Dietary Fiber Ameliorates Lipopolysaccharide-Induced Intestinal Barrier Function Damage in Piglets by Modulation of Intestinal Microbiome

Effects of supplemental Glycyrrhiza polysaccharide on growth performance and intestinal health in weaned piglets

In this study, we investigated the effects of supplemental Glycyrrhiza polysaccharide (GCP) on growth performance and intestinal health of weaned piglets. Ninety piglets weaned at 28 days of age were randomly allocated to three groups with five replicates per treatment. Piglets were fed the following diets for 28 days: (1) CON (control group), basal diet; (2) G500, CON + 500 mg/kg GCP; (3) G1000, CON + 1000 mg/kg GCP. The results showed that supplementation with 1000 mg/kg GCP increased the average daily gain (ADG) and decreased the feed-to-gain ratio (F/G) (P < 0.05). Serum diamine oxidase (DAO) and D-lactic acid (DL-A) levels were lower in the G1000 group (P < 0.05). Dietary GCP 1000 mg/kg improved mucosal trypsin activity in the duodenum, jejunum and ileum and increased lipase and amylase activity in the jejunum (P < 0.05). Moreover, in the G1000 group, ZO-1, claudin 1 and occludin levels were increased in the jejunum mucosa, whereas interleukin-1β (IL-1β) and IL-6 levels were decreased (P < 0.05). The 16S rRNA gene analysis indicated that dietary 1000 mg/kg GCP altered the jejunal microbial community, with increased relative abundances of beneficial bacteria. In conclusion, dietary GCP 1000 mg/kg can improve growth performance, digestive enzyme activity, intestinal immunity, barrier function and microbial community in weaned piglets.

Effects of different dietary fiber supplement strategies on incidence of acute gastrointestinal injury in ICU patients: A prospective observational study

OBJECTIVE

This study aimed to explore the effects of dietary fiber (DF) supplement strategies on the incidence of acute gastrointestinal injury (AGI) in critically ill patients.

DESIGN

A prospective observational study.

SETTING

The study was conducted in the First Affiliated Hospital of Soochow University from April 2021 to March 2023.

METHODS

Using a five-day dietary log counted the amount of DF supplement. The best fitting trajectories of DF supplement were determined based on the latent class trajectory modelling (LCTM). The data of AGI were evaluated on the day 5 (D5) and day 7 (D7) after intensive care unit admission.

RESULTS

A total of 179 patients were included in the study. The LCTM yielded a four-trajectories of models, named; Sustained Low - Group, Slowly Rising - Group, Early Supplement & Slowly Rising - Group and Rapidly Rising - Group, respectively. The incidences of AGI on D5 and D7 were 51.4 % and 40.0 %, respectively. There was an increased risk in the grade of AGI in the Sustained Low - Group compared with the Rapidly Rising - Group on D5 [odds ratio (OR), 4.8; 95 % confidence interval (CI), 1.9-12.1] and D7 (OR, 12.0; 95 % CI, 3.9-37.0); and an increased risk in the Slowly Rising - Group on D5 (OR, 3.6; 95 % CI, 1.3-9.9).

CONCLUSION

The supplement of DF in critically ill patients may be insufficient and the incidence of AGI is high. Sustained low and slow rising DF supplement may be associated with an increased risk in the AGI.

IMPLICATIONS FOR CLINICAL PRACTICE

The clinical staff could focus on the supplementation of not only the three macronutrients, but also DF in critically ill patients.

Baicalin methyl ester prevents the LPS - induced mice intestinal barrier damage in vivo and in vitro via P65/TNF-α/MLCK/ZO-1 signal pathway

The effect of baicalin methyl ester (BME) on the regulation of mice intestinal barrier in the inflammatory response was studied in vivo and in vitro. Thirty six C57/BL mice were randomly divided into six groups (n = 6): control group; LPS group (LPS 3.5 mg/kg given intraperitoneal [ip] on day 7 of the study only), PBS group, and three BME groups (low: 50 mg/kg; medium: 100 mg/kg; high: 200 mg/kg) orally dosed with BME for 7d and LPS ip on day 7. All mice were sacrificed on day 8, and jejunum tissue collected for histopathology (H&E and PAS staining), protein expression of pro-inflammatory factors (TNF-α, IL-6, IL-8, IFN-γ) by ELISA, and intestinal tight junction proteins (ZO-1, occludin, claudin-1 and claudin-4) by Western Blot. Compared with the control group, LPS significantly increased the serum cytokines DAO (p < 0.01) and DLA (p < 0.01), upregulated the expression of pro-inflammatory factors, MLCK proteins (p <0.05) and increased the MLCK/ZO-1ratio (p <0.001). LPS also decreased the expression of claudin-4 (p < 0.01) in the jejunum and induced an inflammatory response damaging the jejunal mucosal barrier. Pretreatment with BME (100-200 mg/kg) significantly decreased the cytokines DAO (p < 0.05) and DLA (p < 0.01) in the serum, pro-inflammatory factors in the jejunum, significantly down-regulated the expression of MLCK (p <0.05) and the ratio of MLCK/ZO-1(p <0.001) but upregulated the expressions of ZO-1(p < 0.01), occludin (p < 0.05), claudin-1(p < 0.05) and claudin-4 (p < 0.05), and thereby restored the intestinal tissue structure, suggestive of alleviation of LPS-induced intestinal inflammation by BME. In vitro, MODE-K cells (derived from mice intestinal epithelium) were exposed to BME at 0 (control group-No LPS), 10, 20 and 40 μM BME for 24 h prior to LPS addition at 50 μg/mL for 2 h. LPS significantly increased the expression of pro-inflammatory factors, MLCK (p < 0.01) and the ratio of MLCK/ZO-1(p <0.001), decreased the expressions of ZO-1 (p < 0.05), occludin (p < 0.01), claudin-1 (p < 0.01) and claudin-4 (p < 0.01) in MODE-K cells compared with the control group. Compared with the LPS group, BME (10 - 40 μM) significantly decreased the expression of pro-inflammatory factors, MLCK (p < 0.05) and the ratio of MLCK/ZO-1(p <0.01) but increased the expressions of ZO-1(p < 0.01), occludin (p < 0.05) and claudin-4(p < 0.01) indicating an up-regulation of the expression of tight junction proteins by BME. On addition of extrinsic TNF-α plus LPS, the TNF- α level increased (p < 0.001) in MODE-K cells and the protein expression of MLCK (p < 0.01) was markedly up-regulated. Molecular docking predicted BME interacted with P65 by forming hydrogen bonds. IP-WB further confirmed that BME was directly bound to P65 protein in MODE-K cells. In conclusion, BME was able to restore the intestinal barrier through the P65 / TNF-α / MLCK / ZO-1 signaling pathway.

Different Physiochemical Properties of Novel Fibre Sources in the Diet of Weaned Pigs Influence Animal Performance, Nutrient Digestibility, and Caecal Fermentation

The effect of including micronised fibre sources (FS) differing in fermentability and hydration capacity (HC) on growth performance, faecal digestibility, and caecal fermentation was investigated in piglets. There were four dietary treatments: a control diet (CON) and three treatments differing in the HC and fermentability of FS added at 1.5% to prestarter (28-42 d) and starter (42-61 d) diets. These were: LHC (low-HC by-product-based insoluble fibre (IF) with a prebiotic fraction (PF) from chicory root); MHC (medium-HC by-product-based IF with a PF); and HHC (high-HC non-fermentable wood-based IF with no PF). There were eight replicates per treatment. Over the entire period, LHC and MHC piglets showed a 10% increase in daily growth and feed intake (p ≤ 0.019) and tended to have a reduced feed conversion ratio (p = 0.087) compared to HHC piglets. At 42 d, faecal protein digestibility increased by 5% in the LHC and MHC groups compared with the HHC group (p = 0.035) and did not differ from the CON group. Both LHC and MHC fibres were more fermented in vitro with caecal inocula from 61 d old piglets than HHC fibre (p ≤ 0.003). These results suggest that balanced soluble and insoluble fibre concentrates can improve piglet performance.

