Fatty acids, inflammation and intestinal health in pigs

Insect meal in aquafeeds: A sustainable path to enhanced mucosal immunity in fish

The mucosal surfaces of fish, including their intestines, gills, and skin, are constantly exposed to various environmental threats, such as water quality fluctuations, pollutants, and pathogens. However, various cells and microbiota closely associated with these surfaces work in tandem to create a functional protective barrier against these conditions. Recent research has shown that incorporating specific feed ingredients into fish diets can significantly boost their mucosal and general immune response. Among the various ingredients being investigated, insect meal has emerged as one of the most promising options, owing to its high protein content and immunomodulatory properties. By positively influencing the structure and function of mucosal surfaces, insect meal (IM) has the potential to enhance the overall immune status of fish. This review provides a comprehensive overview of the potential benefits of incorporating IM into aquafeed as a feed ingredient for augmenting the mucosal immune response of fish.

Carrier state of enterotoxigenic Escherichia coli virulence markers in pigs: Effects on gut microbiota modulation and immune markers transcription

Enterotoxigenic Escherichia coli (ETEC) causes diarrhea in pigs at early age, leading to high mortality rates and significant economic losses in the swine industry. ETEC effect on gut microbiota and immune system is mostly studied in diarrheic model under controlled laboratory conditions, however its impact on asymptomatic carriers remains unknown. Thus, we investigated whether ETEC can modulate gut microbiota or regulate the transcription of immune markers in asymptomatic pigs in farm environment. Stool samples from newborn piglets, nursery and growing pigs, and sows were screened for ETEC markers, then submitted to 16S-rDNA sequencing to explore gut microbiota composition in carriers (ETEC+) and non-carriers (ETEC-) animals. We observed a reduced α-diversity in ETEC+ animals (p < 0.05), while bacterial compositions were mostly driven by ageing (p > 0.05). Prevotella marked ETEC-carrier group, while Rikenellaceae RC9 gut group was a marker for a healthy gut microbiota, suggesting that they might be biomarker candidates for surveillance and supplementation purposes. Furthermore, we observed transcription regulation of il6 and tff2 genes in ETEC+ in newborn and nursery stages, respectively. Our findings indicate that ETEC presence modulate gut microbiota and the immune response in asymptomatic pigs; nevertheless, further studies using a probabilistic design must be performed to assess the effect of ETEC presence on gut imbalance in pigs despite the age bias.

Short-chain fatty acids modulate the IPEC-J2 cell response to pathogenic E. coli LPS-activated PBMC

Intestinal disorders can affect pigs of any age, especially when animals are young and more susceptible to infections and environmental stressors. For instance, pathogenic E. coli can alter intestinal functions, thus leading to altered nutrient adsorption by interacting with local cells through lipopolysaccharide (LPS). Among several compounds studied to counteract the negative effects on the intestine, short-chain fatty acids (SCFA) were demonstrated to exert beneficial effects on gut epithelial cells and resident immune cells. In this study, acetate and propionate were tested for their beneficial effects in a co-culture model of IPEC-J2 and porcine PBMC pre-stimulated with LPS from E. coli 0111:B4 aimed at mimicking the interaction between intestinal cells and immune cells in an inflammatory/activated status. IPEC-J2 viability was partially reduced when co-cultured with activated PBMC and nitric oxide concentration increased. IPEC-J2 up-regulated innate and inflammatory markers, namely BD-1, TLR-4, IL-8, TNF-α, NF-κB, and TGF-β. Acetate and propionate positively modulated the inflammatory condition by sustaining cell viability, reducing the oxidative stress, and down-regulating the expression of inflammatory mediators. TNF-α expression and secretion showed an opposite effect in IPEC-J2 depending on the extent of LPS stimulation of PBMC and TGF-β modulation. Therefore, SCFA proved to mediate a differential effect depending on the degree and duration of inflammation. The expression of the tight junction proteins (TJp) claudin-4 and zonula occludens-1 was up-regulated by LPS while SCFA influenced TJp with a different kinetics depending on PBMC stimulation. The co-culture model of IPEC-J2 and LPS-activated PBMC proved to be feasible to address the modulation of markers related to anti-bacterial immunity and inflammation, and intestinal epithelial barrier integrity, which are involved in the in vivo responsiveness and plasticity to infections.

The possibly role of GnIH in stress and gut dysfunction in chicken

Stress is known to disrupt the intestinal barrier and induce intestinal dysfunction. A critical role for gonadotropin inhibitory hormone (GnIH) in stress has emerged. However, whether GnIH mediates stress-induced intestinal dysfunction remains unknown. The present study explored this question through in vivo and in vitro experiments in hens. Our in vivo experiments showed that continuous intraperitoneal injection of GnIH not only significantly increased the concentration of stress hormones in serum, but also significantly elevated the mRNA expression of glucocorticoid receptor (GR) in the duodenum and jejunum. Moreover, morphological and molecular analyses revealed that GnIH disrupted the physical and chemical barriers of the intestine and dramatically increased inflammatory factor levels in the intestine and serum of hens. Interestingly, the microbiomics results showed that GnIH altered the structure and composition of the gut flora in the cecum, revealing an increased abundance of harmful intestinal bacteria such as Desulfovibrionaceae. Similar results were found in in vitro studies in which the GnIH-induced intestinal mucosal barrier was disrupted, and inflammation increased in jejunal explants, although no significant difference was found in the expression of GR between the control and GnIH groups. Our results demonstrated that GnIH not only directly damaged intestinal barriers and elevated intestinal inflammation but also mediated stress and microflora imbalance-induced intestinal function disorder, suggesting that GnIH is a potential therapeutic target for gut dysfunction, stress-induced intestinal function disorder, and inflammatory bowel disease in animals and humans.

Bacillus amyloliquefaciens SC06 Relieving Intestinal Inflammation by Modulating Intestinal Stem Cells Proliferation and Differentiation via AhR/STAT3 Pathway in LPS-Challenged Piglets

Bacillus amyloliquefaciens is a well-accepted probiotic, with many benefits for both humans and animals. The ability of intestinal stem cells (ISCs) to develop into several intestinal epithelial cell types helps accelerate intestinal epithelial regeneration. Limited knowledge exists on how bacteria regulated ISCs proliferation and regeneration. Our study investigated the effects of Bacillus amyloliquefaciens supplementation on ISC proliferation and regeneration and intestinal mucosal barrier functions in piglets exposed to lipopolysaccharide (LPS). Eighteen piglets (male, 21 days old) were randomly split into 3 clusters: CON cluster, LPS cluster, and SC06+LPS cluster. On day 21, 100 μg/kg body weight of LPS was intraperitoneally administered to the SC06+LPS and LPS groups. We found SC06 supplementation maintained the intestinal barrier integrity, enhanced intestinal antioxidant capacity, reduced generation of inflammatory response, and suppressed enterocyte apoptosis against the deleterious effects triggered by LPS. In addition, our research indicated that the SC06 supplementation not only improved the ISC regeneration, but also resulted in upregulation of aryl hydrocarbon receptor (AhR) in LPS-challenge piglets. Further studies showed that SC06 also induced ISC differentiation toward goblet cells and inhibited their differentiation to intestinal absorptive cells and enterocytes. The coculture system of SC06 and ileum organoids revealed that SC06 increased the growth of ISCs and repaired LPS-induced organoid damage through activating the AhR/STAT3 signaling pathway. These findings showed that SC06, possibly through the AhR/STAT3 pathway, accelerated ISC proliferation and promoted epithelial barrier healing, providing a potential clinical treatment for IBD. Our research demonstrated that SC06 is effective in preventing intestinal epithelial damage after pathological injury, restoring intestinal homeostasis, and maintaining intestinal epithelial regeneration.

Influence of a Mixture of Protein Hydrolysate from Black Soldier Fly Larvae and Schizochytrium on Palatability, Plasma Biochemistry, and Antioxidative and Anti-Inflammatory Capacity in Cat Diets

The objective of this research was to evaluate palatability, plasma biochemistry, antioxidative and anti-inflammatory capacity, and immune levels in cats by feeding supplementing inclusion of different levels of a mixture of protein hydrolysate from black soldier fly larvae and schizochytrium (BSFPs) in diets. In the feed experiment, a total of 24 adult cats (12 females and 12 males; BW: 3.02 ± 0.06 kg) were randomly divided into four groups: (1) diet with chicken and fish meal as primary protein resource (CON); (2) diet with 5% BSFPs replacing chicken meal, fish meal, chicken oil, and fish oil (5% BSFPs); (3) 10% BSFPs; and (4) 15% BSFPs. The body weight and feed intake were recorded, and a blood sample was collected for analysis. In the palatability experiment, three diets containing 5%, 10%, and 15% BSFPs were evaluated by comparing with CON. These results suggested that different levels of BSFPs could improve palatability in cat diets by enhancing the first sniff, the first bite, and feed intake (p < 0.05). However, no significant influence existed in body weight and average daily feed intake (p > 0.05). In comparison to the CON group, 5% and 15% BSFPs significantly increased the total protein content, and all treatment groups decreased the triglyceride content and enhanced the calcium concentration in plasma; in addition, the activity of aspartate aminotransferase and alanine aminotransferase and the content of creatinine and urea nitrogen were significantly reduced by the supplementation inclusion of BSFPs in the diets (p < 0.05). The enzyme activity of glutathione peroxidase was dramatically enhanced by the supplementation of 10% and 15% BSFPs in diets compared with the CON diet, and the activity of superoxide dismutase was increased and the malondialdehyde concentration was remarkably reduced in all three treatments (p < 0.05). Compared with the CON group, different levels of BSFPs in the diets significantly increased the immunoglobulin A content in plasma; similarly, the immunoglobulin G concentration was significantly enhanced by the supplementation of 10% and 15% BSFPs in the diets (p < 0.05). Furthermore, the interleukin-1β content was significantly reduced in the inclusion of 10% and 15% BSFPs in the diets, and 15% BSFPs remarkably decreased the content of interleukin-8 in plasma compared with the CON diet (p < 0.05). To sum up, the supplementation of different levels of BSFPs exhibited a positive effect on palatability and enhanced the antioxidant, anti-inflammatory, and immune capacity. Particularly, the addition levels of 10% and 15% BSFPs were more effective in antioxidation, anti-inflammation, and immunity.

