Piglet Gut Research Articles

Probiotics in piglet: from gut health to pathogen defense mechanisms

Various problems and obstacles are encountered during pig farming, especially the weaning phase when switching from liquid to solid feed. Infection by pathogenic bacteria causes damage to the intestinal barrier function of piglets, disrupts the balance of the intestinal microbiota, and destroys the chemical, mechanical, and immune barriers of the intestinal tract, which is one of the main causes of gut inflammation or gut diseases in piglets. The traditional method is to add antibiotics to piglet diets to prevent bacterial infections. However, long-term overuse of antibiotics leads to bacterial resistance and residues in animal products, threatening human health and causing gut microbiota dysbiosis. In this context, finding alternatives to antibiotics to maintain pre- and post-weaning gut health in piglets and prevent pathogenic bacterial infections becomes a real emergency. The utilization of probiotics in piglet nutrition has emerged as a pivotal strategy to promote gut health and defend against pathogenic infections, offering a sustainable alternative to traditional antibiotic usage. This review introduces recent findings that underscore the multifaceted roles of probiotics in enhancing piglet welfare, from fortifying the gut barrier to mitigating the impacts of common bacterial pathogens. Meanwhile, this study introduces the functions of probiotics from different perspectives: positive effects of probiotics on piglet gut health, protecting piglets against pathogen infection, and the mechanisms of probiotics in preventing pathogenic bacteria.

PSVIII-23 Attenuation of oxidative stress and inflammatory response improves gut integrity in piglets after infection

Abstract Enterotoxigenic Escherichia coli (ETEC) is a primary cause of post-weaning diarrhea in piglets, leading to serious health issues and economic loss in the swine industry. Increased oxidative stress and inflammation have detrimental effects on gut health. The present study aimed to investigate the regulation of oxidative stress and inflammatory response in a piglet model challenged with ETEC and to evaluate whether the chosen probiotic could improve intestinal function in piglets. A total of 24 weaned piglets susceptible to ETEC F4 infection were randomly divided into four groups: Group 1 (control), Group 2 (E. coli infection), Group 3 (E. coli infection received antibiotic avilamycin), and Group 4 (E. coli infection received B. licheniformis HG76). Group 2, Group 3 and Group 4 were infected with E. coli by an oral gavage of ETEC F4 (5 mL, 1 × 106 CFU/mL). Five days after infection, piglets in all groups were euthanized. The blood and intestine samples (a mid-jejunum segment) were collected, and serum was prepared. ETEC infection significantly increased serum and jejunal malondialdehyde (MDA) concentrations and serum diamine oxidase (DAO) activity (P < 0.05). ETEC infection also significantly decreased tight-junction proteins (ZO1, occludin), superoxide dismutase-1 (SOD), and heme oxygenase-1 (HO-1) expression (P < 0.05). Furthermore, ETEC infection significantly increased the expression of pro-inflammatory cytokines [interlueken (IL) -6, tumor necrosis factor (TNF) -α] in the intestine (P < 0.05). Antibiotic or probiotic supplementation mitigated oxidative stress and inflammation, as evidenced by decreased oxidative stress biomarkers, increased expression of antioxidant enzymes (SOD, HO-1) and downregulated the expression of proinflammatory cytokines (IL-6, TNF-α; P < 0.05). Antibiotic or probiotic supplementation also improved intestinal integrity, as demonstrated by decreased DAO activity and increased tight-junction proteins expression (P < 0.05). These results suggest that attenuation of oxidative stress and inflammatory response can improve piglet gut integrity after ETEC infection.

Defined Pig Microbiota Mixture as Promising Strategy against Salmonellosis in Gnotobiotic Piglets.

Probiotics are a potential strategy for salmonellosis control. A defined pig microbiota (DPM) mixture of nine bacterial strains previously exhibited probiotic and anti-Salmonella properties in vitro. Therefore, we evaluated its gut colonization ability and protection effect against S. typhimurium LT2-induced infection in the gnotobiotic piglet model. The DPM mixture successfully colonized the piglet gut and was stable and safe until the end of the experiment. The colon was inhabited by about 9 log CFU g-1 with a significant representation of bifidobacteria and lactobacilli compared to ileal levels around 7-8 log CFU g-1. Spore-forming clostridia and bacilli seemed to inhabit the environment only temporarily. The bacterial consortium contributed to the colonization of the gut at an entire length. The amplicon profile analysis supported the cultivation trend with a considerable representation of lactobacilli with bacilli in the ileum and bifidobacteria with clostridia in the colon. Although there was no significant Salmonella-positive elimination, it seems that the administered bacteria conferred the protection of infected piglets because of the slowed delayed infection manifestation without translocations of Salmonella cells to the blood circulation. Due to its colonization stability and potential protective anti-Salmonella traits, the DPM mixture has promising potential in pig production applications. However, advanced immunological tests are needed.

