Effect of zinc on growth performance, gut morphometry, and cecal microbial community in broilers challenged with Salmonella enterica serovar typhimurium

The Role of Zinc in Developed Countries in Pediatric Patients: A 360-Degree View

Zinc is an important trace element for growth and health at pediatric ages. Zinc is fundamental in inflammatory pathways, oxidative balance, and immune function. Zinc exhibits anti-inflammatory properties by modulating Nuclear Factor-kappa (NF-κB) activity and reducing histamine release from basophils, leukocytes, and mast cells. Furthermore, its antioxidant activity protects against oxidative damage and chronic diseases. Finally, zinc improves the ability to trigger effective immune responses against pathogens by contributing to the maturation of lymphocytes, the production of cytokines, and the regulation of apoptosis. Given these properties, zinc can be considered an adjunctive therapy in treating and preventing respiratory, nephrological, and gastrointestinal diseases, both acute and chronic. This review aims to deepen the role and metabolism of zinc, focusing on the role of supplementation in developed countries in pediatric diseases.

Protective effects of sodium humate and its zinc and selenium chelate on the oxidative stress, inflammatory, and intestinal barrier damage of Salmonella Typhimurium-challenged broiler chickens

The objective of this study was to investigate the protective effects and mechanisms of dietary administration of sodium humate (HNa) and its zinc and selenium chelate (Zn/Se-HNa) in mitigating Salmonella Typhimurium (S. Typhi) induced intestinal injury in broiler chickens. Following the gavage of 109 CFU S. Typhi to 240 broilers from 21-d to 23-d aged, various growth performance parameters such as body weight (BW), average daily gain (ADG), average daily feed intake (ADFI), and feed ratio (FCR) were measured before and after infection. Intestinal morphology was assessed to determine the villus height, crypt depth, and chorionic cryptologic ratio. To evaluate intestinal barrier integrity, levels of serum diamine oxidase (DAO), D-lactic acid, tight junction proteins, and the related genes were measured in each group of broilers. An analysis was conducted on inflammatory-related cytokines, oxidase activity, and Nuclear Factor Kappa B (NF-κB) and Nuclear factor erythroid2-related factor 2 (Nrf2) pathway-related proteins and mRNA expression. The results revealed a significant decrease in BW, ADG, and FCR in S. typhi-infected broilers. HNa tended to increase FCR (P = 0.056) while the supplementation of Zn/Se-HNa significantly restored BW and ADG (P < 0.05). HNa and Zn/Se-HNa exhibit favorable and comparable effects in enhancing the levels of serum DAO, D-lactate, and mRNA and protein expression of jejunum and ileal tight junction. In comparison to HNa, Zn/Se-HNa demonstrates a greater reduction in S. Typhi shedding in feces, as well as superior efficacy in enhancing the intestinal morphology, increasing serum catalase (CAT) activity, inhibiting pro-inflammatory cytokines, and suppressing the activation of the NF-κB pathway. Collectively, Zn/Se-HNa was a more effective treatment than HNa to alleviate adverse impact of S. Typhi infection in broiler chickens.

Effect of Zinc Oxide Nanoparticles as Feed Additive on Blood Indices, Physiological, Immunological Responses, and Histological Changes in Broiler Chicks

A feeding trial of 5-week duration was performed to assess the response of broiler chicks to dietary supplementation with different doses of myco-fabricated zinc oxide nanoparticles (ZONPs) on blood indices, physiological, immunological response, antioxidant status, intestinal microbial count, and histological changes in immune organs. A total of 162 3-day-old Ross 308 broiler chicks were weighed individually and distributed equally into 3 dietary treatments with 6 replicate of 9 chicks in each in a completely randomized design. Chicks were fed ad libitum a basal ration prepared as starter, grower, and finisher supplemented with 0 (T1, control), 40 (T2), and 60 (T3) mg zinc oxide nanoparticles (ZONPs)/kg feed. Results showed that supplementing with ZONPs at both studied levels increased the relative weights of the spleen, bursa, thymus, and liver and decreased the relative weight of the kidney, gizzard, and intestine. A significant increase in the concentrations of hemoglobin (Hb), hematocrit (PCV%), red and white blood cell counts, total protein (TP), globulin (GLOB), aspartate transferase (AST), alanine transferase (ALT), alkaline phosphatase (ALP), superoxide dismutase (SOD), glutathione peroxidase (GPx), and total antioxidant capacity (TAC) and a significant decrease in malonaldehyde (MDA), uric acid, and creatinine concentration were observed. Furthermore, all immunological organs showed histological alteration and increased both types of immunity in ZONPs groups with more pronounced effects in the T2 group.

Effects of Salmonella Outer Membrane Vesicles on Intestinal Microbiota and Intestinal Barrier Function

Salmonella enterica is one of the most important zoonotic pathogens causing foodborne gastroenteritis worldwide. Outer membrane vesicles (OMVs) are lipid-bilayer vesicles produced by Gram-negative bacteria, which contain biologically active components. We hypothesized that OMVs are an important weapon of S. enterica to initiate enteric diseases pathologies. In this study, the effects of S. enterica OMVs (SeOMVs) on intestinal microbiota and intestinal barrier function were investigated. In vitro fecal culture experiments showed that alpha diversity indexes and microbiota composition were altered by SeOMV supplementation. SeOMV supplementation showed an increase of pH, a decrease of OD630 and total short chain fatty acid (SCFA) concentrations. In vitro IPEC-J2 cells culture experiments showed that SeOMV supplementation did not affect the IPEC-J2 cell viability and the indicated genes expression. In vivo experiments in mice showed that SeOMVs had adverse effects on average daily gain (p < 0.05) and feed:gain ratio (p < 0.05), and had a tendency to decrease the final body weight (p = 0.073) in mice. SeOMV administration decreased serum interleukin-10 level (p < 0.05), decreased the relative abundance of bacteria belonging to the genera BacC-u-018 and Akkermansia (p < 0.05). Furthermore, SeOMV administration damaged the ileum mucosa (p < 0.05). These findings suggest that SeOMVs play an important role in the activation of intestinal inflammatory response induced by S. enterica, and downregulation of SCFA-producing bacteria is a possible mechanism.

Complexed amino acid minerals vs. bis-glycinate chelated minerals: Impact on the performance of old laying hens

The present study was to evaluate the effect of trace minerals (Zn, Mn, and Cu) from complexed amino acid minerals (ZMCAA) and bis-glycinate chelated minerals (ZMCGly) in laying hen diets on performance, internal and external egg quality, yolk mineral deposition, intestinal morphometry, and bone characteristics. From 78 to 98 weeks of age, 400 White LSL-Lite strain laying hens were distributed in a randomized design with 4 treatments with 10 replicates per treatment. Treatments were distributed in a 2 × 2 factorial arrangement using either Zn, Mn, and Cu of ZMCAA or ZMCGly source at 2 levels: low (20, 20, and 3.5 mg/kg of Zn, Mn, and Cu, respectively) or high (40, 40, and 7 mg/kg of Zn, Mn, and Cu, respectively). The analysis of variance was performed, and in cases where differences were observed, the means were compared using Tukey's test (P < 0.05). The source and level of trace mineral supplementation had a significant impact on the performance of laying hens. Hens fed ZMCAA had higher egg production (P = 0.01), egg weight (P = 0.02), egg mass (P = 0.01), and lower feed conversion ratio (P = 0.05) compared to those fed ZMCGly. The ZMCAA supplementation showed higher albumen height (P = 0.01), albumen weight (P = 0.01), and eggshell thickness (P < 0.01). The deposition of Zn (P < 0.01), Mn (P < 0.01), and Cu (P < 0.01) in the egg yolk was greater for hens received ZMCAA. Tibia weight (P = 0.04) and bone densitometry (P < 0.01) in the tibia were higher with ZMCAA supplementation. In the small intestine, ZMCAA resulted in longer villi (P = 0.02) and shorter crypt depth (P = 0.01) in the duodenum. Jejunum and ileum measurements were influenced by the level and source of trace minerals (P < 0.05). Laying hens fed ZMCAA exhibited superior performance, egg quality, deposition of trace minerals in the egg yolk, and bone density compared to hens fed ZMCGly. In this study, older laying hens supplemented with ZMCAA at lower levels demonstrated adequate levels of supplementation.

Zinc Oxide Nanoparticles Significant Role in Poultry and Novel Toxicological Mechanisms

Zinc oxide nanoparticles (ZnO NPs) have involved a lot of consideration owing to their distinctive features. The ZnO NPs can be described as particularly synthesized mineral salts via nanotechnology, varying in size from 1 to 100 nm, while zinc oxide (ZnO), it is an inorganic substrate of zinc (Zn). The Zn is a critical trace element necessary for various biological and physiological processes in the body. Studies have revealed ZnO NPs' efficient immuno-modulatory, growth-promoting, and antimicrobial properties in poultry birds. They offer increased bioavailability as compared to their traditional sources, producing better results in terms of productivity and welfare and consequently reducing ecological harm in the poultry sector. However, they have also been reported for their toxicological effects, which are size, shape, concentration, and exposure route dependent. The investigations done so far have yielded inconsistent results, therefore, a lot of additional studies and research are required to clarify the harmful consequences of ZnO NPs and to bring them to a logical end. This review explores an overview of efficient possible role of ZnO NPs, while comparing them with other nutritional Zn sources, in the poultry industry, primarily as dietary supplements that effect the growth, health, and performance of the birds. In addition to the anti-bacterial mechanisms of ZnO NPs and their promising role as antifungal, and anti-colloidal agent, this paper also covers the toxicological mechanisms of ZnO NPs and their consequent toxicological hazards to vital organs and the reproductive system of poultry birds.