Transcriptomic analysis of intestinal organoids, derived from pigs divergent in feed efficiency, and their response to Escherichia coli

BACKGROUND

There is increasing interest in using intestinal organoids to study complex traits like feed efficiency (FE) and host-microbe interactions. The aim of this study was to investigate differences in the molecular phenotype of organoids derived from pigs divergent for FE as well as their responses to challenge with adherent and invasive Escherichia coli (E. coli).

RESULTS

Colon and ileum tissue from low and high FE pigs was used to generate 3D organoids and two dimensional (2D) monolayers of organoid cells for E. coli challenge. Genome-wide gene expression was used to investigate molecular differences between pigs that were phenotypically divergent for FE and to study the difference in gene expression after challenge with E. coli. We showed, (1) minor differences in gene expression of colon organoids from pigs with low and high FE phenotypes, (2) that an E. coli challenge results in a strong innate immune gene response in both colon and ileum organoids, (3) that the immune response seems to be less pronounced in the colon organoids of high FE pigs and (4) a slightly stronger immune response was observed in ileum than in colon organoids.

CONCLUSIONS

These findings demonstrate the potential for using organoids to gain insights into complex biological mechanisms such as FE.

Effects of increasing omega-3 fatty acids on growth performance, immune response, and mortality in nursery pigs

Three experiments evaluated omega-3 fatty acids, provided by O3 trial feed, on nursery pig growth performance, mortality, and response to an LPS immune challenge or natural Porcine reproductive and respiratory virus (PRRSV) outbreak. In experiment 1, 350 pigs (241 × 600, DNA; initially 5.8 kg) were used. Pens of pigs were randomly assigned to one of the five dietary treatments containing increasing omega-3 fatty acids (0%, 1%, 2%, 3%, and 4% O3 trial feed) with 14 replications per treatment. On day 25, two pigs per pen were injected intramuscularly with 20 μg Escherichia coli LPS per kg BW and one pig per pen was injected with saline as a control. Body temperature was taken from all three pigs prior to and 2, 4, 6, and 12 h post-LPS challenge. Serum IL-1β and TNF-α concentrations were determined in LPS-challenged pigs 24 h prior and 4 h post-LPS challenge. There was no interaction between treatment and time for change in body temperature (P > 0.10). Overall, increasing the O3 trial feed did not affect (P > 0.10) ADG, ADFI, G:F, IL-1β, or TNF-α. In experiment 2, 1,056 pigs (PIC TR4 × [Fast LW × PIC L02] initially 7.3 kg) were used. Pens of pigs were randomly assigned to one of the four dietary treatments containing increasing omega-3 fatty acids (0%, 0.75%, 1.5%, and 3% O3 trial feed) with 12 replications per treatment. Oral fluids tested negative on days 7 and 14, but then positive for North American PRRSV virus via PCR on days 21, 28, 35, and 42. Overall, increasing O3 trial feed increased (linear, P < 0.001) ADG, ADFI, and G:F and decreased (linear, P = 0.027) total removals and mortality. In experiment 3, 91,140 pigs (DNA 600 × PIC 1050; initially 5.1 kg), originating from PRRSV-positive sow farms, were used across eight nursery sites. Each site contained five barns with two rooms per barn and ~1,100 pigs per room. Rooms of pigs were blocked by nursery site and allocated within sow source to one of the two dietary treatments (control or 3% O3 trial feed) with 40 replications per treatment. Oral fluids from 61 of the 80 rooms tested positive for North American PRRSV virus 1 wk postweaning and 78 of the 80 rooms tested positive 3 wk after weaning. Overall, O3 trial feed did not affect ADG, ADFI, or G:F but increased (P < 0.001) total removals and mortalities. In summary, increasing omega-3 fatty acids, sourced by O3 trial feed, did not improve growth performance or immune response in healthy pigs given an LPS challenge. However, it appears that if omega-3 fatty acids are fed prior to a natural PRRSV break (as in experiment 2), growth performance may be improved, and mortality reduced.

Effects of dietary xylanase supplementation on growth performance, intestinal health, and immune response of nursery pigs fed diets with reduced metabolizable energy

This study aimed to investigate the effects of xylanase on growth performance and intestinal health of nursery pigs fed diets with reduced metabolizable energy (ME). One hundred ninety-two pigs at 8.7 kg ± 0.7 body weight (BW) after 7 d of weaning were allotted in a randomized complete block design with initial BW and sex as blocks. Eight dietary treatments consisted of 5 ME levels (3,400, 3,375, 3,350, 3,325, and 3,300 kcal ME/kg) below the NRC (2012) requirement and 4 levels of xylanase (0, 1,200, 2,400, and 3,600 XU/kg) to a diet with 3,300 kcal ME/kg. All pigs received their respective treatments for 35 d in 2 phases, pre-starter (14 d) and starter (21 d). On day 35, eight pigs in 3,400 kcal/kg (CON), 3,300 kcal/kg (LE), and 3,300 kcal/kg + 3,600 XU xylanase/kg (LEX) were euthanized to collect jejunal tissues and digesta for the evaluation of mucosa-associated microbiota, intestinal immune response, oxidative stress status, intestinal morphology, crypt cell proliferation, and digesta viscosity as well as ileal digesta to measure apparent ileal digestibility. Data were analyzed using the MIXED procedure on SAS 9.4. The LE increased (P < 0.05) jejunal digesta viscosity, tended to have decreased (P = 0.053) relative abundance of Prevotella, and tended to increase (P = 0.055) Lactobacillus. The LE also increased (P < 0.05) the concentration of protein carbonyl whereas malondialdehyde, villus height (VH), villus height to crypt depth ratio (VH:CD), apparent ileal digestibility (AID) of nutrients, and finally average daily feed intake were decreased (P < 0.05). The LE did not affect average daily gain (ADG). The LEX decreased (P < 0.05) digesta viscosity, increased (P < 0.05) the relative abundance of Prevotella, decreased (P < 0.05) Helicobacter, decreased (P < 0.05) the concentration of protein carbonyl, tended to increase (P = 0.065) VH, and decreased (P < 0.05) VH:CD and crypt cell proliferation. Moreover, LEX increased (P < 0.05) the AID of dry matter and gross energy and tended to increase (P = 0.099; P = 0.076) AID of crude protein, and ether extract. The LEX did not affect ADG but did tend to decrease (P = 0.070) fecal score during the starter phase. Overall, reducing ME negatively affected intestinal health parameters and nutrient digestibility without affecting growth. Supplementation of xylanase mitigated some of the negative effects observed by ME reduction on intestinal health and digestibility of nutrients without affecting growth.

The potential of dietary fiber in building immunity against gastrointestinal and respiratory disorders

The numerous health benefits of dietary fibers (DFs) justify their inclusion in human diets and biomedical products. Given the short- and long-term human impacts of the COVID-19 virus on human health, the potential of DFs in building immunity against gastrointestinal and respiratory disorders is currently receiving high attention. This paper reviews the physicochemical properties of DFs, together with their immune functions and effects on the gastrointestinal tract and respiratory system mainly based on research in the last ten years. Possible modes of action of DFs in promoting health, especially building immunity, are explored. We seek to highlight the importance of understanding the exact physical and chemical characteristics and molecular behaviors of DFs in providing specific immune function. This review provides a perspective beyond the existing recognition of DFs' positive effects on human health, and offers a theoretical framework for the development of special DFs components and their application in functional foods and other therapeutic products against gastrointestinal and respiratory disorders. DFs enhance immunity from gastrointestinal and respiratory diseases to promote host health.

Glycerol monolaurate improved intestinal barrier, antioxidant capacity, inflammatory response and microbiota dysbiosis in large yellow croaker (Larimichthys crocea) fed with high soybean oil diets

Glycerol monolaurate (GML) is a potential candidate for regulating metabolic syndrome and inflammatory response. However, the role of GML in modulating intestinal health in fish has not been well determined. In this study, a 70-d feeding trial was conducted to evaluate the effect of GML on intestinal barrier, antioxidant capacity, inflammatory response and microbiota community of large yellow croaker (13.05 ± 0.09 g) fed with high level soybean oil (SO) diets. Two basic diets with fish oil (FO) or SO were formulated. Based on the SO group diet, three different levels of GML 0.02% (SO0.02), 0.04% (SO0.04) and 0.08% (SO0.08) were supplemented respectively. Results showed that intestinal villus height and perimeter ratio were increased in SO0.04 treatment compared with the SO group. The mRNA expressions of intestinal physical barrier-related gene odc and claudin-11 were significantly up-regulated in different addition of GML treatments compared with the SO group. Fish fed SO diet with 0.04% GML addition showed higher activities of acid phosphatase and lysozyme compared with the SO group. The content of malonaldehyde was significantly decreased and activities of catalase and superoxide dismutase were significantly increased in 0.02% and 0.04% GML groups compared with those in the SO group. The mRNA transcriptional levels of inflammatory response-related genes (il-1β, il-6, tnf-α and cox-2) in 0.04% GML treatment were notably lower than those in the SO group. Meanwhile, sequencing analysis of bacterial 16S rRNA V4-V5 region showed that GML addition changed gut microbiota structure and increased alpha diversity of large yellow croaker fed diets with a high level of SO. The correlation analysis results indicated that the change of intestinal microbiota relative abundance strongly correlated with intestinal health indexes. In conclusion, these results demonstrated that 0.02%-0.04% GML addition could improve intestinal morphology, physical barrier, antioxidant capacity, inflammatory response and microbiota dysbiosis of large yellow croaker fed diets with a high percentage of SO.