Impact of dietary Laminaria digitata with alginate lyase or carbohydrase mixture on nutrient digestibility and gut health of weaned piglets

Laminaria digitata is a brown seaweed rich in prebiotic polysaccharides, mainly laminarin, but its alginate-rich cell wall could compromise nutrient access. Carbohydrase supplementation, such as individual alginate lyase and carbohydrases mixture (Rovabio® Excel AP), could enhance nutrient digestibility and prebiotic potential. This study aimed to evaluate the effect of these enzymes on nutrient digestibility and gut health of weaned piglets fed with 10% L. digitata. Diets did not affect growth performance (P > 0.05). The majority of the feed fractions had similar digestibility across all diets, but the supplementation of alginate lyase increased hemicellulose digestibility by 3.3% compared to the control group (P = 0.047). Additionally, we observed that algal zinc was more readily available compared to the control group, even without enzymatic supplementation (P < 0.001). However, the increased digestibility of some minerals, such as potassium, raises concerns about potential mineral imbalance. Seaweed groups had a higher abundance of beneficial bacteria in colon contents, such as Prevotella, Oscillospira and Catenisphaera. Furthermore, the addition of alginate lyase led to a lower pH in the colon (P < 0.001) and caecum (P < 0.001) of piglets, which is possibly a result of released fermentable laminarin, and is consistent with the higher proportion of butyric acid found in these intestinal compartments. L. digitata is a putative supplement to enhance piglet gut health due to its prebiotic polysaccharides. Alginate lyase supplementation further improves nutrient digestibility and prebiotic potential. These results suggest the potential use of L. digitata and these enzymatic supplements in commercial piglet-feeding practices.

PSIII-14 Effect of a combined supplementation of Bacillus spp. and lactic acid bacteria probiotics on growth performance and fecal score in nursery pigs

Abstract This experiment was conducted to evaluate the effect of a combined supplementation of Bacillus spp. and lactic acid bacteria probiotics on growth performance and fecal score in nursery pigs. Bacillus spp. probiotics have been shown to improve the proliferation of lactic acid bacteria in the gut of piglets. A total of 45 newly weaned piglets (initial body weight = 8.37 ± 1.38 kg; weaning age = 27.2 ± 1.05 d) were allotted to 3 treatments in 3 replicates with 5 pigs per pen based on body weight, gender, and breed for a 28-d feeding trial. Treatments were: 1) Control: no probiotic supplementation, 2) PB: Bacillus spp. probiotic supplementation, and 3) PBL: Bacillus spp. and lactic acid bacteria probiotic supplementation. The Bacillus spp. probiotic consisted of Bacillus subtilis and Bacillus licheniformis and was supplemented to the PB and PBL diets at the recommended level (3.2 × 109 CFU/kg diet). The lactic acid bacteria probiotic consisted of Lactobacillus acidophilus, plantarum, casei, and Enterococcus faecium strains and was supplemented to the diets at the recommended level (4 and 2 × 107 CFU/kg diet for Phase 1 and 2, respectively). Corn-soybean meal-based diets were used for d 0-15 (Phase 1) and d 15-28 (Phase 2) postweaning. Growth performance and fecal score (1 = normal, 4 = severe diarrhea) were measured in each phase. In the Phase 1 (d 0-15 postweaning), average daily gain tended to be greater in the PBL treatment compared with the Control treatment (P = 0.13; 0.268 and 0.210 kg/d, respectively), and average daily feed intake tended to be greater in the PBL treatment compared with the Control and PB treatments (P = 0.12; 0.385, 0.375, and 0.424 kg/d for the Control, PB, and PBL treatments, respectively). In the overall period (d 0-28 postweaning), average daily feed intake tended to be greater in the PBL treatment compared with the PB treatment (P = 0.07; 0.651 and 0.596 kg/d, respectively), and gain to feed ratio in the PB treatment tended to be greater compared with the Control and PBL treatments (P = 0.10; 0.618, 0.649, and 0.620 kg/d for the Control, PB, and PBL treatments, respectively). Fecal score was significantly improved in both PB and PBL treatments compared with the Control treatment from d 7 postweaning (P = 0.08) to the end of experiment (P &amp;lt; 0.05; 1.75, 1.41, and 1.42 for the Control, PB, and PBL treatments, respectively). In conclusion, both lactic acid bacteria and Bacillus spp. probiotic supplementation to nursery diets may have potential to improve growth rate and feed intake in early nursery period and probiotic supplementation could improve fecal consistency of weaning pigs in the nursery period.

