Symbiotic Synergy from Sponges to Humans: Microflora-Host Harmony Is Crucial for Ensuring Survival and Shielding against Invading Pathogens

Gut microbiota plays several roles in the host organism's metabolism and physiology. This phenomenon holds across different species from different kingdoms and classes. Different species across various classes engage in continuous crosstalk via various mechanisms with their gut microbiota, ensuring homeostasis of the host. In this Review, the diversity of the microflora, the development of the microflora in the host, its regulations by the host, and its functional implications on the host, especially in the context of dysbiosis, are discussed across different organisms from sponges to humans. Overall, our review aims to address the indispensable nature of the microbiome in the host's survival, fitness, and protection against invading pathogens.

Intestinal microbiota analyses of five economic fishery resources in the South China Sea

The investigation of intestinal microbiota can provide evidence for revealing the growth and development regulation, feeding habits, environmental adaptability and pollutant indication of marine organisms. To data, the intestinal microbiota of marine organisms in the South China Sea is relatively lacking. To supplement these information, we sequenced intestinal microbiota from five fishery resources (including Auxis rochei, A. thazard, Symplectoteuthis oualaniensis, Thunnus albacores, and Coryphaena equiselis) in the South China Sea using high-throughput Illumina sequencing technology. After filtering, a total of 18,706,729 reads were finally produced and then clustered into OTUs. The mean number of OTUs detected in A. rochei, A. thazard, C. equiselis, S. oualaniensis, and T. albacores was 127, 137, 52, 136, and 142, respectively. Although the Actinobacteria, Bacteroidetes, Cyanobacteria, Deferribacteres, Firmicutes, Proteobacteria, Spirochaetes, Tenericutes, [Thermi], and unclassified_Bacteria were the most abundant in the five species, Photobacterium is the most abundant microbiota. Meanwhile, intestinal microbiota showed species- and sampling sites- specificity, thus only 84 microbiota species were common to all species. Additionally, the potential functions of OTUs in the five species is mainly involved in the synthesis and metabolism of carbohydrate, amino acid, fatty acid and vitamin. This study can provide basic data for clarifying the diversity and species- specificity of intestinal microbiota of five species in the South China Sea, and help to improve the intestinal microbiota database of marine organisms.

Novel Antioxidant Insights of Myricetin on the Performance of Broiler Chickens and Alleviating Experimental Infection with Eimeria spp.: Crosstalk between Oxidative Stress and Inflammation

In the modern poultry industry, the application of novel phytogenic bioactive compounds with antioxidant potential aims to enhance productivity and quality and to minimize the stress of associated diseases. Herein, myricetin, a natural flavonoid, was evaluated for the first time on broiler chickens' performance, antioxidants and immune modulating functions, and tackling avian coccidiosis. A total of 500 one-day-old chicks were divided into five groups. The negative (NC) and infected control (IC) groups were fed a control diet without additives, and the latter was infected with Eimeria spp. Groups supplemented with myricetin (Myc) were fed a control diet of Myc (200, 400 and 600 mg/kg diet each). On d 14, all chicks except those in NC were challenged with oocysts of mixed Eimeria spp. Significant improvements in the overall growth rate and feed conversion ratio were detected in the group that was fed 600 mg/kg, unlike the IC group. Notably, groups that were fed 400 and 600 mg/kg showed higher total meat antioxidant capacity with an inverse reduction in oxidative and lipid peroxidation biomarkers (hydrogen peroxide: H₂O₂; reactive oxygen species: ROS; Malondialdehyde: MDA). Of note, the upregulation of glutathione peroxidase; GSH-Px, catalase; CAT, superoxide dismutase; SOD, heme oxygenase-1; HO-1 and NAD(P)H dehydrogenase quinone 1 NQO1 genes in jejunum and muscle were prominently observed with increasing levels of supplemental Myc. At 21 dpi, the severity of coccoidal lesions (p < 0.05) induced by mixed Eimeria spp. and oocyst excretion were greatly reduced in the group that was fed 600 mg/kg of Myc. In the IC group, higher serum levels of C-reactive protein; CRP and nitric oxide; and NO and the upregulated expression of inflammatory biomarkers (interleukin-1β; IL-1β, interleukin-6; IL-6, tumor necrosis factor-α; TNF-α, chemotactic cytokines; CCL20, stromal cell-derived factor-1; CXCL13, and avian defensins; AvBD612) were subsided in higher levels in the Myc-fed groups. Taken together, these findings indicate the promising antioxidant role of Myc in modulating immune responses and reducing growth depression associated with coccidia challenges.