Insects as an alternative protein source for poultry nutrition: a review

This review summarizes the most relevant scientific literature related to the use of insects as alternative protein sources in poultry diets. The black soldier fly, the housefly, the beetle, mealworms, silkworms, earthworms, crickets, and grasshoppers are in the spotlight because they have been identified as an important future source of sustainable animal proteins for poultry feeding. Insect meals meet poultry requirements in terms of nutritional value, essential amino acid composition, nutrient digestibility, and feed acceptance. Furthermore, they are enriched with antimicrobial peptides and bioactive molecules that can improve global health. Results from poultry studies suggest equivalent or enhanced growth performances and quality of end-products as compared to fish meal and soybean meal. To outline this body of knowledge, this article states established threads of research about the nutrient profiles and the digestibility of insect meals, their subsequent effects on the growth and laying performances of poultry as well as the quality of meat, carcass, and eggs. To fully exploit insect-derived products, the effects of insect bioactive molecules (antimicrobial peptides, fatty acids, and polysaccharides) were addressed. Furthermore, as edible insects are likely to take a meaningful position in the feed and food chain, the safety of their derived products needs to be ensured. Some insights into the current knowledge on the prevalence of pathogens and contaminants in edible insects were highlighted. Finally, the effect of insect farming and processing treatment on the nutritive value of insect larvae was discussed. Our overview reveals that using insects can potentially solve problems related to reliance on other food sources, without altering the growth performances and the quality of meat and eggs.

Utilization of Tenebrio molitor Larvae Reared with Different Substrates as Feed Ingredients in Growing Pigs

The procurement of adequate feed resources is one of the most important challenges for the animal industry worldwide. While the need for feeds rich in protein is constantly increasing, their production cannot readily keep up. Consequently, to overcome this challenge in a sustainable way, it is necessary to identify and develop new feeding strategies and feed ingredients, such as insect meals. In the present study, Tenebrio molitor larvae that were reared on two different substrates (standard and enriched with medicinal aromatic plant material) were used as feed ingredients for growing pigs. A total of 36 weaned pigs (34 days old) were randomly allocated to three treatment groups and fed either the control diet (A) or diets supplemented at 10% with one of the two insect meals (B and C). At the end of the trial (42 days), blood, feces, and meat samples were collected for analysis. The insect meal supplementation did not affect (p > 0.05) overall performance but significantly modified (p < 0.001) the fecal microflora balance and the blood cholesterol (p < 0.001), while the rest of the blood parameters tested were not affected. Moreover, this dietary supplementation significantly affected some microbial populations (p < 0.001), improved the total phenolic content (p < 0.05), and the fatty acid profile (p < 0.001) of the meat cuts, but did not affect (p > 0.05) meat color or proximate composition. Further research is needed to evaluate the different types and levels of inclusion of insect meals in pig nutrition.

Maternal and/or post-weaning supplementation with Bacillus altitudinis spores modulates the microbial composition of colostrum, digesta and faeces in pigs

This study examined the effects of maternal and/or post-weaning Bacillus altitudinis supplementation on the microbiota in sow colostrum and faeces, and offspring digesta and faeces. Sows (n = 12/group) were assigned to: (1) standard diet (CON), or (2) CON supplemented with probiotic B. altitudinis spores (PRO) from day (d)100 of gestation to weaning (d26 of lactation). At weaning, offspring were assigned to CON or PRO for 28d, resulting in: (1) CON/CON, (2) CON/PRO, (3) PRO/CON, and (4) PRO/PRO, after which all received CON. Samples were collected from sows and selected offspring (n = 10/group) for 16S rRNA gene sequencing. Rothia was more abundant in PRO sow colostrum. Sow faeces were not impacted but differences were identified in offspring faeces and digesta. Most were in the ileal digesta between PRO/CON and CON/CON on d8 post-weaning; i.e. Bacteroidota, Alloprevotella, Prevotella, Prevotellaceae, Turicibacter, Catenibacterium and Blautia were more abundant in PRO/CON, with Firmicutes and Blautia more abundant in PRO/PRO compared with CON/CON. Lactobacillus was more abundant in PRO/CON faeces on d118 post-weaning. This increased abundance of polysaccharide-fermenters (Prevotella, Alloprevotella, Prevotellaceae), butyrate-producers (Blautia) and Lactobacillus likely contributed to previously reported improvements in growth performance. Overall, maternal, rather than post-weaning, probiotic supplementation had the greatest impact on intestinal microbiota.

Acetate and propionate effects in response to LPS in a porcine intestinal co-culture model

BACKGROUND

The interest in acetate and propionate as short chain fatty acids (SCFA) derives from research on alternative strategies to the utilization of antibiotics in pig farms. SCFA have a protective role on the intestinal epithelial barrier and improve intestinal immunity by regulating the inflammatory and immune response. This regulation is associated with an increase in intestinal barrier integrity, mediated by the enhancement of tight junction protein (TJp) functions, which prevent the passage of pathogens through the paracellular space. The purpose of this study was to evaluate the effect of in vitro supplementation with SCFA (5 mM acetate and 1 mM propionate) on viability, nitric oxide (NO) release (oxidative stress), NF-κB gene expression, and gene and protein expression of major TJp (occludin [OCLN], zonula occludens-1 [ZO-1], and claudin-4 [CLDN4]) in a porcine intestinal epithelial cell (IPEC-J2) and peripheral blood mononuclear cell (PBMC) co-culture model upon LPS stimulation, through which an acute inflammatory state was simulated.

RESULTS

Firstly, the inflammatory stimulus induced by LPS evaluated in the IPEC-J2 monoculture was characterized by a reduction of viability, gene expression of TJp and OCLN protein synthesis, and an increase of NO release. The response evaluated in the co-culture showed that acetate positively stimulated the viability of both untreated and LPS-stimulated IPEC-J2 and reduced the release of NO in LPS-stimulated cells. Acetate also promoted an increase of gene expression of CLDN4, ZO-1, and OCLN, and protein synthesis of CLDN4, OCLN and ZO-1 in untreated and LPS-stimulated cells. Propionate induced a reduction of NO release in both untreated and LPS-stimulated IPEC-J2. In untreated cells, propionate induced an increase of TJp gene expression and of CLDN4 and OCLN protein synthesis. Contrarily, propionate in LPS-stimulated cells induced an increase of CLDN4 and OCLN gene expression and protein synthesis. PBMC were influenced by acetate and propionate supplementation, in that NF-κB expression was strongly downregulated in LPS-stimulated cells.

CONCLUSIONS

The present study demonstrates the protective effect of acetate and propionate upon acute inflammation by regulating epithelial tight junction expression and protein synthesis in a co-culture model, which simulates the in vivo interaction between epithelial intestinal cells and local immune cells.

Beneficial Effects of Daily Consumption of Garlic and Onion Extract Concentrate on Infectious Respiratory Diseases in Elderly Resident Volunteers

Aging is a biological process with high susceptibility to several infections. This risk increases in older patients in residential care facilities (RCF). Thus, there is a clear demand for developing preventive interventions with new therapeutic compounds that combine efficacy and safety. This could be the case of compounds derived from plants of the genus Allium spp. The purpose of this study was to evaluate the impact of a combination of a garlic and onion extract concentrate standardized in organosulfur compounds derived from propiin on the incidence of respiratory tract infections in elderly patients of RCF. Sixty-five volunteers were selected at random to receive a placebo or a single daily dose of the extract for thirty-six weeks. Different clinical visits were performed to evaluate the main respiratory diseases with an infectious origin, as well as the associated symptoms and their duration. The extract showed a clinical safety profile and significantly reduced the incidence of respiratory infections. Moreover, the treatment decreased the number and duration of the associated symptoms compared with the placebo group. For the first time, we demonstrated the protective effect of Alliaceae extract in respiratory infectious diseases in elderly healthy volunteers, which could be used prophylactically against the most common infectious respiratory diseases.

Effects of dietary supplementation of bacteriophage cocktail on health status of weanling pigs in a non-sanitary environment

BACKGROUND

The study evaluated the effects of bacteriophage cocktail (BP) and ZnO administered during weaning time for piglets exposed to a non-sanitary environment. The bacteriophages were designed to eliminate Escherichia coli (K88, K99 and F41), Salmonella (typhimurium and enteritidis), and Clostridium perfreingens (types A and C). Forty 21-day-old crossbreed piglets were assigned to four treatments, including the PC (sanitary environment), NC (non-sanitary environment), BP (NC plus 10⁸ pfu/kg BP), and ZO (NC plus 2,500 mg/kg ZnO). Piglets in the NC, BP and ZO were kept in a non-sanitary environment for 14 d, which was contaminated with the feces of infected pigs.

RESULTS

Pigs in the BP and ZO treatments had a higher final body weight compared with the NC. The NC treatment showed the highest concentration of inflammatory cytokines including interleukin (IL)-1β, IL-6 and tumor necrosis factor-α in the plasma. The administration of BP and ZO showed lower myeloperoxidase concentrations compared with the NC. The NC treatment showed a lower concentration of superoxide dismutase in serum compared with the PC. Among the treatments in non-sanitary environment, the NC treatment showed a higher concentration of malondialdehyde compared with the ZO. The PC treatment showed a lower concentration of butyric acid in the feces compared with the BP treatment. Among non-sanitary treatments, the villus height in the duodenum was greater in the BP and ZO compared with the NC. The lower abundance of Proteobacteria phylum was observed in the BP and PC treatments compared with the NC. The highest relative abundance of Eubacterium was recorded in the BP treatment. The abundance of Megasphaera and Schwartzia was higher in the NC pigs compared with the BP piglets. The abundance of Desulfovibrio was lower in the supplemented treatments (BP and ZO) compared with non-supplemented (NC and PC). The abundance of Cellulosilyticum genera was higher in the BP and ZO treatments rather than in the NC. The piglets in the NC treatment had the highest abundance of Escherichia-Shigella, followed by the PC and ZO treatments.

CONCLUSION

In conclusion, these results suggest that the supplementation of bacteriophage cocktail could effectively control Proteobacteria phylum, Clostridium spp. and coliforms population and mitigated the adverse influences of weaning stress in piglets.

