A study was conducted to determine the effects of a diet supplemented with fruits and vegetables (FV) on the host whole blood cell (WBC) transcriptome and the composition and function of the intestinal microbiome. Nine six-week-old pigs were fed a pig grower diet alone or supplemented with lyophilized FV equivalent to half the daily recommended amount prescribed for humans by the Dietary Guideline for Americans (DGA) for two weeks. Host transcriptome changes in the WBC were evaluated by RNA sequencing. Isolated DNA from the fecal microbiome was used for 16S rDNA taxonomic analysis and prediction of metabolomic function. Feeding an FV-supplemented diet to pigs induced differential expression of several genes associated with an increase in B-cell development and differentiation and the regulation of cellular movement, inflammatory response, and cell-to-cell signaling. Linear discriminant analysis effect size (LEfSe) in fecal microbiome samples showed differential increases in genera from Lachnospiraceae and Ruminococcaceae families within the order Clostridiales and Erysipelotrichaceae family with a predicted reduction in rgpE-glucosyltransferase protein associated with lipopolysaccharide biosynthesis in pigs fed the FV-supplemented diet. These results suggest that feeding an FV-supplemented diet for two weeks modulated markers of cellular inflammatory and immune function in the WBC transcriptome and the composition of the intestinal microbiome by increasing the abundance of bacterial taxa that have been associated with improved intestinal health.

DNA methylation (DNAm) regulates gene expression and genomic imprinting. This study aimed to investigate the effect of gastrointestinal (GI) nematode infection on host DNAm. Helminth-free Holstein steers were either infected with Ostertagia ostertagi (the brown stomach worm) or given tap water only as a control. Animals were euthanized 30 days post-infection, and tissues were collected at necropsy. We conducted epigenome-wide profiling using a mammalian methylation array to explore the impact of infection on methylation patterns in the mucosa from abomasal fundus (FUN), pylorus (PYL), draining lymph nodes (dLNs), and the duodenum (DUO). The analysis covered 31,107 cattle CpGs of 5082 genes and revealed infection-driven, tissue-specific, differential methylation patterns. A total of 389 shared and 2770 tissue-specific, differentially methylated positions (DMPs) were identified in dLN and FUN, particularly in genes associated with immune responses. The shared DMPs were found in 263 genes, many of which are involved in immune responses. Furthermore, 282, 244, 52, and 24 differentially methylated regions (DMRs) were observed in dLN, FUN, PYL, and DUO, respectively. More hypomethylated DMRs were detected in dLN and FUN, while more hypermethylated DMRs were found in PYL and DUO. Genes carrying DMPs and DMRs and enriched pathways relating to immune functions/responses were detected in infected animals, indicating a link between DNA methylation and the infection. The data may implicate a crucial role of DNAm in regulating the nature/strength of host immunity to infection and contribute to a deeper understanding of the epigenetic regulatory landscape in cattle infected by GI nematodes.

Ostertagia ostertagi, also known as the brown stomach worm, causes significant pathology in the abomasum, resulting in production and nutritional losses in cattle. Alternative control measures, such as vaccination, are urgently needed because of rapidly growing anthelmintic drug resistance. There is a need to understand host responses to the infection, especially immune responses, to advance vaccine discovery and design. Therefore, the present study investigated comprehensive changes in gene transcription in the abomasal mucosa of cattle infected with O. ostertagi at 0, 3–5, 7–9, 10, and 21 days post-infection (dpi) using RNA sequencing (RNA-seq). Compared to uninfected controls, infected animals exhibited significant increases in differentially expressed genes (DEGs) throughout the infection period. Infection induced more upregulated than downregulated genes in the abomasal fundic mucosa (FUN) when compared to the abomasal pyloric mucosa (PYL). The largest transcriptional changes occurred between 7–9 and 10 dpi during the final development of the L4 and their emergence from the gastric glands. Most DEGs are associated with host immunity, cellular reorganization, cell migration, and proliferation. Tuft/epithelial cell response to the infection was atypical, lacking an anticipated increase in key alarmin cytokine genes. Numerous genes associated with T helper (Th) 1, Th2, and Th17 responses and T cell exhaustion were upregulated, suggesting altered immune regulation. The data collectively indicate that O. ostertagi infection elicits massive host responses, particularly immune responses, which are intertwined with the parasite’s disruption of abomasal function, which likely impairs the nutrient utilization of the host. The infection is characterized by the absence of a dominant Th response and displaying a mixed activation of Th1, Th2, and Th17 pathways. Elevated expression of T cell exhaustion genes and lack of increase in epithelial alarmin cytokine genes suggest a downregulation of, or a deficiency in initiating, effective host immunity to the infection. Understanding mechanisms of parasite-mediated immune evasion and their nutritional consequences will facilitate the rational design of protective vaccines against infections of complex nematode parasites.

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Haemonchus contortus is a blood-feeding gastrointestinal nematode that significantly impacts the health and productivity of small ruminants. The burden of parasitism and the escalating incidence of anthelmintic resistance necessitate alternative control methods. Here, we characterize the enzymatic activities of five mammalian cell-expressed recombinant H. contortus cysteine proteases (HcCPs), which include two cathepsin B-like proteins (HcCBP1 and HcCBP2) and three cysteine protease 1 proteins (HcCP1a, HcCP1b, and HcCP1c). We hypothesize that these enzymes degrade host blood proteins, thereby facilitating the parasite’s nutrient acquisition and survival. Using synthetic cathepsin (cat) substrates, we show that HcCBP2 was the only protein that exhibited high catB/L but low catB or catK activity, which was inhibited by the cysteine protease inhibitor E-64. All mHcCPs degraded fibrinogen (Fg), which led to delayed plasma clotting, reduced clot density, and lysed plasma clots. All HcCPs partially degraded hemoglobin (Hb), except for mHcCBP2, which degraded Hb and bovine serum albumin completely and bovine IgG partially in the presence of a reducing agent. In conclusion, by sustaining blood feeding and facilitating immune evasion and nutrient acquisition, the HcCPs may play an essential role in the parasite’s survival. Thus, vaccines or cysteine protease inhibitors targeting these parasitic enzymes may mitigate or prevent infections.

Background/Objectives: Dietary intake of fruits and vegetables (FVs) has been inversely associated with a lower risk of ulcerative colitis. Using a pig model, we evaluated the effect of FV supplementation on dextran sulfate sodium (DSS)-induced colitis. Methods: Six-week-old pigs were fed a grower diet (negative control), grower diet + 4% DSS (positive control), half-FV diet + DSS, or full-FV diet + DSS. FV levels matched half or full daily recommendations from the Dietary Guidelines for Americans (DGA). Clinical signs were monitored; proximal colon contents (PCs) and mucosa (PCM) were analyzed for metagenome, transcriptome and histopathology. Results: Full-FV pigs showed no diarrhea, less fecal occult blood (FOB), crypt hyperplasia, but no changes in gene expression or microbiome diversity (p < 0.05). Half-FV pigs had increased FOB, differentially expressed genes (DEGs) linked to tissue remodeling, crypt/goblet cell hyperplasia and two cases of diarrhea (p < 0.05). DSS controls showed reduced immune-related DEGs, altered microbiome, PCM erosion, FOB, and persistent diarrhea in one pig (p < 0.05). Conclusions: A three-week full-FV diet conferred protection against DSS-induced colitis, with a dose-dependent protection of intestinal tissue and gut metagenome under inflammatory challenge.