The Impact of Phytase and Different Levels of Supplemental Amino Acid Complexed Minerals in Diets of Older Laying Hens

A study was conducted to evaluate the effects of different sources and levels of supplemental amino acid-complexed minerals (AACM), with and without enzyme phytase (EZ). A total of 512 Dekalb White laying hens at 67 weeks of age were used in a 2 × 3 + 2 factorial arrangement of 8 treatments and 8 replications each. The main effects included EZ supplementation (10,000 FTU kg-1) and AACM inclusion level (100, 70, and 40% of inorganic mineral recommendations), plus 2 control treatments. The group of hens fed AACM-100 showed lower feed intake than the inorganic mineral (IM) group. The diet containing AACM-EZ-70 provided a higher (p < 0.05) laying percentage and a lower (p < 0.05) feed conversion ratio than both the IM and IM-EZ diets. The groups fed AACM-EZ-40, AACM-EZ-100, and AACM-70 produced heavier yolks (p < 0.05). Hens fed IM laid eggs with the lowest yolk and albumen weights (p < 0.05). Layers fed with AACM-100 and AACM-70 produced the most resistant eggshells to breakage (p < 0.05). In diets containing phytase, the optimal AACM recommendations for better performance and egg quality in older laying hens are: 42, 49, 5.6, 28, 0.175, and 0.70 mg kg-1 for Zn, Mn, Cu, Fe, Se, and I, respectively.

Effects of Zinc Source and Level on the Intestinal Immunity of Xueshan Chickens under Heat Stress

Heat stress can cause intestinal inflammation, impaired barrier integrity, and decreased immunity in poultry. While zinc is known to mitigate the adverse effects of heat stress, how the dietary supplementation of different sources and levels of it can improve the heat stress capacity of Chinese landraces remains unclear. This study investigated Xueshan chickens, which are an important local breed in China. The effects of different levels of ZnS and Zn-Prot M on their intestinal immune function under heat stress were compared. We found that different levels of ZnS and Zn-Prot M could effectively reduce the secretion level of IL-6 in the serum, and 60 mg/kg was optimal. Compared with ZnS, Zn-Prot M significantly increased duodenal villus height and VH/CD ratio, thus Zn-Prot M was more effective than ZnS. Both ZnS and Zn-Prot M significantly down-regulated TNF-α, IL-1β, and MyD88 in 102-day-old duodenum, and IL-1β, IL-6, and NFKBIA in jejunum and ileum at 74, 88, and 102 days old, with 60 mg/kg Zn-Prot M determined as optimal. In conclusion, our study demonstrates that Zn-Prot M is superior to ZnS in improving intestinal immunity in Xueshan chickens, and 60 mg/kg is the optimal addition dose.

A bioinformatic analysis of zinc transporters in intestinal Lactobacillaceae

As the second most abundant transition element and a crucial cofactor for many proteins, zinc is essential for the survival of all living organisms. To maintain required zinc levels and prevent toxic overload, cells and organisms have a collection of metal transport proteins for uptake and efflux of zinc. In bacteria, metal transport proteins are well defined for model organisms and many pathogens, but fewer studies have explored metal transport proteins, including those for zinc, in commensal bacteria from the gut microbiota. The healthy human gut microbiota comprises hundreds of species and among these, bacteria from the Lactobacillaceae family are well documented to have various beneficial effects on health. Furthermore, changes in dietary metal intake, such as for zinc and iron, are frequently correlated with changes in abundance of Lactobacillaceae. Few studies have explored zinc requirements and zinc homeostasis mechanisms in Lactobacillaceae, however. Here we applied a bioinformatics approach to identify and compare predicted zinc uptake and efflux proteins in several Lactobacillaceae genera of intestinal relevance. Few Lactobacillaceae had zinc transporters currently annotated in proteomes retrieved from the UniProt database, but protein sequence-based homology searches revealed that high-affinity ABC transporter genes are likely common, albeit with genus-specific domain features. P-type ATPase transporters are probably also common and some Lactobacillaceae genera code for predicted zinc efflux cation diffusion facilitators. This analysis confirms that Lactobacillaceae harbor genes for various zinc transporter homologs, and provides a foundation for systematic experimental studies to elucidate zinc homeostasis mechanisms in these bacteria.

Multiple micronutrient deficiencies alter energy metabolism in host and gut microbiome in an early-life murine model

Introduction

Micronutrients perform a wide range of physiological functions essential for growth and development. However, most people still need to meet the estimated average requirement worldwide. Globally, 2 billion people suffer from micronutrient deficiency, most of which are co-occurring deficiencies in children under age five. Despite decades of research, animal models studying multiple micronutrient deficiencies within the early-life period are lacking, which hinders our complete understanding of the long-term health implications and may contribute to the inefficacy of some nutritional interventions. Evidence supporting the Developmental Origins of Health and Disease (DOHaD) theory demonstrates that early-life nutritional deficiencies carry life-long consequences mediated through various mechanisms such as abnormal metabolic programming, stunting, altered body composition, and the gut microbiome. However, this is largely unexplored in the multiple micronutrient deficient host.

Methods

we developed a preclinical model to examine undernutrition's metabolic and functional impact on the host and gut microbiome early in life. Three-week-old weanling C57BL/6N male mice were fed a low-micronutrient diet deficient in zinc, folate, iron, vitamin A, and vitamin B12 or a control diet for 4-weeks.

Results

Our results showed that early-life multiple micronutrient deficiencies induced stunting, altered body composition, impaired glucose and insulin tolerance, and altered the levels of other micronutrients not depleted in the diet within the host. In addition, functional metagenomics profiling and a carbohydrate fermentation assay showed an increased microbial preference for simple sugars rather than complex ones, suggestive of a less developed microbiome in the low-micronutrient-fed mice. Moreover, we found that a zinc-only deficient diet was not sufficient to induce these phenotypes, further supporting the importance of studying co-occurring deficiencies.

Discussion

Together, these findings highlight a previously unappreciated role of early-life multiple micronutrient deficiencies in shaping the metabolic phenome of the host and gut microbiome through altered glucose energy metabolism, which may have implications for metabolic disease later in life in micronutrient-deficient survivors.

Effects of Major Families of Modulators on Performances and Gastrointestinal Microbiota of Poultry, Pigs and Ruminants: A Systematic Approach

Considering the ban on the use of antibiotics as growth stimulators in the livestock industry, the use of microbiota modulators appears to be an alternative solution to improve animal performance. This review aims to describe the effect of different families of modulators on the gastrointestinal microbiota of poultry, pigs and ruminants and their consequences on host physiology. To this end, 65, 32 and 4 controlled trials or systematic reviews were selected from PubMed for poultry, pigs and ruminants, respectively. Microorganisms and their derivatives were the most studied modulator family in poultry, while in pigs, the micronutrient family was the most investigated. With only four controlled trials selected for ruminants, it was difficult to conclude on the modulators of interest for this species. For some modulators, most studies showed a beneficial effect on both the phenotype and the microbiota. This was the case for probiotics and plants in poultry and minerals and probiotics in pigs. These modulators seem to be a good way for improving animal performance.

Pioneer colonizers: Bacteria that alter the chicken intestinal morphology and development of the microbiota

Microbes commonly administered to chickens facilitate development of a beneficial microbiome that improves gut function, feed conversion and reduces pathogen colonization. Competitive exclusion products, derived from the cecal contents of hens and shown to reduce Salmonella colonization in chicks, possess important pioneer-colonizing bacteria needed for proper intestinal development and animal growth. We hypothesized that inoculation of these pioneer-colonizing bacteria to day of hatch chicks would enhance the development of their intestinal anatomy and microbiome. A competitive exclusion product was administered to broiler chickens, in their drinking water, at day of hatch, and its impact on intestinal morphometrics, intestinal microbiome, and production parameters, was assessed relative to a control, no treatment group. 16S rRNA gene, terminal restriction fragment length polymorphism (T-RFLP) was used to assess ileal community composition. The competitive exclusion product, administered on day of hatch, increased villus height, villus height/width ratio and goblet cell production ∼1.25-fold and expression of enterocyte sugar transporters 1.25 to 1.5-fold in chickens at 3 days of age, compared to the control group. As a next step, chicks were inoculated with a defined formulation, containing Bacteroidia and Clostridia representing pioneer-colonizing bacteria of the two major bacterial phyla present in the competitive exclusion product. The defined formulation, containing both groups of bacteria, were shown, dependent on age, to improve villus height (jejunum: 1.14 to 1.46-fold; ileum: 1.17-fold), goblet cell numbers (ileum 1.32 to 2.51-fold), and feed efficiency (1.18-fold, day 1) while decreasing Lactobacillus ileal abundance by one-third to half in birds at 16 and 42 days of age, respectively; compared to the phosphate buffered saline treatment group. Therefore, specific probiotic formulations containing pioneer colonizing species can provide benefits in intestinal development, feed efficiency and body weight gain.

