Metarhizium spp. have emerged as an alternative to chemical pesticides for protecting crops from insect pest. Here, we investigated midgut microbial community and metabolites of Spodoptera litura at three different timepoints after infection with Metarhizium flavoviride. The innate immune system of S. litura was activated with levels of polyphenol oxidase, carboxylesterase, multifunctional oxidase, and glutathione S-transferase activity significantly increasing. Exposure to the fungal pathogen also altered bacterial abundance and diversity in host\'s midgut, and these changes varied depending on the time elapsed since exposure. We identified more operational taxonomic units in the treated samples as compared to the control samples at all tested time points. A total of 372 metabolites were identified, and 88, 149, and 142 differentially accumulated metabolites (DAMs) were identified between the treatment and control groups at 3 timepoints after treatment, respectively. Based on the changes of DAMs in response to M. flavoviride infection at different timepoints and significantly enriched KEGG pathways, we speculated that \"tyrosine metabolism,\" \"galactose metabolism,\" \"ATP-binding cassette transporters,\" \"neuroactive ligand-receptor interaction,\" \"purine metabolism,\" \"arginine and proline metabolism,\" \"beta-alanine metabolism,\" \"lysosome,\" and \"carbon metabolism\" may participate in the metabolic-level defense response. An integrated pathway-level analysis of the 16S-rDNA and metabolomic data illustrated the connections and interdependencies between the metabolic responses of S. litura and the midgut microorganisms to M. flavoviride infection. This work emphasizes the value of integrated analyses of insect-pathogen interactions, provides a framework for future studies of critical microorganisms and metabolic determinants of these interactions, establishes a theoretical basis for the sustainable use of M. flavoviride.

Ticks are hematophagous ectoparasites associated with a wide range of vertebrate hosts. Within this group, the Ixodidae family stands out, in which the Ixodes genus contains at least 245 species worldwide, from which 55 species are present in the Neotropical region. Ixodes affinis, a tick described in 1899, has a wide distribution from the Southern Cone of America to the United States. However, since its description, morphological variability has been reported among its populations. Furthermore, attempts have been made to clarify its status as a species complex using mitochondrial markers, but mainly in restricted populations of South and Central America. Thus, information related to populations of the transition region between the Neotropical and Nearctic zones is lacking. For these reasons, the objectives of the study were to evaluate the genetic diversity and structure of I. affinis across the Americas and to compile all the published records of I. affinis in America, to elucidate the host-parasite relationships and to identify their geographical distribution. For this, a phylogeny, and AMOVA analyses were performed to assess the genetic structure of samples obtained by field work in South Carolina, USA and Yucatán, Mexico. A total of 86 sequences were retrieved from a fragment of the 16S region. Phylogeny and genetic structure analysis showed four groups that were geographically and genetically related with high branch support and Fst values, all of them statistically significant. The results obtained support the hypothesis that I. affinis it corresponds to a complex of four species, which must be validated through future morphological comparisons.

Controlling early blight of tomatoes using endophytic bacteria is an eco-friendly and sustainable approach to manage this common fungal disease caused by Alternaria solani, Alternaria alternata, and Curvularia lunata. Endophytic bacteria are microorganisms that live inside plant tissues without causing harm and can help protect the host plant from pathogens. In this work, twenty endophytic bacterial isolates from tomato healthy plants were tested against pathogenic fungal isolates that caused early blight disease in vitro. Out of the 20 tested isolates, three (B4, B7, and B17) were considered effective isolates against the growth of fungal pathogens. The three isolates were recognized as Enterobacter cloacae HS-6 (B4), Pseudomonas gessardii HS-5 (B 7), and Pseudomonas mediterranea HS-4 (B17) using 16s-rDNA sequencing. Different concentrations of bacterial cultural diltrates at 20, 40, and 60% were tested for their antagonistic effects on the development of pathogenic fungi in vitro. The lowest dry weights of pathogenic isolates in all bacterial culture filtrates were discovered at 60%. In all culture filtrates, phenolic compounds showed the largest peak area. Under greenhouse conditions, the least disease severity of tomato early blight was found for E. cloacae and its culture filtrate compared to other treatments. Real-time PCR was used to examine the expression pattern of the defense response gene β-1.3 glucanase gene in infected tomato plants with pathogenic fungi (control) as well as its relations with efficient biocontrol agent (E. cloacae). The expression of the gene increased substantially and significantly after three days from the inoculation-infected plants with C. lunata and E. cloacae while it reached the maximum after five days from the inoculation with A. alternata, A. solani and E. cloacae. Our study concluded that the endophytic bacterial isolate E. cloacae can be considered a promising biocontrol agent for preventing tomato early blight.