Feeding broiler chickens with arginine above recommended levels: effects on growth performance, metabolism, and intestinal microbiota

BACKGROUND

Arginine is an essential amino acid for chickens and feeding diets with arginine beyond the recommended levels has been shown to influence the growth performance of broiler chickens in a positive way. Nonetheless, further research is required to understand how arginine supplementation above the widely adopted dosages affects metabolism and intestinal health of broilers. Therefore, this study was designed to assess the effects of arginine supplementation (i.e., total arginine to total lysine ratio of 1.20 instead of 1.06-1.08 recommended by the breeding company) on growth performance of broiler chickens and to explore its impacts on the hepatic and blood metabolic profiles, as well as on the intestinal microbiota. For this purpose, 630 one-day-old male Ross 308 broiler chicks were assigned to 2 treatments (7 replicates each) fed a control diet or a crystalline L-arginine-supplemented diet for 49 d.

RESULTS

Compared to control birds, those supplemented with arginine performed significantly better exhibiting greater final body weight at D49 (3778 vs. 3937 g; P < 0.001), higher growth rate (76.15 vs. 79.46 g of body weight gained daily; P < 0.001), and lower cumulative feed conversion ratio (1.808 vs. 1.732; P < 0.05). Plasma concentrations of arginine, betaine, histidine, and creatine were greater in supplemented birds than in their control counterparts, as were those of creatine, leucine and other essential amino acids at the hepatic level. In contrast, leucine concentration was lower in the caecal content of supplemented birds. Reduced alpha diversity and relative abundance of Firmicutes and Proteobacteria (specifically Escherichia coli), as well as increased abundance of Bacteroidetes and Lactobacillus salivarius were found in the caecal content of supplemented birds.

CONCLUSIONS

The improvement in growth performance corroborates the advantages of supplementing arginine in broiler nutrition. It can be hypothesized that the performance enhancement found in this study is associated with the increased availability of arginine, betaine, histidine, and creatine in plasma and the liver, as well as to the ability of extra dietary arginine to potentially ameliorate intestinal conditions and microbiota of supplemented birds. However, the latter promising property, along with other research questions raised by this study, deserve further investigations.

Microrobots for Targeted Delivery and Therapy in Digestive System

Untethered miniature robots enable targeted delivery and therapy deep inside the gastrointestinal tract in a minimally invasive manner. By combining actuation systems and imaging tools, significant progress has been made toward the development of functional microrobots. These robots can be actuated by external fields and fuels while featuring real-time tracking feedback toward certain regions and can perform the therapeutic process by rational exertion of the local environment of the gastrointestinal tract (e.g., pH, enzyme). Compared with conventional surgical tools, such as endoscopic devices and catheters, miniature robots feature minimally invasive diagnosis and treatment, multifunctionality, high safety and adaptivity, embodied intelligence, and easy access to tortuous and narrow lumens. In addition, the active motion of microrobots enhances local penetration and retention of drugs in tissues compared to common passive oral drug delivery. Based on the dissimilar microenvironments in the various sections of the gastrointestinal tract, this review introduces the advances of miniature robots for minimally invasive targeted delivery and therapy of diseases along the gastrointestinal tract. The imaging modalities for the tracking and their application scenarios are also discussed. We finally evaluate the challenges and barriers that retard their applications and hint on future research directions in this field.

A review of heat stress in chickens. Part I: Insights into physiology and gut health

Heat stress (HS) compromises the yield and quality of poultry products and endangers the sustainability of the poultry industry. Despite being homeothermic, chickens, especially fast-growing broiler lines, are particularly sensitive to HS due to the phylogenetic absence of sweat glands, along with the artificial selection-caused increase in metabolic rates and limited development of cardiovascular and respiratory systems. Clinical signs and consequences of HS are multifaceted and include alterations in behavior (e.g., lethargy, decreased feed intake, and panting), metabolism (e.g., catabolic state, fat accumulation, and reduced skeletal muscle accretion), general homeostasis (e.g., alkalosis, hormonal imbalance, immunodeficiency, inflammation, and oxidative stress), and gastrointestinal tract function (e.g., digestive and absorptive disorders, enteritis, paracellular barrier failure, and dysbiosis). Poultry scientists and companies have made great efforts to develop effective solutions to counteract the detrimental effects of HS on health and performance of chickens. Feeding and nutrition have been shown to play a key role in combating HS in chicken husbandry. Nutritional strategies that enhance protein and energy utilization as well as dietary interventions intended to restore intestinal eubiosis are of increasing interest because of the marked effects of HS on feed intake, nutrient metabolism, and gut health. Hence, the present review series, divided into Part I and Part II, seeks to synthesize information on the effects of HS on physiology, gut health, and performance of chickens, with emphasis on potential solutions adopted in broiler chicken nutrition to alleviate these effects. Part I provides introductory knowledge on HS physiology to make good use of the nutritional themes covered by Part II.

