Effects of supplemental bacteriophage on the gut microbiota and nutrient digestibility of ileal-cannulated pigs

Lacticaseibacillus casei IDCC 3451 alleviates cognitive and behavioral functions by reshaping the gut microbiome and regulating intestinal barrier integrity in chronic stress animal models

Lacticaseibacillus casei IDCC 3451 (3451) was evaluated for its effects on the gut-brain axis using Caenorhabditis elegans (C. elegans) and mouse models of stress and inflammation. In C. elegans, 3451 extended lifespans by 25 %, improved motility, and chemotaxis, enhanced survival under pathogen challenge, and reduced amyloid beta accumulation by 42 %. Transcriptomic profiling revealed upregulation of genes involved in neurotransmitter signaling and serine/threonine pathways. In the unpredictable chronic mild stress (UCMS) mouse model, 3451 administration increased the time spent in the center of the open field by 65 % and reduced immobility in the forced swim test by 32 %, indicating anxiolytic and antidepressant effects. Serum levels of aspartate aminotransferase (AST) and gamma-glutamyl transferase (GGT) were decreased by 18 % and 24 %, respectively. Additionally, 3451 restored the expressions of 5HT1AR, GABAR, and tight junction proteins, including ZO-1 and Claudin1. Metabolomic analysis showed increased glycine and decreased palmitic acid levels, associated with an increased abundance of Ruminococcus and Akkermansia. In the dextran sulfate sodium (DSS)-induced colitis model, 3451 reduced the disease activity index by 36 %, improved colon histology, increased goblet cell preservation, and upregulated ZO-1 and IL-10 expression. Threonine levels were also increased and correlated with a higher abundance of Coprococcus. These findings demonstrate that 3451 improved behavioral and intestinal outcomes through coordinated modulation of host signaling, metabolite production, and gut microbial composition, highlighting its therapeutic potential for managing IBD and neurobehavioral disorders.

Apparent metabolizable energy concentration and ileal amino acid digestibility in cereal grains fed to broiler chickens

OBJECTIVE

This study aimed to determine apparent metabolizable energy concentrations and ileal amino acid (AA) digestibility in cereal grains and to compare those metabolizable energy values between the total collection and index methods for 21-day-old broilers.

METHODS

On day 17 post-hatch, a total of 336 Ross 308 male broilers were assigned to 6 dietary treatments with 8 replicate cages (7 birds/cage). Five experimental diets were formulated to incorporate non-extruded corn, extruded corn, wheat, wheat flour, and barley as the sole source of AA and energy.

RESULTS

Retention of dry matter and nitrogen, and energy concentrations in cereal grains determined by the total collection method were greater (p<0.05) than those determined by the index method. Energy concentrations of non-extruded and extruded corn were greater (p<0.05) than those of wheat, wheat flour, and barley. Wheat flour exhibited greater (p<0.05) ileal AA digestibility than non-extruded and extruded corn. Extruded corn and wheat showed comparable ileal AA digestibility values, whereas barley had the lowest among cereal grains.

CONCLUSION

Energy concentrations of cereal grains determined by the total collection method were greater than those determined by the index method. Energy concentrations of non-extruded and extruded corn were greater compared to wheat, wheat flour, and barley, irrespective of the method used. The ileal AA digestibility in wheat flour was the greatest, followed by non-extruded corn, extruded corn, wheat, and barley in broilers.

Lactic Acid and Glutamine Have Positive Synergistic Effects on Growth Performance, Intestinal Function, and Microflora of Weaning Piglets

The objective of this study was to evaluate the effects of dietary addition of lactic acid and glutamine, and their interactions, on growth performance, nutrient digestibility, digestive enzyme activity, intestinal barrier functions, microflora, and expressions of intestinal development-related genes of weaning piglets. Ninety-six 24-day-old weaning piglets (Duroc × Landrace × Yorkshire, weaned at 21 ± 1 d and fed the basal diet for a 3 d adaptation period) with initial body weight of 7.24 ± 0.09 kg were randomly assigned to one of four dietary treatments with six replicates per treatment and four pigs per replicate in a 2 × 2 factorial treatment arrangements: (1) CON (a 2-period basal diet; control), (2) LS (supplemented with 2% lactic acid), (3) GS (supplemented with 1% glutamine), and (4) LGS (supplemented with 2% lactic acid and 1% glutamine). The study lasted for 28 d. On days 25-28, fresh fecal samples were collected to evaluate apparent total tract digestibility (ATTD) of nutrients. After 28 d, one weaning pig per pen was euthanized, and physiological samples obtained. Results showed that the supplementation of lactic acid improved the ADFI of the pigs (p < 0.05), while the pigs fed the glutamine diet had a greater ADFI and higher G/F (p < 0.05), and there were significant interactive effects between lactic acid and glutamine on the ADFI and G/F of the pigs (p < 0.05). The ATTD of CP and ash for pigs fed with lactic acid was significantly enhanced, and pigs fed the glutamine diet had greater ATTD of CP and ash (p < 0.05), while there were significant interactive effects between lactic acid and glutamine on the ATTD of CP and ash of the pigs (p < 0.05). Pigs fed with lactic acid exhibited greater activity of α-amylase and lipase (p < 0.05); moreover, the activity of lipase in the pigs showed a significant interactive effect between lactic acid and glutamine (p < 0.05). There was a greater villus height and villus height to crypt depth ratio in pigs fed with lactic acid (p < 0.05), and the villus height to crypt depth ratio of pigs fed with glutamine was greater (p < 0.05). There were greater GLUT2, IGF-1, TGF-β2, OCLN, and ZO-1 mRNA levels in pigs fed with lactic acid (p < 0.05), and the supplementation of glutamine increased SGLT1, GLUT2, PepT1, IGF-1, IGF-1R, TGFβ-2, GLP-2, and OCLN mRNA levels (p < 0.05), Additionally, expressions of SGLT1, GLUT2, PepT1, IGF-1, IGF-1R, TGFβ-2, GLP-2, CLDN-2, OCLN, and ZO-1 mRNA levels of pigs showed a positive interactive effect between lactic acid and glutamine (p < 0.05). Supplementation of lactic acid significantly increased the populations of Bifidobacterium in cecal digesta, Lactobacillus in colonic digesta, and the content of butyric acid in colonic digesta (p < 0.05). In addition, there were significant interactive effects between lactic acid and glutamine on populations of Bifidobacterium in cecal digesta, Lactobacillus in colonic digesta, and the content of acetic acid, butyric acid, and total VFAs in cecal digesta of the pigs (p < 0.05). Collectively, the current results indicate that dietary supplementation with lactic acid and glutamine had a positive synergistic effect on weaning pigs, which could improve growth performance through promoting the development of the small intestine, increasing digestive and barrier function, and regulating the balance of microflora in pigs, and which might be a potential feeding additive ensemble to enhance the health and growth of weaning piglets in the post-antibiotic era.