PSI-17 Effect of timing of high dietary zinc supplementation on the microbiome of gestating sows and their piglets

Abstract The objective of this study was to assess if high dietary zinc (Zn) fed to gestating sows modulates the microbiome of the sow and that of their offspring. Sows were fed 1 of 3 dietary treatments: 1) Control: a corn-soybean meal-based diet containing 125 ppm total supplemental zinc, 2) Breed-to-Farrow: as Control + 141 ppm supplemental Zn as ZnSO4 fed from 5 d post-breeding to farrowing; and 3) Day 110-to-Farrow: as Control + 2,715 ppm supplemental Zn as ZnSO4 starting on d 110 of gestation until farrowing. A subset of third parity sows (n = 30; 10 per treatment) were selected to assess the microbiome of colostrum, milk, and rectal and vaginal surfaces of sows. At farrowing, 4 pigs per litter (n = 120) were selected based on birthweight (BiW; 2 average BiW pigs and 2 pigs with BiW below the litter average) were selected to assess the piglet gut microbiome on the day of birth (d 0) and d5 of age. 16S rRNA sequencing was implemented for colostrum and milk samples while all other sample types were sequenced using shotgun metagenomics to determine taxonomic and functional profiles. Measures of alpha and beta diversity were conducted along with determination of differentially abundant taxa and pathways in tandem with generalized linear mixed models. Greater dietary concentrations of Zn fed to gestating sows minimally affected their colostrum, milk, and vaginal microbiome. However, fecal samples of Breed-to-Farrow sows showed decreased abundance of potentially pathogenic bacteria such as Salmonella enterica and Shigella flexneri and greater abundance of bacteria typically involved in fiber fermentation compared with Control sows (Figure 1a). Piglets born to Day 110-to-Farrow sows also showed greater abundance of some taxa typically involved in fiber breakdown and short chain fatty acid (SCFA) generation on d 5 compared with Control pigs (Figure 1b). At d 0, Breed-to-Farrow piglets showed less abundance of methanogenic archaea and differential abundance of taxa with potentially pathogenic roles, compared with Control pigs (Figure 1c). Gene families and pathways playing roles in central metabolic functions (starch, pyruvate, sucrose, amino acid metabolism) were more abundant in Breed-to-Farrow piglets compared with pigs born to Control sows on d 0 and 5 of age. In conclusion, greater Zn fed to gestating sows impacted the abundance of gut taxa with potential roles in SCFA-production and pathogenicity in both sow and piglet, despite overall minor effects. However, the physiological significance of these findings for the sow and piglet remains unclear.

Protecting the piglet gut microbiota against ETEC-mediated post-weaning diarrhoea using specific binding proteins

Post-weaning diarrhoea (PWD) in piglets presents a widespread problem in industrial pig production and is often caused by enterotoxigenic E. coli (ETEC) strains. Current solutions, such as antibiotics and medicinal zinc oxide, are unsustainable and are increasingly being prohibited, resulting in a dire need for novel solutions. Thus, in this study, we propose and evaluate a protein-based feed additive, comprising two bivalent heavy chain variable domain (VHH) constructs (VHH-(GGGGS)3-VHH, BL1.2 and BL2.2) as an alternative solution to manage PWD. We demonstrate in vitro that these constructs bind to ETEC toxins and fimbriae, whilst they do no affect bacterial growth rate. Furthermore, in a pig study, we show that oral administration of these constructs after ETEC challenge reduced ETEC proliferation when compared to challenged control piglets (1-2 log10 units difference in gene copies and bacterial count/g faeces across day 2–7) and resulted in week 1 enrichment of three bacterial families (Prevotellaceae (estimate: 1.12 ± 0.25, q = 0.0054), Lactobacillaceae (estimate: 2.86 ± 0.52, q = 0.0012), and Ruminococcaceae (estimate: 0.66 ± 0.18, q = 0.049)) within the gut microbiota that appeared later in challenged control piglets, thus pointing to an earlier transition towards a more mature gut microbiota. These data suggest that such VHH constructs may find utility in industrial pig production as a feed additive for tackling ETEC and reducing the risk of PWD in piglet populations.

The pig intestinal phageome is an important reservoir and transfer vector for virulence genes

Bacteriophages (phages) can significantly influence the composition and functions of their host communities, and enhance host pathogenicity via the transport of phage-encoded virulence genes. Phages are the main component of animal gut viruses, however, there are few reports on the piglet gut phageome and its contribution to virulence genes. Here, a total of 185 virulence genes from 59,955 predicted genes of gut phages in weaned piglets were identified, with 0.688 % of the phage contigs coding for at least one virulence gene. The virulence gene pblA was the most abundant, with various virulence genes significantly correlated with gut phages and their encoded mobile gene element (MGE) genes. Importantly, multiple virulence genes and MGE genes coexist in some phage sequences, and up to 12 virulence genes were detected in a single phage sequence, greatly increasing the risk of phage-mediated transmission of virulence genes into the bacterial genome. In addition, diarrhoea has driven changes in the composition and structure of phage and bacterial communities in the intestinal tract of weaned piglets, significantly increasing the abundance of phage contigs encoding both virulence genes and MGE genes in faecal samples, which potentially increases the risk of phage-mediated virulence genes being transfected into the gut bacterial genome. In summary, this study expands our understanding of the gut microbiome of piglets, advances our understanding of the potential role of phages in driving host pathogenesis in the gut system, and provides new insights into the sources of virulence genes and genetic evolution of bacteria in pig farm environments.