Alternatives to antibiotics for organic poultry production: types, modes of action and impacts on bird's health and production

The poultry industry contributes significantly to bridging the nutritional gap in many countries because of its meat and eggs products rich in protein and valuable nutrients at a cost less than other animal meat sources. The natural antibiotics alternatives including probiotics, prebiotics, symbiotics, organic acids, essential oils, enzymes, immunostimulants, and phytogenic (phytobiotic) including herbs, botanicals, essential oils, and oleoresins are the most common feed additives that acquire popularity in poultry industry following the ban of antibiotic growth promoters (AGPs). They are commonly used worldwide because of their unique properties and positive impact on poultry production. They can be easily mixed with other feed ingredients, have no tissue residues, improve feed intake, feed gain, feed conversion rate, improve bird immunity, improve digestion, increase nutrients availability as well as absorbability, have antimicrobial effects, do not affect carcass characters, decrease the usage of antibiotics, acts as antioxidants, anti-inflammatory, compete for stress factors and provide healthy organic products for human consumption. Therefore, the current review focuses on a comprehensive description of different natural antibiotic growth promoters’ alternatives, the mode of their action, and their impacts on poultry production.

Dietary Regulation of the Crosstalk between Gut Microbiome and Immune Response in Inflammatory Bowel Disease

Inflammatory bowel disease (IBD), a chronic, recurring inflammatory response, is a growing global public health issue. It results from the aberrant crosstalk among environmental factors, gut microbiota, the immune system, and host genetics, with microbiota serving as the core of communication for differently-sourced signals. In the susceptible host, dysbiosis, characterized by the bloom of facultative anaerobic bacteria and the decline of community diversity and balance, can trigger an aberrant immune response that leads to reduced tolerance against commensal microbiota. In IBD, such dysbiosis has been profoundly proven in animal models, as well as clinic data analysis; however, it has not yet been conclusively ascertained whether dysbiosis actually promotes the disease or is simply a consequence of the inflammatory disorder. Better insight into the complex network of interactions between food, the intestinal microbiome, and host immune response will, therefore, contribute significantly to the diagnosis, treatment, and management of IBD. In this article, we review the ways in which the mutualistic circle of dietary nutrients, gut microbiota, and the immune system becomes anomalous during the IBD process, and discuss the roles of bacterial factors in shaping the intestinal inflammatory barrier and adjusting immune capacity.

Morph-anatomic and histochemical study of ileum of goose (Alopochen egyptiacus) with special references to immune cells, mucous and serous goblet cells, telocytes, and dark and light smooth muscle fibers

The morphological characteristics of the ileum of 20 adult male Egyptian geese were determined using LM, SEM, and TEM. The mean length of the ileum in the male goose was approximately 158.71 mm, representing nearly 10.19% of the total length of the small intestine. The ileum is composed of four layers: mucosa, submucosa, muscular layer, and serosa. The mucosal layer comprises the epithelium, lamina propria, and muscularis mucosa. The mucosa forms finger-like villi and is invaginated at the bases, forming the crypts of Lieberkühn. The ileum is lined by simple columnar epithelium that contains absorptive dark and light enterocytes with two types of goblet cells (mucous and serous varieties) microfold like cells, dendritic reticulum cells, Paneth cells, and a closed type of enteroendocrine cells. The lamina propria has diffuse lymphoid tissue containing lymphocytes, macrophages, mast cells, plasma cells, and heterophils as well as telocytes. The muscularis mucosa comprises circular smooth muscle fibers extending into the core of the villi. The submucosa is a thin layer of elastic-rich connective tissue. The muscular level consists of four layers, with light and dark smooth muscle fibers. We described in detail the structure of all cellular components and histomorphometric measurements.

Nutrition, feeding and laying hen welfare

The relationship between nutrition and welfare is usually considered to be a direct result of supplying the hen with adequate quantities of feed and water. This simple notion of freedom from hunger and thirst belies the fact that nutrients play a pivotal role in the body’s response to challenges whether they relate to ambient temperature, gastrointestinal health, pathogen exposure, metabolic disorders, or social and mental stress. In all instances, maintaining homeostasis and allowing for physiologic response is dependent on an adequate and balanced nutrient supply. It is accepted that most laying hens are fed a complete diet, formulated commercially to provide the required nutrients for optimal health, egg production and welfare. In other words, the laying hen, irrespective of her housing, does not experience hunger or thirst. However, despite adequate nutrient and water supply, certain senarios can significantly affect and alter the nutrient requirements of the hen. Furthermore, the chemical composition and also the physical form of feed can significantly contribute to prevent or treat welfare and health conditions and is, therefore, a highly relevant tool to ensure and maintain an adequate welfare status. Therefore, this review takes a broader perspective of nutritional welfare and considers the nutrition of hens managed in different production systems in relation to nutritional physiology, gut microbiota, stress, metabolic disorders and feeding management.