Gut Health and Influencing Factors in Pigs

The gastrointestinal tract (GIT) is a complex, dynamic, and critical part of the body, which plays an important role in the digestion and absorption of ingested nutrients and excreting waste products of digestion. In addition, GIT also plays a vital role in preventing the entry of harmful substances and potential pathogens into the bloodstream. The gastrointestinal tract hosts a significant number of microbes, which throughout their metabolites, directly interact with the hosts. In modern intensive animal farming, many factors can disrupt GIT functions. As dietary nutrients and biologically active substances play important roles in maintaining homeostasis and eubiosis in the GIT, this review aims to summarize the current status of our knowledge on the most important areas.

Effects of Exposure to Low Zearalenone Concentrations Close to the EU Recommended Value on Weaned Piglets’ Colon

Pigs are the most sensitive animal to zearalenone (ZEN) contamination, especially after weaning, with acute deleterious effects on different health parameters. Although recommendations not to exceed 100 µg/kg in piglets feed exists (2006/576/EC), there are no clear regulations concerning the maximum limit in feed for piglets, which means that more investigations are necessary to establish a guidance value. Due to these reasons, the present study aims to investigate if ZEN, at a concentration lower than the EC recommendation for piglets, might affect the microbiota or induce changes in SCFA synthesis and can trigger modifications of nutritional, physiological, and immunological markers in the colon (intestinal integrity through junction protein analysis and local immunity through IgA production). Consequently, the effect of two concentrations of zearalenone were tested, one below the limit recommended by the EC (75 µg/kg) and a higher one (290 µg/kg) for comparison reasons. Although exposure to contaminated feed with 75 µg ZEN/kg feed did not significantly affect the observed parameters, the 290 µg/kg feed altered several microbiota population abundances and the secretory IgA levels. The obtained results contribute to a better understanding of the adverse effects that ZEN can have in the colon of young pigs in a dose-dependent manner.

Potential of Capric Acid in Neurological Disorders: An Overview

To solve the restrictions of a classical ketogenic diet, a modified medium-chain triglyceride diet was introduced which required only around 60% of dietary energy. Capric acid (CA), a small molecule, is one of the main components because its metabolic profile offers itself as an alternate source of energy to the brain in the form of ketone bodies. This is possible with the combined capability of CA to cross the blood-brain barrier and achieve a concentration of 50% concentration in the brain more than any other fatty acid in plasma. Natural sources of CA include vegetable oils such as palm oil and coconut oil, mammalian milk and some seeds. Several studies have shown that CA has varied action on targets that include AMPA receptors, PPAR-γ, inflammatory/oxidative stress pathways and gut dysbiosis. Based on these lines of evidence, CA has proved to be effective in the amelioration of neurological diseases such as epilepsy, affective disorders and Alzheimer's disease. But these studies still warrant more pre-clinical and clinical studies that would further prove its efficacy. Hence, to understand the potential of CA in brain disease and associated comorbid conditions, an advance and rigorous molecular mechanistic study, apart from the reported in-vitro/in-vivo studies, is urgently required for the development of this compound through clinical setups.

Dietary utilization of mealworm frass in rabbit feeding regimes and its effect on growth, carcass characteristics, and meat quality

This study aimed to shed light on the use of mealworm (Tenebrio molitor) frass (TMF) in rabbit diets and its effects on growth performance, blood profiles, rabbit meat quality, and fatty acid profiles. A total of 48 Gabali rabbits were divided equally and randomly into four groups to be fed one of four dietary treatments: a control (T0) group and three TMF groups, which included TMF meal at 1 (T1), 2 (T2), and 3 (T3) %, respectively. The rabbits were fed on isonitrogenous and isoenergetic diets for 11 weeks, and the growth performance data were recorded. Six rabbits per group were slaughtered at the end of the 11th week, then the pharmacochemical parameters and carcass traits were measured, and meat quality and fatty acid profiles were analyzed. The results indicated that the growth performance of different groups was similar (P > 0.05). The levels of globulin, glucose, and alanine transaminase (ALT) were lower in the mealworm frass groups compared with the control group. Carcass traits were not affected by experimental regimes. Fat was higher in the TMF treatment groups, while moisture was lower compared with the control group. The shear force had a lower value in the treatment groups T3 and T2 compared with the control group. The highest values of redness and chroma (color parameter) of rabbit meat were observed in the treatment groups vs. the control group. Moreover, the proportion of total saturated fatty acids in the meat of rabbits that were fed on the T2 and T3 diets was higher compared to those fed on the control (i.e., T0) and T1 diets. Furthermore, the proportion of monounsaturated fatty acid was higher in the T2, T3, and T1 groups vs. T0 rabbits, whereas the PUFA proportions were lower. It could be concluded that frass has great potential to be used as a partial substitute for rabbit diets.

Dietary lactate supplementation can alleviate DSS-induced colitis in piglets

Colitis is a common and complex intestinal inflammatory disease in which lactate, a metabolite of anaerobic glycolysis, plays a crucial role. Our study aimed to investigate the alleviated effect of lactate in colitis, and to provide a nutritional measure to alleviate colitis injury. The variations in colonic lactate in piglets with DSS-induced colitis were investigated in Experiment 1 (Exp.1). Thirty weaned pigs were allotted into three groups and sampled at different stages of DSS-induced colitis (days 0, 5, and 7). The colonic level of lactate and interleukin 10 (IL-10) was significantly decreased on day 5 when compared to day 0. Colonic lactate, IL-10, and G protein receptor 81 (GPR81) levels were significantly increased on day 7 when compared to day 5. Sixty weaned piglets were assigned to control (basal diet), DSS (basal diet with DSS gavage), or lactate (2% lactate supplementation diet with DSS gavage) groups to investigate the effects of lactate on DSS-induced colitis in Experiment 2 (Exp.2). Lactate reduced the disease activity index (DAI), DSS-induced impairment of colonic structure in response to the critical inflammatory cytokines interleukin 1β (IL-1β) and interleukin 18 (IL-18) when compared with the DSS group. Furthermore, GPR-81 levels, colonic M2 macrophages, and IL-10 levels, the colonic antioxidant capacity, colonic butyrate levels were increased, and eventually improved growth performance post-colitis. The results of this study show that lactate was decreased at the peak of colitis, accumulated in subsidized colitis. Furthermore, dietary lactate supplementation helped to alleviate DSS-induced colitis injury.

Beneficial Effects of Phytogenic Feed Additives on Epithelial Barrier Integrity in an In Vitro Co-Culture Model of the Piglet Gut

Industrial farming of livestock is increasingly focused on high productivity and performance. As a result, concerns are growing regarding the safety of food and feed, and the sustainability involved in their production. Therefore, research in areas such as animal health, welfare, and the effects of feed additives on animals is of significant importance. In this study, an in vitro co-culture model of the piglet gut was used to investigate the effects of two phytogenic feed additives (PFA) with similar compositions. Intestinal porcine epithelial cells (IPEC-J2) were co-cultivated with peripheral blood mononuclear cells (PBMC) to model the complex porcine gut environment in vitro. The effects of treatments on epithelial barrier integrity were assessed by means of transepithelial electrical resistance (TEER) in the presence of an inflammatory challenge. Protective effects of PFA administration were observed, depending on treatment duration and the model compartment. After 48 h, TEER values were significantly increased by 12-13% when extracts of the PFA were applied to the basolateral compartment (p < 0.05; n = 4), while no significant effects on cell viability were observed. No significant differences in the activity of a PFA based mainly on pure chemical compounds versus a PFA based mainly on complex, natural essential oils, and extracts were found. Overall, the co-culture model was used successfully to investigate and demonstrate beneficial effects of PFAs on intestinal epithelial barrier function during an inflammatory challenge in vitro. In addition, it demonstrates that the two PFAs are equivalent in effect. This study provides useful insights for further research on porcine gut health status even without invasive in vivo trials.

Dietary supplementation with full-fat Hermetia illucens larvae and multi-probiotics, as a substitute for antibiotics, improves the growth performance, gut health, and antioxidative capacity of weaned pigs

BACKGROUND

Dietary supplementation of full-fat black soldier fly larvae (BSFL full-fat meal; alone or in combination with multi-probiotics) was tested as an alternative to dietary antibiotics in weaning piglets. We also tested the effects of these diets on growth performance, nutrient digestibility coefficients, immune status, oxidative stress, intestinal histomorphology, and rectal microbial modulations in weaned pigs. A total of 80 piglets [(Landrace × Large White) × Duroc] of both sexes (a ratio of gilts and barrows; 1:1), were randomly allotted to four diet groups: positive control (PC) diet supplemented with 0.02% amoxicillin; negative control (NC) diet without supplement addition; BSFL12 diet (NC + 12% BSFL full-fat meal); and BSFL + Pro diet (BSFL full-fat meal + 0.1% multi-probiotics, including Bacillus subtilis, B. licheniformis, and Saccharomyces cerevisiae). All groups had five replicates, with four piglets per replicate.

RESULTS

Dietary BSFL + Pro improved the overall average daily gain (P = 0.013), and gain-to-feed ratio (P = 0.032). The BSFL12 and BSFL + Pro diets improved nutrient digestibility and increased the serum levels of immunoglobulin A and glutathione peroxidase, while reducing the levels of pro-inflammatory cytokines. The spleen weight was higher and caecal pH was lower in pigs fed the BSFL + Pro diet than in those fed the NC diet (P = 0.011 and P = 0.021, respectively). Pigs fed the BSFL diets had longer duodenal villi, a higher villus height-to-crypt depth ratio (P = 0.004), and shorter crypt depth (P = 0.017) than those fed NC. The BSFL + Pro diet also increased faecal Lactobacillus spp. count (P = 0.008) and reduced Escherichia coli (P = 0.021) counts compared with that seen with PC and NC diets, respectively.

CONCLUSIONS

Dietary supplementation with BSFL or BSFL + multi-probiotics can improve the growth performance and intestinal health of pigs and may be an effective strategy to replace antibiotics for weaned pigs.