Effects of early postnatal gastric and colonic microbiota transplantation on piglet gut health

BackgroundDiarrhea is a major cause of reduced growth and mortality in piglets during the suckling and weaning periods and poses a major threat to the global pig industry. Diarrhea and gut dysbiosis may in part be prevented via improved early postnatal microbial colonization of the gut. To secure better postnatal gut colonization, we hypothesized that transplantation of colonic or gastric content from healthy donors to newborn recipients would prevent diarrhea in the recipients in the post-weaning period. Our objective was to examine the impact of transplanting colonic or gastric content on health and growth parameters and paraclinical parameters in recipient single-housed piglets exposed to a weaning transition and challenged with enterotoxigenic Escherichia coli (ETEC).MethodsSeventy-two 1-day-old piglets were randomized to four groups: colonic microbiota transplantation (CMT, n = 18), colonic content filtrate transplantation (CcFT, n = 18), gastric microbiota transplantation (GMT, n = 18), or saline (CON, n = 18). Inoculations were given on d 2 and 3 of life, and all piglets were milk-fed until weaning (d 20) and shortly after challenged with ETEC (d 24). We assessed growth, diarrhea prevalence, ETEC concentration, organ weight, blood parameters, small intestinal morphology and histology, gut mucosal function, and microbiota composition and diversity.ResultsEpisodes of diarrhea were seen in all groups during both the milk- and the solid-feeding phase, possibly due to stress associated with single housing. However, CcFT showed lower diarrhea prevalence on d 27, 28, and 29 compared to CON (all P < 0.05). CcFT also showed a lower ETEC prevalence on d 27 (P < 0.05). CMT showed a higher alpha diversity and a difference in beta diversity compared to CON (P < 0.05). Growth and other paraclinical endpoints were similar across groups.ConclusionIn conclusion, only CcFT reduced ETEC-related post-weaning diarrhea. However, the protective effect was marginal, suggesting that higher doses, more effective modalities of administration, longer treatment periods, and better donor quality should be explored by future research to optimize the protective effects of transplantation.

Metagenomic Sequencing Analysis of the Effects of Acetylcysteine on the Pig Gut Microbiome

The gut microbiota is engaged in multiple interactions affecting host health, and gut dysbiosis can lead to many diseases. However, the effects of acetylcysteine (NAC) on the gut microbiome composition in pigs using metagenomic sequencing have not been reported. In this study, we used metagenome sequencing to study the effects of NAC on the pig gut microbiome. Sequencing results showed that microbial diversity was changed after NAC treatment. Antibiotic Resistance Genes Database (ARDB) analysis demonstrated that the main genes modified were macb, tsnr, norm, bl2be-per, vansb and pbp1b in the NAC group. Our data showed that NAC could affect microbial distribution at the phylum, gene and species levels. At the species level, NAC significantly increased the abundances of Megasphaera, Lactobacillus reuteri and Megasphaeraelsdenii and reduced the abundances of Phascolarctobacterium succinatutens, Prevotellacopri and Selenomonasbovis compared with the control group. In addition, Gene Ontology (GO) analysis revealed that in the NAC group, cellular process, metabolic process and single-organism process were the dominant terms. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis demonstrated that RNA transport, MAPK signaling pathway, cell cycle, glycosylphosphatidylinositol (GPI)-anchor biosynthesis and VEGF signaling pathway were the dominant signaling pathways in the NAC group. In conclusion, our results suggest that NAC may modify the piglet gut microbiome composition and these findings might provide a new strategy for maintaining animal and human health in the future.

PSXI-11 Microbiome Taxa Involved in Carbohydrate Breakdown and Synthesis of Short Chain Fatty Acids in the Piglet Gut