Ningxiang pig-derived Enterococcus hirae HNAU0516 ameliorates postweaning diarrhoea by promoting intestinal health and modulating the gut microbiota in piglets

Early weaning-induced stress precipitates diarrhoea, significantly curtailing the growth performance of piglets. A pivotal contributor to this postweaning affliction is the emergence of gut bacterial dysbiosis. Enterococcus hirae, a promising probiotic, has indicated unclear effects and mechanisms on intestinal health. In this study, we investigated the effects and underlying mechanisms of oral supplementation with Ningxiang pig-derived Enterococcus hirae HNAU0516 orally supplementation on the gut bacterial community, immune response and gut barrier function in piglets. 21 d age Duroc × (Landrace × Yorkshire) piglets with a similar BW were randomly allocated to two groups. The Enterococcus hirae HNAU0516 administration group was inoculated orally with Ningxiang pig-derived Enterococcus hirae HNAU0516 throughout the trial period. Conversely, the control group received the same volume of physiological saline. Our findings revealed that Enterococcus hirae HNAU0516 supplementation effectively reduced diarrhoea rates of piglets (P = 0.010). Notably, this probiotic promoted intestinal development and enhanced intestinal barrier function. It also showed potential anti-inflammatory properties. Furthermore, Enterococcus hirae HNAU0516 supplementation significantly remodelled the colonic microbiota and increased the production of acetate (P = 0.007). In conclusion, our study highlights that Ningxiang pig-derived Enterococcus hirae HNAU0516 improves postweaning diarrhoea by promoting intestinal development, enhancing intestinal barrier function, decreasing intestinal permeability, modulating intestinal microbiota, and increasing short-chain fatty acids production.

Dietary Citrus Flavonoids Improved Growth Performance and Intestinal Microbiota of Weaned Piglets via Immune Function Mediated by TLR2/NF-κB Signaling Pathway

This study investigated the effects of citrus flavonoids (CF) and compared to antibiotics on piglet growth and gut health. Weaned piglets were fed either a basal diet (CON) or a basal diet supplemented with 75 mg/kg chlortetracycline (CTC), 20 mg/kg CF (CF1), 40 mg/kg CF (CF2), or 80 mg/kg CF (CF3). The CF group, especially CF3, exhibited improved growth performance; reduced diarrhea; significantly higher levels of serum growth factors, immunoglobulins, and anti-inflammatory cytokines; and significantly lower levels of pro-inflammatory factors and markers of intestinal barrier damage (P < 0.05). The intestinal mucosa proteins ZO-1 and occludin increased, while NF-κB and TLR2 decreased, correlating with CF dosage (P < 0.05). Furthermore, CF promoted a favorable balance in the gut microbiota, with an increased relative abundance of Bacteroidetes and Prevotella and decreased taxa Tenericutes and Clostridiales. Overall, CF enhanced piglet growth and gut health by modulating the TLR2/NF-κB pathway, offering a natural antibiotic alternative. The optimal dose of CF was 80 mg/kg.

Let food be your medicine - dietary fiber

Dietary fiber (DF) cannot be digested and absorbed by the digestive tract, nor can it provide the energy needed to be burned for metabolic activities. Therefore, from the 1950s to the 1980s, DF received little attention in nutrition studies. With in-depth research and developments in global nutrition, people have gradually paid attention to the fact that DF occupies an essential position in the structure of nutrition, and it can ensure the healthy development of human beings. As early as 390 B.C., the ancient Greek physician Hippocrates proposed, "Let your food be your medicine, and your medicine be your food". This concept has been more systematically validated in modern scientific research, with numerous epidemiological studies showing that the dietary intake of DF-rich foods such as whole grains, root vegetables, legumes, and fruits has the potential to regulate the balance of the gut microbiota and thereby prevent diseases. However, the crosstalk between different types of DF and the gut microbiota is quite complex, and the effects on the organism vary. In this paper, we discuss research on DF and the gut microbiota and related diseases, aiming to understand the relationship between all three better and provide a reference basis for the risk reduction of related diseases.

Dietary nutrition, intestinal microbiota dysbiosis and post-weaning diarrhea in piglets

Weaning is a critical transitional point in the life cycle of piglets. Early weaning can lead to post-weaning syndrome, destroy the intestinal barrier function and microbiota homeostasis, cause diarrhea and threaten the health of piglets. The nutritional components of milk and solid foods consumed by newborn animals can affect the diversity and structure of their intestinal microbiota, and regulate post-weaning diarrhea in piglets. Therefore, this paper reviews the effects and mechanisms of different nutrients, including protein, dietary fiber, dietary fatty acids and dietary electrolyte balance, on diarrhea and health of piglets by regulating intestinal function. Protein is an essential nutrient for the growth of piglets; however, excessive intake will cause many harmful effects, such as allergic reactions, intestinal barrier dysfunction and pathogenic growth, eventually aggravating piglet diarrhea. Dietary fiber is a nutrient that alleviates post-weaning diarrhea in piglets, which is related to its promotion of intestinal epithelial integrity, microbial homeostasis and the production of short-chain fatty acids. In addition, dietary fatty acids and dietary electrolyte balance can also facilitate the growth, function and health of piglets by regulating intestinal epithelial function, immune system and microbiota. Thus, a targeted control of dietary components to promote the establishment of a healthy bacterial community is a significant method for preventing nutritional diarrhea in weaned piglets.

Dietary Fiber-Derived Butyrate Alleviates Piglet Weaning Stress by Modulating the TLR4/MyD88/NF-κB Pathway

During weaning, piglets are susceptible to intestinal inflammation and impairment in barrier function. Dietary fiber (DF) plays an active role in alleviating weaning stress in piglets. However, the effects of different sources of dietary fiber on the performance of weaned piglets are inconsistent, and the mechanisms through which they affect intestinal health need to be explored. Therefore, in this study, sixty weaned piglets were randomly divided into three treatment groups: basal diet (control, CON), beet pulp (BP), and alfalfa meal (AM) according to the feed formulation for a 28-day trial. The results showed that both AM and BP groups significantly reduced diarrhea rate and serum inflammatory factors (IL-1β and TNF-α) and increased antioxidant markers (T-AOC and SOD), in addition to decreasing serum MDA and ROS concentrations in the AM group. At the same time, piglets in the AM group showed a significant reduction in serum intestinal permeability indices (LPS and DAO) and a substantial increase in serum immunoglobulin levels (IgA, IgG, and IgM) and expression of intestinal barrier-associated genes (Claudin1, Occludin, ZO-1, and MUC1), which resulted in an improved growth performance. Interestingly, the effect of DF on intestinal inflammation and barrier function can be attributed to its modulation of gut microbes. Fiber-degrading bacteria enriched in the AM group (Christensenellaceae_R-7_group, Pediococcus and Weissella) inhibited the production of TLR4- through the promotion of SCFAs (especially butyrate). MyD88-NF-κB signaling pathway activation reduces intestinal inflammation and repairs intestinal barrier function. In conclusion, it may provide some theoretical support and rationale for AM to alleviate weaning stress and improve early intestinal dysfunction, which may have implications for human infants.

