Effects on proteins could be linked to some of these responses, for instance, Li and collaborators suggested that olfactory recognition could be affected as imidacloprid decreases the binding affinity of odorant-binding proteins to floral volatiles (Li et al., 2015). Moreover, neonicotinoids can affect the Toll and Imd immune pathways, which are essential in triggering the innate immune response in insects (Di Prisco et al., 2013;Chmiel et al., 2019). In accordance with literature data, we found an interaction between some proteins involved in the innate immune response with some pesticides including neonicotinoids. ...
Abstract A global decline of the honey bee Apis mellifera has been observed in the last decades. This pollinator plays a fundamental role in food production and the economy in Europe. The decline of honey bee colonies is linked to several stressors, including pesticides. The current pesticide risk assessment of honey bees in Europe focuses on lethal effects and lacks reflection on sublethal effects. A better understanding of the consequences that exposure to these chemicals has on honey bees is still needed. In this context, the aim of this European Food Risk Assessment Fellowship Programme fellowship project has been to use in silico methodologies, such as virtual screening, as a first step to identify possible interactions at the molecular level between A. mellifera proteins and pesticide ligands. For this purpose, a docking study of the proteins from A. mellifera and pesticide ligands extracted from online databases has been performed by using the software Autodock Vina. The results obtained were a ranking based on the predicted affinity of the pesticides for specific and non‐specific binding sites on bee macromolecules. These results were compared with data obtained from the literature and linked to potential sublethal effects. Finally, a risk assessment analysis of the identified molecular stressors of honey bees was performed. The results of this study are considered a starting point to identify new sources of possible stress for honey bees and thereby contribute to the overall understanding of the honey bee decline.
... Beyond direct cell-to-cell inhibition of P. larvae, the LX3 strains also upregulated larval gene expression of Def-1 and Pcbd, encoding an AMP with strong activity against P. larvae [80] and a peritrophin/chitin-binding protein involved with structural maintenance of peritrophic matrix [61], respectively. These immunomodulatory effects were likely derived from either L. plantarum Lp39 or L. rhamnosus GR-1, or both, based on past modeling in Drosophila melanogaster [81,82]. Thus, the findings together support the notion that certain probiotics, such as the LX3 strains, can offer multifactorial protection against AFB via direct (e.g., microbial competitive interactions) and indirect (e.g., modulation of host gene expression) mechanisms, as depicted in Figure 3. ...
Paenibacillus larvae is a spore-forming bacterial entomopathogen and causal agent of the important honey bee larval disease, American foulbrood (AFB). Active infections by vegetative P. larvae are often deadly, highly transmissible, and incurable for colonies but, when dormant, the spore form of this pathogen can persist asymptomatically for years. Despite intensive investigation over the past century, this process has remained enigmatic. Here, we provide an up-to-date synthesis on the often overlooked microbiota factors involved in the spore-to-vegetative growth transition (corresponding with the onset of AFB disease symptoms) and offer a novel outlook on AFB pathogenesis by focusing on the 'collaborative' and 'competitive' interactions between P. larvae and other honey bee-adapted microorganisms. Furthermore, we discuss the health trade-offs associated with chronic antibiotic exposure and propose new avenues for the sustainable control of AFB via probiotic and microbiota management strategies.
... Compared to the WT, w 1118 flies have a reduced capacity to circulate such hormones, and this might mitigate their protective properties (52,54,55). In line with these findings, w 1118 flies have a dampened stress tolerance and are more susceptible to compounds such as pesticides and ROS than WT flies (52,56). In humans, p-cresol enhances ROS production (57,58). ...
... Flies were stored at 280°C until DNA was extracted. DNA extraction was performed as previously described (56,73) with the Qiagen QIAamp DNA minikit (Qiagen catalog no. 51304). ...
... Relative abundance was determined by 2 DCT , where DCT was determined by CT Calibrator 2 CT Target . Copy numbers of target 16S rRNA genes were calculated as previously described using established primer efficiencies and limits of detection (56,74). ...