The effects of dietary essential fatty acid ratios and energy level on growth performance, lipid metabolism, and inflammation in grow-finish pigs

The objective of this study was to investigate the effects of dietary metabolizable energy (ME) level and the ratio of linoleic acid:α-linolenic acid (LA:ALA) on the growth performance, lipid metabolism, circulatory and joint inflammatory status, and synovial fluid proteome of grow-finish pigs. A total of 224 pigs (BW = 41.5 ± 6.1 kg; PIC Genus 337 × 1050, Hendersonville, TN) were randomly assigned to either a high (3.55 Mcal/kg; HE) or low (3.29 Mcal/kg; LE) ME dietary treatment with a high (23:1) or low (12:1) LA:ALA in a 2 × 2 factorial arrangement. Diets were fed across three 28-d phases. Pigs were housed either four barrows or four gilts per pen. Blood samples were collected on days 0, 21, 42, and 84. Synovial fluid was collected from the hock and carpus joints on days 0 and 84. Liver and adipose tissue samples were collected on day 84. Data were analyzed as repeated measures using PROC MIXED (SAS 9.4) with pen as the experimental unit and energy level, essential fatty acid ratio, sex, phase, and their interactions as fixed effects. Compared to LE, HE increased days 28, 56, and 84 body weight (BW; P = 0.005). For the overall period, HE increased average daily gain (ADG) compared to LE (P < 0.001) and improved feed efficiency (P = 0.001), while LE increased feed intake compared to HE (P < 0.001). Gilts receiving diets with low LA:ALA had similar final BW to barrows receiving a low LA:ALA at days 28, 56, and 84 (P = 0.024), resulting from improved overall days 0-84 ADG compared to gilts receiving the high LA:ALA (P = 0.031). In the liver, HE decreased the mRNA abundance of acetyl CoA carboxylase (ACACA; P = 0.004), cluster of differentiation 36 (P = 0.034), and tended to decrease fatty acid synthase (FASN; P = 0.056). In adipose tissue, HE decreased ACACA (P = 0.001) and FASN (P = 0.017). Plasma inflammatory markers C-reactive protein (CRP) and tumor necrosis factor-α (TNFα) were reduced on day 84 compared to day 0 (P ≤ 0.014). In the hock and carpus synovial fluid, LE tended to reduce CRP and TNFα (P ≤ 0.096). Hock and carpus synovial fluid CRP were also reduced on day 84 compared to day 0 (P = 0.001). Age of the pig impacted serum and hock synovial fluid protein abundance, but not energy level, LA:ALA, or their interactions (P < 0.05). To conclude, the high and low LA:ALA ratios utilized in this study can be fed at varying energy levels without impacting growth. Additionally, LA:ALA ratios can differentially impact the growth of barrows and gilts.

The interaction between dietary fiber and gut microbiota, and its effect on pig intestinal health

Intestinal health is closely associated with overall animal health and performance and, consequently, influences the production efficiency and profit in feed and animal production systems. The gastrointestinal tract (GIT) is the main site of the nutrient digestive process and the largest immune organ in the host, and the gut microbiota colonizing the GIT plays a key role in maintaining intestinal health. Dietary fiber (DF) is a key factor in maintaining normal intestinal function. The biological functioning of DF is mainly achieved by microbial fermentation, which occurs mainly in the distal small and large intestine. Short-chain fatty acids (SCFAs), the main class of microbial fermentation metabolites, are the main energy supply for intestinal cells. SCFAs help to maintain normal intestinal function, induce immunomodulatory effects to prevent inflammation and microbial infection, and are vital for the maintenance of homeostasis. Moreover, because of its distinct characteristics (e.g. solubility), DF is able to alter the composition of the gut microbiota. Therefore, understanding the role that DF plays in modulating gut microbiota, and how it influences intestinal health, is essential. This review gives an overview of DF and its microbial fermentation process, and investigates the effect of DF on the alteration of gut microbiota composition in pigs. The effects of interaction between DF and the gut microbiota, particularly as they relate to SCFA production, on intestinal health are also illustrated.

Influence of dietary n-3 long-chain fatty acids on microbial diversity and composition of sows' feces, colostrum, milk, and suckling piglets' feces

Introduction

Very little is known about the impact of n-3 long-chain fatty acids (n-3 LCFAs) on the microbiota of sows and their piglets. The aim of this study was to evaluate the effect of n-3 LCFA in sow diets on the microbiota composition of sows' feces, colostrum, and milk as well as that of piglets' feces.

Methods

Twenty-two sows were randomly assigned to either a control or an n-3 LCFA diet from service to weaning. Sows' and piglets' performance was monitored. The gestating and lactating sows' microbiomes in feces, colostrum, and milk were characterized by 16s ribosomal RNA gene sequencing. The fecal microbiome from the two lowest (>800 g) and the two highest birth weight piglets per litter was also characterized, and the LPS levels in plasma were analyzed at weaning.

Results and Discussion

n-3 LCFA increased microbiota alpha diversity in suckling piglets' and gestating sows' feces. However, no effects were observed in colostrum, milk, or lactating sows' feces. Dietary n-3 LCFA modified the microbiota composition of gestating sows' feces, milk, and suckling piglets' feces, without affecting lactating sows' feces or colostrum. In gestating sows' feces and milk, the decrease in genus Succinivibrio and the increase of Proteobacteria phylum, due to the increased genera Brenneria and Escherichia, respectively, stand out. In the feces of suckling piglets, the higher abundance of the beneficial genus Akkermansia and Bacteroides, and different species of Lactobacillus are highlighted. In addition, positive correlations for families and genera were found between lactating sows' feces and milk, milk and suckling piglets' feces, and lactating sows' feces and suckling piglets' feces. To conclude, dietary n-3 LCFA had a positive impact on the microbiome of suckling piglet's feces by increasing microbial diversity and some beneficial bacteria populations, had a few minor modifications on the microbiome of milk and gestating sows' feces and did not change the microbiome in lactating sows' feces or colostrum. Therefore, this study shows the effect of dietary n-3 LCFA on the microbiota of sows, colostrum, milk, and suckling piglets during the lactation period providing crucial information on the microbiota status at the early stages of life, which have an impact on the post-weaning.

Performance and gut health status of broilers fed diets supplemented with two graded levels of a monoglyceride blend

The present study was undertaken to evaluate the efficacy of 2 graded levels (0.03 and 0.05% of diet) of a monoglyceride blend containing butyric, caprylic, and capric acids in broilers' diet for optimizing gut structure and animal growth performance. For this purpose, a total of 210, one-day-old male Ross 308 broiler chicks were randomly allocated to 3 experimental treatments using 7 replicates each and 10 birds/replicate. The treatment groups involved supplementation of blend of short and medium chain fatty acids at the level of 0, 0.03, and 0.05% of the diet for 42 d. The incorporation of mixes of monoglycerides into broilers' diet linearly improved BWG between d 0 and 21 (P = 0.034). At the end of trial, however, no significant changes were observed in performance indexes (BWG, FI, FCR). Jejunal morphometric parameters (villus height, crypt depth, and their ratio) remained unaltered with the monoglyceride supplementation on d 21. The results further showed that monoglycerides supplementation increased the goblet cell counts along the jejunal villi (P = 0.034) and crypt regions (P = 0.022), as well as it effectively modulated the mRNA abundances of tight junction protein (ZO-1, P = 0.033) and nutrient transporters (SGLT, PePT1; P = 0.005, 0.023, respectively) in the jejunum. Moreover, the downregulation in mRNA abundance of TNFα (P = 0.030) was observed with the monoglyceride supplementation. The SCFAs analysis of cecal contents showed no notable differences with monoglyceride blend supplementation when compared to the unsupplemented group. Collectively, high goblet cell numbers in the jejunum along with downregulation of the mRNA abundances of pro-inflammatory cytokines, upregulation of tight junction proteins, and nutrient transporters showed favorable responses of low doses of monoglycerides blend in broiler feeding. Further studies should be conducted in different rearing conditions to examine the effectiveness of such low levels of a monoglyceride blend in the modulation of gut structure, its functionality and animal performance.

Weaning Stress in Piglets Alters the Expression of Intestinal Proteins Involved in Fat Absorption

BACKGROUND

In vivo data on intestinal fat absorption in weanling piglets are scarce.

OBJECTIVES

This study aimed to investigate the effect of weaning stress on intestinal fat absorption.

METHODS

Eighteen 7-d-old sow-reared piglets (Duroc-Landrace-Yorkshire) were assigned to 3 groups (n = 6/group, 3 males and 3 females per group). Piglets were nursed by sows until 24 d of age (suckling piglets, S), or weaned at 21 d of age to a corn-soybean meal-based diet until 24 d (3 d postweaning, W3) or 28 d (7 d postweaning, W7) of age, respectively. Duodenum, jejunum, and ileum were collected to determine intestinal morphology and abundance of proteins related to fat absorption.

RESULTS

Compared with the S group, the W3 group had lower villus height (17-34%) and villus height to crypt depth ratio (13-53%), as well as 1-1.45 times greater crypt depth; these values were 1.18-1.31, 0.69-1.15, and 1.47-1.87 times greater in the W7 group than in the W3 group, respectively. Compared with the S group, weaning stress for both W3 and W7 groups reduced intestinal alkaline phosphatase activity (26-73%), serum lipids (26-54%), and abundances of proteins related to fatty acid transport [fatty acid transport protein 4 (FATP4) and intestinal fatty acid-binding protein (I-FABP)] and chylomicron assembly [microsomal triglyceride transfer protein (MTTP), apolipoprotein A-IV (APOA4), B (APOB), and A-I (APOA1)] in the duodenum and ileum (10-55%), as well as in the jejunum (25-85%). All these indexes did not differ between W3 and W7 groups. Compared with the S group, the W3 group had lower mRNA abundances of duodenal APOA4 and APOA1 (25-50%), as well as jejunal FATP4, IFABP, MTTP, APOA4, and APOA1 (35-50%); these values were 5-15% and 10-37% lower in the W7 group than in the W3 group, respectively.

CONCLUSIONS

Weaning stress in piglets attenuates the expression of intestinal proteins related to fatty acid transport (FATP4 and I-FABP) and chylomicron synthesis (APOA4).