Astragalus polysaccharide: implication for intestinal barrier, anti-inflammation, and animal production

Intestine is responsible for nutrients absorption and plays a key role in defending against various dietary allergens, antigens, toxins, and pathogens. Accumulating evidence reported a critical role of intestine in maintaining animal and human health. Since the use of antibiotics as growth promoters in animal feed has been restricted in many countries, alternatives to antibiotics have been globally investigated, and polysaccharides are considered as environmentally friendly and promising alternatives to improve intestinal health, which has become a research hotspot due to its antibiotic substitution effect. Astragalus polysaccharide (APS), a biological macromolecule, is extracted from astragalus and has been reported to exhibit complex biological activities involved in intestinal barrier integrity maintenance, intestinal microbiota regulation, short-chain fatty acids (SCFAs) production, and immune response regulation, which are critical for intestine health. The biological activity of APS is related to its chemical structure. In this review, we outlined the source and structure of APS, highlighted recent findings on the regulation of APS on physical barrier, biochemical barrier, immunological barrier, and immune response as well as the latest progress of APS as an antibiotic substitute in animal production. We hope this review could provide scientific basis and new insights for the application of APS in nutrition, clinical medicine and health by understanding particular effects of APS on intestine health, anti-inflammation, and animal production.

Supplementing Ryegrass Ameliorates Commercial Diet-Induced Gut Microbial Dysbiosis-Associated Spleen Dysfunctions by Gut-Microbiota-Spleen Axis

The type and composition of food strongly affect the variation and enrichment of the gut microbiota. The gut-microbiota-spleen axis has been developed, incorporating the spleen's function and maturation. However, how short-chain fatty-acid-producing gut microbiota can be considered to recover spleen function, particularly in spleens damaged by changed gut microbiota, is unknown in geese. Therefore, the gut microbial composition of the caecal chyme of geese was assessed by 16S rRNA microbial genes, and a Tax4Fun analysis identified the enrichment of KEGG orthologues involved in lipopolysaccharide production. The concentrations of LPS, reactive oxygen species, antioxidant/oxidant enzymes, and immunoglobulins were measured from serum samples and spleen tissues using ELISA kits. Quantitative reverse transcription PCR was employed to detect the Kelch-like-ECH-associated protein 1-Nuclear factor erythroid 2-related factor 2 (Keap1-Nrf2), B cell and T cell targeting markers, and anti-inflammatory/inflammatory cytokines from the spleen tissues of geese. The SCFAs were determined from the caecal chyme of geese by using gas chromatography. In this study, ryegrass-enriched gut microbiota such as Eggerthellaceae, Oscillospiraceae, Rikenellaceae, and Lachnospiraceae attenuated commercial diet-induced gut microbial alterations and spleen dysfunctions in geese. Ryegrass significantly improved the SCFAs (acetic, butyric, propionic, isovaleric, and valeric acids), AMPK pathway-activated Nrf2 redox signaling cascades, B cells (B220, CD19, and IgD), and T cells (CD3, CD4, CD8, and IL-2, with an exception of IL-17 and TGF-β) to activate anti-inflammatory cytokines (IL-4 and IL-10) and immunoglobulins (IgA, IgG, and IgM) in geese. In conclusion, ryegrass-improved reprogramming of the gut microbiota restored the spleen functions by attenuating LPS-induced oxidative stress and systemic inflammation through the gut-microbiota-spleen axis in geese.

Effects of weaning on intestinal longitudinal muscle-myenteric plexus function in piglets

Weaning piglets usually suffer from severe diarrhea (commonly known as postweaning diarrhea, PWD) along with intestinal motility disorder. Intestinal peristalsis is mainly regulated by the longitudinal muscle-myenteric plexus (LM-MP). To understand the relationship between intestinal LM-MP function and the development of PWD, we compared the intestinal electrical activity, and the transcriptional profile of the LM-MP between 21-day-old piglets (just weaned, n=7) and 24-day-old piglets (suffered the most severe weaning stress, n=7). The results showed that 24-day-old piglets exhibited different degrees of diarrhea. A significant increase in the slow-wave frequency in the ileum and colon was observed in 24-day-old piglets, while c-kit expression in the intestinal LM-MPs was significantly decreased, indicating that PWD caused by elevated slow-wave frequency may be associated with loss of c-kit. The real-time quantitative PCR (RT-qPCR) and enzyme-linked immunosorbent assay (ELISA) showed that intestinal LM-MPs in 24-day-old piglets may undergo inflammation and oxidative stress. Significant increases in 8-hydroxy-2'-deoxyguanosine and decreases in thioredoxin suggest that weaning may lead to DNA damage in the LM-MP of 24-day-old piglets. In addition, activating transcription factor 3 was significantly upregulated, indicating nerve damage in the LM-MP of 24-day-old piglets. The transcriptomic results showed that most of the differentially expressed genes in the ileal LM-MP after weaning were downregulated and closely related to the cell cycle process. Subsequent RT-qPCR analysis showed that the relative expression of p21 was upregulated, while the expression of cyclin A2, cyclin B1, and proliferating cell nuclear antigen was downregulated in the ileal and colonic LM-MP of 24-day-old piglets, suggesting that weaning may inhibit cell proliferation and cause G1/S cell cycle arrest in ileal and colonic LM-MP. In conclusion, weaning may lead to cell cycle arrest by causing DNA damage in the LM-MP, impairing intestinal motility regulation, and ultimately leading to diarrhea in piglets.

Caffeic acid modulates intestinal microbiota, alleviates inflammatory response, and enhances barrier function in a piglet model challenged with lipopolysaccharide

Young animals are highly susceptible to intestinal damage due to incomplete intestinal development, making them vulnerable to external stimuli. Weaning stress in piglets, for instance, disrupts the balance of intestinal microbiota and metabolism, triggering intestinal inflammation and resulting in gut damage. Caffeic acid (CA), a plant polyphenol, can potentially improve intestinal health. Here, we evaluated the effects of dietary CA on the intestinal barrier and microbiota using a lipopolysaccharide (LPS)-induced intestinal damage model. Eighteen piglets were divided into three groups: control group (CON), LPS group (LPS), and CA + LPS group (CAL). On the 21st and 28th day, six piglets in each group were administered either LPS (80 μg/kg body weight; Escherichia coli O55:B5) or saline. The results showed that dietary CA improved the intestinal morphology and barrier function, and alleviated the inflammatory response. Moreover, dietary CA also improved the diversity and composition of the intestinal microbiota by increasing Lactobacillus and Terrisporobacter while reducing Romboutsia. Furthermore, the LPS challenge resulted in a decreased abundance of 14 different bile acids and acetate, which were restored to normal levels by dietary CA. Lastly, correlation analysis further revealed the potential relationship between intestinal microbiota, metabolites, and barrier function. These findings suggest that dietary CA could enhance intestinal barrier function and positively influence intestinal microbiota and its metabolites to mitigate intestinal damage in piglets. Consuming foods rich in CA may effectively reduce the incidence of intestinal diseases and promote intestinal health in piglets.