Abstract The gut microbiome plays a critical role in swine health and growth, and diet is a key factor which shapes microbiome communities. In particular, the fermentation of indigestible carbohydrates by microbes has important consequences for microbiome composition and host health. Pigs do not encode all the enzymes needed to breakdown dietary polysaccharides, but bacteria contain numerous carbohydrate-active enzymes (CAZys) which contribute to this task. In addition, microbial fermentation of carbohydrates produces many bioactive metabolites such as short chain fatty acids (SCFAs). The relationships between microbes, dietary components, and the pig are complex, but a thorough understanding of these interactions would promote the design of interventions which target the microbiome and improve swine growth, especially during the critical weaning transition. At weaning, the microbiome undergoes rapid compositional changes as the diet shifts from milk to plant based. Here, we use quantitative (TMT)-based liquid chromatography tandem mass spectrometry (LC-MS/MS) to identify and quantitate piglet and microbial proteins in the gut during the weaning transition, with a focus on those involved in carbohydrate breakdown and nutrient synthesis. We analyzed 6 fecal samples from healthy, nursery piglets at weaning [day 21 postnatal (PN)] and 6 samples taken two weeks later, after acclimation to nursery diet (day 49 PN). In total, we detected 14,319 bacterial and fungal protein groups and 1,835 pig protein groups, and abundances of roughly one-half of the protein groups changed significantly over time (P = 0.05, fold change &amp;gt; 1.5). As expected, from weaning to day 49 PN, expression of glycoside hydrolases (GHs) which degrade milk oligosaccharides decreased, while the abundance of most enzymes which degrade plant carbohydrates such as xylan, cellulose, and starch, increased. Some plant-degrading enzymes were most abundant during weaning, which may reflect the tendency for piglets to steal solid feed from their mothers during nursing. Subdoligranulum was one of the top producers of multiple GHs capable of degrading milk or plant carbohydrates, while other genera specialized in the production of enzymes which targeted either milk oligosaccharides (Blautia, Lachnoclostridium Clostridium, Fournierella, Faecalibacterium, Eisenbergiella) or plant carbohydrates (Prevotella, Selemonas, Anaerovibrio). Aspergillus produced an uncharacterized protein predicted to degrade plant xyloglucan, highlighting the contributions of fungi in swine digestion. Host glycan-degrading enzymes decreased over time. Last, we detected acetate and butyrate production enzymes including acetate kinase (26 genera) and phosphate acetyltransferase (9 genera), and butyrate kinase and phosphate butyryltransferase from Subdoligranulum. Together, these data identify specific enzymes and the microbes that produce them during the transition from a milk to plant-based diet. This information provides a more robust understanding of digestion in the weanling pig and will ultimately provide a basis for effective design of probiotics and other therapeutics which target the gut microbiome to enhance swine growth and productivity.

276 Investigating the Colonization History of Early-Life Microbiome of Piglets

Abstract Early-life microbiome establishment and colonization is essential for gut development, nutrient digestion and metabolism, and modulation of the immune system. Microbial colonization of the infant digestive tract begins at birth, and as such, maternal microbiota has an important influence on the early-life establishment and colonization of the infant gut microbiota. Therefore, perturbations during early life establishment of the infant gut microbiome may have long-term impact on the microbiota composition and function, and may serve as a major determinant on host health and development. To evaluate the effects of early life microbiomes on long-term colonization of the microbiome, and effect host function, we set out to quantify the percentage of the sow microbiome that contributes to early-life colonization in the piglet and how such microbiomes would persist within the piglet gut. To this end, we investigated the colonization history and the role of the sow microbiome in establishment of the piglet microbiome over time using 16S rRNA sequencing. We observed 125 amplicon sequence variants to be persistent across different sampling time points, day 0, day 14, and day 21, representing 89.73%, 68.99%, and 67.30% of the total reads on day 0, day 14 and day 21, recovered from the piglets respectively. Comparing the piglet microbiota to that of the sow, we observed 114 of the 125 persistent ASVs in the piglet microbiota to arise from the sow that account for 75% of the total reads in the sow microbiota. This core microbiome includes Bacteroides, Methanobrevibacter, Lachnoclostridium, Lactobacillus, Escherichia-Shigella, Clostridium sensu stricto 1, Christensenellaceae R-7 group, Ruminococcaceae Genus, Romboutsia, Phascolarctobacterium, Erysipelotrichaceae Genus, Muribaculaceae Genus, Streptococcus, [Eubacterium] coprostanoligenes group Genus and others. The species abundance increased for Bacteroides, Methanobrevibacter, Lachnoclostridium, Clostridium sensu stricto 1, Lactobacillus, Christensenellaceae R-7 group, Ruminococcaceae Genus, Romboutsia, Phascolarctobacterium, Erysipelotrichaceae Genus, Muribaculaceae Genus, Streptococcus, [Eubacterium] coprostanoligenes group Genus and other species over time while species abundance of pathogens or opportunistic pathogens such as Escherichia-Shigella and Salmonella species decreased over time. In conclusion, the maternal microbiota has an important role in early-life microbiome establishment and can be utilized to develop a more beneficial microbiome to increase pig health and productivity.

