Intestinal villus structure contributes to even shedding of epithelial cells

Effects of Tibetan Sheep-Derived Compound Probiotics on Growth Performance, Immune Function, Intestinal Tissue Morphology, and Intestinal Microbiota in Mice

Probiotics play an important role in animal growth, immunity, and gut microbial balance and are now widely used in agriculture, food, and medicine. This study analysed the effects of different concentrations of Tibetan sheep compound probiotics on the immunity, tissue morphology, and intestinal microbiota of mice using histological, molecular, and 16S rRNA techniques. The results showed that the composite probiotics sourced from Tibetan sheep improved the growth performance of mice, increased the length of small intestinal villi and mucosal thickness, and enhanced the intestinal barrier function of mice. DZ-L and DZ-M significantly increased the mRNA expression levels of ZO-1, Occludin, and Claudin-1 mRNA. They also up-regulated IL-10 and TNF-β, and down-regulated TNF-α, IL-1β, and IL-8. The immune function of mice was enhanced, with DZ-M treatment having an extremely significant effect, while the effect of DZ-H treatment was slightly lower compared to DZ-L and DZ-M. In addition, the composition and diversity of the intestinal microbiota were modulated, and at the phylum level, the relative abundance of Firmicutes was higher in the DZ-M group, the relative abundance of Desulfobacterota, Actinobacteriota, and Patescibacteria was reduced in the probiotic complex group, and the relative abundance of Verrucomicrobiota was higher. At the genus level, the relative abundance of Muribaculaceae was higher in the DZ-L and DZ-M groups, and the relative abundance of Lachnospiraceae_NK4A136_group in the DZ-H group; and the relative abundance of Bacteroides and Roseburia in the composite probiotic group. This study can improve the reference for the development of new green feed additives instead of antibiotics, which will also further promote the development of the livestock industry.

Blueberry extract for the treatment of ischaemic stroke through regulating the gut microbiota and kynurenine metabolism

Although the gut microbiota and kynurenine (KYN) metabolism have significant protective effects against ischaemic stroke (IS), the exact mechanism has yet to be fully elucidated. Combined serum metabolomics and 16S rRNA gene sequencing were used to reveal the differences between the gut microbiota and metabolites in rats treated with or without blueberry extract. Faecal microbiota transplantation (FMT) was employed to validate the protective role of the gut microbiota in IS. Furthermore, the interaction between Prevotella and IS was also confirmed in patients. Rats with IS experienced neurological impairments accompanied by an impaired intestinal barrier and disturbed intestinal flora, which further contributed to heightened inflammatory responses. Furthermore, Prevotella played a critical role in IS pathophysiology, and a positive correlation between Prevotella and KYN was detected. The role of KYN metabolism in IS was further demonstrated by the finding that IDO was significantly upregulated and that the use of the IDO inhibitor, attenuated KYN metabolic pathway activity and ameliorated neurological damage in rats with IS. Prevotella intervention also significantly improved stroke symptoms and decreasing KYN levels in rats with IS. FMT showed that the beneficial effects of blueberry extract on IS involve gut bacteria, especially Prevotella, which were confirmed by microbiological analyses conducted on IS patients. Moreover, blueberry extract led to significant changes in kynurenic acid levels and tryptophan and IDO levels through interactions with Prevotella. Our study demonstrates for the first time that blueberry extract could modulate "intestinal microecology-KYN metabolism" to improve IS.

Omics analysis revealed the intestinal toxicity induced by aflatoxin B1 and aflatoxin M1