Effects of Bacillus licheniformis on growth performance, immune and antioxidant functions, and intestinal microbiota of broilers

Bacillus licheniformis (BL) has been widely regarded as an important growth promoter in recent years. However, its usage in animal industry still needs more foundations. The aim of our study was to study the effects of BL on the growth performance, immunity, oxidative function and intestinal flora of broilers. A total of 760 one-day-old yellow-feathered broilers were randomly divided into 4 groups with 10 replicates per group and 19 broilers per replicate. The broilers in the control group (CON) were fed with basal diet. The treatment groups were supplemented with 250 mg/kg (BL250), 500 mg/kg (BL500) and 750 mg/kg (BL750) BL in the basal diet for 70 d. Results showed that BL groups significantly increased the body weight (BW) and average daily gain (ADG), decreased average daily feed intake (ADFI) and feed conversion ratio (FCR). In addition, the spleen and bursa indexes were higher in the BL groups than that in the CON group at d 70. BL supplementation also markedly increased the levels of immunoglobulins Y (IgY), IgA and anti-inflammatory interleukin 10 (IL-10), reduced the levels of proinflammatory IL-1β, tumor necrosis factor α (TNF-α) and IL-2 in the serum at 70 d in a concentration-dependent manner. Besides, BL addition significantly increased the levels of series antioxidant enzymes including total antioxidant capacity (T-AOC), glutathione peroxidase (GPX), superoxide dismutase (SOD), and catalase (CAT), and decreased the level of malondialdehyde (MDA) in the serum. Moreover, BL groups showed an obvious increase of isobutyric acid markedly and BL500 group significantly promoted the level of isovaleric acid in cecal contents of broilers. Finally, microbial analysis showed that BL supplementation presented visual separations of microbial composition and increased the relative abundance of p_Proteobacteria, g_Elusimicrobium, and g_Parasutterella comparing with the CON group. Together, this study inferred that dietary BL supplementation improved the growth performance, immune and antioxidant functions, changed the intestinal microflora structure and metabolites of yellow-feathered broilers, which laid a good basis for the application of probiotics in the future.

Chinese Materia Medica in Treating Depression: The Role of Intestinal Microenvironment

Depression is a highly heterogeneous mental illness. Drug treatment is currently the main therapeutic strategy used in the clinic, but its efficacy is limited by the modulation of a single target, slow onset, and side effects. The gut-brain axis is of increasing interest because intestinal microenvironment disorders increase susceptibility to depression. In turn, depression affects intestinal microenvironment homeostasis by altering intestinal tissue structure, flora abundance and metabolism, hormone secretion, neurotransmitter transmission, and immune balance. Depression falls into the category of "stagnation syndrome" according to Traditional Chinese Medicine (TCM), which further specifies that "the heart governs the spirit and is exterior-interior with the small intestine". However, the exact mechanisms of the means by which the disordered intestinal microenvironment affects depression are still unclear. Here, we present an overview of how the Chinese materia medica (CMM) protects against depression by repairing intestinal microenvironment homeostasis. We review the past five years of research progress in classical antidepressant TCM formulae and single CMMs on regulating the intestinal microenvironment for the treatment of depression. We then analyze and clarify the multitarget functions of CMM in repairing intestinal homeostasis and aim to provide a new theoretical basis for CMM clinical application in the treatment of depression.

The triple interactions between gut microbiota, mycobiota and host immunity

The gut microbiome is mainly composed of microbiota and mycobiota, both of which play important roles in the development of the host immune system, metabolic regulation, and maintenance of intestinal homeostasis. With the increasing awareness of the pathogenic essence of infectious, immunodeficiency, and tumor-related diseases, the interactions between gut bacteria, fungi, and host immunity have been shown to directly influence the disease process or final therapeutic outcome, and collaborative and antagonistic relationships are commonly found between bacteria and fungi. Interventions represented by probiotics, prebiotics, engineered probiotics, fecal microbiota transplantation (FMT), and drugs can effectively modulate the triple interactions. In particular, traditional probiotics represented by Bifidobacterium and Lactobacillus and next-generation probiotics represented by Akkermansia muciniphila and Faecalibacterium prausnitzii showed a high enrichment trend in the gut of patients with a high response to inflammation remission and tumor immunotherapy, which predicts the potential medicinal value of these beneficial microbial formulations. However, there are bottlenecks in all these interventions that need to be broken. Meanwhile, further unraveling the underlying mechanisms of the "triple interactions" model can guide precise interventions and ultimately improve the efficiency of interventions on the host gut microbiome and immune modulation, thus directly or indirectly improving anti-inflammatory and tumor immunotherapy effects.

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.

Dietary lysozyme improves growth performance and intestinal barrier function of weaned piglets

Lysozyme (LZ) is a purely natural, nonpolluting and nonspecific immune factor, which has beneficial effects on the healthy development of animals. In this study, the influences of LZ on the growth performance and intestinal barrier of weaned piglets were studied. A total of 48 weaned piglets (Landrace × Yorkshire, 22 d old) were randomly divided into a control group (basal diet) and a LZ group (0.1% LZ diet) for 19 d. The results showed that LZ could significantly improve the average daily gain (ADG, P < 0.05) and average daily feed intake (ADFI, P < 0.05). LZ also improved the intestinal morphology and significantly increased the expression of occludin in the jejunum (P < 0.05). In addition, LZ down-regulated the expression of interleukin-1β (IL-1β, P < 0.05) and tumor necrosis factor-α (TNF-α, P < 0.05), and inhibited the expression of the genes in the nuclear factor-k-gene binding (NF-κB, P < 0.05) signaling pathway. More importantly, the analysis of intestinal flora showed LZ increased the abundance of Firmicutes (P < 0.05) and the ratio of Firmicutes to Bacteroidota (P = 0.09) at the phylum level, and increased the abundance of Clostridium_sensu_stricto_1 (P < 0.05) and reduced the abundance of Olsenella and Prevotella (P < 0.05) at the genus level. In short, this study proved that LZ could effectively improve the growth performance, relieve inflammation and improve the intestinal barrier function of weaned piglets. These findings provided an important theoretical basis for the application of LZ in pig production.

Beet pulp as soluble fiber source and dietary energy levels for growing pigs under heat stress

The study evaluated the effects of dietary fiber and energy levels administered during two growing periods (d 0-28 and d 29-56) for pigs exposed to a high temperature. A total of 96 growing pigs were used in six treatments as: Two treatments in thermoneutral temperature (21°C-24°C) with dietary energy of 3,300 and the inclusion of high or low fiber, two treatments in heat stress (30°C-34°C) with dietary energy of 3,300 and the inclusion of high or low fiber, and two treatments in heat stress with dietary energy of 3,450 and the inclusion of high or low fiber. Among standard energy level treatments, heat-stressed pigs showed lower average daily gain (ADG), feed intake, digestibility of dry matter, gross energy, crude protein, and crude fiber in phases 1 and 2. Moreover, higher concentrations of acetate, propionate, butyrate, and total short-chain fatty acid (SCFA) in feces were shown in pigs fed high fiber diets. There was a negative interaction between dietary fiber and energy for the fecal concentration of isobutyrate in phase 1 and valerate in phase 2. Pigs in heat stress treatments showed a higher rectal temperature, respiratory rate, hair cortisol, plasma zonulin, and fecal lipocalin-2. Among heat stress treatments, the overall ADG was increased in pigs fed high fiber. Pigs fed high dietary fiber showed a greater concentration of acetate, propionate, butyrate, and total SCFA. High fiber treatments decreased plasma zonulin. In conclusion, the inclusion of beet pulp, soluble fiber, at the level of 4% looks necessary in pigs diet during heat stress.