Evaluation of digestively resistant or soluble fibers, short- and medium-chain fatty acids, trace minerals, and antibiotics in nonchallenged nursery pigs on performance, digestibility, and intestinal integrity

Three experiments (EXP) were conducted to determine the effect of feed additives on performance, intestinal integrity, gastrointestinal volatile fatty acids (VFA), and energy and nutrient digestion in nonchallenged nursery pigs. In EXP 1, 480 pigs (6.36-kg body weight, BW) were placed into 96 pens with 5 pigs/pen, and allotted to 1 of 10 dietary treatments: 1) negative control containing no feed additive (NC), 2) NC + 44 mg chlortetracycline and 38.5 mg tiamulin/kg diet (CTsb), 3) NC + 5% resistant potato starch (RSpo), 4) NC + 5% soluble corn fiber (SCF), 5) NC + 5% sugar beet pulp (SBP), 6) NC + 0.30% fatty acid mix (FAM), 7) NC + 0.10% phytogenic blend of essential oils and flavoring compounds (PHY), 8) NC + 50 mg Cu and 1,600 mg zinc oxide/kg diet (CuZn), 9) NC + 5% resistant corn starch (RScn), and 10) NC + 0.05% β-glucan (BG) for 28 d. There was no impact of dietary treatment on BW gain or feed intake (P ≥ 0.22). Pigs fed diets containing SCF, CTsb, and RSpo resulted in microbial community differences compared to pigs fed the NC (P < 0.05). In EXP 2, 48 barrows (12.8 kg BW) were selected at the end of EXP 1 and fed the same dietary treatments they had previously received: 1) NC, 2) NC + 5% RScn, 3) NC + 5% SCF, and 4) NC + FAM for 8 d. There was no effect of feeding diets containing RScn, SCF, or FAM on in vivo intestinal permeability (P ≤ 0.21). Ileal or colon pH, concentrations of VFA did not differ due to dietary treatment (P ≥ 0.36), but pigs fed diets containing FAM resulted in a greater butyric acid concentration in the cecum compared to pigs fed the NC (P ≤ 0.05). In EXP 3, 156 pigs (6.11 kg BW) were placed into 52 pens with 3 pigs/pen and allotted to 1 of 4 dietary treatments arranged in a factorial manner: 1) NC, 2) NC + 5% RSpo, 3) NC + 0.30% FAM, and 4) NC + 5% RSpo + 0.30% FAM for 24 d. Feeding pigs diets containing RSpo did not affect BW gain (P = 0.91) while pigs fed diets containing FAM grew improved BW gain (P = 0.09). Colonic butyric acid concentrations were greater in pigs fed diets containing RSpo (P = 0.03), while pigs fed diets containing FAM exhibited reduced total VFA concentrations (P = 0.11). The results indicate that supplementing diets with digestively resistant but fermentable fibers, short- and medium-chain fatty acids, or antibiotics do not have a consistent effect, positive or negative, on markers of intestinal integrity or barrier function, intestinal VFA patterns, ATTD of energy and nutrients, or on pig performance.

Review on Preventive Measures to Reduce Post-Weaning Diarrhoea in Piglets

In many countries, medical levels of zinc (typically as zinc oxide) are added to piglet diets in the first two weeks post-weaning to prevent the development of post-weaning diarrhoea (PWD). However, high levels of zinc constitute an environmental polluting agent, and may contribute to the development and/or maintenance of antimicrobial resistance (AMR) among bacteria. Consequently, the EU banned administering medical levels of zinc in pig diets as of June 2022. However, this may result in an increased use of antibiotic therapeutics to combat PWD and thereby an increased risk of further AMR development. The search for alternative measures against PWD with a minimum use of antibiotics and in the absence of medical levels of zinc has therefore been intensified over recent years, and feed-related measures, including feed ingredients, feed additives, and feeding strategies, are being intensively investigated. Furthermore, management strategies have been developed and are undoubtedly relevant; however, these will not be addressed in this review. Here, feed measures (and vaccines) are addressed, these being probiotics, prebiotics, synbiotics, postbiotics, proteobiotics, plants and plant extracts (in particular essential oils and tannins), macroalgae (particularly macroalgae-derived polysaccharides), dietary fibre, antimicrobial peptides, specific amino acids, dietary fatty acids, milk replacers, milk components, creep feed, vaccines, bacteriophages, and single-domain antibodies (nanobodies). The list covers measures with a rather long history and others that require significant development before their eventual use can be extended. To assess the potential of feed-related measures in combating PWD, the literature reviewed here has focused on studies reporting parameters of PWD (i.e., faeces score and/or faeces dry matter content during the first two weeks post-weaning). Although the impact on PWD (or related parameters) of the investigated measures may often be inconsistent, many studies do report positive effects. However, several studies have shown that control pigs do not suffer from diarrhoea, making it difficult to evaluate the biological and practical relevance of these improvements. From the reviewed literature, it is not possible to rank the efficacy of the various measures, and the efficacy most probably depends on a range of factors related to animal genetics and health status, additive doses used, composition of the feed, etc. We conclude that a combination of various measures is probably most recommendable in most situations. However, in this respect, it should be considered that combining strategies may lead to additive (e.g., synbiotics), synergistic (e.g., plant materials), or antagonistic (e.g., algae compounds) effects, requiring detailed knowledge on the modes of action in order to design effective strategies.

Long-chain PUFA ameliorate enterotoxigenic Escherichia coli-induced intestinal inflammation and cell injury by modulating pyroptosis and necroptosis signaling pathways in porcine intestinal epithelial cells

This study was aimed to investigate whether EPA and arachidonic acid (ARA), the representative n-3 or n-6 PUFA, could alleviate enterotoxigenic Escherichia coli (ETEC) K88-induced inflammation and injury of intestinal porcine epithelial cells 1 (IPEC-1) by modulating pyroptosis and necroptosis signalling pathways. IPEC-1 cells were cultured with or without EPA or ARA in the presence or absence of ETEC K88. EPA and ARA reduced ETEC K88 adhesion and endotoxin content in the supernatant. EPA and ARA increased transepithelial electrical resistance, decreased permeability of fluorescein isothiocyanate-labelled dextran, increased membrane protein expression of occludin, ZO-1 and claudin-1 and relieved disturbed distribution of these proteins. EPA and ARA also reduced cell necrosis ratio. EPA or ARA reduced mRNA and concentration of TNF-α, IL-6 and IL-8 and decreased mRNA abundances of intestinal toll-like receptors 4 and its downstream signals. Moreover, EPA and ARA downregulated mRNA expression of nod-like receptor protein 3 (NLRP3), caspase 1 and IL-18 and inhibited protein expression of NLRP3, apoptosis-associated speck-like protein containing a CARD (ASC), gasdermin D and caspase-1. Finally, EPA and ARA reduced mRNA expression of fas-associated death domain protein, caspase 8, receptor-interacting protein kinase (RIP) 1, mixed lineage kinase-like protein (MLKL), phosphoglycerate mutase 5 (PGAM5), motility-related protein 1 (Drp1) and high mobility protein 1 (HMGB1) and inhibited protein expression of phosphorylated-RIP1, p-RIP3, p-MLKL and HMGB1. These data demonstrate that EPA and ARA prevent ETEC K88-induced cell inflammation and injury, which is partly through inhibiting pyroptosis and necroptosis signalling pathways.

Costa M. In Vitro Screening of Non-Antibiotic Components to Mitigate Intestinal Lesions Caused by Brachyspira hyodysenteriae, Lawsonia intracellularis and Salmonella enterica Serovar Typhimurium

Simple Summary

The prevention, treatment, and control of swine dysentery, ileitis, and porcine salmonellosis diseases, respectively, caused by infection with Brachyspira hyodysenteriae, Lawsonia intracellularis, and Salmonella enterica serovar Typhimurium, still relies on the use of antimicrobials. The goal of this study was to evaluate the effectiveness of four commercially available non-antimicrobial compounds in preventing lesions caused by these bacteria using an in vitro intestinal culture model. The findings suggest that the non-antimicrobial compounds studied may have beneficial effects for the host based on the explant model data shown. These findings represent a step towards finding alternatives to antimicrobials usage and control of swine diseases in pork production.

Abstract

Swine dysentery, ileitis, and porcine salmonellosis are production-limiting diseases of global importance for swine production. They are caused by infection with Brachyspira hyodysenteriae, Lawsonia intracellularis, and Salmonella enterica serovar Typhimurium, respectively. Currently, the prevention, treatment, and control of these diseases still relies on antimicrobials. The goal of this study was to evaluate the effectiveness of four commercially available non-antimicrobial compounds in preventing lesions caused by the bacteria cited above using an in vitro intestinal culture model. A total of five pigs per pathogen were used and multiple compounds were evaluated. For compound F (a fungal fermented rye), S (a blend of short and medium chain fatty acids), and P (a synergistic blend of short and medium chain fatty acids, including coated butyrates), a total of four explants/pig for each treatment were used, while for compound D (an extract of carob and thyme) only 12 explants/pig for each treatment were used. Explants were exposed to a combination of pathogen only (n = 4/compound/pig), compound only (n = 4/compound/pig), or pathogen and compound (n = 4/compound/pig) and sampled at two time-points. Histopathology and gene expression levels were evaluated to investigate the treatment effect on explants. Short and medium-chain fatty acids, and an extract of carob and thyme, was found to mitigate lesions due to B. hyodysenteriae exposure. A fungal fermented prebiotic increased healthy epithelial coverage when explants were exposed to L. intracellularis or S. Typhimurium. These findings represent a step towards finding alternatives to antimicrobials usage and control of swine dysentery, ileitis, and salmonellosis in pork production.

