The Influence of Topinambur and Inulin Preventive Supplementation on Microbiota, Anxious Behavior, Cognitive Functions and Neurogenesis in Mice Exposed to the Chronic Unpredictable Mild Stress

Daily living and functioning under stress can lead to mental health problems such as anxiety or depression. Over the past decades, a number of studies have been conducted to determine the relationship between the central nervous system (CNS), intestinal flora and bidirectional communication along the gut brain axis (GBA) in the maintaining of homeostasis. One of the most important factors regulating GBA functioning in exposure to stress may be a proper diet enriched in the supplementation with pre-, pro-and synbiotics. In the present study, we examined whether a 10-week oral preventive supplementation with natural prebiotics: topinambur powder (TPB) and chicory root inulin (INU) influenced an anxiety, depressive behavior and cognition in mice exposed to the chronic unpredictable mild stress (CUMS). Additionally, a fluoxetine (FLU) has been used as a reference antidepressive drug. Furthermore, we assessed the effect of TPB, INU and FLU administration on neurogenesis in mice exposed to CUMS and finally analyzed fecal microbiota for possible changes after TPB and INU supplementation in CUMS induced mice. Results obtained from the behavioral studies (elevated plaze maze, forced swim and Morris water maze test) indicated, that 10 week supplementation with TPB (250 mg/kg) and INU (66 mg/kg), similarly to FLU (12 mg/kg), significantly mitigated an anxiety and stress as well as protected learning and memory functions in the CUMS induced mice compared to the control stressed group. Additionally, TPB and INU CUMS mice showed significantly higher level of neurogenesis in comparison to control CUMS group. Interestingly, results obtained from the fecal microbiota analysis showed a beneficial effect of TPB and INU supplementation against CUMS-induced intestinal dysbiosis in mice. In conclusion, the obtained results showed that a long-term, preventive supplementation with TPB or INU alleviates the negative effects such as anxiety, cognitive disorders or dysbiosis in mice exposed to chronic unpredictable stress.

The Effect of a Diet Enriched with Jerusalem artichoke, Inulin, and Fluoxetine on Cognitive Functions, Neurogenesis, and the Composition of the Intestinal Microbiota in Mice

The aim of the study was to assess the effect of long-term administration of natural prebiotics: Jerusalem artichoke (topinambur, TPB) and inulin (INU) as well as one of the most popular antidepressants, fluoxetine (FLU), on the proliferation of neural stem cells, learning and memory functions, and the composition of the intestinal microbiota in mice. Cognitive functions were assessed using the Morris Water Maze (MWM)Test. Cells were counted using a confocal microscope and ImageJ software. We performed 16S rRNA sequencing to assess changes in the gut microbiome of the mice. The obtained results showed that the 10-week supplementation with TPB (250 mg/kg) and INU (66 mg/kg) stimulates the growth of probiotic bacteria, does not affect the learning and memory process, and does not disturb the proliferation of neural stem cells in the tested animals. Based on this data, we can assume that both TPB and INU seem to be safe for the proper course of neurogenesis. However, 2-week administration of FLU confirmed an inhibitory impact on Lactobacillus growth and negatively affected behavioral function and neurogenesis in healthy animals. The above studies suggest that the natural prebiotics TPB and INU, as natural supplements, may have the potential to enrich the diversity of intestinal microbiota, which may be beneficial for the BGM axis, cognitive functions, and neurogenesis.

Gut microbial composition in developmental stages of gall inducing thrips Gynaikothrips uzeli and associated plant pathogenesis

Gut bacteria play a crucial role in the several metabolic activity of the insects. In the present work, effort has been made to decipher the gut microbiota associated with the developmental stages of Gynaikothrips uzeli a gall inducing thrips along with their predicted functional role. Further, an effort has been made to correlate the bacterial communities with plant pathogenesis and thelytoky behaviour of G. uzeli. Findings obtained revealed that genus Arsenophonus dominated the total bacterial diversity and was transmitted vertically through the developmental stages. Further, it was observed that the high abundance of genus Arsenophonus promotes the thelytoky behaviour in G. uzeli and results in the killing of males. Furthermore, strong connecting link between Arsenophonus abundance and gall induction in F. benjamina was observed in the current dataset. G. uzeli being in the category of phloem sucking insect was known for the induction of galls and the current findings for the first time unveiled the facts that high abundance of genus Arsenophonus a well-known plant pathogen may be one of the major reason for inducing galls in F. benjamina. Moreover, PICRUSt2 analysis revealed that predicted functional pathways like biosynthesis of amino acids, and metabolism of carbon, nitrogen, carbohydrates and amino acids (e.g. Arginine, Alanine, Aspartate, Glutamate, Proline, Cysteine, Methionine, Glycine, Threonine, and Serine) were frequently noticed in profiles associated with all the developmental stages of G. uzeli. More to this, the high abundance of Arsenophonus in G. uzeli suggest that representatives of this genus may be resistant and/or tolerant to different antibacterial agents, alkaloids, flavonoids, and glycosides (e.g. quercetin). The correlation of bacterial diversity in pathogenicity can be extrapolated in different pest and vector species of other arthropods.