279 Maternal Programming of the Piglet Microbiome Through Supplementation with a Yeast Feed Additive

Abstract The objective of this study was to investigate effects of live yeast supplementation of sow diets during late gestation and lactation on sow reproductive performance and piglet microbiome development. Three dietary treatments were imposed on mixed-parity sows (n = 92) from three contemporary farrowing groups during late gestation and lactation. Dietary treatments were based upon the inclusion level (%) of Actisaf Sc47 in corn/soybean meal-based diets: Control (C, 0%), Low (L, 0.1%), and High (H, 0.5%). Sows were fed their assigned gestation diet (1.8 kg ∙animal-1∙day-1/) from days 85 to 110 of gestation. On day 111 of gestation, sows were fed their assigned lactation diet (3.6 kg/head/day) until parturition. Sows were allowed ad libitum access to their assigned lactation diet beginning day one postpartum until piglets were weaned. Fecal and vaginal swabs were collected from all sows on day 85 of gestation (T1-S) and the day before parturition (T2-S). Colostrum and milk samples were collected from 30 focal sows (10/treatment group), and fecal swabs were collected from 6 piglets per focal sow (n = 180) at 24 to 36 hours after birth (T1-P) and weaning (T2-P, ~19 days old). Extracted DNA from swab samples was sequenced on the MiSeq platform targeting the V4 variable region of the 16S rRNA bacterial gene, and sequence data were analyzed using DADA2 plus various packages within the R statistical software. Generalized linear mixed models were built for sow performance data using the R lme4 package, with treatment as a fixed effect, and farrowing group, parity, and sire as random effects. Piglet performance models also included sex as a fixed effect and maternal origin instead of sire as a random effect. No significant differences were observed among dietary treatment groups for gestation or lactation length, lactation feed intake, sow body weights, sow backfat depth, litter size at birth or weaning, pre-weaning piglet mortalities, or piglet growth performance. Although alpha and beta diversity did not differ among maternal dietary treatment groups in sow colostrum, milk, fecal, or vaginal samples (T1-S or T2-S), several taxa were significantly enriched or less abundant in sow samples based upon dietary yeast inclusion levels. Diversity of piglet fecal microbiomes was not different across maternal dietary treatment groups, but community composition was different at both time-points (T1-P: PERMANOVA, R2 = 0.13, P=0.02; T2-P: PERMANOVA, R2 = 0.01, P=0.048). These results indicate that yeast supplementation in sow diets in late gestation and lactation may influence development and composition of piglet gut microbiomes in early life.

87 Improving Pig Livability Before, During, and After Parturition

Abstract Nearly a quarter of piglets are lost from farrowing to weaning, with stillbirths representing about 7.5% and preweaning mortality contributing another 15.7% in North America (Pigchamp, Metafarm). This averages to a loss of 7.37 pigs per sow per year resulting in significant economic loss and animal welfare concerns. Main contributors of low piglet survivability include poor sow body condition at farrowing, long farrowing duration, piglet asphyxiation, insufficient colostrum consumption, and health challenges. Piglet livability can be improved through nutrition and management solutions before, during, and after parturition. In this context three main strategies have been shown to be effective: 1) managing sow body composition, 2) improving fetal oxygen and nutrient supply via the nitric oxide pathway, and 3) improving piglet health through functional ingredients in the diet of the sow. Highly prolific sows (&amp;gt; 16 born alive) lose both backfat and muscle during the later stages of gestation. Additionally, loin depth loss is more detrimental for piglet survival compared with backfat loss. Sows with the highest stillborn (&amp;gt; 2 per litter) lose the most loin muscle depth regardless of genetics. A solution to reduce this effect and improve piglet survivability is a two-phase gestation feeding with more amino acids in late gestation. Average farrowing duration of a highly prolific sow is 300 minutes and increasing with larger litters. To make things worse, most sows are going through farrowing without food and/or drink. Nutrients and energy supply to sow are critical for shorting farrowing duration and piglet survivability. Compared with pigs that died before weaning, surviving pigs at weaning have greater blood oxygen and less carbon dioxide and lactate at birth. Nitric oxide boosting technologies have been used widely to enhance athletic performance and increase endurance. This vasodilative effect of nitric oxide can be used similarly in sows to increased placental blood flow and thus oxygen and nutrient supply to fetuses. This reduces the risk of asphyxiation and therefore can increase piglet vitality at birth and decreases stillbirth and pre-weaning mortality. Post-parturition health challenge poses a large risk to piglet survivability. Functional feed ingredients, such as botanicals, are a potential solution to improve piglet health and resilience to challenging conditions. Some botanicals can pass through placenta and milk to supply piglets. Milk from sows fed specific botanicals has been shown to improve inhibitory activity against Bacillus subtilis and Staphylococcus aureus. Some specific botanicals can improve sow and piglet antioxidant status, and piglet gut health. In conclusion, managing sow body condition, nitric oxide pathway stimulation, and functional sow diets are effective ways to improve piglet survivability in challenging environments.