Maternal and/or direct supplementation with a combination of a casein hydrolysate and yeast β-glucan on post-weaning performance and intestinal health in the pig

A 2 × 2 factorial experiment was conducted to investigate the effect of maternal supplementation from day 83 of gestation and/or direct supplementation from weaning of a bovine casein hydrolysate plus a yeast β-glucan (CH-YBG) on pig performance and intestinal health on day ten post-weaning. Twenty cross bred gilts (Large White × Landrace) were randomly assigned to one of two dietary groups (n = 10 gilts/group): basal diet (basal sows) and basal diet supplemented with CH-YBG (supplemented sows) from day 83 of gestation until weaning (2g/sow/day). At weaning, 120 pigs (6 pigs/sow) were selected. The two dam groups were further divided, resulting in four experimental groups (10 replicates/group; 3 pigs/pen) as follows: 1) BB (basal sows + basal pigs); 2) BS (basal sows + supplemented pigs); 3) SB (supplemented sows + basal pigs); 4) SS (supplemented sows + supplemented pigs). Supplemented pigs were offered 0.5g CH-YBG/kg of feed for 10 days post-weaning. On day 10 post-weaning, 1 pig/pen was humanely sacrificed and samples were taken from the gastrointestinal tract for analysis. Pigs weaned from supplemented sows (SS, SB) had reduced faecal scores and incidence of diarrhoea (P<0.05) compared to pigs weaned from basal sows (BB, BS), with SS pigs not displaying the transient rise in faecal scores seen in the other three groups from day 3 to day 10 post-weaning (P<0.05). Pigs weaned from supplemented sows had reduced feed intake (P<0.05), improved feed efficiency (P<0.05), increased butyrate concentrations (P<0.05), increased abundance of Lactobacillus (P<0.05) and decreased abundance of Enterobacteriaceae and Campylobacteraceae (P<0.05) compared to pigs weaned from basal sows. In conclusion, maternal supplementation increased the abundance of Lactobacillus and decreased the abundance of Enterobacteriaceae and Campylobacteraceae while also increasing butyrate concentrations. The combination of maternal and direct supplementation led to pigs having the lowest faecal scores compared to all other groups.

Stimbiotic Supplementation Alleviates Poor Performance and Gut Integrity in Weaned Piglets Induced by Challenge with E. coli

The aim of this study was to investigate the effects of stimbiotic (STB), a xylanase and xylo-oligosaccharide complex. A total of 36 male weaned pigs with initial body weights of 8.49 ± 0.10 kg were used in a 3-week experiment. The experiment was conducted in a 2 × 3 factorial arrangement (six replicates/treatment) of treatments consisting of two levels of challenge (challenge and non-challenge) and three levels of STB (0, 0.5, and 1 g/kg diet). Supplementations STB 0.5 g/kg (STB5) and STB 1 g/kg (STB10) improved the G:F (p = 0.04) in piglets challenged with STEC. STB supplementation, which also decreased (p < 0.05) the white blood cells, neutrophils, lymphocytes, and expression levels of tumor necrosis factor-alpha and interleukin-6. Supplementations STB5 and STB10 improved (p < 0.01) the lymphocytes and neutrophils in piglets challenged with STEC on 14 dpi. Additionally, supplementations STB5 and STB10 improved (p < 0.01) the tumor necrosis factor-alpha in piglets challenged with STEC on 3 dpi. Supplementations STB5 and STB10 also improved the villus height-to-crypt depth ratio (p < 0.01) in piglets challenged with STEC. Supplementation with STB reduced (p < 0.05) the expression levels of calprotectin. In conclusion, STB could alleviate a decrease of the performance, immune response, and inflammatory response induced by the STEC challenge.

Gut microbiome-produced metabolites in pigs: a review on their biological functions and the influence of probiotics

The gastrointestinal tract is a complex ecosystem that contains a large number of microorganisms with different metabolic capacities. Modulation of the gut microbiome can improve the growth and promote health in pigs. Crosstalk between the host, diet, and the gut microbiome can influence the health of the host, potentially through the production of several metabolites with various functions. Short-chain and branched-chain fatty acids, secondary bile acids, polyamines, indoles, and phenolic compounds are metabolites produced by the gut microbiome. The gut microbiome can also produce neurotransmitters (such as γ-aminobutyric acid, catecholamines, and serotonin), their precursors, and vitamins. Several studies in pigs have demonstrated the importance of the gut microbiome and its metabolites in improving growth performance and feed efficiency, alleviating stress, and providing protection from pathogens. The use of probiotics is one of the strategies employed to target the gut microbiome of pigs. Promising results have been published on the use of probiotics in optimizing pig production. This review focuses on the role of gut microbiome-derived metabolites in the performance of pigs and the effects of probiotics on altering the levels of these metabolites.

Effects of Tetrabasic Zinc Chloride on Growth Performance, Nutrient Digestibility and Fecal Microbial Community in Weaned Piglets

The study was conducted to explore the effects of tetrabasic zinc chloride (TBZC), as an alternative to zinc oxide (ZnO), on growth performance, serum indexes, and fecal microbiota of weaned piglets. A total of 108 weaned piglets (average initial body weight of 7.84 ± 0.97 kg) were randomly allocated into one of three dietary treatments with six replicate pens and six piglets per pen. The dietary treatments included a control diet (CON, negative control), a ZnO diet (CON + 1,600 mg Zn/kg from ZnO, positive control), and a TBZC diet (CON + 1,000 mg Zn/kg from TBZC). The average daily gain of pigs in the TBZC group was greater (P < 0.05) than those in CON and ZnO groups during the whole period. Piglets fed the ZnO and TBZC diets showed lower (P < 0.05) diarrhea incidence than those fed the CON diet during d 1-14 and the whole period. Piglets fed the TBZC diet had higher (P < 0.05) digestibility of crude protein and gross energy than those fed the CON diet. Serum concentrations of IGF-I and GH, as well as ALP activity, were significantly elevated (P < 0.05) in the TBZC treatment group compared to the CON group on d 14. Piglets fed the ZnO diet had greater (P < 0.05) acetate and total short-chain fatty acids concentrations, while the TBZC diet had greater (P < 0.05) fecal acetate and propionate concentrations on d 28. Moreover, TBZC supplementation significantly increased (P < 0.05) microbial α-diversity compared with the CON group. The fecal microbiota of piglets in ZnO and TBZC treatment groups tended (P = 0.08) to have greater relative abundance of Prevotellaceae compared with the CON piglets. In conclusion, TBZC acted as a suitable alternative to ZnO to reduce zinc excretion, and improve growth performance of weaned piglets.

Glyceryl butyrate attenuates enterotoxigenic Escherichia coli-induced intestinal inflammation in piglets by inhibiting the NF-κB/MAPK pathways and modulating the gut microbiota

The aims of this study were to evaluate whether a diet supplemented with glyceryl butyrate could attenuate the immune-inflammatory response in piglets challenged with enterotoxigenic Escherichia coli (ETEC), and to explore the mechanisms of its regulation. Eighteen weaning piglets were assigned to three diets: basal diet (CON), antibiotics diet (ATB), and 0.5% glyceryl butyrate diet (GB group). Significantly lower concentrations of IL-1β, IL-6 and TNF-α in the jejunum and IL-6 in the ileum were observed in the GB group than that in the CON group (P < 0.05). Moreover, a decreasing trend of IL-1β (P = 0.075) and TNF-α (P = 0.070) was observed in the ileum in the GB group. Correspondingly, the GB group had significantly increased mRNA expression of porcine beta defensins (pBDs) in the jejunum (pBD1, pBD2, pBD114 and pBD129) and ileum (pBD2, pBD3, pBD114 and pBD129) (P < 0.05), and protein abundance of Claudin 1, Occludin, and ZO-1 in the jejunum and ileum (P < 0.05). Further research results showed that the improvement of beta defensins and tight junctions in the GB group was related to the decreased phosphorylation of the NFκB/MAPK pathway. In addition, the results of 16S rDNA sequencing showed that glycerol butyrate supplementation altered the ileal microbiota composition of piglets, increasing the relative abundance of Lactobacillus reuteri, Lactobacillus salivarius, and Lactobacillus agrilis. In summary, glyceryl butyrate attenuated the immune-inflammatory response in piglets challenged with ETEC by inhibiting the NF-κB/MAPK pathways and modulating the gut microbiota, and thus improved piglet intestinal health.

Effects of Maternal Factors and Postpartum Environment on Early Colonization of Intestinal Microbiota in Piglets

Intestinal microbiota significantly influences the intake, storage, and utilization of body nutrients, as well as animal growth and development. The establishment of microbiota is affected by many factors, such as delivery and feeding modes, antibiotics, disease, and the surrounding environment. In this study, we selected Chinese indigenous Mashen and Jinfen White pigs as the study subjects. To explore the source and factors affecting the piglet intestinal microbiota, 16S rRNA gene sequencing was performed to analyze the microbial composition of the feces, saliva, vaginal secretions, and colostrum of parturient sows, feces and saliva of newborn piglets, and surrounding environment samples. The results showed that the microbiota of the saliva of sows and piglets is structurally similar to that of the environment and is dominated by the phylum Proteobacteria, including Acinetobacter, Actinomyces, and Pseudomonas. The core genus in the vaginal secretions and colostrum of sows was Pseudomonas. Among the fecal samples, the core bacterial genera in sows before and after delivery were Clostridium sensu_stricto_1 and Christensenellaceae_R-7_group, while in piglets at 1 d of age, Pseudomonas and Escherichia-Shigella were most abundant. These results indicate that microbiota in feces, colostrum, and vaginal secretions of sows more easily colonized piglet intestines through a symbiotic effect. The environmental and salivary microbiota could also affect the early colonization and succession of the intestinal microbiota of piglets to some extent. This study provides a theoretical basis for sow delivery protection and early nursing of piglets and background for the research and development of microbial agents to improve piglet intestinal health.

Establishment of an In Vitro Co-Culture Model of the Piglet Gut to Study Inflammatory Response and Barrier Integrity

In intensive farming, piglets are exposed to various challenges that activate intestinal inflammatory processes, negatively affecting animal health and leading to economic losses. To study the role of the inflammatory response on epithelial barrier integrity, co-culture systems that mimic in vivo complexity are more and more preferred over cell monocultures. In this study, an in vitro gut co-culture model consisting of intestinal porcine epithelial cells and porcine peripheral blood mononuclear cells was established. The model provides an appropriate tool to study the role of the inflammatory response on epithelial barrier integrity and to screen for feed and food components, exerting beneficial effects on gut health. In the established model, inflammation-like reactions and damage of the epithelial barrier, indicated by a decrease of transepithelial electrical resistance, were elicited by activation of peripheral blood mononuclear cells via one of 3 stimuli: lipopolysaccharide, lipoteichoic acid, or concanavalin A. Two phytogenic substances that are commonly used as feed additives, licorice extract and oregano oil, have been shown to counteract the drop in transepithelial electrical resistance values in the gut co-culture model. The established co-culture model provides a powerful in vitro tool to study the role of intestinal inflammation on epithelial barrier integrity. As it consists of porcine epithelial and porcine blood cells it perfectly mimics in vivo conditions and imitates the inter-organ communication of the piglet gut. The developed model is useful to screen for nutritional components or drugs, having the potential to balance intestinal inflammation and strengthen the epithelial barrier integrity in piglets.