Dietary Zinc Glycine Supplementation Improves Tibia Quality of Meat Ducks by Modulating the Intestinal Barrier and Bone Resorption

Leg problems characterized by gait abnormity and bone structure destruction are associated with a high risk of fractures and continuous pain in poultry. Zinc (Zn) acts a pivotal part in normal bone homeostasis and has proven to be highly effective in alleviating leg problems. Therefore, the effects of graded concentration of Zn on bone quality were evaluated in this study. A total of 512 1-d-old male ducks were fed 4 basal diets added 30 mg/kg Zn, 60 mg/kg Zn, 90 mg/kg Zn, and 120 mg/kg Zn as Zn glycine for 35 d. Tibia Zn content, ash percentage, and breaking strength linearly increased with dietary elevated Zn level (P < 0.05). Broken-line analysis revealed that the recommended level of Zn from Zn glycine was 55.13 mg/kg and 64.48 mg/kg based on tibia ash and strength, respectively. To further confirm the role of dietary Zn glycine addition on bone characteristics, data from birds fed either 60 mg/kg Zn as Zn sulfate (ZnSO₄), 30 mg/kg Zn, or 60 mg/kg Zn in the form of Zn glycine indicated that birds given 60 mg/kg Zn from Zn glycine diet exhibited higher tibia ash, strength, and trabecular volume compared to those fed the 30 mg/kg Zn diet (P < 0.05). Dietary 60 mg/kg Zn as Zn glycine addition decreased intestinal permeability, upregulated the mRNA expression of tight junction protein, and increased the abundance of Lactobacillus and Bifidobacterium, which was companied by declined the level of inflammatory cytokines in both the ileum and bone marrow. Regarding bone turnover, the diet with 60 mg/kg Zn from Zn glycine induced osteoprotegerin expression and thus decreased osteoclast number and serum bone resorption biomarker levels including serum tartrate-resistant acid phosphatase activity and C-terminal cross-linked telopeptide of type I collagen level when compared to 30 mg/kg Zn diet (P < 0.05). Except for the upregulation in runt-related transcription factor 2 transcription, the experimental treatments did not apparently change the bone formation biomarker contents in serum. Additionally, Zn glycine displayed a more efficient absorption rate, evidenced by higher serum Zn level, and thus had potentially greater a protective role in the intestine barrier and tibia mass as compared to ZnSO₄. Collectively, the dietary supplementation of 60 mg/kg in the form of Zn glycine could suppress bone resorption mediated by osteoclast and consequently improve tibial quality of meat ducks, in which enhanced intestinal integrity and optimized gut microbiota might be involved.

Dietary trace mineral pattern influences gut microbiota and intestinal health of broilers

Dietary trace minerals can impact gut flora, which can further affect intestinal health. However, the dietary balance pattern of trace minerals for the intestinal health of broilers needs to be explored. The present study was conducted to investigate the effect of the dietary pattern of Cu, Fe, Mn, Zn, and Se on the intestinal morphology, microbiota, short-chain fatty acid concentrations, antioxidant status, and the expression of tight junction proteins in broilers. A total of 240 1-d-old Arbor Acres male broilers were randomly assigned to one of five treatments with six replicate cages of eight birds per cage for each treatment. The birds were fed the corn-soybean meal basal diet supplemented with five combination patterns of trace minerals for 42 d. The dietary treatments were as follows: the inorganic sources were added to the diet based on the recommendations of the current National Research Council (NRC, T1) and Ministry of Agriculture of P.R. China (MAP) (T2) for broiler chicks, respectively; the inorganic sources were added to the diet at the levels based on our previous results of inorganic trace mineral requirements for broilers (T3); the organic sources were added to the diet at the levels considering the bioavailabilities of organic trace minerals for broilers described in our previous studies (T4); and the organic sources were added to the diet based on the recommendations of the current MAP for broiler chicks (T5). The results showed that broilers from T1 had lower (P < 0.05) crypt depth (CD), and a higher (P < 0.05) villus height: CD in duodenum on day 21 and lower CD (P < 0.05) in jejunum on day 42 than those from T3 and T4. Broilers from T1, T3, and T5 had a higher (P < 0.05) Shannon index in cecum on day 21 than those from T4. Broilers from T1 had a higher (P < 0.05) abundance of Lactobacillus in ileum on day 21 than those from T2 and T3. Broilers from T1, T2, and T5 had a higher (P < 0.05) valeric acid concentrations in cecum on day 42 than those from T3 and T4. In addition, Birds from T2 had higher (P < 0.05) Claudin-1 mRNA levels in jejunum on day 42 than those from T3 and T4. And birds from T3, T4, and T5 had a higher (P < 0.05) Occludin protein expression levels in duodenum on day 42 than those from T2. These results indicate that dietary pattern of Cu, Fe, Mn, Zn, and Se influenced gut flora and intestinal health of broilers, and the appropriate pattern of Cu, Fe, Mn, Zn, and Se in the diet for intestinal health of broilers would be Cu 12 mg, Fe 229 mg, Mn 81 mg, Zn 78 mg, and Se 0.24 mg/kg (1 to 21 d of age), and Cu 11 mg, Fe 193 mg, Mn 80 mg, Zn 73 mg, and Se 0.22 mg/kg (22 to 42 d of age), when the trace minerals as inorganic sources were added to diets according to the recommendations of the current NRC.

Respuesta histomorfométrica de la mucosa del intestino delgado en cuyes (Cavia porcellus) de engorde desafiados con Salmonella enterica var. Typhimurium

Con el objetivo de evaluar la respuesta histomorfométrica de la mucosa del intestino delgado en cuyes (Cavia porcellus) desafiados con Salmonella enterica var. Typhimurium (SeVT) (2×106 UFC·0,5mL-1 por cuy) se tomaron 40 cuyes machos de 15 días (d) de edad, distribuidos aleatoriamente en cuatro tratamientos SeVT; 1.- cuyes que recibieron dieta base (DB) y se desafiaron con SeVT (T1); 2.- cuyes que recibieron DB con 50 ppm de zinc bacitracina y se desafiaron con SeVT (T2); 3.- cuyes que recibieron DB con 50 ppm de zinc bacitracina, sin desafío (T3) y 4.- cuyes que recibieron únicamente DB, sin desafío (T4, Grupo Control). Cada T estuvo conformado por 10 repeticiones. Al finalizar la fase experimental en la 8va semana (sem) se colectaron muestras de las secciones duodeno, yeyuno e íleon y se procesaron con hematoxilina y eosina (H-E) para el análisis histomorfométrico. Los parámetros evaluados fueron longitud de la vellosidad (LV), ancho de la vellosidad (AV), profundidad de la cripta de Lieberkühn (PC) y la relación longitud/cripta (LV/PC). Los datos se analizaron mediante análisis de varianza y la prueba de Tukey. Los resultados (promedio ± DE) fueron significativamente diferentes a P<0,05 en todos los T indicando vellosidades reducidas en longitud, ancho y con una relación LV/PC, menor de 2:1 en el T1, observando vellosidades hasta 40 % más largas en duodeno, 39 % en yeyuno y 55 % en íleon en los cuyes que no fueron desafiados con SeVT, concluyendo que existe un efecto negativo de este enteropatógeno sobre la histomorfometría de las vellosidades del intestino delgado en esta especie.

Metallobiology of Lactobacillaceae in the gut microbiome

Lactobacillaceae are a diverse family of lactic acid bacteria found in the gut microbiota of humans and many animals. These bacteria exhibit beneficial effects on intestinal health, including modulating the immune system and providing protection against pathogens, and many species are frequently used as probiotics. Gut bacteria acquire essential metal ions, like iron, zinc, and manganese, through the host diet and changes to the levels of these metals are often linked to alterations in microbial community composition, susceptibility to infection, and gastrointestinal diseases. Lactobacillaceae are frequently among the organisms increased or decreased in abundance due to changes in metal availability, yet many of the molecular mechanisms underlying these changes have yet to be defined. Metal requirements and metallotransporters have been studied in some species of Lactobacillaceae, but few of the mechanisms used by these bacteria to respond to metal limitation or excess have been investigated. This review provides a current overview of these mechanisms and covers how iron, zinc, and manganese impact Lactobacillaceae in the gut microbiota with an emphasis on their biochemical roles, requirements, and homeostatic mechanisms in several species.

Influence of Dietary Biosynthesized Zinc Oxide Nanoparticles on Broiler Zinc Uptake, Bone Quality, and Antioxidative Status

A total of 180 broiler chickens (Cobb500) were randomly allotted to five experimental groups consisting of six replicates and six birds in each pen. Each group was fed a basal diet supplemented with 100 mg/kg ZnO (control) and 10, 40, 70, and 100 mg/kg ZnO NPs for 35 days. Resultantly, Zn uptake and accumulation in serum, breast muscle, tibia bone, and liver were linearly and significantly (p < 0.05) increased with increasing dietary ZnO NPs supplementation at 100 mg/kg compared to the control group (dietary 100 mg/kg ZnO), implying effective absorption capacity of ZnO NPs. This was followed by lower Zn excretion in feces in broilers fed ZnO NPs compared to controls (p < 0.05). Furthermore, dietary ZnO NPs at 40, 70, and 100 mg/kg levels improved broiler tibia bone morphological traits, such as weight, length, and thickness. Similarly, tibia bone mineralization increased in broilers fed ZnO NPs at 100 mg/kg compared to the control (p < 0.05), as demonstrated by tibia ash, Zn, Ca, and P retention. Antioxidative status in serum and liver tissue was also increased in broilers fed dietary ZnO NPs at 70 and 100 mg/kg compared to the control (p < 0.05). In conclusion, dietary ZnO NPs increased Zn absorption in broiler chickens and had a positive influence on tibia bone development and antioxidative status in serum and liver tissue, with dietary ZnO NPs supplementation at 70 and 100 mg/kg showing the optimum effects.