Aflatoxin B1 (AFB1), a common mycotoxin, can occur in agricultural products. As a metabolite of AFB1, aflatoxin M1 (AFM1) mainly exist in dairy products. These two mycotoxins threaten human health, although it is unclear how they affect the function of the intestinal barrier. In this study, mice were exposed to AFB1 (0.3 mg/kg body b.w.) and AFM1(3.0 mg/kg b.w.) either individually or in combination for 28 days to explore the main differentially expressed proteins (DEPs) and the associated enriched pathways. These findings were preliminarily verified by the transcriptomic and proteomic analyses in differentiated Caco-2 cells. The results revealed that AFB1 and AFM1 exposure in mice disrupted the function of the intestinal barrier, and the combined toxicity was greater than that of each toxin alone. Further proteomic analysis in mice demonstrated that the mechanisms underlying these differences could be explained as follows: (i) lipid metabolism was enriched by AFB1-induced DEPs. (ii) protein export pathway was stimulated by AFM1-induced DEPs. (iii) cell metabolic ability was inhibited (as evidenced by changes in UDP-GT1, UDP-GT2, and Gatm6), apoptosis was induced (MAP4K3), and epithelial cell integrity was disrupted (Claudin7 and IQGAP2), resulting in more extensive intestinal damage after combined treatment. In conclusion, the hazardous impact of co-exposure to AFB1 and AFM1 from proteomic perspectives was demonstrated in the present study.

Effects of Dietary Supplementation of Bile Acids on Growth, Glucose Metabolism, and Intestinal Health of Spotted Seabass (Lateolabrax maculatus)

An 8-week feeding trial was performed to investigate the effects of dietary bile acids on growth, glucose metabolism, and intestinal health in spotted seabass (Lateolabrax maculatus) reared at high temperatures (33 °C). The fish (20.09 ± 1.12 g) were fed diets supplemented with bile acids: 0 (Con), 400 (BA400), 800 (BA800), and 1200 (BA1200) mg/kg, respectively. The results showed that the growth was promoted in fish at the BA800 treatment compared with the control (p < 0.05). Increased enzyme activities and transcripts of gluconeogenesis in the liver were observed, whereas decreased enzyme activities and transcripts of glycolysis, as well as glycogen content, were shown in the BA800 treatment (p < 0.05). The transcripts of bile acid receptors fxr in the liver were up-regulated in the BA800 treatment (p < 0.05). A bile acid supplementation of 800 mg/kg improved the morphological structure in the intestine. Meanwhile, intestinal antioxidant physiology and activities of lipase and trypsin were enhanced in the BA800 treatment. The transcripts of genes and immunofluorescence intensity related to pro-inflammation cytokines (il-1β, il-8, and tnf-α) were inhibited, while those of genes related to anti-inflammation (il-10 and tgf-β) were induced in the BA800 treatment. Furthermore, transcripts of genes related to the NF-κB pathway in the intestine (nfκb, ikkα, ikkβ, and ikbα1) were down-regulated in the BA800 treatment. This study demonstrates that a dietary bile acid supplementation of 800 mg/kg could promote growth, improve glucose metabolism in the liver, and enhance intestinal health by increasing digestive enzyme activity and antioxidant capacity and inhibiting inflammatory response in L. maculatus.

Ageratina adenophora causes intestinal integrity damage in goats via the activation of the MLCK/ROCK signaling pathway

As a global toxin invasive species, the whole herb of Ageratina adenophora (A. adenophora) contains various sesquiterpenes, which can cause various degrees of toxic reactions characterized by inflammatory damage when ingested by animals. Current studies on the toxicity of A. adenophora have focused on parenchymatous organs such as the liver and spleen, but few studies have been conducted on the intestine as the organ that is first exposed to A. adenophora and digests and absorbs its toxic components. In this study, after feeding goats with 40 % A. adenophora herb powder for 90 d, we found that the intestinal structure of goats showed pathological changes characterized, and the damage to the small intestinal segments was more severe than that of the large intestine. The MLCK/ROCK signaling pathway was activated, the cytoskeleton underwent centripetal contraction, the composition of tight junctions between intestinal epithelial cells was altered table, Occludin, Claudin-1 and Zonula occluden (ZO-1) amount was decreased, and the intestinal mechanical barrier was disrupted. The intestinal damage markers diamine oxidase (DAO) and D-lactate (D-LA) levels were elevated. In addition, we also found that intestinal bacteria translocate and enter the portal vein to colonize the liver and mesenteric lymph nodes. The expression of intestinal pro-inflammatory factors and anti-inflammatory factors was changed, the intestinal immune function was disrupted. The present study is the first to analyze the mechanism of poisoning of A. adenophora from the intestinal tract in compound-gastric animals.