Renal impairment associated with chronic kidney disease (CKD) causes the buildup of uremic toxins that are deleterious to patient health. Current therapies that manage toxin accumulation in CKD offer an incomplete therapeutic effect against toxins such as para-cresol (p-cresol) and p-cresyl sulfate. Probiotic therapies can exploit the wealth of microbial diversity to reduce toxin accumulation. Using in vitro culture techniques, strains of lactobacilli and bifidobacteria from a 24-strain synbiotic were investigated for their ability to remove p-cresol. Four strains of bifidobacteria internalized p-cresol from the extracellular environment. The oral supplementation of these toxin-clearing probiotics was more protective than control strains in a Drosophila melanogaster toxicity model. Bifidobacterial supplementation was also associated with higher abundance of lactobacilli in the gut microbiota of p-cresol-exposed flies. The present findings suggest that these strains might reduce p-cresol in the gut in addition to increasing the prevalence of other beneficial bacteria, such as lactobacilli, and should be tested clinically to normalize the dysbiotic gut microbiota observed in CKD patients.
IMPORTANCE Chronic kidney disease (CKD) affects approximately 10% of the global population and has limited treatment options. The accumulation of gut microbiota-derived uremic toxins, such as para-cresol (p-cresol) and p-cresyl sulfate, is associated with the onset of comorbidities (i.e., atherosclerosis and cognitive disorders) in CKD. Unfortunately, dialysis, the gold standard therapy is unable to remove these toxins from the bloodstream due to their highly protein-bound nature. Some strains of Bifidobacterium have metabolic properties that may be useful in managing uremic toxicity. Using a Drosophila model, the present work highlights why dosing with certain probiotic strains may be clinically useful in CKD management.
... Several studies on bees or other model insects have demonstrated the strain-specific benefits of Lactobacillus, Apilactobacillis and Pediococcus spp. for increasing host survival against single or combinatorial stressors of infection and pesticide exposure 20,21,110,111 . Together with a high safety profile, this suggests that probiotic lactobacilli could offer a cost-effective and convenient solution to mitigate two of the major factors responsible for bee population decline. ...
Global biodiversity loss and mass extinction of species are two of the most critical environmental issues the world is currently facing, resulting in the disruption of various ecosystems central to environmental functions and human health. Microbiome-targeted interventions, such as probiotics and microbiome transplants, are emerging as potential options to reverse deterioration of biodiversity and increase the resilience of wildlife and ecosystems. However, the implementation of these interventions is urgently needed. We summarize the current concepts, bottlenecks and ethical aspects encompassing the careful and responsible management of ecosystem resources using the microbiome (termed microbiome stewardship) to rehabilitate organisms and ecosystem functions. We propose a real-world application framework to guide environmental and wildlife probiotic applications. This framework details steps that must be taken in the upscaling process while weighing risks against the high toll of inaction. In doing so, we draw parallels with other aspects of contemporary science moving swiftly in the face of urgent global challenges. Careful and responsible microbiome management is a critical strategy to counter biodiversity loss, but practical and regulatory hurdles must be addressed to maximize its utility.
... Recently, emerging research have suggested associations between insect gut microbiome and pesticide resistance. Several studies ranging from community diversity surveys to molecular analyses have focused on the gut bacteria's interactions with the host immune systems (Kikuchi et al., 2012;Engel and Moran, 2013;Xia et al., 2013;Chmiel et al., 2019). ...
Insect pests cause significant agricultural and economic losses to crops worldwide due to their destructive activities. Pesticides are designed to be poisonous and are intentionally released into the environment to combat the menace caused by these noxious pests. To survive, these insects can resist toxic substances introduced by humans in the form of pesticides. According to recent findings, microbes that live in insect as symbionts have recently been found to protect their hosts against toxins. Symbioses that have been formed are between the pests and various microbes, a defensive mechanism against pathogens and pesticides. Insects’ guts provide unique conditions for microbial colonization, and resident bacteria can deliver numerous benefits to their hosts. Insects vary significantly in their reliance on gut microbes for basic functions. Insect digestive tracts are very different in shape and chemical properties, which have a big impact on the structure and composition of the microbial community. Insect gut microbiota has been found to contribute to feeding, parasite and pathogen protection, immune response modulation, and pesticide breakdown. The current review will examine the roles of gut microbiota in pesticide detoxification and the mechanisms behind the development of resistance in insects to various pesticides. To better understand the detoxifying microbiota in agriculturally significant pest insects, we provided comprehensive information regarding the role of gut microbiota in the detoxification of pesticides.