Functional Gastrointestinal Disorders with Psychiatric Symptoms: Involvement of the Microbiome-Gut-Brain Axis in the Pathophysiology and Case Management

Functional Gastrointestinal Disorders have been an important cause of poor life quality in affected populations. The unclear etiology and pathophysiological mechanism alter the clinical evolution of the patient. Although a strong connection with psychological stress has been observed, it was not until recently that the gut-brain axis involvement has been revealed. Furthermore, the current literature not only promotes the gut-brain axis modulation as a therapeutical target for functional digestive disorders but also states that the gut microbiome has a main role in this bi-directional mechanism. Psychiatric symptoms are currently recognized as an equally important aspect of the clinical manifestation and modulation of both the digestive and central nervous systems and could be the best approach in restoring the balance. As such, this article proposes a detailed description of the physiology of the microbiome-gut-brain axis, the pathophysiology of the functional gastrointestinal disorders with psychiatric symptoms and current perspectives for therapeutical management, as revealed by the latest studies in the scientific literature.

Protective Effects of Zinc on Salmonella Invasion, Intestinal Morphology and Immune Response of Young Pigeons Infected with Salmonella enterica Serovar Typhimurium

The study aimed to determine the effects of orally supplemental zinc on body weight, Salmonella invasion, serum IgA, intestinal histomorphology, and immune response of Salmonella enterica serovar Typhimurium (S. typhimurium)-challenged young pigeons. A total of 72 healthy White King pigeons (25 days old) with similar weight were randomly assigned to 3 treatments with six replicate cages. The 3 treatments were unchallenged, S. typhimurium-challenged, and S. typhimurium-challenged orally supplemented with 1 mg zinc per bird. Salmonella infection decreased (P < 0.05) the body weight, the bursa index, the serum IgA content, and the villus height/crypt depth ratio in the ileum, but increased the neutrophil proportion (P < 0.001) and the mRNA expressions of IL-1β and IL-8 in the jejunum (P < 0.05). Orally supplemental zinc reduced (P = 0.007) the bacterial load in the liver and improved (P < 0.05) the body weight, the bursa index, the serum IgA content, the villus height/crypt depth ratio, and the NOD-like receptor family pyrin domain containing 3 (NLRP3) protein expression, as well as tended to increase (P = 0.064) the protein abundance of caspase-1 of the jejunum, but did not alleviate the high level of neutrophil proportion and IL-1β mRNA expression of the jejunum (P > 0.05). The results indicated that oral zinc supplementation improved the intestinal mucosal morphology and enhanced the immune response, as well as activated caspase-1-dependent cell pyroptosis pathways in the jejunal epithelium, thereby restricting Salmonella invasion of the challenged young pigeons.

A perspective review on the effect of different forms of zinc on poultry production of poultry with special reference to the hazardous effects of misuse

Zinc (Zn) is a unique micro-mineral because it is an essential component in many enzymes such as superoxide dismutase, carbonic anhydrase, and alkaline phosphatase, as well as being important for regulation of proteins and lipids metabolism, and sex hormones. This mineral is applied in poultry production in three forms; inorganic, organic, and nanoparticle form. The nano-form of Zn is preferable in application to other conventional forms with regard to absorption, bioavailability, and efficacy. Broilers fed on diets supplemented with Zn showed improvement of growth performance, carcass meat yield, and meat quality. In addition, Zn plays an important role in enhancing of both cellular and humeral immune responses, beside its antimicrobial and antioxidant activities. In laying hens, dietary addition of Zn improves the eggshell quality and the quantity of eggs. Moreover, Zn has a vital role in breeders in terms of improving the egg production, fertility, hatchability, embryonic development, and availability of the hatched chicks. Therefore, this review article is focused on the effects of using Zn on the performance and immunity of poultry, as well as its antimicrobial and antioxidant properties with special reference to the hazardous effects of the misusing of this mineral.

Effects of Dietary Nutrients on Fatty Liver Disease Associated With Metabolic Dysfunction (MAFLD): Based on the Intestinal-Hepatic Axis

Non-alcoholic fatty liver disease (NAFLD) has recently become the most common liver disease with a global prevalence of over 25% and is expected to increase. Recently, experts have reached a consensus that “fatty liver disease associated with metabolic dysfunction or MAFLD” may be a more appropriate and inclusive definition than NAFLD. Like the former name NAFLD, MAFLD, as a manifestation of multiple system metabolic disorders involving the liver, has certain heterogeneity in its pathogenesis, clinical manifestations, pathological changes and natural outcomes. We found that there is a delicate dynamic balance among intestinal microflora, metabolites and host immune system to maintain a healthy intestinal environment and host health. On the contrary, this imbalance is related to diseases such as MAFLD. However, there are no clear studies on how dietary nutrients affect the intestinal environment and participate in the pathogenesis of MAFLD. This review summarizes the interactions among dietary nutrients, intestinal microbiota and MAFLD in an attempt to provide evidence for the use of dietary supplements to regulate liver function in patients with MAFLD. These dietary nutrients influence the development and progression of MAFLD mainly through the hepatic-intestinal axis by altering dietary energy absorption, regulating bile acid metabolism, changing intestinal permeability and producing ethanol. Meanwhile, the nutrients have the ability to combat MAFLD in terms of enriching abundance of intestinal microbiota, reducing Firmicutes/Bacteroidetes ratio and promoting abundance of beneficial gut microbes. Therefore, family therapy with MAFLD using a reasonable diet could be considered.

Effect of Dietary Zinc Methionine Supplementation on Growth Performance, Immune Function and Intestinal Health of Cherry Valley Ducks Challenged With Avian Pathogenic Escherichia coli

This study was carried out to evaluate the effects of supplemental zinc methionine (Zn-Met) on growth performance, immune function, and intestinal health of meat ducks challenged with avian pathogenic Escherichia coli (APEC). A total of 480 1-day-old Cherry Valley male ducks were randomly assigned to 8 treatments with 10 replicates, each replicate containing 10 ducks. A 4 × 2 factor design was used with four dietary zinc levels (0, 30, 60, 120 mg Zn/kg in the form Zn-Met was added to the corn-soybean basal diet) and challenged with or without APEC at 8-days-old ducks. The trial lasted for 14 days. The results showed that a dietary Zn-Met supplementation significantly increased body weight (BW) of 14 days and BW gain, and decreased mortality during 7-14-days-old ducks (p < 0.05). Furthermore, dietary 30, 60, 120 mg/kg Zn-Met supplementation noticeably increased the thymus index at 2 days post-infection (2 DPI) and 8 DPI (p < 0.05), and 120 mg/kg Zn-Met enhanced the serum IgA at 2 DPI and IgA, IgG, IgM, C3 at 8 DPI (p < 0.05). In addition, dietary 120 mg/kg Zn-Met supplementation dramatically increased villus height and villus height/crypt depth (V/C) of jejunum at 2 DPI and 8 DPI (p < 0.05). The TNF-α and IFN-γ mRNA expression were downregulated after supplemented with 120 mg/kg Zn-Met in jejunum at 8 DPI (p < 0.05). Moreover, dietary 120 mg/kg Zn-Met supplementation stimulated ZO-3, OCLN mRNA expression at 2 DPI and ZO-2 mRNA expression in jejunum at 8 DPI (p < 0.05), and improved the MUC2 concentration in jejunum at 2 DPI and 8 DPI (p < 0.05). At the same time, the cecal Bifidobacterium and Lactobacillus counts were increased (p < 0.05), and Escherichia coli counts were decreased (p < 0.05) after supplemented with Zn-Met. In conclusion, inclusion of 120 mg/kg Zn-Met minimizes the adverse effects of APEC challenge on meat ducks by improving growth performance and enhancing immune function and intestinal health.

Differential Effects of Transition Metals on Growth and Metal Uptake for Two Distinct Lactobacillus Species

Lactobacillus is a genus of Gram-positive bacteria and comprises a major part of the lactic acid bacteria group that converts sugars to lactic acid. Lactobacillus species found in the gut microbiota are considered beneficial to human health and commonly used in probiotic formulations, but their molecular functions remain poorly defined. Microbes require metal ions for growth and function and must acquire them from the surrounding environment. Therefore, lactobacilli need to compete with other gut microbes for these nutrients, although their metal requirements are not well-understood. Indeed, the abundance of lactobacilli in the microbiota is frequently affected by dietary intake of essential metals like zinc, manganese, and iron, but few studies have investigated the role of metals, especially zinc, in the physiology and metabolism of Lactobacillus species. Here, we investigated metal uptake by quantifying total cellular metal contents and compared how transition metals affect the growth of two distinct Lactobacillus species, Lactobacillus plantarum ATCC 14917 and Lactobacillus acidophilus ATCC 4356. When grown in rich or metal-limited medium, both species took up more manganese, zinc, and iron compared with other transition metals measured. Distinct zinc-, manganese- and iron-dependent patterns were observed in the growth kinetics for these species and while certain levels of each metal promoted the growth kinetics of both Lactobacillus species, the effects depend significantly on the culture medium and growth conditions. IMPORTANCE The gastrointestinal tract contains trillions of microorganisms, which are central to human health. Lactobacilli are considered beneficial microbiota members and are often used in probiotics, but their molecular functions, and especially those which are metal-dependent, remain poorly defined. Abundance of lactobacilli in the microbiota is frequently affected by dietary intake of essential metals like manganese, zinc, and iron, but results are complex, sometimes contradictory, and poorly predictable. There is a significant need to understand how host diet and metabolism will affect the microbiota, given that changes in microbiota composition are linked with disease and infection. The significance of our research is in gaining insight to how metals distinctly affect individual Lactobacillus species, which could lead to novel therapeutics and improved medical treatment. Growth kinetics and quantification of metal contents highlights how distinct species can respond differently to varied metal availability and provide a foundation for future molecular and mechanistic studies.