Spermidine improves the antioxidant capacity and morphology of intestinal tissues and regulates intestinal microorganisms in Sichuan white geese

Introduction

Intestinal health is very important to the health of livestock and poultry, and is even a major determining factor in the performance of livestock and poultry production. Spermidine is a type of polyamine that is commonly found in a variety of foods, and can resist oxidative stress, promote cell proliferation and regulate intestinal flora.

Methods

In this study, we explored the effects of spermidine on intestinal health under physiological states or oxidative stress conditions by irrigation with spermidine and intraperitoneal injection of 3-Nitropropionic acid (3-NPA) in Sichuan white goose.

Results and discussion

Our results showed that spermidine could increase the ratio of intestinal villus to crypt and improve intestinal morphology. In addition, spermidine can also reduce malondialdehyde (MDA) accumulation caused by 3-NPA by increasing superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX) enzyme activity, thus alleviating intestinal damage. Furthermore, spermidine can regulate intestinal digestive enzyme activities and affect intestinal digestion and absorption ability. Spermidine can also promote an increase in intestinal microbial diversity and abundance and alleviate the change of microflora structure caused by 3-NPA. In conclusion, spermidine promotes the production of beneficial intestinal metabolites such as Wikstromol, Alpha-bisabolol and AS 1-5, thus improving the level of intestinal health. Taken together, these results indicate that spermidine can improve intestinal health by improving intestinal morphology, increasing antioxidant capacity and regulating intestinal flora structure.

Prolonged Fasting Induces Histological and Ultrastructural Changes in the Intestinal Mucosa That May Reduce Absorption and Revert after Enteral Refeeding

Background: Malnutrition is usual in patients referred for endoscopic gastrostomy (PEG). Refeeding syndrome is rarely observed in PEG-fed patients, which could possibly be associated with reduced absorption induced by prolonged starvation. Objective: In patients submitted to PEG after a significant period of fasting, the present study aims to: 1. evaluate the histological/ultrastructural initial changes in the intestinal mucosa, potentially associated with reduced absorption, and 2. assess if these changes could reverse with enteral refeeding. Methods: The present study is an observational, prospective, controlled study. Adult patients with ingestion below 50% of daily needs for at least one month and/or diagnosis of malnutrition were enrolled. Duodenal biopsies were taken at baseline and after 3-6 months of PEG feeding, which then underwent histological/ultrastructural analysis. Random healthy individuals were used as controls. Results: A total of 30 patients (16 men/14 women) aged 67.1 ± 13.5 years were included. Malnutrition was found in 40% of patients. Approximately 14 patients completed follow-up during both periods (46.7%). At baseline: duodenal mucosal atrophy was evident in three patients (10%); the median villi length (MVL) was 0.4 mm (0.25-0.6 mm), with it being shorter than the controls, which was 0.6 mm (0.4-0.7 mm) (p = 0.006); ultrastructural changes included focal shortening, bending, and disruption of enterocyte microvilli, the presence of citoplasmatic autophagic vacuoles, dilation and vesiculation of the smooth endoplasmic reticulum, and the presence of dilated intercellular spaces with basement membrane detachment. After refeeding, most patients displayed normal histology (92.9%) and increase MVL (p < 0.001), ultrastructural changes disappeared, and enterocytes resumed a normal appearance, although retaining scarce, small, dense bodies in apical regions from the evolution of previous autophagy. Conclusions: Prolonged fasting induces histological and ultrastructural changes in the intestinal mucosa that may reflect impaired absorption in the early post-PEG period. These changes were reverted after refeeding with enteral nutrition.

Radiation-Induced Intestinal Injury: Injury Mechanism and Potential Treatment Strategies

Radiation-induced intestinal injury (RIII) is one of the most common intestinal complications caused by radiotherapy for pelvic and abdominal tumors and it seriously affects the quality of life of patients. However, the treatment of acute RIII is essentially symptomatic and nutritional support treatment and an ideal means of prevention and treatment is lacking. Researchers have conducted studies at the cellular and animal levels and found that some chemical or biological agents have good therapeutic effects on RIII and may be used as potential candidates for clinical treatment. This article reviews the injury mechanism and potential treatment strategies based on cellular and animal experiments to provide new ideas for the diagnosis and treatment of RIII in clinical settings.