Men with prediabetes often exhibit concomitant low-quality sperm production or even infertility, problems which urgently require improved therapeutic options. In this study, we have established a sheep model of diet-induced prediabetes that is associated with spermatogenic defects and have explored the possible underlying metabolic causes.
We compared male sheep fed a normal diet with those in which prediabetes was induced by a rich diet and with a third group in which the rich diet was supplemented by melatonin. Only the rich diet group had symptoms of prediabetes, and in these sheep, we found impaired spermatogenesis characterized by a block in the development of round spermatids and an increased quantity of testicular apoptotic cells. Comparing the gut microbiomes and intestinal digest metabolomes of the three groups revealed a distinctive difference in the taxonomic composition of the microbiota in prediabetic sheep, and an altered metabolome, whose most significant feature was altered sphingosine metabolism; elevated sphingosine was also found in blood and testes. Administration of melatonin alleviated the symptoms of prediabetes, including those of impaired spermatogenesis, while restoring a more normal microbiota and metabolic levels of sphingosine. Fecal microbiota transplantation from prediabetic sheep induced elevated sphingosine levels and impaired spermatogenesis in recipient mice, indicating a causal role of gut microbiota in these phenotypes.
Our results point to a key role of sphingosine in the disruption of spermatogenesis in prediabetic sheep and suggest it could be a useful disease marker; furthermore, melatonin represents a potential prebiotic agent for the treatment of male infertility caused by prediabetes.

BACKGROUND: Although there are many hypotheses, the pathogenesis of Crohn\'s disease (CD) is not completely clear so far. Exclusive enteral nutrition (EEN) is a routine measure in the treatment of active CD. We aimed at investigating the impact of EEN on patients with active CD from microbial metabolomics.
METHODS: 16S-rDNA sequencing technology and gas chromatography-mass spectrometer analysis were employed to investigate the modification of the intestinal flora and fecal short-chain fatty acid (SCFA) during the EEN.
RESULTS: Seven patients with CD, who conducted EEN, were followed up successfully in the present study. The 8-week EEN resulted in a remission of the condition of subjects with active CD, as revealed by a significant decrease in erythrocyte sedimentation rate (ESR) (P = 0.018), C-reactive protein (CRP) (P = 0.028), and Crohn\'s disease activity index (CDAI) (P = 0.018). The nutrition of the subjects was improved after an 8-week treatment course with EEN, which was associated with an increase in body mess index (BMI) (P = 0.018) and serum albumin (ALB) (P = 0.018) levels. Furthermore, our investigations revealed a significantly increased abundance of Firmicutes paralleled by decreased levels of Proteobacteria. With respect to the genus, five species of bacteria including Ruminococcus (P = 0.01), Lachnospiraceae (P = 0.02), Anaerotruncus (P = 0.04), Flavonifractor (P = 0.04), and Novosphingobium (P = 0.05) showed significantly increased abundance. This was accompanied by relative changes in fecal short-chain fatty acids levels. Moreover, we successfully constructed a stable model by combining these five significantly different genera to predict the therapeutic effect of EEN on patients with CD (AUC = 0.9598).
CONCLUSIONS: The findings indicated that EEN can alleviate the condition and the nutrition of patients with active CD by regulating the intestinal flora and influencing the expression level of fecal short-chain fatty acids.

OBJECTIVE: This study aimed to explore the effects of Psidium guajava L. extracts on mice diarrhea model and changes in their intestinal microflora diversity.
METHODS: Mice diarrhea model was constructed with Folium Sennae. and The therapeutic effects of Psidium guajava L. extracts on diarrhea were evaluated by loose stools rates, diarrhea rates, diarrhea index and motor functions of intestine.
RESULTS: Our results showed that all three kinds of extracts from Psidium guajava L. had inhibitory effects on Folium Sennae -induced diarrhea model. The proportion of Bacteroidetes is lower in Group DF (diarrhea model group) compared with Group B (blank group), while abundance of Deferribacteraceae was found in Group DF. The proportion of Deferribacteraceae lowered in Group DTF (diarrhea treatment group) treated with extracts from Psidium guajava L.
CONCLUSIONS: However, mechanisms underlying the therapeutic effect of Psidium guajava L. and the changes in intestinal microflora still await further exploration.