Gut Microbiota as a Mediator of Essential and Toxic Effects of Zinc in the Intestines and Other Tissues

The objective of the present study was to review the existing data on the association between Zn status and characteristics of gut microbiota in various organisms and the potential role of Zn-induced microbiota in modulating systemic effects. The existing data demonstrate a tight relationship between Zn metabolism and gut microbiota as demonstrated in Zn deficiency, supplementation, and toxicity studies. Generally, Zn was found to be a significant factor for gut bacteria biodiversity. The effects of physiological and nutritional Zn doses also result in improved gut wall integrity, thus contributing to reduced translocation of bacteria and gut microbiome metabolites into the systemic circulation. In contrast, Zn overexposure induced substantial alterations in gut microbiota. In parallel with intestinal effects, systemic effects of Zn-induced gut microbiota modulation may include systemic inflammation and acute pancreatitis, autism spectrum disorder and attention deficit hyperactivity disorder, as well as fetal alcohol syndrome and obesity. In view of both Zn and gut microbiota, as well as their interaction in the regulation of the physiological functions of the host organism, addressing these targets through the use of Zn-enriched probiotics may be considered an effective strategy for health management.

Effect of zinc supplementation on growth performance, intestinal development, and intestinal barrier function in Pekin ducks with lipopolysaccharide challenge

This study was conducted to investigate the influence of zinc (Zn) supplementation on growth performance, intestinal development and intestinal barrier function in Pekin ducks. A total of 480, one-day-old male Pekin ducks were divided into 6 groups with 8 replicates: 0 mg/kg Zn, 0 mg/kg Zn +0.5 mg/kg lipopolysaccharide (LPS), 30 mg/kg Zn, 30 mg/kg Zn +0.5 mg/kg LPS, 120 mg/kg Zn, 120 mg/kg Zn +0.5 mg/kg LPS. The duck primary intestinal epithelial cells (DIECs) were divided into 6 groups: D-Zn (Zinc deficiency, treated with 2 µmol/L zinc Chelator TPEN), A-Zn (Adequate Zinc, basal medium), H-Zn (High level of Zn, supplemented with 20 µmol/L Zn), D-Zn + 20 µg/mL LPS, A-Zn + 20 µg/mL LPS, H-Zn + 20 µg/mL LPS. The results were as follows: in vivo, with Zn supplementation of 120 mg/kg reduced LPS-induced decrease of growth performance and intestine damage (P < 0.05), and increased intestinal digestive enzyme activity of Pekin ducks (P < 0.05). In addition, Zn supplementation also attenuated LPS-induced intestinal epithelium permeability (P < 0.05), inhibited LPS-induced the expression of proinflammatory cytokines and apoptosis-related genes (P < 0.05), as well as reduced LPS-induced the intestinal stem cells mobilization of Pekin ducks (P < 0.05). In vitro, 20 µmol/L Zn inhibited LPS-induced expression of inflammatory factors and apoptosis-related genes (P < 0.05), promoted the expression of cytoprotection-related genes, and attenuated LPS-induced intestinal epithelium permeability in DIECs (P < 0.05). Mechanistically, 20 µmol/L Zn enhanced tight junction protein markers including CLDN-1, OCLD, and ZO-1 both at protein and mRNA levels (P < 0.05), and also increased the level of phosphorylation of TOR protein (P < 0.05) and activated the TOR signaling pathway. In conclusion, Zn improves growth performance, digestive enzyme activity, and intestinal barrier function of Pekin ducks. Importantly, Zn also reverses LPS-induced intestinal barrier damage via enhancing the expression of tight junction proteins and activating the TOR signaling pathway.

Antibacterial Potential of Biosynthesized Zinc Oxide Nanoparticles against Poultry-Associated Foodborne Pathogens: An In Vitro Study

Simple Summary

The overuse of antibiotics in the poultry industry has led to the emergence of multidrug-resistant microorganisms. Thus, there is a need to find an alternative to conventional antibiotics. Recently, zinc oxide nanoparticles (ZnO NPs) have gained much attention due to their excellent antibacterial activity. In addition, ZnO NPs is an essential trace mineral in poultry diets. In this sense, incorporating ZnO NPs into poultry can promote growth and performance while serving as an alternative antibacterial agent to control diseases. Therefore, this study aimed to assess the in vitro antibacterial activity and antibacterial mechanisms of ZnO NPs against poultry-associated foodborne pathogens (Salmonella spp., Escherichia coli, and Staphylococcus aureus). The obtained findings demonstrated effective antibacterial actions against the tested microorganisms. The nanotechnology approach could represent a new tool for combating pathogens in the poultry industry.

Abstract

Since the emergence of multidrug-resistant bacteria in the poultry industry is currently a serious threat, there is an urgent need to develop a more efficient and alternative antibacterial substance. Zinc oxide nanoparticles (ZnO NPs) have exhibited antibacterial efficacy against a wide range of microorganisms. Although the in vitro antibacterial activity of ZnO NPs has been studied, little is known about the antibacterial mechanisms of ZnO NPs against poultry-associated foodborne pathogens. In the present study, ZnO NPs were successfully synthesized using Lactobacillus plantarum TA4, characterized, and their antibacterial potential against common avian pathogens (Salmonella spp., Escherichia coli, and Staphylococcus aureus) was investigated. Confirmation of ZnO NPs by UV-Visual spectroscopy showed an absorption band center at 360 nm. Morphologically, the synthesized ZnO NPs were oval with an average particle size of 29.7 nm. Based on the dissolution study of Zn²⁺, ZnO NPs released more ions than their bulk counterparts. Results from the agar well diffusion assay indicated that ZnO NPs effectively inhibited the growth of the three poultry-associated foodborne pathogens. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were assessed using various concentrations of ZnO NPs, which resulted in excellent antibacterial activity as compared to their bulkier counterparts. S. aureus was more susceptible to ZnO NPs compared to the other tested bacteria. Furthermore, the ZnO NPs demonstrated substantial biofilm inhibition and eradication. The formation of reactive oxygen species (ROS) and cellular material leakage was quantified to determine the underlying antibacterial mechanisms, whereas a scanning electron microscope (SEM) was used to examine the morphological changes of tested bacteria treated with ZnO NPs. The findings suggested that ROS-induced oxidative stress caused membrane damage and bacterial cell death. Overall, the results demonstrated that ZnO NPs could be developed as an alternative antibiotic in poultry production and revealed new possibilities in combating pathogenic microorganisms.

Efficacy of Trace Mineral-Amino Acid Complexes in a Necrotic Enteritis Challenge Model

Necrotic enteritis (NE) is a common and costly disease of poultry caused by virulent toxigenic strains of Clostridium perfringens. Although the importance of trace minerals for intestinal integrity and health is well documented, there is little information on their role in ameliorating the effects of NE. The two studies reported here examined the effects of replacing a portion of the dietary zinc (Zn), copper (Cu), and manganese (Mn) supplied as sulfates in the control diets with metal-amino acid-complexed minerals in a NE-challenge model consisting of coccidiosis and Clostridium perfringens. In a 28-day battery study, the treatments were the following: (1) no additional Zn or Mn, unchallenged (negative control); (2) no added Zn or Mn, challenged (positive control); (3) added ZnSO4 and MnSO4 at 100 ppm each, challenged; (4) additional ZnSO4 at 60 ppm, Availa-Zn at 40 ppm (Low), and MnSO4 at 100 ppm, challenged; (5) added ZnSO4 at 60 ppm, Availa-Zn at 60 ppm (high), and MnSO4 at 100 ppm, challenged; and (6) added ZnSO4 at 60 ppm, Availa-Zn at 40 ppm, MnSO4 at 60 ppm, and Availa-Mn at 40 ppm, challenged. None of the treatments ameliorated gross lesion scores, but all reduced NE-associated mortality compared with the positive control. At 28 days, the group supplemented with Availa-Zn at 40 ppm (low) had a lower body weight than challenged groups supplemented with Zn and the negative control. In a floor pen study, the five treatment groups were the following: (1) Zn, Mn, and Cu from sulfate sources at 100, 100, and 20 ppm respectively; (2) Zn, Mn, and Cu from sulfate sources at 40, 100, and 20 ppm, respectively, plus Zn from Availa-Zn at 60 ppm; (3) Zn and Mn from sulfate sources at 40 and 100 ppm, respectively, plus Zn from Availa-Zn at 60 ppm and Cu from Availa-Cu at 10 ppm; (4) Zn, Mn, and Cu from sulfate sources at 60, 60, and 20 ppm, respectively, plus Zn and Mn from Availa-Zn/Mn at 40 and 40 ppm, respectively; and (5) bacitracin methylene disalicylate at 55 g/metric ton with Zn, Mn, and Cu from sulfate sources at 100, 100, and 20 ppm, respectively (Zoetis, Inc., Kalamazoo, MI). None of the treatments reduced lesion scores. The Availa-Zn and Availa-Zn/Mn had lower mortality than the sulfate-supplemented feed, whereas Availa-Zn/Cu and bacitracin methylene disalicylate were intermediate and did not differ from the other groups. Considering both trials together, and by using NE mortality as the discriminating factor, we found that adding Zn and Mn exceeding National Research Council requirements reduced NE-associated mortality, and in the floor pen study, complexed Zn and complexed Zn plus Mn appeared to be superior to sulfates.

