Host-microbiota interaction in intestinal stem cell homeostasis.

Intestinal stem cells (ISCs) play a pivotal role in gut physiology by governing intestinal epithelium renewal through the precise regulation of proliferation and differentiation. The gut microbiota interacts closely with the epithelium through myriad of actions, including immune and metabolic interactions, which translate into tight connections between microbial activity and ISC function. Given the diverse functions of the gut microbiota in affecting the metabolism of macronutrients and micronutrients, dietary nutrients exert pronounced effects on host-microbiota interactions and, consequently, the ISC fate. Therefore, understanding the intricate host-microbiota interaction in regulating ISC homeostasis is imperative for improving gut health. Here, we review recent advances in understanding host-microbiota immune and metabolic interactions that shape ISC function, such as the role of pattern-recognition receptors and microbial metabolites, including lactate and indole metabolites. Additionally, the diverse regulatory effects of the microbiota on dietary nutrients, including proteins, carbohydrates, vitamins, and minerals (e.g. iron and zinc), are thoroughly explored in relation to their impact on ISCs. Thus, we highlight the multifaceted mechanisms governing host-microbiota interactions in ISC homeostasis. Insights gained from this review provide strategies for the development of dietary or microbiota-based interventions to foster gut health.

Identification of an Acinetobacter pittii acyltransferase involved in transformation of deoxynivalenol to 3-acetyl-deoxynivalenol by transcriptomic analysis.

Deoxynivalenol (DON), a mycotoxin primarily produced by Fusarium graminearum (F. graminearum), is widely present in food and feed, posing great hazards to human and livestock health. In this study, a strain of Acinetobacter pittii (A. pittii) S12 capable of degrading DON was isolated from soil samples and identified through morphological characterization, biochemistry analysis, and 16 S rRNA gene sequencing. The results of HPLC-MS indicated that the degradation products underwent a conversion from [M-H]- to [M+CH3CO], with concomitant transformation of the hydroxyl group into an acetyl moiety. Based on transcriptome sequencing analysis, the acyltransferase encoded by DLK06_RS13370 was predicted to be the pivotal gene responsible for DON biotransformation. The result of molecular docking analysis suggest a high affinity between the enzyme and DON. The recombinant protein encoded by DLK06_RS13370 was expressed in Escherichia coli (E. coli) and demonstrated the capacity to catalyze the conversion of DON into 3-Acetyl-deoxynivalenol (3-ADON), as confirmed by HPLC analysis. In conclusion, our findings confirm that the acyltransferase encoded by DLK06-RS13370 is responsible for the acetylation of DON. This sheds light on the co-occurrence of DON and its acetyl-derivatives in wheat-based products. DATA AVAILABILITY: Not applicable.

Dietary supplementation with Clostridium butyricum improves growth performance of broilers by regulating intestinal microbiota and mucosal epithelial cells.

Clostridium butyricum has been widely considered an antibiotic substitute in recent years. It can promote growth performance, improve the immune response and enhance the intestinal barrier function of the host. In the present study, 1-d-old Arbor Acres (AA) broilers were fed C. butyricum (1 × 109 cfu/kg) for 28 d. The transcriptomic characteristics of epithelial cells of the cecal mucosa were determined by RNA-sequence, and the cecal microbiota composition was explored by 16S ribosomal RNA gene sequencing. The changes in the intestinal mucosa of broilers were then analyzed by tissue staining. Gene Ontology (GO) annotations identified substance transport and processes and pathways that might participate in intestinal development and cell viability. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed that the differentially expressed genes are involved in numerous pathways related to amino acid and vitamin metabolism and antioxidant and defensive functions, among others. The relative expression of some genes associated with intestinal barrier function (claudins 2, 15, 19, and 23, tight junction proteins 1, 2, and 3 and mucin 1) was significantly increased in the treatment group (P < 0.05 or P < 0.01). Moreover, the proportion of Firmicutes was higher in the C. butyricum-treated group, whereas the proportion of Proteobacteria was higher in the control group. At the genus level, the relative abundances of Butyricicoccus and Lactobacillus, among other bacteria, were increased after C. butyricum supplementation. The tissue staining analysis showed that the cecal mucosa of broilers was significantly ameliorated after the addition of C. butyricum (P < 0.05 or P < 0.01). These results showed that dietary supplementation with C. butyricum can enhance the antioxidant capacity, mucosal barrier function, and stabilize the cecal microbiota, resulting in improving the growth performance.