Dietary Mannan-oligosaccharides potentiate the beneficial effects of Bifidobacterium bifidum in broiler chicken

This study investigated the effects of dietary Bifidobacterium bifidum (BFD) and mannan-oligosaccharide (MOS), as a synbiotic, on the production performance, gut microbiology, serum biochemistry, antioxidant profile and health indices of broiler chicken. Six dietary treatments were T1 (negative control), T2 (positive control-20 mg antibiotic BMD kg^-1 diet; BMD: bacitracin methylene disalicylate), T3 (0·1% MOS + 10⁶  CFU BFD per g feed), T4 (0·1% MOS + 10⁷  CFU BFD per g feed), T5 (0·2% MOS + 10⁶  CFU BFD per g feed) and T6 (0·2% MOS + 10⁷  CFU BFD per g feed). Significantly (P < 0·01) better growth performance and efficiency was observed in birds supplemented with 0·2% MOS along with 10⁶  CFU BFD per g of feed compared to BMD and control birds. Supplementation with 0·2% MOS along with either 10⁶ or 10⁷  CFU BFD per g feed reduced (P < 0·01) the gut coliform, Escherichia coli, total plate count, and Clostridium perfringens count and increased the Lactobacillus and Bifidobacterium count. Significantly (P < 0·01) higher serum and liver antioxidant enzyme pool, serum HDL cholesterol and lower serum glucose, triglyceride, total cholesterol, cardiac risk ratio, atherogenic coefficient and atherogenic index of plasma were observed in birds supplemented with 0·2% MOS along with 10⁶  CFU BFD per g of feed compared to control or BMD supplemented birds. Better production performance, gut microbial composition, serum biochemistry, antioxidant profile and health indices were depicted by broiler chicken supplemented with 0·2% MOS and 10⁶  CFU BFD per g of feed.

Growth performance, apparent retention of components, and excreta dry matter content in Shaver White pullets (5 to 16 week of age) in response to dietary supplementation of graded levels of a single strain Bacillus subtilis probiotic

Administered in adequate amounts, probiotics can be an alternative to antibiotic growth promoters in poultry production. This study evaluated dose response of a single strain of Bacillus subtilis (SSB, DSM29784) on growth performance, apparent retention (AR) of components, and excreta DM content in pullets. A basal corn-soybean meal diet was formulated to meet the specifications for grower (week 5 to 10) and developer (week 11 to 16) phases. In each phase, SSB was added to the basal diet to create 4 test diets: 0 (control, CON), 1.1E+08 (low; LSSB), 2.2E+08 (medium; MSSB), or 1.1E+09 (high; HSSB) CFU of SSB/kg of feed. All diets had TiO2 (0.5%) as a digestibility marker. A total of 720 day-old Shaver White chicks were placed in 48 cages (15 pullets per cage) and reared on a commercial antibiotic free diet for a 4-wk period. At the beginning of week 5, treatments were allocated based on cage BW (n = 12). Birds had free access to feed and water throughout. The BW, BW uniformity, feed intake (FI) and FCR were obtained weekly. Excreta was collected at the end of each phase for AR of DM, organic matter, CP, neutral detergent fiber, minerals, and AME, as well as excreta DM content. In response to SSB inclusion, BW improved in a linear (P < 0.005) and quadratic (P < 0.0001) manner in grower. FI decreased in a linear and quadratic pattern (P < 0.05, week 8 to 10) in grower, and linearly (P < 0.05) across the developer phase. Overall FCR improved in linear and quadratic pattern (P < 0.01) in the grower phase. In both the phases, AME improved in a quadratic pattern (P < 0.05). Inclusion of SSB had a linear reduction (P < 0.0001) in excreta moisture content in the grower phase. In summary, these results demonstrate that B. subtilis probiotic improved performance through enhanced nutrient utilization and reduced excreta moisture content indicating improved pullet gut health.

Essential Oils as an Intervention Strategy to Reduce Campylobacter in Poultry Production: A Review

Campylobacter is a major foodborne pathogen and can be acquired through consumption of poultry products. With 1.3 million United States cases a year, the high prevalence of Campylobacter within the poultry gastrointestinal tract is a public health concern and thus a target for the development of intervention strategies. Increasing demand for antibiotic-free products has led to the promotion of various alternative pathogen control measures both at the farm and processing level. One such measure includes utilizing essential oils in both pre- and post-harvest settings. Essential oils are derived from plant-based extracts, and there are currently over 300 commercially available compounds. They have been proposed to control Campylobacter in the gastrointestinal tract of broilers. When used in concentrations low enough to not influence sensory characteristics, essential oils have also been proposed to decrease bacterial contamination of the poultry product during processing. This review explores the use of essential oils, particularly thymol, carvacrol, and cinnamaldehyde, and their role in reducing Campylobacter concentrations both pre- and post-harvest. This review also details the suggested mechanisms of action of essential oils on Campylobacter.