Modulation of Gut Microbiota for the Prevention and Treatment of COVID-19

The gut microbiota is well known to exert multiple benefits on human health including protection from disease causing pathobiont microbes. It has been recognized that healthy intestinal microbiota is of great importance in the pathogenesis of COVID-19. Gut dysbiosis caused by various reasons is associated with severe COVID-19. Therefore, the modulation of gut microbiota and supplementation of commensal bacterial metabolites could reduce the severity of COVID-19. Many approaches have been studied to improve gut microbiota in COVID-19 including probiotics, bacterial metabolites, and prebiotics, as well as nutraceuticals and trace elements. So far, 19 clinical trials for testing the efficacy of probiotics and synbiotics in COVID-19 prevention and treatment are ongoing. In this narrative review, we summarize the effects of various approaches on the prevention and treatment of COVID-19 and discuss associated mechanisms.

Zinc hydroxychloride supplementation improves tibia bone development and intestinal health of broiler chickens

This study was conducted to investigate the effects of zinc (Zn), as a combination of oxide (ZnO) and sulfate (ZnSO₄), compared with incremental levels of zinc hydroxychloride (ZH) on tibia traits, intestinal integrity, expression of selected jejunal genes, cecal short chain fatty acids and microbial composition in broilers. Day-old male Ross 308 chicks (n = 784) were randomly allocated to seven dietary treatments, each replicated seven times with 16 chicks per replication. The dietary treatments included a negative control diet (NC) with no supplemental Zn, a positive control (PC) with 100 mg/kg supplemental Zn from an ionic bound source combination (50 mg/kg ZnO + 50 mg/kg ZnSO₄), and the NC diet supplemented with one of 20, 40, 60, 80, or 100 mg/kg Zn as ZH. The diets were fed over starter (1–14 d) and grower (14–35 d) phases, with tissue and digesta samples collected from 3 birds per replicate on days 14 and 35. The results showed that dietary Zn level had a significant effect on tibia breaking strength on d 35 (P < 0.05), and tibia Zn concentration both on d 14 and d 35 (P < 0.01). Dietary Zn levels linearly (P < 0.01) increased cecal lactic acid production, increased Lactobacillus, and decreased Bacillus and total bacteria counts (P < 0.05). Inclusion of 80 and 100 mg/kg Zn as ZH tended to upregulate the expression of claudin-1 (P = 0.088) and tight junction protein-1 (P = 0.086). The results obtained in this study suggest that a non-Zn supplemented diet can negatively influence tibia development and gut microbiota composition in broiler chickens. Higher supplemental Zn in the diet alters cecal microbiota population in favor of Lactobacillus and can decrease the total bacterial load. Supplemental Zn level in the feed have the potential to manipulate the jejunal gut integrity at a molecular level.

Thymol nanoemulsion promoted broiler chicken's growth, gastrointestinal barrier and bacterial community and conferred protection against Salmonella Typhimurium

The present study involved in vivo evaluation of the growth promoting effects of thymol and thymol nanoemulsion and their protection against Salmonella Typhimurium infection in broilers. One-day old 2400 chicks were randomly divided into eight groups; negative and positive control groups fed basal diet without additives and thymol and thymol nanoemulsion groups (0.25, 0.5 and 1% each). At d 23, all chicks except negative control were challenged with S. Typhimurium. Over the total growing period, birds fed 1% thymol nanoemulsion showed better growth performance even after S. Typhimurium challenge, which came parallel with upregulation of digestive enzyme genes (AMY2A, PNLIP and CCK). Additionally, higher levels of thymol nanoemulsion upregulated the expression of MUC-2, FABP2, IL-10, IgA and tight junction proteins genes and downregulated IL-2 and IL-6 genes expression. Moreover, 1% thymol nanoemulsion, and to lesser extent 0.5% thymol nanoemulsion and 1% thymol, corrected the histological alterations of cecum and liver postinfection. Finally, supplementation of 1% thymol, 0.5 and 1% thymol nanoemulsion led to increased Lactobacilli counts and decreased S. Typhimurium populations and downregulated invA gene expression postinfection. This first report of supplying thymol nanoemulsion in broiler diets proved that 1% nano-thymol is a potential growth promoting and antibacterial agent.

Do Only Calcium and Vitamin D Matter? Micronutrients in the Diet of Inflammatory Bowel Diseases Patients and the Risk of Osteoporosis

Osteoporosis is one of the most common extraintestinal complications among patients suffering from inflammatory bowel diseases. The role of vitamin D and calcium in the prevention of a decreased bone mineral density is well known, although other nutrients, including micronutrients, are also of extreme importance. Despite the fact that zinc, copper, selenium, iron, cadmium, silicon and fluorine have not been frequently discussed with regard to the prevention of osteoporosis, it is possible that a deficiency or excess of the abovementioned elements may affect bone mineralization. Additionally, the risk of malnutrition, which is common in patients with ulcerative colitis or Crohn's disease, as well as the composition of gut microbiota, may be associated with micronutrients status.

Regulatory effects of transition metals supplementation/deficiency on the gut microbiota

Transition metal ions are essential micronutrients for all living organisms and exert a wide range of effects on human health. The uptake of transition metal ions occurs primarily in the gastrointestinal tract, which is colonized by trillions of bacterial cells. In recent years, increasing studies have indicated that transition metals have regulatory effects on the gut microbiota. In view of the significant effect of the gut microbiota on human health and involvement in the pathogenesis of a wide range of diseases, in this paper, we provide a comprehensive discussion on the regulatory effects of four kinds of transition metal ions on the gut microbiota. A total of 20 animal model and human studies concerning the regulatory effects of four types of transition metal ions (i.e., iron, copper, zinc, and manganese) on gut microbiota were summarized. Both the deficiency and supplementation of these transition metal ions on the gut microbiota were considered. Furthermore, the potential mechanisms governing the regulatory effects of transition metal ions on the gut microbiota were also discussed. KEY POINTS : • Regulatory effects of iron, copper, zinc, and manganese on gut microbiota were reviewed. • Both deficiency and supplementation of metal ions on gut microbiota were considered. • Mechanisms governing effects of metal ions on gut microbiota were discussed.

Nano-sized Zinc in Broiler Chickens: Effects on Growth Performance, Zinc Concentration in Organs, and Intestinal Morphology

The effects of dietary supplementation of zinc (Zn) sources and concentrations were investigated on growth performance, absorption into tissues, fecal excretion, nutrient retention, and intestinal morphology in broilers fed a corn-soybean meal basal diet. A total of 525 one-day-old chicks (Ross 308) were assigned based on body weight to seven dietary treatments. There were five replicate pens for each treatment and 15 broilers per replicate pen. The dietary treatments included a basal diet (control, without supplementing Zn), and basal diet supplemented with Zn, as inorganic zinc sulfate (ZnS; 110 mg/kg); organic Zn-methionine (ZnM; 110 mg/kg); hot-melt extruded (HME) 25 zinc sulfate (27.5 mg/kg); HME50 zinc sulfate (55 mg/kg); HME75 zinc sulfate (82.5 mg/kg); or HME100 zinc sulfate (110 mg/kg) for 35 days in two phases (d 1-21, phase I and d 22-35, phase II). Bodyweight and feed efficiency of broiler chicks fed diets supplemented with increasing dietary concentrations of HME-Zn improved linearly during the study period (P<0.05). Compared to the control treatment, the ZnS, ZnM, and HME diets increased Zn concentrations in the serum and liver. Inorganic ZnS supply resulted in the highest Zn concentration in excreta. Increasing supplemented Zn content in diets as HME linearly increased Zn concentration in the excreta, serum, liver, and tibia. Broiler chicks fed diets supplemented with increasing concentrations of HME increased villus height (VH; linear and quadratic) of the jejunum and VH of the ileum (linear). Increasing concentrations of dietary Zn supplied as HME resulted in linearly enhanced dry matter, gross energy, and nitrogen retention of broilers on day 21. These results suggest that dietary HME-Zn at a lower level (55 ppm) shows the same growth performance as common ZnSO₄ at 110 ppm.

Zinc, manganese and copper amino acid complexed in laying hens' diets affect performance, blood parameters and reproductive organs development

In the intestinal lumen, excess of oxides and sulfates interfere with the absorption of minerals due to competition from the same absorption site. Amino acids-mineral complexed (AACM) is intended to minimize these problems, which might be absorbed by different absorption sites. Then, a study including Zinc (Zn), Manganese (Mn) and Copper (Cu) from different sources was carried out to evaluate the performance, blood parameters and reproductive organs development of Brown Laying Hens. A total of 800 Lohmann Brown Lite were fed, from one-day-old to 182-days-old, Zn, Mn and Cu from different sources. Measurements were made from 105 to 182-days-old. The laying hens were distributed according to a completely randomized design with 20 replicates and 20 birds per experimental unit. The treatments consisted of a diet supplemented with 70, 70 and 8 mg/kg of Zn, Mn and Cu; respectively, from inorganic sources (IM). The second treatment contained 40, 40 and 2.75 mg/kg of Zn, Mn and Cu, respectively from IM plus 30, 30 and 5.25 mg/kg of Zn, Mn and Cu; respectively, from AACM sources. Performance and reproductive organs development (oviduct and ovary weight), tibia weight, liver weight, egg output and body weight, and blood variables were evaluated. Data were compared by Student's t-test (P < 0.05). Laying hens fed AACM reached 35% of egg output two days earlier and presented heavier tibia bone than the IM group. Those hens also presented greater oviduct weight, greater hematocrit and greater serum concentration of total leukocytes, erythrocytes, eosinophils, monocytes and the hormones T4 and FSH, than the hens fed IM. The supplementation of AACM in laying hens' diets since one-day-old improves the productive performance from the beginning of egg output to peak production, which is justified by better development of bones and oviduct, hormone production and immune system support.