Villi Inspired Mechanical Interlocking for Intestinal Retentive Devices

Intestinal retentive devices have applications ranging from sustained oral drug delivery systems to indwelling ingestible medical devices. Current strategies to retain devices in the small intestine primarily focus on chemical anchoring using mucoadhesives or mechanical coupling using expandable devices or structures that pierce the intestinal epithelium. Here, the feasibility of intestinal retention using devices containing villi-inspired structures that mechanically interlock with natural villi of the small intestine is evaluated. First the viability of mechanical interlocking as an intestinal retention strategy is estimated by estimating the resistance to peristaltic shear between simulated natural villi and devices with various micropost geometries and parameters. Simulations are validated in vitro by fabricating micropost array patches via multistep replica molding and performing lap-shear tests to evaluate the interlocking performance of the fabricated microposts with artificial villi. Finally, the optimal material and design parameters of the patches that can successfully achieve retention in vivo are predicted. This study represents a proof-of-concept for the viability of micropost-villi mechanical interlocking strategy to develop nonpenetrative multifunctional intestinal retentive devices for the future.

Immunomodulatory Effects of Microcin C7 in Cyclophosphamide-Induced Immunosuppressed Mice

Microcin C7 (McC) as a viable immunomodulator peptide can be a potential solution for pathogenic microbial infection in the post-antibiotic era and has gained substantial attention. This study was designed to evaluate the immunomodulatory activity of Microcin C7 in a cyclophosphamide (CTX)-induced immunodeficient mouse model. We show that Microcin C7 treatment significantly alleviated the CTX-caused body weight loss, improved the feed and water consumption to improve the state of the mice, and elevated the absolute number and proportion of peripheral blood lymphocytes as well as the level of hemoglobulin. We further aim to characterize the phenotypes of the immune function and intestinal health profiles. The results demonstrate that Microcin C7 treatment increased serum levels of immunoglobulin A (IgA), IgG, interleukin 6, and hemolysin, promoted splenic lymphocyte proliferation induced by concanavalin A and LPS, and enhanced the phagocytosis of peritoneal macrophages immunized by sheep red blood cells. Additionally, Microcin C7 treatment decreased levels of diamine oxidase and d-lactate, ameliorated CTX-induced intestinal morphological damage, and increased the levels of zonula occluden 1, occludin, claudin-1, mucin 2, and secretary IgA in the jejunum and colon. Moreover, Microcin C7 administration is sufficient to reverse CTX-induced intestinal microbiota dysbiosis by increasing the number of Lactobacillus and Bifidobacterium, decreasing the number of Escherichia coli in colonic contents. Collectively, our results demonstrate that Microcin C7 may have protective and immunomodulatory functions and could be a potential candidate used in animal feed, functional foods, and immunological regimens..

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.

Recent Trends on Mitigative Effect of Probiotics on Oxidative-Stress-Induced Gut Dysfunction in Broilers under Necrotic Enteritis Challenge: A Review

Gut health includes normal intestinal physiology, complete intestinal epithelial barrier, efficient immune response, sustained inflammatory balance, healthy microbiota, high nutrient absorption efficiency, nutrient metabolism, and energy balance. One of the diseases that causes severe economic losses to farmers is necrotic enteritis, which occurs primarily in the gut and is associated with high mortality rate. Necrotic enteritis (NE) primarily damages the intestinal mucosa, thereby inducing intestinal inflammation and high immune response which diverts nutrients and energy needed for growth to response mediated effects. In the era of antibiotic ban, dietary interventions like microbial therapy (probiotics) to reduce inflammation, paracellular permeability, and promote gut homeostasis may be the best way to reduce broiler production losses. The current review highlights the severity effects of NE; intestinal inflammation, gut lesions, alteration of gut microbiota balance, cell apoptosis, reduced growth performance, and death. These negative effects are consequences of; disrupted intestinal barrier function and villi development, altered expression of tight junction proteins and protein structure, increased translocation of endotoxins and excessive stimulation of proinflammatory cytokines. We further explored the mechanisms by which probiotics mitigate NE challenge and restore the gut integrity of birds under disease stress; synthesis of metabolites and bacteriocins, competitive exclusion of pathogens, upregulation of tight junction proteins and adhesion molecules, increased secretion of intestinal secretory immunoglobulins and enzymes, reduction in pro-inflammatory cytokines and immune response and the increased production of anti-inflammatory cytokines and immune boost via the modulation of the TLR/NF-ĸ pathway. Furthermore, increased beneficial microbes in the gut microbiome improve nutrient utilization, host immunity, and energy metabolism. Probiotics along with biosecurity measures could mitigate the adverse effects of NE in broiler production.