Short-chain arabinoxylans prepared from enzymatically treated wheat grain exert prebiotic effects during the broiler starter period

Carbohydrate-degrading multi-enzyme preparations (MEP) are used to improve broiler performances. Their mode of action is complex and not fully understood. In this study, we compared the effect of water-soluble fractions isolated at the pilot scale from wheat grain incubated with (WE) and without (WC) MEP. The fractions were incorporated in a wheat-based diet (0.1% w/w) to feed Ross PM3 broilers and compared with a non-supplemented control group (NC). The body weight gain (BWG), feed intake (FI), and feed conversion ratio (FCR) until d 14 were determined. At d 14, ileal and cecal contents and tissue samples were collected from euthanized animals. The intestinal contents were used to measure the short-chain fatty acids (SCFA) concentration using gas chromatography and to determine the abundance and composition of microbiota using 16S sequencing. Villi length of ileal samples was measured, while L-cell and T-cell densities were determined using immuno-histochemistry. The MEP treatment increased the amount of water-soluble arabinoxylans (AX) and reduced their molecular weight while retaining their polymer behavior. The WE fraction significantly (P < 0.05) increased FI by 13.8% and BWG by 14.7% during the first wk post hatch when compared to NC. No significant effect on FCR was recorded during the trial. The WE increased the abundance of Enterococcus durans and Candidatus arthromitus in the ileum and of bacteria within the Lachnospiraceae and Ruminococcaceae families, containing abundant butyrate-producing bacteria, in the ceca. It also increased the concentration of SCFA in the ceca, decreased the T-lymphocyte infiltration in the intestinal mucosa, and increased the glucagon-like-peptide-2 (GLP-2)-producing L-cell density in the ileal epithelium compared with WC and NC. No significant effects were observed on villi length. These results showed that AX present in the WE fraction altered the microbiota composition towards butyrate producers in the ceca. Butyrate may be responsible for the reduction of inflammation, as suggested by the decrease in T-lymphocyte infiltration, which may explain the higher feed intake leading to improved animal growth.

Nutrients central to maintaining intestinal absorptive efficiency and barrier integrity with fowl

The small intestinal mucosa acts to recover nutrients from the lumen while providing a barrier against potential hazards. Its unstirred water layer (USWL) at the lumen interface involves membrane associated mucin linearly protruding from underlying microvilli that entangles secretory mucin released from local goblet cells. Both mucin sources are dominated by repetitive O-glycosylated areas dependant on threonine, serine, glycine, and proline. Secretory mucin differs from membrane attached mucin by further employing multiple cystines that interconnect these areas into a net-like molecular sieve. All of the glycosylated areas have ionizable acidic groups credited with reducing pH from that in the lumen to create a micro environment favoring enzymes finalizing digestion while optimizing nutrient terms for absorption. Erosion of the USWL and/or abuse of the membrane due to lumen threats require continuous repair. The aforementioned amino acids are necessary in substantial amounts while vitamin B6 collaborates with vitamin A as meaningful cofactors for mucin synthesis. Marginal inadequacies of these nutrients during inordinate demand are expected to impair mucin replacement. In turn, marginal increases in feed conversion likely occur while fostering the probability of necrotic enteritis together with gizzard erosions. Abuse of the absorptive membrane is of particular concern from fatty acid hydroperoxides because of their continual presence in feed and inability of the USWL to provide protection. These hydroperoxides threaten membrane integrity by their inclusion in micelles during digestive events with fat thereby permitting transit through the USWL. Once coalesced with membrane phospholipids, structural aberrations are visualized as interfering with nutrient recovery while enabling leakage of cell contents to potentiate wet excreta. Inclusion of dietary vitamin E along with vitamin A into micelles with fatty acid hydroperoxides provides relief by quenching further peroxidation. Assuring cystine, threonine, glycine, and serine that are directly available as such together with vitamins A, E, and B6 represents one approach toward optimizing maintenance of the intestinal mucosa.

Regulation of intestinal health by branched-chain amino acids

Besides its primary role in the digestion and absorption of nutrients, the intestine also interacts with a complex external milieu, and is the first defense line against noxious pathogens and antigens. Dysfunction of the intestinal barrier is associated with enhanced intestinal permeability and development of various gastrointestinal diseases. The branched-chain amino acids (BCAAs) are important nutrients, which are the essential substrates for protein biosynthesis. Recently, emerging evidence showed that BCAAs are involved in maintaining intestinal barrier function. It has been reported that dietary supplementation with BCAAs promotes intestinal development, enhances enterocyte proliferation, increases intestinal absorption of amino acids (AA) and glucose, and improves the immune defenses of piglets. The underlying mechanism of these effects is mediated by regulating expression of genes and proteins associate with various signaling pathways. In addition, BCAAs promote the production of beneficial bacteria in the intestine of mice. Compelling evidence supports the notion that BCAAs play important roles in both nutrition and intestinal health. Therefore, as functional amino acids with various physiological effects, BCAAs hold key roles in promoting intestinal development and health in animals and humans.