The Patterns and Puzzles of Genetic Diversity of Endangered Freshwater Mussel Unio crassus Philipsson, 1788 Populations from Vistula and Neman Drainages (Eastern Central Europe)

Mussels of the family Unionidae are important components of freshwater ecosystems. Alarmingly, the International Union for Conservation of Nature and Natural Resources Red List of Threatened Species identifies almost 200 unionid species as extinct, endangered, or threatened. Their decline is the result of human impact on freshwater habitats, and the decrease of host fish populations. The Thick Shelled River Mussel Unio crassus Philipsson, 1788 is one of the examples that has been reported to show a dramatic decline of populations. Hierarchical organization of riverine systems is supposed to reflect the genetic structure of populations inhabiting them. The main goal of this study was an assessment of the U. crassus genetic diversity in river ecosystems using hierarchical analysis. Different molecular markers, the nuclear ribosomal internal transcribed spacer ITS region, and mitochondrial DNA genes (cox1 and ndh1), were used to examine the distribution of U. crassus among-population genetic variation at multiple spatial scales (within rivers, among rivers within drainages, and between drainages of the Neman and Vistula rivers). We found high genetic structure between both drainages suggesting that in the case of the analyzed U. crassus populations we were dealing with at least two different genetic units. Only about 4% of the mtDNA variation was due to differences among populations within drainages. However, comparison of population differentiation within drainages for mtDNA also showed some genetic structure among populations within the Vistula drainage. Only one haplotype was shared among all Polish populations whereas the remainder were unique for each population despite the hydrological connection. Interestingly, some haplotypes were present in both drainages. In the case of U. crassus populations under study, the Mantel test revealed a relatively strong relationship between genetic and geographical distances. However, in detail, the pattern of genetic diversity seems to be much more complicated. Therefore, we suggest that the observed pattern of U. crassus genetic diversity distribution is shaped by both historical and current factors i.e. different routes of post glacial colonization and history of drainage systems, historical gene flow, and more recent habitat fragmentation due to anthropogenic factors.

Passenger for millenniums: association between stenothermic microcrustacean and suctorian epibiont - the case of Eurytemora lacustris and Tokophyra sp

Epibionts often colonize the exoskeleton of crustaceans, which sometimes results in the development of a long-term relationship between them. Our present work confirmed that a specific epibiont is closely associated with the pelagic calanoid copepod Eurytemora lacustris, regardless of the region, which suggests a preserved interaction between these species. Molecular analyses revealed that the epibiont belongs to the genus Tokophrya. We also found that the level of basibiont colonization is related to its size and identified that the most intensely inhabited body parts are those located near the center of the copepod body. We hypothesize that the relationship between Eurytemora (basibiont) and Tokophrya (epibiont) was established during the Quaternary period, following which these two populations were fragmented into lakes where they survived in close interaction. In addition, we suppose that the close relationship between the two species indicates the coevolution of stenotherms. Further studies on the interactions between Eurytemora lacustris and Tokophrya are required in order to gain insight into the long-term relationship between the copepods and the epibionts.

First Insight into Microbiome Profiles of Myrmecophilous Beetles and Their Host, Red Wood Ant Formica polyctena (Hymenoptera: Formicidae)-A Case Study

Formica polyctena belongs to the red wood ant species group. Its nests provide a stable, food rich, and temperature and humidity controlled environment, utilized by a wide range of species, called myrmecophiles. Here, we used the high-throughput sequencing of the 16S rRNA gene on the Illumina platform for identification of the microbiome profiles of six selected myrmecophilous beetles (Dendrophilus pygmaeus, Leptacinus formicetorum, Monotoma angusticollis, Myrmechixenus subterraneus, Ptenidium formicetorum and Thiasophila angulata) and their host F. polyctena. Analyzed bacterial communities consisted of a total of 23 phyla, among which Proteobacteria, Actinobacteria, and Firmicutes were the most abundant. Two known endosymbionts-Wolbachia and Rickettsia-were found in the analyzed microbiome profiles and Wolbachia was dominant in bacterial communities associated with F. polyctena, M. subterraneus, L. formicetorum and P. formicetorum (>90% of reads). In turn, M. angusticollis was co-infected with both Wolbachia and Rickettsia, while in the microbiome of T. angulata, the dominance of Rickettsia has been observed. The relationships among the microbiome profiles were complex, and no relative abundance pattern common to all myrmecophilous beetles tested was observed. However, some subtle, species-specific patterns have been observed for bacterial communities associated with D. pygmaeus, M. angusticollis, and T. angulata.

The microbiome profiling of fungivorous black tinder fungus beetle Bolitophagus reticulatus reveals the insight into bacterial communities associated with larvae and adults

Saproxylic beetles play a crucial role in key processes occurring in forest ecosystems, and together with fungi contribute to the decomposition and mineralization of wood. Among this group are mycetophilic beetles which associate with wood-decaying fungi and use the fruiting body for nourishment and development. Therefore, their feeding strategy (especially in the case of fungivorous species) requires special digestive capabilities to take advantage of the nutritional value of fungal tissue. Although polypore-beetle associations have been investigated in numerous studies, detailed studies focusing on the microbiome associated with species feeding on fruiting bodies of polypores remain limited. Here we investigated the bacterial communities associated with larvae and adults of Bolitophagus reticulatus collected from Fomes fomentarius growing on two different host tree: beech (Fagus sp.) and birch (Betula sp.), respectively. Among 24 identified bacterial phyla, three were the most relatively abundant (Proteobacteria, Actinobacteria and Bacteroidetes). Moreover, we tried to find unique patterns of bacteria abundances which could be correlated with the long-term field observation showing that the fruiting bodies of F. fomentarius, growing on birch are more inhabited by beetles than fruiting bodies of the same fungus species growing on beech. Biochemical analyses showed that the level of protease inhibitors and secondary metabolites in F. fomentarius is higher in healthy fruiting bodies than in the inhabited ones. However, tested microbiome samples primarily clustered by developmental stage of B. reticulatus and host tree did not appear to impact the taxonomic distribution of the communities. This observation was supported by statistical analyses.