Rice bran oil supplementation protects swine weanlings against diarrhea and lipopolysaccharide challenge

Early weaned piglets suffer from oxidative stress and enteral infection, which usually results in gut microbial dysbiosis, serve diarrhea, and even death. Rice bran oil (RBO), a polyphenol-enriched by-product of rice processing, has been shown to have antioxidant and anti-inflammatory properties both in vivo and in vitro. Here, we ascertained the proper RBO supplementation level, and subsequently determined its effects on lipopolysaccharide (LPS)-induced intestinal dysfunction in weaned piglets. A total of 168 piglets were randomly allocated into four groups of seven replicates (42 piglets each group, (21±1) d of age, body weight (7.60±0.04) kg, and half males and half females) and were given basal diet (Ctrl) or basal diet supplemented with 0.01% (mass fraction) RBO (RBO1), 0.02% RBO (RBO2), or 0.03% RBO (RBO3) for 21 d. Then, seven piglets from the Ctrl and the RBO were treated with LPS (100 μg/kg body weight (BW)) as LPS group and RBO+LPS group, respectively. Meanwhile, seven piglets from the Ctrl were treated with the saline vehicle (Ctrl group). Four hours later, all treated piglets were sacrificed for taking samples of plasma, jejunum tissues, and feces. The results showed that 0.02% was the optimal dose of dietary RBO supplementation based on diarrhea, average daily gain, and average daily feed intake indices in early weaning piglets. Furthermore, RBO protected piglets against LPS-induced jejunal epithelium damage, which was indicated by the increases in villus height, villus height/crypt depth ratio, and Claudin-1 levels, as well as a decreased level of jejunal epithelium apoptosis. RBO also improved the antioxidant ability of LPS-challenged piglets, which was indicated by the elevated concentrations of catalase and superoxide dismutase, and increased total antioxidant capacity, as well as the decreased concentrations of diamine oxidase and malondialdehyde in plasma. Meanwhile, RBO improved the immune function of LPS-challenged weaned piglets, which was indicated by elevated immunoglobulin A (IgA), IgM, β‍‍-defensin-1, and lysozyme levels in the plasma. In addition, RBO supplementation improved the LPS challenge-induced dysbiosis of gut microbiota. Particularly, the indices of antioxidant capacity, intestinal damage, and immunity were significantly associated with the RBO-regulated gut microbiota. These findings suggested that 0.02% RBO is a suitable dose to protect against LPS-induced intestinal damage, oxidative stress, and jejunal microbiota dysbiosis in early weaned piglets.

Compound organic acid could improve the growth performance, immunity and antioxidant properties, and intestinal health by altering the microbiota profile of weaned piglets

This study aimed to investigate the impact of compound organic acid (COA) and chlortetracycline (CTC) on serum biochemical parameters, intestinal health, and growth performance of weaned piglets. Twenty-four piglets (24 d of age) were randomly allocated into three treatments with eight replicate pens (one piglet per pen). Feed the basal diet or a diet containing 3,000 mg/kg COA or 75 mg/kg CTC, respectively. Results showed that both COA and CTC significantly increased average daily gain and reduced diarrhea rates (P < 0.05). They also upregulated serum total antioxidant capacity and downregulated serum interleukin (IL-10) levels (P < 0.05), increased crude protein digestibility and propionic acid concentration in the colon, and decreased spermidine and putrescine contents (P < 0.05). Intestinal microbiota analysis revealed that both COA and CTC increased the Shannon and Chao1 index and decreased the relative abundance of Blautia and Roseburia, but increased the relative abundance of Clostridium-sensu-stricto-1. Correlation analysis indicated that Clostridium-sensu-stricto-1 may be closely related to inflammation levels and microbial metabolites in piglets. Based on the results, COA may be a potential substitute for CTC to reduce antibiotic use and biogenic amine emission while improving piglet growth and intestinal health.

Pectin supplement alleviates gut injury potentially through improving gut microbiota community in piglets

As pectin is widely used as a food and feed additive due to its tremendous prebiotic potentials for gut health. Yet, the underlying mechanisms associated with its protective effect remain unclear. Twenty-four piglets (Yorkshire × Landrace, 6.77 ± 0.92 kg) were randomly divided into three groups with eight replicates per treatment: (1) Control group (CON), (2) Lipopolysaccharide-challenged group (LPS), (3) Pectin-LPS group (PECL). Piglets were administrated with LPS or saline on d14 and 21 of the experiment. Piglets in each group were fed with corn-soybean meal diets containing 5% citrus pectin or 5% microcrystalline cellulose. Our result showed that pectin alleviated the morphological damage features by restoring the goblet numbers which the pig induced by LPS in the cecum. Besides, compared with the LPS group, pectin supplementation elevated the mRNA expression of tight junction protein [Claudin-1, Claudin-4, and zonula occludens-1 (ZO-1)], mucin (Muc-2), and anti-inflammatory cytokines [interleukin 10 (IL-10), and IL-22]. Whereas pectin downregulated the expression of proinflammatory cytokines (IL-1β, IL-6, IL-18), tumor necrosis factor-&alpha (TNF-α), and NF-κB. What is more, pectin supplementation also significantly increased the abundance of beneficial bacteria (Lactobacillus, Clostridium_sensu_stricto_1, Blautia, and Subdoligranulum), and significantly reduced the abundance of harmful bacteria, such as Streptococcus. Additionally, pectin restored the amount of short-chain fatty acids (SCFAs) after being decreased by LPS (mainly Acetic acid, Propionic acid, and Butyric acid) to alleviate gut injury and improve gut immunity via activating relative receptors (GPR43, GPR109, AhR). Mantel test and correlation analysis also revealed associations between intestinal microbiota and intestinal morphology, and intestinal inflammation in piglets. Taken together, dietary pectin supplementation enhances the gut barrier and improves immunity to ameliorate LPS-induced injury by optimizing gut microbiota and their metabolites.

Pasture intake protects against commercial diet-induced lipopolysaccharide production facilitated by gut microbiota through activating intestinal alkaline phosphatase enzyme in meat geese

Introduction

Diet strongly affects gut microbiota composition, and gut bacteria can influence the intestinal barrier functions and systemic inflammation through metabolic endotoxemia. In-house feeding system (IHF, a low dietary fiber source) may cause altered cecal microbiota composition and inflammatory responses in meat geese via increased endotoxemia (lipopolysaccharides) with reduced intestinal alkaline phosphatase (ALP) production. The effects of artificial pasture grazing system (AGF, a high dietary fiber source) on modulating gut microbiota architecture and gut barrier functions have not been investigated in meat geese. Therefore, this study aimed to investigate whether intestinal ALP could play a critical role in attenuating reactive oxygen species (ROS) generation and ROS facilitating NF-κB pathway-induced systemic inflammation in meat geese.

Methods

The impacts of IHF and AGF systems on gut microbial composition via 16 sRNA sequencing were assessed in meat geese. The host markers analysis through protein expression of serum and cecal tissues, hematoxylin and eosin (H&E) staining, localization of NF-қB and Nrf2 by immunofluorescence analysis, western blotting analysis of ALP, and quantitative PCR of cecal tissues was evaluated.