Characterization of host responses induced by Toll-like receptor ligands in chicken cecal tonsil cells

The innate responses of cecal tonsils against invading microorganisms are mediated by conserved pattern recognition receptors (PRRs) such as the Toll-like receptors (TLRs). TLRs expressed by mammalian and avian immune system cells have the capability to recognize pathogen-associated molecular patterns (PAMPs). Although, the role of TLR ligands in innate and adaptive responses in chickens has been characterized in spleen and bursa of Fabricius, considerably less is known about responses in cecal tonsils. The aim of the current study was to assess responses of mononuclear cells from cecal tonsils to treatment with the TLR2, TLR4 and TLR21 ligands, Pam3CSK4, lipopolysaccharide (LPS), and CpG oligodeoxynucleotide (ODN), respectively. All three ligands induced significant up-regulation of interferon (IFN)-γ, interleukin (IL)-1β, IL-6 and CxCLi2/IL-8, whereas no significant changes were observed in expression of IL-13 or the antimicrobial peptides, avian β-defensin (AvBD) 1, AvBD2 and cathelicidin 3 (CATHL-3). In general, CpG ODN elicited the highest cytokine responses by cecal tonsil mononuclear cells, inducing significantly higher expression compared to LPS and Pam3CSK4, for IFNγ, IL-1β, IL-6 and CxCLi2 at various time points. These findings suggest the potential use of TLR21 ligands as mucosal vaccine adjuvants, especially in the context of pathogens of the intestinal tract.

Evaluation of the efficacy of sequential or continuous administration of probiotics and phytogenics in broiler diets

Three dietary combinations of probiotics and phytogenics administered sequentially or continuously were assessed for their effects on broiler performance, nutrient digestibility, caecal microbiota composition, volatile fatty acid (VFA) pattern and plasma total antioxidant capacity (TAC). One-day-old Cobb male broilers (n = 525) were allocated to five experimental treatments for 42 days. Each treatment had three replicates of 35 broilers each. Depending on the time-frame of sequential or continuous addition in the basal diet (BD) of the probiotics (108 CFU/kg BD) and phytogenics (125 mg/kg BD), experimental treatments were: control (no additions, Days 1–42); PE1, probiotic Days 1–14 and phytogenic Days 15–42; PE2, probiotic Days 1–28 and phytogenic Days 29–42; PE3, probiotic and phytogenic continuously (Days 1–42); and A (2.5 mg avilamycin/kg diet, Days 1–42). There was no loss of probiotic viability upon mixing with the phytogenic for up to 7 days. Overall bodyweight gain was higher (P = 0.025) in the control and PE1 than PE2 and PE3, whereas Treatment A was intermediate and not different from the rest. Overall feed intake in the control was the highest (P = 0.003). Treatments PE1, PE2 and PE3 had better (P = 0.004) overall feed conversion ratio (FCR) than the control. The FCR in PE1 and PE3 did not differ from A, which had the best FCR. Mortality did not differ among treatments. Nutrient digestibility and caecal microbiota composition did not differ among treatments. However, differences (P ≤ 0.05) in caecal VFA pattern were noted, with the control having the lowest acetate molar ratio as well as the highest sum of valeric, hexanoic and heptanoic acids. Plasma TAC in the control was lower than in PE3, PE1 and PE2 at Day 14 (P < 0.001) and PE1 (P = 0.003) at Day 42. The concept of sequential or throughout probiotic and phytogenic administration showed promising results regarding feed efficiency and plasma TAC.

Effect of dietary inclusion level of a multi-species probiotic on broiler performance and two biomarkers of their caecal ecology

The effect of the dietary inclusion level of a three-species probiotic on broiler performance, nutrient digestibility, caecal microbiota composition and volatile fatty acid (VFA) pattern was evaluated. Day-old Cobb broilers (n = 448) were allocated in four treatments for 6 weeks. Each treatment had four replicates (two per gender) of 28 broilers each. Depending on the type of addition per kg basal diet, treatments were C (no other addition), PL (108 colony forming units of probiotic), PH (109 colony forming units of probiotic) and A (2.5 mg avilamycin). Overall bodyweight gain was better (P = 0.002) in PL and PH than in the control (2082 g) by 8.7% and 7.5%, respectively, while treatment PL did not differ from A (2341 g), which showed the highest bodyweight gain. The ileal and total-tract apparent digestibility of DM and the apparent metabolisable energy content corrected for N improved linearly (P ≤ 0.05) with the probiotic level. Fluorescent in situ hybridisation analysis showed caecal Bifidobacterium levels to increase linearly (P = 0.006) with the probiotic level. Probiotic administration resulted in altered caecal VFA patterns compared with the control. Gender effects (P ≤ 0.05) were noted for caecal levels of C. histolyticum group, Bacteroides fragilis group and Streptococcus spp., while interactions (P ≤ 0.05) of treatment with gender were seen for Bifidobacterium and all VFA components, except for acetate. In conclusion, beneficial effects on bodyweight gain, DM digestibility, apparent metabolisable energy content corrected for N, caecal Bifidobacterium levels and VFA patterns were noted with both probiotic inclusion levels.

Intestinal microbiome of poultry and its interaction with host and diet

The gastrointestinal (GI) tract of poultry is densely populated with microorganisms which closely and intensively interact with the host and ingested feed. The gut microbiome benefits the host by providing nutrients from otherwise poorly utilized dietary substrates and modulating the development and function of the digestive and immune system. In return, the host provides a permissive habitat and nutrients for bacterial colonization and growth. Gut microbiome can be affected by diet, and different dietary interventions are used by poultry producers to enhance bird growth and reduce risk of enteric infection by pathogens. There also exist extensive interactions among members of the gut microbiome. A comprehensive understanding of these interactions will help develop new dietary or managerial interventions that can enhance bird growth, maximize host feed utilization, and protect birds from enteric diseases caused by pathogenic bacteria.