Regulation of serotonin production by specific microbes from piglet gut

BackgroundSerotonin is an important signaling molecule that regulates secretory and sensory functions in the gut. Gut microbiota has been demonstrated to affect serotonin synthesis in rodent models. However, how gut microbes regulate intestinal serotonin production in piglets remains vague. To investigate the relationship between microbiota and serotonin specifically in the colon, microbial composition and serotonin concentration were analyzed in ileum-cannulated piglets subjected to antibiotic infusion from the ileum when comparing with saline infusion. Microbes that correlated positively with serotonin production were isolated from piglet colon and were further used to investigate the regulation mechanisms on serotonin production in IPEC-J2 and a putative enterochromaffin cell line RIN-14B cells.ResultsAntibiotic infusion increased quantities of Lactobacillus amylovorus (LA) that positively correlated with increased serotonin concentrations in the colon, while no effects observed for Limosilactobacillus reuteri (LR). To understand how microbes regulate serotonin, representative strains of LA, LR, and Streptococcus alactolyticus (SA, enriched in feces from prior observation) were selected for cell culture studies. Compared to the control group, LA, LR and SA supernatants significantly up-regulated tryptophan hydroxylase 1 (TPH1) expression and promoted serotonin production in IPEC-J2 cells, while in RIN-14B cells only LA exerted similar action. To investigate potential mechanisms mediated by microbe-derived molecules, microbial metabolites including lactate, acetate, glutamine, and γ-aminobutyric acid were selected for cell treatment based on computational and metabolite profiling in bacterial supernatant. Among these metabolites, acetate upregulated the expression of free fatty acid receptor 3 and TPH1 while downregulated indoleamine 2,3-dioxygenase 1. Similar effects were also recapitulated when treating the cells with AR420626, an agonist targeting free fatty acid receptor 3.ConclusionsOverall, these results suggest that Lactobacillus amylovorus showed a positive correlation with serotonin production in the pig gut and exhibited a remarkable ability to regulate serotonin production in cell cultures. These findings provide evidence that microbial metabolites mediate the dialogue between microbes and host, which reveals a potential approach using microbial manipulation to regulate intestinal serotonin biosynthesis.

Temporal Microbial Dynamics in Feces Discriminate by Nutrition, Fecal Color, Consistency and Sample Type in Suckling and Newly Weaned Piglets.

Feces enable frequent samplings for the same animal, which is valuable in studies investigating the development of the gut microbiome in piglets. Creep feed should prepare the piglet's gut for the postweaning period and shape the microbiome accordingly. Little is known about the variation that is caused by differences in fecal color and consistency and different sample types (feces versus swab samples). Therefore, this study evaluated the age-related alterations in the microbiome composition (16S rRNA gene) in feces of suckling and newly weaned piglets in the context of nutrition and fecal consistency, color and sample type from day 2 to 34 of life. Feces from 40 healthy piglets (2 each from 20 litters) were collected on days 2, 6, 13, 20, 27, 30 and 34. Weaning occurred on day 28. Half of the litters only drank sow milk during the suckling phase, whereas the other half had access to creep feed from day 10. Creep feeding during the suckling phase influenced the age-related total bacterial and archaeal abundances but had less of an influence on the relative bacterial composition. Results further showed different taxonomic compositions in feces of different consistency, color and sample type, emphasizing the need to consider these characteristics in comprehensive microbiome studies.

In Vitro Effect on Piglet Gut Microbiota and In Vivo Assessment of Newly Isolated Bacteriophages against F18 Enterotoxigenic Escherichia coli (ETEC).

Enterotoxigenic Escherichia coli (ETEC) causing post-weaning diarrhea (PWD) in piglets have a detrimental impact on animal health and economy in pig production. ETEC strains can adhere to the host's small intestinal epithelial cells using fimbriae such as F4 and F18. Phage therapy could represent an interesting alternative to antimicrobial resistance against ETEC infections. In this study, four bacteriophages, named vB_EcoS_ULIM2, vB_EcoM_ULIM3, vB_EcoM_ULIM8 and vB_EcoM_ULIM9, were isolated against an O8:F18 E. coli strain (A-I-210) and selected based on their host range. These phages were characterized in vitro, showing a lytic activity over a pH (4-10) and temperature (25-45 °C) range. According to genomic analysis, these bacteriophages belong to the Caudoviricetes class. No gene related to lysogeny was identified. The in vivo Galleria mellonella larvae model suggested the therapeutic potential of one selected phage, vB_EcoS_ULIM2, with a statistically significant increase in survival compared to non-treated larvae. To assess the effect of this phage on the piglet gut microbiota, vB_EcoS_ULIM2 was inoculated in a static model simulating the piglet intestinal microbial ecosystem for 72 h. This study shows that this phage replicates efficiently both in vitro and in vivo in a Galleria mellonella model and reveals the safety of the phage-based treatment on the piglet microbiota.

Age Rather Than Supplementation with Oat β-Glucan Influences Development of the Intestinal Microbiota and SCFA Concentrations in Suckling Piglets.