Results and Discussion

In the gut microbiota analysis, meat geese supplemented with pasture showed a significant increase in commensal microbial richness and diversity compared to IHF meat geese demonstrating the antimicrobial, antioxidant, and anti-inflammatory ability of the AGF system. A significant increase in intestinal ALP-induced Nrf2 signaling pathway was confirmed representing LPS dephosphorylation mediated TLR4/MyD88 induced ROS reduction mechanisms in AGF meat geese. Further, the correlation analysis of top 44 host markers with gut microbiota showed that artificial pasture intake protected gut barrier functions via reducing ROS-mediated NF-κB pathway-induced gut permeability, systemic inflammation, and aging phenotypes. In conclusion, the intestinal ALP functions to regulate gut microbial homeostasis and barrier function appear to inhibit pro-inflammatory cytokines by reducing LPS-induced ROS production in AGF meat geese. The AGF system may represent a novel therapy to counteract the chronic inflammatory state leading to low dietary fiber-related diseases in animals.

The Ingestion of Dietary Prebiotic Alternatives during Lactation Promotes Intestinal Health by Modulation of Gut Microbiota

Palm kernel expeller (PKE), a by-product of palm oil extraction, contains higher amounts of fiber than corn and soybean meal, but offers low energy density, protein value, and amino acid (AA) composition, limiting its use for swine. Recently however, it was reported that dietary fiber has a positive effect on the gut microbiota of the host, and therefore it is necessary to study the effect of PKE feeding on the intestinal microbiota of swine. In this study, we investigated the effects of supplementation with PKE in lactation diets on the gut microbiota composition of lactating sows and their litters. A total of 12 sows were randomly assigned to two dietary treatment groups in a completely randomized design. The treatments were a diet based on corn-soybean meal (CON) and CON supplemented with 20% of PKE. Sow and piglet fecal samples were collected before farrowing, on days 7 and 28 (weaning) after farrowing, and on days 7 and 28 (weaning) after farrowing, respectively, to verify gut microbiota composition by pyrosequencing analysis. The beta-diversity result showed a significant difference only in weaning-stage piglets, but dietary PKE altered the gut microbiota in sows by increasing the abundance of Lactobacillus compared with CON. In piglets, dietary PKE decreased the abundance of opportunistic pathogen Proteus and increased the abundance of potentially beneficial bacteria, such as Prevotellaceae and Prevotella. Our results can be helpful in developing feeding strategies and support the beneficial effects of dietary PKE to improve the gut health of animals.

Dietary L-Arginine or N-Carbamylglutamate Alleviates Colonic Barrier Injury, Oxidative Stress, and Inflammation by Modulation of Intestinal Microbiota in Intrauterine Growth-Retarded Suckling Lambs

Our previous studies have revealed that dietary N-carbamylglutamate (NCG) and L-arginine (Arg) supplementation improves redox status and suppresses apoptosis in the colon of suckling Hu lambs with intrauterine growth retardation (IUGR). However, no studies have reported the function of Arg or NCG in the colonic microbial communities, barrier function, and inflammation in IUGR-suckling lambs. This work aimed to further investigate how dietary Arg or NCG influences the microbiota, barrier function, and inflammation in the colon of IUGR lambs. Forty-eight newborn Hu lambs of 7 d old were assigned to four treatment groups (n = 12 per group; six male, six female) as follows: CON (normal birth weight, 4.25 ± 0.14 kg), IUGR (3.01 ± 0.12 kg), IUGR + Arg (2.99 ± 0.13 kg), and IUGR + NCG (3.03 ± 0.11 kg). A total of 1% Arg or 0.1% NCG was supplemented in a basal diet of milk replacer, respectively. Lambs were fed the milk replacer for 21 d until 28 d after birth. Compared to the non-supplemented IUGR lambs, the transepithelial electrical resistance (TER) was higher, while fluorescein isothiocyanate dextran 4 kDa (FD4) was lower in the colon of the NCG- or Arg-supplemented IUGR lambs (p < 0.05). The IUGR lambs exhibited higher (p < 0.05) colonic interleukin (IL)-6, IL-1β, tumor necrosis factor (TNF)-α, reactive oxygen species (ROS), and malondialdehyde (MDA) levels than the CON lambs; the detrimental effects of IUGR on colonic proinflammatory cytokine concentrations and redox status were counteracted by dietary Arg or NCG supplementation. Both IUGR + Arg and IUGR + NCG lambs exhibited an elevated protein and mRNA expression of Occludin, Claudin-1, and zonula occludens-1 (ZO-1) compared to the IUGR lambs (p < 0.05). Additionally, the lipopolysaccharide (LPS) concentration was decreased while the levels of acetate, butyrate, and propionate were increased in IUGR + Arg and IUGR + NCG lambs compared to the IUGR lambs (p < 0.05). The relative abundance of Clostridium, Lactobacillus, and Streptococcus was lower in the colonic mucosa of the IUGR lambs than in the CON lambs (p < 0.05) but was restored upon the dietary supplementation of Arg or NCG to the IUGR lambs (p < 0.05). Both Arg and NCG can alleviate colonic barrier injury, oxidative stress (OS), and inflammation by the modulation of colonic microbiota in IUGR-suckling lambs. This work contributes to improving knowledge about the crosstalk among gut microbiota, immunity, OS, and barrier function and emphasizes the potential of Arg or NCG in health enhancement as feed additives in the early life nutrition of ruminants.

“King of the forage”—Alfalfa supplementation improves growth, reproductive performance, health condition and meat quality of pigs

As one kind of high-quality feed with rich nutrients, including high quality protein and amino acids, dietary fiber, enriched vitamins and mineral elements and bioactive molecules, alfalfa has been widely used in the production of ruminant livestock. As the understanding of alfalfa becomes more and more comprehensive, it is found that the high-quality nutrients in alfalfa could have positive effects on pigs. An increasing number of researches have shown that supplementing dietary alfalfa to the diet of gestating sows reduced constipation, alleviated abnormal behavior, improved satiety and reproductive performance; supplementing dietary alfalfa to the diet of piglets improved growth performance and intestinal barrier function, reduced intestinal inflammatory response and diarrhea; supplementing dietary alfalfa to the diet of growing-fattening pigs improved production performance and pork quality. Moreover, the mechanisms by which various nutrients of alfalfa exert their beneficial effects on pigs mainly including dietary fiber stimulating intestinal peristalsis, enhancing the activity of digestive enzymes, and promoting the colonization of beneficial bacteria in the intestinal tract through fermentation in the intestine, producing short-chain fatty acids and thus improving intestinal health; high quality protein and amino acids are beneficial to improve animal health condition; rich vitamins and mineral elements play an important role in various physiological functions and growth and development of the body; and bioactive molecules can improve the antioxidant and anti-inflammatory level. Therefore, alfalfa could be used as pig feed ingredient to alleviate various problems in the pig industry and to improve pig production performance. In this review, we detail the current application of alfalfa in pigs and discuss the potential mechanisms involved in how alfalfa improves growth and reproductive performance, pork quality, and intestinal health of the animals, thus laying the foundation for the increased application of high-quality forage in pig production.