The anti-inflammatory effect of lutein in broilers is mediated by regulating TLR4/MyD88 signaling pathway

The anti-inflammatory role of lutein has been widely recognized, however, the underlying mechanism is still not fully elucidated. Hence, the effects of lutein on the intestinal health and growth performance of broilers and the action of mechanism were investigated. 288 male yellow-feathered broilers (1-day old) were randomly allocated to 3 treatment groups with 8 replicates of 12 birds each, and the control group was fed a broken rice-soybean basal diet, while the test groups were fed a basal diet added with 20 mg/kg and 40 mg/kg of lutein (LU20, LU40), respectively. The feeding trial lasted for 21 d. The results showed that 40 mg/kg lutein supplementation tended to increase ADFI (P = 0.10) and ADG (P = 0.08) of broilers. Moreover, the addition of lutein caused a decreasing trend of gene expression and concentration of proinflammatory cytokines IL-1β (P = 0.08, P = 0.10, respectively) and IL-6 (P = 0.06, P = 0.06, respectively) and also tended to decrease the gene expression of TLR4 (P = 0.09) and MyD88 (P = 0.07) while increasing gene expression and concentration of anti-inflammatory cytokines IL-4 and IL-10 (P < 0.05) in the jejunum mucosa of broilers. Additionally, lutein supplementation increased the jejunal villi height of broilers (P < 0.05) and reduced villi damage. The experiment in vitro showed that lutein treatment reduced the gene expression of IL-1β, IL-6, and IFN-γ in chicken intestinal epithelial cells (P < 0.05). However, this effect was diminished after knock-down of TLR4 or MyD88 genes using RNAi technology. In conclusion, lutein can inhibit the expression and secretion of proinflammatory cytokines in the jejunum mucosa and promote intestinal development of broilers, and the anti-inflammatory effect may be achieved by regulating TLR4/MyD88 signaling pathway.

Asymmetric mucosal structure, mesenteric versus antimesenteric, in mouse, rat, and human small intestines

The morphology of the small intestinal mucosa is reflected by the degree of stimuli. Previous studies have come to different conclusion about whether the mucosa is equally symmetrical. The aim of the study is to investigate whether there are structural differences in the mesenteric versus antimesenteric mucosa in mice, rats, and humans. Jejunal biopsies from mice and rats were saved. Samples from human small intestine were obtained from patients undergoing Roux-en-Y gastric bypass surgery. Fixed samples were used to morphologically evaluate villus height and enlargement factor due to villi. The number of goblet cells, mast cells, enteroendocrine cells, and Paneth cells were histologically analyzed in the villus structure. Cell turnover was analyzed by Ki-67 staining. There was a significant increased villi height and villus enlargement factor antimesenterically in mice, rats, and human small intestines. The distribution of goblet cells, mast cells, and Paneth cells were equal while the number of enteroendocrine cells was increased antimesenteric in the human samples. The crypt mitotic activity was almost 20% higher in the antimesenteric part of jejunum. In summary we found longer villi, greater surface enlargement, and increased number of enteroendocrine cells as well as increased cell turnover antimesenterically. These differences may be of importance in understanding normal gastrointestinal physiology in health and disease.