Reduction of Salmonella Typhimurium Cecal Colonisation and Improvement of Intestinal Health in Broilers Supplemented with Fermented Defatted 'Alperujo', an Olive Oil By-Product

Salmonella spp. contaminates egg and poultry meat leading to foodborne infections in humans. The emergence of antimicrobial-resistant strains has limited the use of antimicrobials. We aimed to determine the effects of the food supplement, fermented defatted 'alperujo' (FDA), a modified olive oil by-product, on Salmonella Typhimurium colonisation in broilers. One hundred and twenty 1-day-old broilers were divided into four experimental groups-two control groups and two treated groups, and challenged with S. Typhimurium at day 7 or 21. On days 7, 14, 21, 28, 35, and 42 of life, duodenum and cecum tissue samples were collected for histopathological and histomorphometric studies. Additionally, cecum content was collected for Salmonella spp. detection by culture and qPCR, and for metagenomic analysis. Our results showed a significant reduction of Salmonella spp. in the cecum of 42-day-old broilers, suggesting that fermented defatted 'alperujo' limits Salmonella Typhimurium colonization in that cecum and may contribute to diminishing the risk of carcass contamination at the time of slaughter. The improvement of the mucosal integrity, observed histologically and morphometrically, may contribute to enhancing intestinal health and to limiting Salmonella spp. colonisation in the host, mitigating production losses. These results could provide evidence that FDA would contribute to prophylactic and therapeutic measures to reduce salmonellosis prevalence in poultry farms.

The relationship among gut microbiota, short-chain fatty acids, and intestinal morphology of growing and healthy broilers

The gut microbiota play an important role in the growth and intestinal health of broilers. The present study was to investigate the gut microbiota, short-chain fatty acids, and intestinal morphology of broilers at different ages. A total of 320 one-day-old male broilers were raised in 8 replicates and fed the same corn–soybean diets for 42 D. The duodenal, jejunal, and ileal segments and their and cecal microbiota were collected on day 1, 7, 14, 21, and 42, respectively. The villous height (VH), crypt depth (CD), and their ratio of VH:CD in the duodenum, jejunum, and ileum all increased (P < 0.05) with age. Caecal acetate, propionate, butyrate, valerate, and isovalerate increased (P < 0.01), but isobutyrate decreased (P < 0.001) with age. The cecum had the greatest (P < 0.001) alpha diversity of bacterial community in broilers at different ages. Beta diversities showed distinct differences in gut microbial compositions among different ages (R = 0.55, P < 0.002) and different intestinal segments (R = 0.53, P < 0.002). Lactobacillus was the most abundant genus in the duodenum (36∼97%), jejunum (39∼72%), and ileum (24∼96%) at all ages, and in the ileum, it was positively correlated with VH (R = 0.559, P < 0.03), VH:CD (R = 0.55, P < 0.03), and acetate contents (R = 0.541, P < 0.04) but negatively correlated (R = -0.50, P < 0.05) with isobutyrate contents. Escherichia–Shigella and Salmonella dominated in the cecum of newly hatched broilers, and then the Bacteroides dominated in the cecum on day 42. In the cecum, Escherichia–Shigella was positively correlated (R = 0.577∼0.662, P < 0.05) with isobutyrate contents and Salmonella negatively correlated (R = -0.539∼-0.843, P < 0.05) with isovalerate, butyrate, and acetate contents. These aforementioned results indicated that the most abundant Lactobacillus from the small intestine and the most diversity of microflora community and short-chain fatty acids in the cecum might contribute to the development of intestinal structure in the whole growing period of broilers.

Bioavailability of Methionine-Coated Zinc Nanoparticles as a Dietary Supplement Leads to Improved Performance and Bone Strength in Broiler Chicken Production

Recently, nanotechnology has been widely adopted in many fields. The goal of this study was to evaluate the potential for amino acid coated nano minerals as a supplement in broiler feed. Zinc was selected as a model mineral for this test and supplementation of nano zinc, both coated and uncoated was compared with organic and inorganic commercial forms of zinc. A total of 48 pens (8 birds each) were assigned to one of the following dietary treatments: Control, methionine-Zinc chelate (M-Zn), nano zinc oxide (Nano-ZnO), and methionine coated nano zinc oxide (M-Nano-ZnO). All experimental diets were formulated with the same total zinc, methionine, protein, and energy content with just the zinc source as a variable. Bird weight, feed intake and feed conversion ratios were recorded weekly, with three birds culled (sacrificed) at day 21 and day 35 for sampling measures. Ileal digestibility of zinc was determined at day 21 and day 35 using titanium dioxide as an inert marker. Blood serum, liver and spleen samples were collected at day 21 and day 35 and analysed for zinc content via inductively coupled plasma mass spectrometry (ICP-MS). Tibia strength and morphometrics were measured from both legs of three birds per pen at day 21 and day 35. The study was conducted at Nottingham Trent University Poultry Unit, UK. The novel method of producing nano minerals coated with amino acids was successfully tested with zinc and material produced to test in the feeding study. Methionine coated nano zinc oxide supplementation significantly improved bird weight gain and the increased feed intake of broilers compared to an inorganic zinc form. Ileal digestibility was also improved with this methionine-nano zinc. Moreover, this supplementation improved the tibia strength of broilers at the age of 21 days, though this was not observed at day 35. Therefore, M-Nano-ZnO could be used to supplement broilers to improve both performance and digestibility with a limited positive impact on bone strength. The results of the current study suggest that the amino acid coating of nano minerals can improve the digestibility of minerals which may have further implications for the field of mineral nutrition in animal feeds.

Role of Dietary Nutrients in the Modulation of Gut Microbiota: A Narrative Review

Understanding how dietary nutrients modulate the gut microbiome is of great interest for the development of food products and eating patterns for combatting the global burden of non-communicable diseases. In this narrative review we assess scientific studies published from 2005 to 2019 that evaluated the effect of micro- and macro-nutrients on the composition of the gut microbiome using in vitro and in vivo models, and human clinical trials. The clinical evidence for micronutrients is less clear and generally lacking. However, preclinical evidence suggests that red wine- and tea-derived polyphenols and vitamin D can modulate potentially beneficial bacteria. Current research shows consistent clinical evidence that dietary fibers, including arabinoxylans, galacto-oligosaccharides, inulin, and oligofructose, promote a range of beneficial bacteria and suppress potentially detrimental species. The preclinical evidence suggests that both the quantity and type of fat modulate both beneficial and potentially detrimental microbes, as well as the Firmicutes/Bacteroides ratio in the gut. Clinical and preclinical studies suggest that the type and amount of proteins in the diet has substantial and differential effects on the gut microbiota. Further clinical investigation of the effect of micronutrients and macronutrients on the microbiome and metabolome is warranted, along with understanding how this influences host health.

Influence of Dietary Zinc, Copper, and Manganese on the Intestinal Health of Broilers Under Eimeria Challenge

The incidence of enteric infections in broiler chickens may increase worldwide due to mounting pressure to limit the use of sub-therapeutic antibiotics and ionophores for coccidia suppression/prevention in the diets of broilers. For this reason, we need expand our knowledge on the role that micro-minerals have in modulating the intestinal physiology, immunology, and microbiology of broiler chickens. There are issues associated with the use of high doses of some micro-minerals in the diets of animals, such as environmental contamination, bacterial resistance, and gizzard erosion. Therefore, there is a need to maximize the absorption of these minerals by the gastrointestinal tract (GIT) of birds when intestinal function may be compromised. Zinc is an essential micromineral required for growth, and influences intestinal development and/or regeneration during and after enteric disease. Two studies were conducted by our lab to determine the effects of Zn source in broilers under coccidia and Clostridium perfringens challenge. In the first study, Zn proteinate had beneficial effects on the performance of chickens challenged with coccidia plus C. perfringens by enhancing intestinal integrity and partially attenuating the inflammatory response. In the second study, Zn proteinate lowered the expression of pro-inflammatory cytokines and modulated the ileal microbiota. Additionally, the poultry industry has used prophylactic concentrations of dietary Cu for its ability to improve feed conversion for a long time. Copper absorption occurs mainly in the duodenum of chickens and, therefore, injuries to the intestinal epithelium of duodenum would impair Cu absorption and decrease its tissue concentration. Although there is a lack of studies relating Mn supplementation and its different sources on the immune response against coccidiosis in poultry, it is likely that Mn is beneficial during enteric challenges due to its role in the production of mucopolysaccharides. Therefore, the proper evaluation of the role of minerals on mitigating the negative impact of coccidiosis in broilers must consider their properties in modulating the physiology, immunology, and the intestinal microbiota of the host during health and disease situation events.