The effects of early supplementation with oat β-glucan during the suckling period on piglet gut microbiota composition, concentrations of short-chain fatty acids, and gut physiological markers were assessed. Fifty piglets from five litters, balanced for sex and birth weight, were divided within litters into two treatment groups: β-glucan and control. Piglets in the β-glucan group received the supplement three times/week from day 7 of age until weaning. Rectal swab samples were collected from 10 piglets per treatment group (balanced across litters) from week 1 to week 4, and plasma samples were collected at 1, 3, and 4 weeks of age. Additional samples of intestinal tissues and jugular and portal vein plasma were collected from 10 animals at weaning (one per treatment group and litter). The concentrations of short-chain fatty acids in plasma and the microbiota composition in rectal swabs were mainly influenced by piglet age, rather than the supplement. There were significant differences in microbiota composition between litters and several correlations between concentrations of short-chain fatty acids in plasma and specific microbial taxa in rectal swabs. Overall, β-glucan supplementation did not have any clear impact on the gut environment in suckling piglets, whereas a clear age-related pattern emerged.

Impact of Intestinal Microbiota on Growth Performance of Suckling and Weaned Piglets.

Small-scale studies investigating the relationship between pigs' intestinal microbiota and growth performance have generated inconsistent results. We hypothesized that on farms under favorable environmental conditions (e.g., promoting sow nest-building behavior, high colostrum production, low incidence of diseases and minimal use of antimicrobials), the piglet gut microbiota may develop toward a population that promotes growth and reduces pathogenic bacteria. Using 16S rRNA gene amplicon sequencing, we sampled and profiled the fecal microbiota from 170 individual piglets throughout suckling and postweaning periods (in total 670 samples) to track gut microbiota development and its potential association with growth. During the suckling period, the dominant genera were Lactobacillus and Bacteroides, the latter being gradually replaced by Clostridium sensu scricto 1 as piglets aged. The gut microbiota during the nursery stage, not the suckling period, predicted the average daily growth (ADG) of piglets. The relative abundances of SCFA-producing genera, in particular Faecalibacterium, Megasphaera, Mitsuokella, and Subdoligranulum, significantly correlated with high ADG of weaned piglets. In addition, the succession of the gut microbiota in high-ADG piglets occurred faster and stabilized sooner upon weaning, whereas the gut microbiota of low-ADG piglets continued to mature after weaning. Overall, our findings suggest that weaning is the major driver of gut microbiota variation in piglets with different levels of overall growth performance. This calls for further research to verify if promotion of specific gut microbiota, identified here at weaning transition, is beneficial for piglet growth. IMPORTANCE The relationship between pigs' intestinal microbiota and growth performance is of great importance for improving piglets' health and reducing antimicrobial use. We found that gut microbiota variation is significantly associated with growth during weaning and the early nursery period. Importantly, transitions toward a mature gut microbiota enriched with fiber-degrading bacteria mostly complete upon weaning in piglets with better growth. Postponing the weaning age may therefore favor the development of fiber degrading gut bacteria, conferring the necessary capacity to digest and harvest solid postweaning feed. The bacterial taxa associated with piglet growth identified herein hold potential to improve piglet growth and health.

Porcine fungal mock community analyses: Implications for mycobiome investigations.

The gut microbiome is an integral partner in host health and plays a role in immune development, altered nutrition, and pathogen prevention. The mycobiome (fungal microbiome) is considered part of the rare biosphere but is still a critical component in health. Next generation sequencing has improved our understanding of fungi in the gut, but methodological challenges remain. Biases are introduced during DNA isolation, primer design and choice, polymerase selection, sequencing platform selection, and data analyses, as fungal reference databases are often incomplete or contain erroneous sequences. Here, we compared the accuracy of taxonomic identifications and abundances from mycobiome analyses which vary among three commonly selected target gene regions (18S, ITS1, or ITS2) and the reference database (UNITE - ITS1, ITS2 and SILVA - 18S). We analyze multiple communities including individual fungal isolates, a mixed mock community created from five common fungal isolates found in weanling piglet feces, a purchased commercial fungal mock community, and piglet fecal samples. In addition, we calculated gene copy numbers for the 18S, ITS1, and ITS2 regions of each of the five isolates from the piglet fecal mock community to determine whether copy number affects abundance estimates. Finally, we determined the abundance of taxa from several iterations of our in-house fecal community to assess the effects of community composition on taxon abundance. Overall, no marker-database combination consistently outperformed the others. Internal transcribed space markers were slightly superior to 18S in the identification of species in tested communities, but Lichtheimia corymbifera, a common member of piglet gut communities, was not amplified by ITS1 and ITS2 primers. Thus, ITS based abundance estimates of taxa in piglet mock communities were skewed while 18S marker profiles were more accurate. Kazachstania slooffiae displayed the most stable copy numbers (83-85) while L. corymbifera displayed significant variability (90-144) across gene regions. This study underscores the importance of preliminary studies to assess primer combinations and database choice for the mycobiome sample of interest and raises questions regarding the validity of fungal abundance estimates.