Identification of a Bacillus amyloliquefaciens H6 Thioesterase Involved in Zearalenone Detoxification by Transcriptomic Analysis.

Zearalenone (ZEA), a nonsteroidal estrogenic mycotoxin produced by Fusarium graminearum, induces hyperestrogenic responses in mammals and can cause reproductive disorders in farm animals. In this study, a transcriptome analysis of Bacillus amyloliquefaciens H6, which was previously identified as a ZEA-degrading bacterium, was conducted with high-throughput sequencing technology, and the differentially expressed genes were subjected to gene ontology (GO) and kyoto encyclopedia of genes and genomes (KEGG) enrichment analyses. Among the 16 upregulated genes, BAMF_RS30125 was predicted to be the key gene responsible for ZEA degradation. The protein encoded by BAMF_RS30125 was then expressed in Escherichia coli, and this recombinant protein (named ZTE138) significantly reduced the ZEA content, as determined by the enzyme-linked immunosorbent assay (ELISA) and high-performance liquid chromatography (HPLC), and decreased the proliferating activity of ZEA in MCF-7 cells. What is more, the liquid chromatography-tandem mass spectrometry (LC-MS/MS) results showed that the relative molecular mass and the structure of ZEA also changed. Sequence alignment of the ZTE138 protein showed that it is a protease that belongs to the YBGC/FADM family of coenzyme A thioesterases, and thus, the protein can presumably cleave the ZEA lactone bond and break down its macrolide ring.

Gut microbiota profiles of commercial laying hens infected with tumorigenic viruses.

BACKGROUND: Studies have shown that some viral infections cause structural changes in the intestinal microflora, but little is known about the effects of tumorigenic viral infection on the intestinal microflora of chickens. RESULTS: A 29-week commercial layer flock positive for avian leukosis virus-J (ALV-J), Marek's disease virus (MDV) and avian reticuloendotheliosis virus (REV) was selected, and fresh fecal samples were collected and examined for the composition of the gut microflora by Illumina sequencing of the V3-V4 region of the 16S rRNA gene. The operational taxonomic units (OTUs) of the fecal microbiota differentiated the chickens infected with only ALV-J and those coinfected with ALV-J and MDV or REV from infection-negative chickens. The enrichment and diversity of cloacal microflora in chickens infected with ALV-J alone were slightly different from those in the infection-negative chickens. However, the diversity of cloacal microflora was significantly increased in chickens coinfected with both ALV-J and MDV or REV. CONCLUSIONS: The intestinal microbiota was more strongly disturbed in chickens after coinfection with ALV-J and MDV or REV than after infection with ALV-J alone, and there may be underlying mechanisms by which the capacity for the stabilization of the intestinal flora was impaired due to viral infection and tumorigenesis.

Characteristics of the fecal microbiota of high- and low-yield hens and effects of fecal microbiota transplantation on egg production performance.

The microbiota that resides in the digestive tract plays pivotal role in maintaining intestinal environmental stability by promoting nutrition digestion and intestinal mucosal immunity. However, whether the intestinal microbiota in laying hens affects egg laying- performance is not known. In this study, 16S rDNA gene sequencing and fecal microbiota transplantation were used to determine the structure of the intestinal microbiota and the effect of the intestinal microbiota on egg production. The results revealed that Firmicutes were dominant in both the H (high egg laying rates) and L (low egg laying rates) groups, while Bacteroides, Actinobacteria and Proteobacteria were significantly enriched in the L group compared to the H group. The laying rates were weakly affected in H hens transplanted with the fecal microbiota from L hens, except for temporary fluctuation, while the egg laying rates were significantly increased in L hens transplanted with the fecal microbiota from H hens. Therefore, we concluded that the population structure of the intestinal microbiota varied between the H and L groups, and the intestinal microbiota of high-yield laying hens had significant effects on low-yield laying hens performance.