A natural carbohydrate fraction Actigen™ fromSaccharomyces cerevisiaecell wall: effects on goblet cells, gut morphology and performance of broiler chickens

A study was conducted to evaluate a natural carbohydrate fraction Actigen™ (NCF), derived from mannanoligosaccharide, in feed on growth performance, intestinal morphology and goblet cell number and area of male broilers'. Dietary treatments included: 1) control diet (antibiotic and NCF free), 2) NCF at 200 g/t, 3) NCF at 400 g/t, and 4) NCF 800 g/t. Two hundred and forty birds were placed into 12 replicate pens per treatment (5 birds/pen), sixty birds per treatment. Body weight and feed intake were recorded weekly up to day 42. At this time a 2.5cm section of jejunum and duodenum were excised post mortem for morphological analysis. Birds fed 200 g/t and 800 g/t NCF were significantly (P < 0.01) heavier from day 14 onwards than the control birds. Feed intake was significantly higher in birds fed 200 g/t NCF compared to those fed the control at 21 and 35 days (P < 0.05). Diets containing 200 g/t and 800 g/t of NCF significantly decreased broiler feed conversion ratio (FCR) compared to the control in the first phase (1–14 days) (P < 0.01) and levels of NCF decreased FCR (P < 0.05) in the second phase (15–28 days). NCF had no significant effect on villus height, villus width, crypt depth or villus to crypt ratio in either duodenum or jejunum. NCF did not significantly affect goblet cell area or goblet cell number in the duodenum, however, in the jejunum, 800 g/t NCF significantly (P < 0.05) increased goblet cell area over the control. In conclusion, NCF showed a positive effect on broiler performance in the starter and grower phases, and increased goblet cell area in the jejunum, suggesting higher levels of mucin production. This indicated that the performance benefit of NCF could be age-dependent, with younger birds responding more than the older ones. There were no additional benefits to performance when feeding NCF for a longer period (after 28 d of age), however it is postulated that birds fed NCF would have greater defence to pathogenic challenge through increased storage capacity of mucin.

Interspecific variations in the gastrointestinal microbiota in penguins

Despite the enormous amount of data available on the importance of the gastrointestinal (GI) microbiota in vertebrate (especially mammals), information on the GI microbiota of seabirds remains incomplete. As with many seabirds, penguins have a unique digestive physiology that enables them to store large reserves of adipose tissue, protein, and lipids. This study used quantitative real-time polymerase chain reaction (qPCR) and 16S rRNA gene pyrosequencing to characterize the interspecific variations of the GI microbiota of four penguin species: the king, gentoo, macaroni, and little penguin. The qPCR results indicated that there were significant differences in the abundance of the major phyla Firmicutes, Bacteroides, Actinobacteria, and Proteobacteria. A total of 132,340, 18,336, 6324, and 4826 near full-length 16S rRNA gene sequences were amplified from fecal samples collected from king, gentoo, macaroni, and little penguins, respectively. A total of 13 phyla were identified with Firmicutes, Bacteroidetes, Proteobacteria, and Fusobacteria dominating the composition; however, there were major differences in the relative abundance of the phyla. In addition, this study documented the presence of known human pathogens, such as Campylobacter, Helicobacter, Prevotella, Veillonella, Erysipelotrichaceae, Neisseria, and Mycoplasma. However, their role in disease in penguins remains unknown. To our knowledge, this is the first study to provide an in-depth investigation of the GI microbiota of penguins.

Growth performance and intestinal morphology in broiler chickens produced from hyperthyroid breeder hens

An association between induced maternal hyperthyroidism and a decreased incidence of cold-induced ascites in broiler chickens has been reported recently. There are also reports suggesting that thyroid hormones have an effect on intestine, a high oxygen-demanding organ. The present study aimed to determine whether the ascites-attenuating effect of maternal hyperthyroidism is associated with morphological changes in intestine and with probable adverse effects on growth performance in progeny chicks. Eighty-eight broiler breeder hens were allotted to control or hyperthyroid [HYPER; thyroxine-treated] groups, and artificially inseminated. Hatching eggs (n = 924) were incubated and day-old male chicks (n = 288) were reared for 42 days under standard or low ambient temperature. Plasma thyroxine was higher in the HYPER hens and their embryos at internal pipping. Maternal hyperthyroidism did not adversely affect the feed : gain ratio and carcass weight, whereas cold stress impaired them. A higher relative weight was found at 42 days of age for all intestinal regions at low ambient temperature. The duodenal and jejunal crypt depths (CD) were lower in HYPER group at 7 days of age. Cold exposure decreased the duodenal and jejunal villus height and CD, and increased the ileal goblet cell number at 21 days. On Day 42, higher values were recorded for CD, goblet cell number, and epithelial thickness of different intestinal regions in cold-exposed birds. In conclusion, growth performance was not adversely influenced by maternal hyperthyroidism and its minimal early effect on intestinal morphology does not appear to be the underlying mechanism for decreased incidence of ascites in broilers.