Effect of dietary resveratrol supplementation on growth performance, antioxidant capacity, intestinal immunity and gut microbiota in yellow-feathered broilers challenged with lipopolysaccharide

Resveratrol (RES) displays strong antioxidant and anti-inflammatory properties in protecting the animals from various stressors and inflammatory injuries, but its interrelationship with the gut microbiota remained largely unclear. This study was carried out to investigate the effects of dietary RES supplementation on growth performance, antioxidant capacity, intestinal immunity and gut microbiota in yellow-feathered broilers challenged by lipopolysaccharide (LPS). A total of 240 yellow-feathered broilers were randomly assigned to four treatment groups in a 2 × 2 factorial design. The broilers were fed with the control diet or control diet supplemented with 400 mg/kg RES, followed by challenge with LPS or the same amount of saline. Dietary RES supplementation significantly alleviated the decreases in the final body weight (BW), average daily gain (ADG), and ADFI induced by LPS (P &lt; 0.05). LPS challenge significantly increased plasma concentrations of triglyceride, high-density lipoprotein cholesterol (HDL-C), aspartate aminotransferase (AST), and cortisol levels, but decreased triiodothyronine (T3) and insulin levels (P &lt; 0.05). Dietary supplementation with RES significantly reversed the elevated creatinine concentrations and the decreased concentrations of T3 and insulin caused by LPS (P &lt; 0.05). Moreover, dietary RES supplementation significantly increased plasma total antioxidant capacity (T-AOC) and catalase (CAT) activities and superoxide dismutase (SOD) and T-AOC activities in jejunal mucosa and reduced malondialdehyde (MDA) concentration in the plasma (P &lt; 0.05). The reduction in the villus height to crypt depth ratio in duodenum, jejunum and ileum and the shortening of villus height in jejunum and ileum caused by LPS were also alleviated by RES treatment (P &lt; 0.05). Furthermore, the increased concentrations of intestinal tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and IL-1β caused by LPS were significantly decreased by RES treatment (P &lt; 0.05). Dietary RES treatment increased the mRNA expression of claudin-1, claudin-5, occludin, and zonula occludens-1 (ZO-1), and decreased mRNA expression of IL-1β, IL-8, IL-17, and TNF-α after LPS challenge (P &lt; 0.05). Dietary RES treatments significantly decreased the dominance of cecal microbiota, and increased the Pieiou-e and Simpson index. Moreover, dietary RES supplementation increased relative abundance of UCG_ 009, Erysipelotrichaceae, Christensenellaceae_R-7_group, Anaerotruncus, RF39, and Ruminococcus while decreasing the abundance of Alistipes at genus level. Spearman correlation analysis revealed that the microbes at the order and genus levels significantly correlated with indicators of growth performance, antioxidant capacity, and intestinal health. Collectively, dietary supplementation with 400 mg/kg RES could improve growth performance and antioxidant capacity, and modulate intestinal immunity in yellow-feathered broilers challenged by LPS at early stage, which might be closely associated with the regulation of gut microbiota community composition.

Pectin supplementation ameliorates intestinal epithelial barrier function damage by modulating intestinal microbiota in lipopolysaccharide-challenged piglets

During weaning, infants and young animals are susceptible to severe enteric infections, thus inducing intestinal microbiota dysbiosis, intestinal inflammation, and impaired intestinal barrier function. Pectin (PEC), a prebiotic polysaccharide, enhances intestinal health with the potential for therapeutic effect on intestinal diseases. One 21-days study was conducted to investigate the protective effect of pectin against intestinal injury induced by intraperitoneal injection of Escherichia coli lipopolysaccharide (LPS) in a piglet model. A total of 24 piglets (6.77±0.92 kg BW; Duroc × Landrace × Large White; barrows; 21 d of age) were randomly assigned into three groups: control group, LPS-challenged group, and PEC + LPS group. Piglets were administrated with LPS or saline on d14 and d21 of the experiment. All piglets were slaughtered and intestinal samples were collected after 3 h administration on d21. Pectin supplementation ameliorated the LPS-induced inflammation response and damage to the ileal morphology. Meanwhile, pectin also improved intestinal mucin barrier function, increased the mRNA expression of MUC2, and improved intestinal mucus glycosylation. LPS challenge reduced the diversity of intestinal microbiota and enriched the relative abundance of Helicobacter. Pectin restored alpha diversity improved the structure of the gut microbiota by enriching anti-inflammatory bacteria and short-chain fatty acid (SCFA)-producing bacteria, and increased the concentrations of acetate. In addition, Spearman rank correlation analysis also revealed the potential relationship between intestinal microbiota and intestinal morphology, intestinal inflammation, and intestinal glycosylation in piglets. Taken together, these results indicate that pectin enhances intestinal integrity and barrier function by altering intestinal microbiota composition and their metabolites, which subsequently alleviates intestinal injury and finally improves the growth performance of piglets.

Phenotyping of Fecal Microbiota of Winnie, a Rodent Model of Spontaneous Chronic Colitis, Reveals Specific Metabolic, Genotoxic, and Pro-inflammatory Properties

Winnie, a mouse carrying a missense mutation in the MUC2 mucin gene, is a valuable model for inflammatory bowel disease (IBD) with signs and symptoms that have multiple similarities with those observed in patients with ulcerative colitis. MUC2 mucin is present in Winnie, but is not firmly compacted in a tight inner layer. Indeed, these mice develop chronic intestinal inflammation due to the primary epithelial defect with signs of mucosal damage, including thickening of muscle and mucosal layers, goblet cell loss, increased intestinal permeability, enhanced susceptibility to luminal inflammation-inducing toxins, and alteration of innervation in the distal colon. In this study, we show that the intestinal environment of the Winnie mouse, genetically determined by MUC2 mutation, selects an intestinal microbial community characterized by specific pro-inflammatory, genotoxic, and metabolic features that could imply a direct involvement in the pathogenesis of chronic intestinal inflammation. We report results obtained by using a variety of in vitro approaches for fecal microbiota functional characterization. These approaches include Caco-2 cell cultures and Caco-2/THP-1 cell co-culture models for evaluation of geno-cytotoxic and pro-inflammatory properties using a panel of 43 marker RNAs assayed by RT-qPCR, and cell-based phenotypic testing for metabolic profiling of the intestinal microbial communities by Biolog EcoPlates. While adding a further step towards understanding the etiopathogenetic mechanisms underlying IBD, the results of this study provide a reliable method for phenotyping gut microbial communities, which can complement their structural characterization by providing novel functional information.

Applications of Omics Technology for Livestock Selection and Improvement

Conventional animal selection and breeding methods were based on the phenotypic performance of the animals. These methods have limitations, particularly for sex-limited traits and traits expressed later in the life cycle (e.g., carcass traits). Consequently, the genetic gain has been slow with high generation intervals. With the advent of high-throughput omics techniques and the availability of multi-omics technologies and sophisticated analytic packages, several promising tools and methods have been developed to estimate the actual genetic potential of the animals. It has now become possible to collect and access large and complex datasets comprising different genomics, transcriptomics, proteomics, metabolomics, and phonemics data as well as animal-level data (such as longevity, behavior, adaptation, etc.,), which provides new opportunities to better understand the mechanisms regulating animals’ actual performance. The cost of omics technology and expertise of several fields like biology, bioinformatics, statistics, and computational biology make these technology impediments to its use in some cases. The population size and accurate phenotypic data recordings are other significant constraints for appropriate selection and breeding strategies. Nevertheless, omics technologies can estimate more accurate breeding values (BVs) and increase the genetic gain by assisting the section of genetically superior, disease-free animals at an early stage of life for enhancing animal productivity and profitability. This manuscript provides an overview of various omics technologies and their limitations for animal genetic selection and breeding decisions.