... Consequently, it caused a significant decrease in important species in the relative abundance of Lactobacillus Firm-5 and Apibacter. It was documented that imidacloprid exposure to Drosophila melanogaster also significantly increased the abundance of Acetobacter and Lactobacillus genera, supporting the potential toxicity of neonicotinoid pesticides targeting gut microbiota [56]. Moreover, exposure to imidacloprid may interact with the immune deficiency pathway, leading to a loss of microbial regulation, as exemplified by a compositional shift on dominant microbiota members [56]. ...
... It was documented that imidacloprid exposure to Drosophila melanogaster also significantly increased the abundance of Acetobacter and Lactobacillus genera, supporting the potential toxicity of neonicotinoid pesticides targeting gut microbiota [56]. Moreover, exposure to imidacloprid may interact with the immune deficiency pathway, leading to a loss of microbial regulation, as exemplified by a compositional shift on dominant microbiota members [56]. The relative abundance of Lactobacillus Firm-5 decreased, which may suppress carbohydrate metabolism, since it functionally degrades flavonoid glycosides to simple sugars and organic acids further [57,58]. ...
Bumblebees are important pollinators for crops and wild flowering plants. Various pesticides have threatened the abundance and diversity of bumblebees. In addition to direct sublethal effects, pesticides may alter the gut microbial communities of bees. Imidacloprid and flupyradifurone insecticides both bind to the nicotinic acetylcholine receptor. However, the latter was assumed to be harmless for honeybees and can even be applied to flowering crops. In this study, we assessed the impacts of these two pesticides on queenless microcolonies and the gut microbiota of Bombus terrestris. We found that 10 μg/L imidacloprid significantly impeded syrup consumption, and postponed the egg-laying period, larvae, and pupae development. It decreased the relative abundance of the bumblebee-specific symbionts, Apibacter and Lactobacillus Firm-5. On the contrary, 10 μg/L flupyradifurone did not reduce syrup consumption, block larvae and pupae development in bumblebees. Although no significant phenotypes were observed, PICRUST revealed that flupyradifurone suppressed pathways, involving carbohydrate metabolism, nucleotide metabolism, translation, and membrane transport. Our findings suggest the appropriate use of this new pesticide may be considered safe for bumblebees, but the underlying mechanism warrants further investigation.
... Recently, emerging research have suggested associations between insect gut microbiome and pesticide resistance. Several studies ranging from community diversity surveys to molecular analyses have focused on the gut bacteria's interactions with the host immune systems (Kikuchi et al., 2012;Engel and Moran, 2013;Xia et al., 2013;Chmiel et al., 2019). ...
Insect pests cause significant agricultural and economic losses on crops worldwide due to their destructive activities. To survive, these insects are able to resist dangerous substances introduced by humans in the form of insecticides. Pesticides may have unintended harmful impacts on non-target creatures, humans, and the environment. As pesticides are designed to be poisonous and are intentionally released into the environment. According to new research, microbes that live in insect symbioses have recently been found to protect insects against toxins. Symbioses have been formed among the pest and various types of microbes, which is a defensive mechanism against pathogens and pesticides. Insect guts provide unique conditions for microbial colonization, and bacteria in the stomach can deliver numerous benefits to their hosts. Insects vary significantly in their reliance on gut microbes for basic functions. Insect digestive tracts are very different in shape and chemical properties, which have a big impact on the structure of the microbial community. Insect gut microbiota has been found to contribute to feeding, parasite and pathogen protection, immune response modulation, and pesticide breakdown. Our study will examine the role of gut microbiota in pesticide detoxification and the mechanisms behind the development of resistance in insects to various pesticides. To better understand detoxifying microbiota in agriculturally significant pest insects, we provided comprehensive information regarding the role of gut microbiota in the detoxification of pesticides.