General principles of nutrition for the newly hatched chick

Nutrition of the newly hatched chick is complex and requires an understanding of the wild-type feeding strategy of the species, the known nutrient requirements of birds, and appropriate application to the species in question. Next, composition of available food items, appropriate physical form, volume and frequency of food items, and desired end results (eg, appropriate fledging weight, ability to successfully find prey items or be socialized for human interactions, etc) need to be considered to provide the highest chance of successful fledging. There are several excellent resources to help guide the practical aspects of rearing chicks (eg, Gage and Duerr), in addition to nutritional resources to guide a better understanding of the fundamentals of avian nutrition (eg, Klasing).

Intestinal mucin dynamic and leukocytic responses of chickens infected with Eimeria acervulina and fed oregano supplemented diet

We studied the effect of oregano supplemented diet on mucin dynamics in small intestine, peripheral blood leukocytes, and jejunal immunocompetent cells in ROSS 308 hybrid broilers infected withEimeria acervulinachickens’ oocyst. From the day of hatching chicks of groups 1 and 2 were fed a commercial diet without anticoccidial drug, the diet of group 3 was supplemented with oregano (0.707g·kg-1), and that of group 4 with anticoccidial drug (Robenidin hydrochloride – 33 mg·kg-1). Chickens of groups 2, 3, and 4 were inoculated withE. acervulinaoocysts (25.103) on day 12. The samples were collected on 3, 10, 17 days post infection (dpi). In blood on 3 dpi significant increase of leukocytes was found in group 3 compared to groups 1, 2, and 4, higher density of IgM+ cells in group 3 than group 2, and on 10 dpi phagocytic activity of group 3 was higher than group 1. Number of jejunal CD4+ and CD8+ cells in group 3 was consistent with values in group 4, despite higher density ofE. acervulinameronts on 10 dpi. The quantity of jejunal mucin adherent layer of group 3 was similar to that in group 4. Counts of oocysts in faeces were lower in group 3 than group 2. Results suggest that dietary supplementation of oregano to chickens infected withE. acervulinahas a modulating effect on some blood indicators and functions of phagocytes. The beneficial effect of oregano components on jejunal mucin quantity and its turnover is the first finding published in relation to oregano and coccidia.

Leukocytic responses and intestinal mucin dynamics of broilers protected with Enterococcus faecium EF55 and challenged with Salmonella Enteritidis

The protective effect of Enterococcus faecium EF55 in chickens challenged with Salmonella enterica serovar Enteritidis phage type 4 (SE PT4) was assessed. The antibacterial effect on the bacterial microflora in the small intestine in relation to white blood cell count, phenotyping of peripheral blood and intestinal lymphocytes, functional activity of lymphocytes and phagocytes and mucin quantitation were investigated. Day-old chicks (85) were randomly divided into four groups. The probiotic group (EF) and Salmonella+probiotic group (EFSE) received E. faecium EF55 (10(9) CFU - 3 g/group/day) for 21 days. The Salmonella group (SE) and EFSE group were infected with Salmonella Enteritidis (10(8) CFU in 0.2 ml PBS) in a single dose per os on day four of the experiment. The control group chicks (C) were fed a commercial diet without added bacteria. Supplementation of EF55 in the diet of the chickens in the EFSE group, challenged with S. Enteritidis, caused the density of the intestinal mucin layer to increase significantly in non-specific regions (duodenum and jejunum), but decrease significantly in target regions (caeca) for S. Enteritidis. Probiotic treatment also appeared to result in a significantly higher number of lymphocytes in peripheral blood and a tendency to increase CD3, CD4, CD8, and IgM positive cells 3 days post-infection with S. Enteritidis. The results demonstrated an antibacterial effect and suggested that EF55 had a moderating effect on intestinal mucin production and leukocytic response in the early phase of S. Enteritidis infection.

Effects of early malnutrition on mental system, metabolic syndrome, immunity and the gastrointestinal tract

The notion of how malnutrition early in life affects ontogenesis has evolved considerably since the mid-1960s. Since then, there have been many studies on the effects of early malnutrition. Nutritional and metabolic exposure during critical periods in early human and animal development may have long-term programming effects in adulthood. This is supported by evidence from epidemiological studies, numerous animal models and clinical intervention trials. In this paper, we review the effects of early malnutrition on cognitive function, metabolic syndrome, immunity and the gastrointestinal tract, as well as possible underlying mechanisms, and consider diarrhoeal disease and poor cognitive function as examples for understanding the interrelation of the harmful effects caused by early malnutrition. Previous studies on early malnutrition have mainly concentrated on humans and rats. Therefore, the main aim of the present review was to give animal scientists a clear understanding of the harmful effects of early malnutrition on animal growth and animal production, and to help identify appropriate feeding techniques to prevent early malnutrition.