Limosilactobacillus fermentum SLAM 216-Derived Extracellular Vesicles Promote Intestinal Maturation in Mouse Organoid Models

Probiotics, when consumed in adequate amounts, can promote the health of the host and beneficially modulate the host's immunity. Particularly during the host's early life, the gut intestine undergoes a period of epithelial maturation in which epithelial cells organize into specific crypt and villus structures. This process can be mediated by the gut microbiota. Recent studies have reported that the administration of probiotics can further promote intestinal maturation in the neonatal intestine. Therefore, in this study, we investigated the effects of extracellular vesicles derived from the Limosilactobacillus fermentum SLAM 216 strain, which is an established probiotic with known immune and anti-aging effects on intestinal epithelial maturation and homeostasis, using mouse small intestinal organoids. As per our findings, treatment with L. fermentum SLAM 216-derived LF216EV (LF216EV) has significantly increased the bud number and size of organoid buds. Furthermore, extracellular vesicle (EV) treatment upregulated the expression of maturation-related genes, including Ascl2, Ephb2, Lgr5, and Sox9. Tight junctions are known to have an important role in the intestinal immune barrier, and EV treatment has significantly increased the expression of genes associated with tight junctions, such as Claudin, Muc2, Occludin, and Zo-1, indicating that it can promote intestinal development. This was supported by RNA sequencing, which revealed the upregulation of genes associated with cAMP-mediated signaling, which is known to regulate cellular processes including cell differentiation. Additionally, organoids exposed to LF216EV exhibited upregulation of genes associated with maintaining brain memory and neurotransmission, suggesting possible future functional implications.

Molecular characterization and environmental impact of newly isolated lytic phage SLAM_phiST1N3 in the Cornellvirus genus for biocontrol of a multidrug-resistant Salmonella Typhimurium in the swine industry chain

Salmonella Typhimurium is a highly lethal pathogenic bacterium in weaned piglets, causing significant treatment costs and economic losses in the swine industry. Additionally, due to its ability to induce zoonotic diseases, resulting in harm to humans through the transmission of the pathogen from pork, it presents a serious public health issue. Bacteriophages (phages), viruses that infect specific bacterial strains, have been proposed as an alternative to antibiotics for controlling pathogenic bacteria. In this study, we isolated SLAM_phiST1N3, a phage infecting a multidrug-resistant (MDR) S. Typhimurium wild-type strain isolated from diseased pigs. First, comparative genomics and phylogenetic analysis revealed that SLAM_phiST1N3 belongs to the Cornellvirus genus. Moreover, utilizing a novel classification approach introduced in this study, SLAM_phiST1N3 was classified at the species level. Host range experiments demonstrated that SLAM_phiST1N3 did not infect other pathogenic bacteria or probiotics derived from pigs or other livestock. While complete eradication of Salmonella was not achievable in the liquid inhibition assay, surprisingly, we succeeded in largely eliminating Salmonella in the FIMM analysis, a gut simulation system using weaned piglet feces. Furthermore, using the C. elegans model, we showcased the potential of SLAM_phiST1N3 to prevent S. Typhimurium infection in living organisms. In addition, it was confirmed that bacterial control could be achieved when phage was applied to Salmonella-contaminated pork. pH and temperature stability experiments demonstrated that SLAM_phiST1N3 can endure swine industry processes and digestive conditions. In conclusion, SLAM_phiST1N3 demonstrates potential environmental impact as a substance for Salmonella prevention across various aspects of the swine industry chain.

The current state of phage therapy in livestock and companion animals

In a global context, bacterial diseases caused by pathogenic bacteria have inflicted sustained damage on both humans and animals. Although antibiotics initially appeared to offer an easy treatment for most bacterial infections, the recent rise of multidrug-resistant bacteria, stemming from antibiotic misuse, has prompted regulatory measures to control antibiotic usage. Consequently, various alternatives to antibiotics are being explored, with a particular focus on bacteriophage (phage) therapy for treating bacterial diseases in animals. Animals are broadly categorized into livestock, closely associated with human dietary habits, and companion animals, which have attracted increasing attention. This study highlights phage therapy cases targeting prominent bacterial strains in various animals. In recent years, research on bacteriophages has gained considerable attention, suggesting a promising avenue for developing alternative substances to antibiotics, particularly crucial for addressing challenging bacterial diseases in the future.