Mechanical forces directing intestinal form and function

The vertebrate intestine experiences a range of intrinsically generated and external forces during both development and adult homeostasis. It is increasingly understood how the coordination of these forces shapes the intestine through organ-scale folding and epithelial organization into crypt-villus compartments. Moreover, accumulating evidence shows that several cell types in the adult intestine can sense and respond to forces to regulate key cellular processes underlying adult intestinal functions and self-renewal. In this way, transduction of forces may direct both intestinal homeostasis as well as adaptation to external stimuli, such as food ingestion or injury. In this review, we will discuss recent insights from complementary model systems into the force-dependent mechanisms that establish and maintain the unique architecture of the intestine, as well as its homeostatic regulation and function throughout adult life.

Dietary Supplementation of Chitosan Oligosaccharide–Clostridium butyricum Synbiotic Relieved Early-Weaned Stress by Improving Intestinal Health on Pigeon Squabs (Columba livia)

According to a previous study, we had found that early weaning causes harm to growth performance, intestinal morphology, activity of digestive enzymes, and antioxidant status in pigeon squabs (Columba livia). Chitosan oligosaccharides (COS) and Clostridium butyricum have been reported to have great potential to improve the growth performance and intestinal health of early-weaned animals. Therefore, the aim of this study is to explore whether dietary supplementation with COS-C. butyricum synbiotic could relieve early-weaned stress by evaluating its effects on growth performance and intestinal health in pigeon squabs. A total of 160 squabs (weaned at 7 days of age) were randomly divided into 5 groups: the control group, fed with artificial crop milk; the COS supplementation group, fed with artificial crop milk + 150 mg/kg COS; and three synbiotic supplementation groups, fed with artificial crop milk + 150 mg/kg COS + 200, 300, and 400 mg/kg C. butyricum. The results showed that a diet supplemented with COS-C. butyricum synbiotic benefitted the growth performance of early-weaned squabs; even so the differences were not significant among the five groups (p > 0.05). In addition, dietary supplementation of 150 mg/kg COS + 300~400 mg/kg C. butyricum significantly improved the intestinal morphology (especially villus surface area and the ratio of villus height to crypt depth), the activity of digestive enzymes (lipase, trypsin, and leucine aminopeptidase) in duodenum contents, and the production of total short-chain fatty acids and acetic acid in ileum content (p < 0.05). Additionally, dietary supplementation of 150 mg/kg COS + 400 mg/kg C. butyricum benefitted gut health by improving the antioxidant capacity (glutathione peroxidase and total antioxidant capacity) and cytokine status (IL-4 and IL-10) (p < 0.05), as well as by improving the intestinal microbiota diversity. In conclusion, our results revealed that dietary supplementation with synbiotic (150 mg/kg COS + 300~400 mg/kg C. butyricum) could relieve early-weaned stress by maintaining intestinal health in pigeon squabs.

Compound Probiotics Improve Body Growth Performance by Enhancing Intestinal Development of Broilers with Subclinical Necrotic Enteritis

The aim of this study is to explore whether or not the combined application of BS15 and H2 is capable to have a more effective control effect on SNE in broilers. A total of 240 1-day-old female chickens were randomly divided into 5 groups: (a) basal diet in negative control group (NC group); (b) basal diet + SNE infection (coccidiosis vaccine + CP) (PC group); (c) basal diet + SNE infection + H2 pre-treatment (BT group); (d) basal diet + SNE infection + BS15 pre-treatment (LT group); and (e) basal diet + SNE infection + H2 pre-treatment + BS15 pre-treatment (MT group). The results showed the MT group had the most positive effect on inhibiting the negative effect of growth performance at 42 days of age. In the detection of the NC, PC, and MT group indicators at 28 days of age, we found that MT group significantly promoted ileum tissue development of broilers, and the ileum of broilers in the MT group formed a flora structure different from NC and PC, although it was found that the MT group had no effect on the butyrate level in the cecum, but it could affect the serum immune level, such as significantly reducing the level of pro-inflammatory cytokine IL-8 and increasing the content of immunoglobulin IgM and IgG. In conclusion, the composite preparation of Lactobacillus johnsonii BS15 and Bacillus licheniformis H2 could effectively improve the growth performance against SNE broilers, which is possibly caused by the improvement of the immune levels, the reduction of inflammation levels, and the promotion of the intestinal development.