Drinking Water Supplemented with Acidifiers Improves the Growth Performance of Weaned Pigs and Potentially Regulates Antioxidant Capacity, Immunity, and Gastrointestinal Microbiota Diversity

This study evaluated the potential effects of adding acidifiers to the drinking water on the growth performance, complete blood count, antioxidant indicators, and diversity of gastrointestinal microbiota for weaned pigs. A total of 400 weaned pigs were randomly divided into four treatments. Pigs were fed the same basal diet and given either water (no acidifier was added, control) or water plus blends of different formulas of acidifiers (acidifier A1, A2, or A3) for 35 days. On d 18 and 35 of the experimental period, 64 pigs (four pigs per pen) were randomly selected to collect blood for a CBC test (n = 128) and an antioxidant indicators test (n = 128); 24 pigs (six pigs per group) were randomly selected to collect fresh feces (n = 48) from the rectum for 16S rRNA gene sequencing. Compared to the control, supplementing the drinking water with acidifiers improved the growth performance and survival rate of weaned pigs. Acidifier groups also increased serum catalase (CAT) and total antioxidant capacity (T-AOC) activities, while also displaying a decreased malondialdehyde (MDA) concentration compared to the control. The relative abundance of Firmicutes in the acidifier A1 group was greater than that in the control group (p < 0.05) on d 35; the relative abundance of Lactobacillus in the acidifier A1 group was greater than that in the control group (p < 0.05) on d 18 and 35. The microbial species Subdoligranulum or Ruminococcaceae_UCG-005 had significantly positive correlations with ADG and ADFI or with serum antioxidant indicators, respectively. These findings suggest that supplementing the drinking water with an acidifier has a potential as an antioxidant, which was reflected in the improvement of growth performance, immunity, antioxidant capacity, and intestinal flora.

Influence of Sodium Humate on the Growth Performance, Diarrhea Incidence, Blood Parameters, and Fecal Microflora of Pre-Weaned Dairy Calves

This study aimed to evaluate the effects of the administration of sodium humate (NaH) on the growth performance, diarrhea incidence, and fecal microflora of pre-weaned Holstein calves. In a 53-day experiment, forty healthy newborn female calves were randomly allocated to the following four treatment groups: (1) control (basal diet); (2) 1-gram NaH (basal diet extra orally supplemented with 1 g of NaH dissolved in 100 mL of milk or milk replacer daily); (3) 3-gram NaH (basal diet extra orally supplemented with 3 g of NaH dissolved in 100 mL of milk or milk replacer daily); and (4) 5-gram NaH (basal diet extra orally supplemented with 5 g of NaH dissolved in 100 mL of milk or milk replacer daily). NaH was mixed with milk (d 2–20) or milk replacer (d 21–53). Calves in the 5-gram NaH group had a higher ADG during d 1 to 21 and d 21 to 53 than the other groups did (p < 0.05). Fecal scores and diarrheal incidence were significantly lower in the 3-gram and 5-gram NaH groups than the 1-gram NaH and control groups during d 1 to 20 (p < 0.05). The serum IgA, IgG and IL-4 concentrations, and T-SOD and T-AOC activities were higher, and the serum IL-6, TNF-α, D-lactic acid, and MDA concentrations were lower in the 5-gram NaH group than the control group (p < 0.05). Furthermore, NaH supplementation increased the abundances of Bifidobacterium and Lactobacillus but decreased the abundance of Escherichia coli in feces (p < 0.05). These encouraging findings indicated that supplementation with 5 g of NaH effectively improved the immune status, antioxidant capacity, and intestinal beneficial bacteria, and further improved the growth performance and reduced the diarrhea incidence of the pre-weaned dairy calves.

The effect of dietary fiber on gut barrier function, gut microbiota, short-chain fatty acids, inflammation and clinical outcomes in critically ill patients: A systematic review and meta-analysis

BACKGROUND

Although some studies have explored the relationships between dietary fiber (DF) supplement and gut barrier function, changes of gut microbiota and other clinical outcomes in critically ill patients, the results from different studies were not consistent.

OBJECTIVE

The purpose of this study was to explore the effect of dietary fiber on gut barrier function, gut microbiota, short-chain fatty acids (SCFAs), inflammation and clinical outcomes in critically ill patients.

METHODS

A search was performed through PubMed, Embase, the Cochrane Central Register of Clinical Trials, Web of Science and EBSCO-host that includes Health Sciences Research from inception to July 12, 2021. Data were pooled using fixed effects model for low heterogeneity and random effects model for high heterogeneity. Data were expressed as mean difference (MD) or odds ratio (OR) with confidence interval.

RESULTS

A total of 21 studies involving 2084 critically ill patients were included. The results showed that there was a significant reduction in intestinal permeability demonstrated by lactulose/rhamnose ratio (MD:-0.04; 95%CI:-0.08, -0.00; P = 0.03) on day 8 in DF supplement group. Three studies reported the relative abundance (RA) of gut microbiota and the results showed the RA of some SCFAs producers increased higher in DF supplement group. There was a significant decrease in C-reactive protein on day 14 (MD:-36.66; 95%CI:-44.40, -28.93; P<0.001) and the duration of hospital stay (MD:-3.16; 95%CI:-5.82, -0.49; P<0.05) after DF supplement. There were no significant differences on SCFAs levels, the duration of mechanical ventilation and mortality between the two groups. However, in subgroup analysis, the results indicated there was a significant reduction on the duration of mechanical ventilation in fiber combined probiotic group (MD:-13; 95%CI:-19.69, -6.31; P<0.001). Besides, significant decreases in the duration of hospital stay and risk of mortality were seen in the subgroups with fiber supplementary dose ≥20 g/d (MD:-5.62; 95%CI: -8.04, -3.21; P<0.0001; OR: 0.18, 95%CI: 0.06, 0.57, P = 0.004), as well as in medical ICU (MD:-4.77; 95%CI: -7.48, -2.07; P<0.01; OR: 0.13; 95%CI: 0.03, 0.65; P<0.05).

CONCLUSIONS

Dietary fiber may improve the gut barrier function, modulate the intestinal microbiota, decrease systemic inflammatory response and may advance the clinical outcomes in critically ill patients. This article is protected by copyright. All rights reserved.

Organic Acids Improve Growth Performance with Potential Regulation of Redox Homeostasis, Immunity, and Microflora in Intestines of Weaned Piglets

The objective of this study is to evaluate the effects of organic acids on piglet growth performance and health status. A total of 360 weanling pigs (5.3 ± 0.6 kg) were randomly allotted to 3 treatment groups with 12 replicates of 10 pigs/pen. Piglets were fed the same basal diet and given either water (control) or water plus 2.0 L/Ton organic acid (OA) blends, such as OA1 or OA2, respectively, for 7 weeks. Compared to the control, OA1 and OA2 improved growth performance and/or reduced the piglets' diarrhea rate during the various periods and improved small intestinal morphology at days 14 and/or 49. OA1 and OA2 also increased serum CAT and SOD activities and/or T-AOC and, as expected, decreased MDA concentration. Moreover, at day 14 and/or day 49, OA1 and OA2 increased the jejunal mRNA levels of host defense peptides (PBD1, PBD2, NPG1, and NPG3) and tight junction genes (claudin-1) and decreased that of cytokines (IL-1β and IL-2). Additionally, the two acidifiers regulated the abundance of several cecum bacterial genera, including Blautia, Bulleidia, Coprococcus, Dorea, Eubacterium, Subdoligranulum, and YRC2. In conclusion, both of the organic acid blends improved piglet growth performance and health status, potentially by regulating intestinal redox homeostasis, immunity, and microflora.