Maternal Nutrition During Late Gestation and Lactation: Association With Immunity and the Inflammatory Response in the Offspring

The immature immune system at birth and environmental stress increase the risk of infection in nursing pigs. Severe infection subsequently induces intestinal and respiratory diseases and even cause death of pigs. The nutritional and physiological conditions of sows directly affect the growth, development and disease resistance of the fetus and newborn. Many studies have shown that providing sows with nutrients such as functional oligosaccharides, oils, antioxidants, and trace elements could regulate immunity and the inflammatory response of piglets. Here, we reviewed the positive effects of certain nutrients on milk quality, immunoglobulin inflammatory response, oxidative stress, and intestinal microflora of sows, and further discuss the effects of these nutrients on immunity and the inflammatory response in the offspring.

Maternal Supplementation with Artemisia annua L. Ameliorates Intestinal Inflammation via Inhibiting the TLR4/NF-κB and MAPK Pathways and Improves Oxidative Stability of Offspring

Artemisia annua L. (A. annua) contains artemisinin, which attracts attention on account of its anti-inflammatory and anti-oxidant effects. The increased intestinal inflammation, oxidative stress, and hypoimmunity commonly occur in the...

Effects of Ellagic Acid Supplementation on Jejunal Morphology, Digestive Enzyme Activities, Antioxidant Capacity, and Microbiota in Mice

Ellagic acid (EA), a plant polyphenol mainly found in nuts and fruits, exhibits various biological effects. However, the effects of EA on intestinal health remain poorly understood. Hence, the present study aimed to assess the effects of EA supplementation on jejunal morphology, digestive enzyme activities, antioxidant capacity, and microbiota in C57BL/6J mice. A total of 144 mice were randomly assigned to three treatments groups: the control (CON) group received a standard pellet diet, the 0.1% EA group received a standard pellet diet plus 0.1% EA, and the 0.3% EA group received a standard pellet diet plus 0.3% EA. The mice were killed at the end of the experimental period, and jejunal samples were collected. The results revealed that the mice in the 0.3% EA group had higher (P < 0.05) average daily gain and greater (P < 0.05) jejunal villus height than those in the CON group. In addition, the jejunal lactase and sucrase activities were higher (P < 0.05) in the 0.1% EA and 0.3% EA groups, and the alkaline phosphatase activity was higher (P < 0.05) in the 0.3% EA group than in the CON group. Compared with the CON group, the administration of EA increased (P < 0.05) the superoxide dismutase and catalase activities but decreased (P < 0.05) the malonaldehyde content in the jejunum. Moreover, the jejunal messenger RNA expression levels of nuclear factor-E2-related factor 2 (Nrf2) and haem oxygenase-1 (HO-1) were higher (P < 0.05) in the 0.3% EA group than in the CON group. Furthermore, compared with the CON group, the count of Escherichia coli decreased (P < 0.05), and that of Lactobacillus species increased (P < 0.05) in the 0.3% EA group. In general, our findings indicate that the administration of EA can enhance the growth of mice, promote intestinal development, increase the antioxidant capacity, and regulate the intestinal microbiota.

Regulatory Effect of Resveratrol on Inflammation Induced by Lipopolysaccharides via Reprograming Intestinal Microbes and Ameliorating Serum Metabolism Profiles

The purpose of this study was to explore the regulatory effect of resveratrol (RES) on lipopolysaccharide (LPS)-induced inflammation and its influence on intestinal microorganisms and serum atlas in murine models during the development of inflammation to explore a novel method for the regulation of inflammation. Mice were randomly assigned to three groups: control (CON), LPS, and RES–LPS. The results showed that RES mitigated the inflammatory damage to the intes-tines and liver induced by LPS. Compared with the LPS group, RES treatment decreased the levels of TNF-α, IL-6, IFN-γ, myeloperoxidase, and alanine aminotransferase in the liver. Serum metabolic profile monitoring showed that, compared with the CON group, LPS decreased the levels of five metabolites, including cycloartomunin and glycerol triundecanoate, and increased the levels of eight metabolites, including N-linoleoyl taurine and PE(O-16:0/20:5(5Z), 8Z, 11Z, 14Z, 17Z). Conversely, RES treatment increased the levels of eight metabolites, including pantothenic acid, homovanillic acid, and S-(formylmethyl)glutathione, and reduced seven metabolites, including lysoPE(20:4(8Z,11Z,14Z,17Z)/0:0) and 13-cis-retinoic acid, etc., in comparison with the LPS group. Moreover, RES treatment alleviated the negative effects of LPS on intestinal microbes by reducing, for instance, the relative abundance of Bacteroidetes and Alistipes, and increasing the relative abundance of Lactobacillus. These results suggest that RES has great potential for preventing in-flammation.

Dietary fatty acids in gut health: Absorption, metabolism and function

In biological responses, fatty acids (FA) are absorbed and metabolized in the form of substrates for energy production. The molecular structures (number of double bonds and chain length) and composition of dietary FA impact digestion, absorption and metabolism, and the biological roles of FA. Recently, increasing evidence indicates that FA are essentially utilized as an energy source and are signaling molecules that exert physiological activity of gut microbiota and immune responses. In addition, FA could serve as natural ligands for orphan G protein-coupled receptors (GPCR), also called free fatty acid receptors (FFAR), which intertwine metabolic and immune systems via multiple mechanisms. The present review explores the recent findings on FA absorption and its impact on gut health, particularly addressing the mechanism by which dietary FA potentially influences intestinal microbiota and epithelial functions. Also, this work attempts to uncover research ideas for devising future strategies for manipulating the composition of dietary FA to regulate gut health and support a normal immune system for metabolic and immune disorders.

Maintaining continuity of nutrient intake after weaning. II. Review of post-weaning strategies

Low feed consumption during the first 3 d post-weaning disrupts nutrient intake and results in what is commonly known as a post-weaning growth check. While most pigs recover from this initial reduction in feed intake (FI), some pigs fail to successfully make this transition leading to morbidity and mortality. In this review, our objective is to describe the different post-weaning strategies that can be used to minimize nutrient intake disruption and improve FI in the immediate post-weaning period. Providing weanling pigs with an environment that encourages them to search out and consume feed is important. This includes appropriate barn temperatures, resource availability, and nursery placement strategies. Research is needed to better understand the ideal environmental temperatures to encourage pen exploration and reduce time to initial FI. Likewise, mat and gruel feeding are commonly practiced throughout the industry to increase feed accessibility; however, limited research data is available to validate protocols or benefits. Nursery placement strategies include sorting light weight pigs into uniform body weight groups and average or heavy weight pigs into variable body weight groups to provide benefit to light pigs while reducing initial aggression in heavy pigs. Furthermore, water enrichment with nutrient dense products have been shown to improve growth performance and reduce morbidity and mortality in the early post-weaning period. Because young pigs are sensitive to palatability, diet form and complexity should also be considered. Weanling pigs prefer diets manufactured with coarse ground corn (700 μm) compared to fine ground corn. Additionally, weanling pigs are more attracted to large diameter pellets (12 mm) compared with small pellets. Despite these preferences, impacts on growth are relatively small. Feeding complex diets with high levels of lactose, animal protein products, or other palatable ingredients is another strategy shown to improve growth performance during the first week post-weaning; however, the initial benefits quickly diminished as pigs become older. Other strategies that warrant further investigation include the effect of crumble diets on feed preference and the concept of perinatal or social interaction flavor learning. In summary, strategic post-weaning nutrition and management practices must focus on maintaining continuity of nutrient intake in order to reduce morbidity and mortality in the immediate post-weaning period.

The effect of supplementation with β-hydroxy-β-methylbutyric acid (HMB) to pregnant sows on the mucosal structure, immunolocalization of intestinal barrier proteins, VIP and leptin in the large intestine in their offspring

The large intestine epithelium plays an important role in water absorption and participates in fluid, acid-base and electrolyte balance, and the removal of waste products. The large intestine is rich in microorganism-presented enzyme activity. Apart from energy supply, the colon also participates in the synthesis of trophic factors and the modulation of the immune system and the systemic inflammatory response. The current study investigated the effects of dietary HMB administration to pregnant sows on the postnatal development of the colon in their offspring, at weaning. From the 70th to the 90th day of gestation, sows received either a basal diet (n = 12) or the basal diet supplemented with HMB (n = 12) at a dose of 0.2 g/kg of body weight/day. Maternal HMB treatment increased serum IgG and glucose concentrations and decreased serum urea concentration in the piglets. Basal histomorphometric analysis of offspring large intestines showed that prenatal HMB treatment led to a reduction in the thickness of the mucosa, submucosa and both types of myenterons, as well as reduced crypt thickness. The immunoreaction performed to mark T0 lymphocytes and total T lymphocytes in the colon wall showed that prenatal HMB treatment decreased the number of both types of lymphocytes. Greater expression for cadherin was found in the colon of piglets delivered by the HMB-treated sows. The expression of both tight junction proteins (occludin and claudin-3), as well as that of leptin, was stronger in the HMB-treated group. Vasoactive intestinal peptide (VIP) expression was stronger in the submucosal plexuses in the HMB maternal treated piglets, while no changes were observed in the myenteric plexuses. The results obtained indicate that the administration of HMB to pregnant sows significantly influenced the expression of leptin, VIP and some proteins of the intestinal barrier in their offspring, with less influence on large intestine basal morphology.