Dietary zinc source impacts intestinal morphology and oxidative stress in young broilers

Zinc is an essential nutritional trace element for all forms of life as it plays an important role in numerous biological processes. In poultry, zinc is provided by in-feed supplementation, mainly as zinc oxide or zinc sulfate. Alternatively zinc can be supplemented as organic sources, which are characterized by using an organic ligand that may be an amino acid, peptide, or protein to bind zinc and have a higher bioavailability than inorganic zinc sources. There are limited number of studies directly comparing the effects of inorganic vs. organic zinc sources on performance and intestinal health in broilers. Therefore, a digestibility and a performance study were conducted to evaluate and compare the effect of an amino acid-complexed zinc source vs. an inorganic zinc source on intestinal health. The experiment consisted of 2 treatments: either a zinc amino acid complex or zinc sulfate was added to a wheat–rye based diet at 60 ppm Zn, with 10 replicates (34 broilers per pen) per treatment. Effects on performance, intestinal morphology, microbiota composition, and oxidative stress were measured. Supplementing zinc amino acid complexes improved the zinc digestibility coefficient as compared to supplementation with zinc sulfate. Broilers supplemented with zinc amino acid complexes had a significantly lower feed conversion ratio in the starter phase compared to birds supplemented with zinc sulfate_. A significantly higher villus length was observed in broilers supplemented with zinc amino acid complexes at days 10 and 28. Supplementation with zinc amino acid complexes resulted in a decreased abundance of several genera belonging to the phylum of Proteobacteria. Plasma malondialdehyde levels and glutathione peroxidase activity showed an improved oxidative status in broilers supplemented with zinc amino acid complexes. In conclusion, zinc supplied in feed as amino acid complex is more readily absorbed, potentially conferring a protective effect on villus epithelial cells in the starter phase.

The Alterations of Copper and Zinc Homeostasis in Acute Appendicitis and the Clinical Significance

Copper (Cu) and zinc (Zn) are involved in inflammatory process. This study was to investigate the clinical significance of Cu and Zn homeostasis alterations in acute appendicitis (AA). One hundred twenty-two AA patients and 102 healthy controls were enrolled in this study. Of which, 85 patients' appendixes were collected after appendectomy. Another six appendixes from colon cancer patients were collected as tissue controls. The contents of Cu and Zn in serum or appendix were detected, and the Cu to Zn ratio (CZr) was calculated. The concentrations of serum ceruloplasmin (CP), Cu/Zn superoxide dismutase (SOD1), interleukin-6 (IL-6), and interleukin-22 in serum were measured, as well as the activity of CP and SOD1. The serum Zn concentration and SOD1 activity, appendix contents of Cu and Zn significantly decreased in AA patients, compared with those of controls, while serum CZr, concentrations of CP, SOD1, and IL-6, as well as CP activity increased significantly in AA patients. Additionally, serum concentrations of Zn, CP, CZr, or SOD1 activity varied in different pathological types of AA. Indicators such as serum SOD1 activity might serve as predictors for pathological classification before surgery. The serum Zn and CZr may be helpful for diagnosis of pure AA. The Cu and Zn homeostasis was altered in AA patients, which might contribute to inflammatory process of AA.

Can dietary zinc diminish the impact of necrotic enteritis on growth performance of broiler chickens by modulating the intestinal immune-system and microbiota?

The objective of this study was to compare the effects of inorganic and proteinate Zn in chickens challenged with coccidia and Clostridium perfringens. A 3 × 2 factorial design was used, with 3 dietary formulations (0 or 90 mg/kg supplemental Zn from ZnSO4 or Zn proteinate, with or without challenge). On day 14, challenged birds were orally gavaged with approx. 5,000 Eimeria maxima sporulated oocysts, and on day 19 to 21 with C. perfringens (108 CFU/D). Productive performance was assessed at day 21 and 28. At 21 D, necrotic enteritis (NE) lesion severity, intestinal permeability, gene expression, and ileal and cecal microbiota were evaluated. An interaction of Zn source by challenge was observed for lesion score and mortality, wherein Zn supplementation decreased the degree of NE lesions (P = 0.02) and mortality due to NE (P = 0.008). In the jejunum, an interaction of Zn source by challenge was observed for the expression of IL-8 (P = 0.001) and INF-γ (P = 0.03), wherein the NE challenge upregulated their expression, but not in the Zn proteinate supplemented birds. Zn proteinate supplementation downregulated iNOS vs. ZnSO4 supplemented birds (P = 0.0003), and supplemental Zn downregulated TLR-2 (P = 0.05) and ZnT5 (P = 0.04), regardless of the source. In the ileal microbiota, Zn proteinate supplementation decreased the frequency of Lactobacillus (P = 0.01), and the challenge increased Enterobacteriaceae (P = 0.01). Dietary Zn decreased NE lesion severity and mortality due to NE; Zn proteinate led to lower expression of IL-8 and INF-γ in challenged birds which may be an indicative of a lessened inflammatory response.

Zinc source modulates intestinal inflammation and intestinal integrity of broiler chickens challenged with coccidia and Clostridium perfringens

Two dietary sources of zinc (ZnSO4 or organic Zn) were tested in chickens challenged with coccidiosis (Co) or coccidiosis plus Clostridium perfringens (CoCPF). On day 14, the chickens were orally gavaged with ∼5,000 Eimeria maxima sporulated oocysts. On day 19, 20, and 21 chickens challenged with C. perfringens were given a broth culture containing 108 cfu of this bacterium. Productive performance parameters were determined at d 14, 21, and 28. On day 21, necrotic enteritis (NE) lesions were scored, and intestinal permeability was evaluated. Jejunum and cecal tonsils were collected for morphology and gene expression analysis. On day 21, organic Zn improved BW gain by 18.6% (P = 0.07), and FCR by 12% (P = 0.09) in CoCPF challenged chickens vs. birds fed ZnSO4. From 1 to 28, organic Zn increased BW gain (P = 0.02), and improved FCR (P = 0.03) vs. birds fed ZnSO4. At 21 d, NE lesions were only observed in CoCPF birds (P < 0.001), and mortality due to NE was only observed when CoCPF birds were fed ZnSO4 (P = 0.001). Organic Zn fed birds had increased villus height in the jejunum (P = 0.005) and decreased intestinal permeability (P = 0.01) vs. ZnSO4. In the jejunum, organic Zn fed birds showed a downregulation of expression of IL-8 (P = 0.02), and upregulation of IL-10 (P = 0.05) in CoCPF birds vs. ZnSO4- CoCPF birds. As main effect, birds supplemented with organic Zn had higher mRNA expression of TLR-2 (P = 0.02) and IgA (P = 0.01). In the cecal tonsils, organic Zn fed birds showed upregulation of iNOS (P = 0.008) in CoCPF birds vs. ZnSO4-CoCPF birds. Organic Zn supplementation reduced intestinal permeability and attenuated intestinal inflammation of broilers co-challenged with coccidia and C. perfringens.

Gut microbiota and inflammation in chronic kidney disease and their roles in the development of cardiovascular disease

The health and proper functioning of the cardiovascular and renal systems largely depend on crosstalk in the gut-kidney-heart/vessel triangle. Recent evidence suggests that the gut microbiota has an integral function in this crosstalk. Mounting evidence indicates that the development of chronic kidney and cardiovascular diseases follows chronic inflammatory processes that are affected by the gut microbiota via various immune, metabolic, endocrine, and neurologic pathways. Additionally, deterioration of the function of the cardiovascular and renal systems has been reported to disrupt the original gut microbiota composition, further contributing to the advancement of chronic cardiovascular and renal diseases. Considering the interaction between the gut microbiota and the renal and cardiovascular systems, we can infer that interventions for the gut microbiota through diet and possibly some medications can prevent/stop the vicious cycle between the gut microbiota and the cardiovascular/renal systems, leading to a decrease in chronic cardiovascular and renal diseases.

Effect of Zinc Supplementation on Growth Performance, Intestinal Development, and Intestinal Barrier-Related Gene Expression in Pekin Ducks

The current study was conducted to investigate the effect of zinc supplementation on the growth performance, intestinal morphology, and the transcription of the barrier function related genes in Pekin ducks. Seven-hundred and sixty-eight 1-day-old Pekin ducks were randomly assigned into six dietary treatments. Each treatment had eight replicates with 16 ducks per replicates. The ducks were fed either a corn-soybean meal basal diet or basal diets supplemented with 15, 30, 60, 120, and 240 mg zinc/kg from zinc sulfate. This experiment lasted for 5 weeks, and the jejunum sample were harvested at 14 and 35 days of age. Results have shown that diets supplemented with zinc significantly increased the duck body weight, average daily gain, and average daily feed intake in different period of experiment (P < 0.05); feed to gain ratio was decreased as the zinc level increased (P < 0.05). Zinc supplementation increased the villus height and decreased the crypt depth in jejunum of ducks (P < 0.05) at 14 and 35 days of age. The transcription of tight junction protein CLDN1, OCND, ZO-1, and ZO-3 in jejunum were increased (P < 0.05), and the messenger RNA (mRNA) levels of leak protein CLDN2 were decreased as the dietary zinc level increased (P < 0.05) at 14 and 35 days of age. The mRNA levels of chemical barrier-related genes MUC2 and TFF-2 in jejunum at 14 and 35 days of age were increased (P < 0.05) by zinc supplementation, and so did the transcription of immunological barrier-related genes lgA, pIgR, LYZ, and AvBD2 (P < 0.05). In conclusion, dietary zinc supplementation exhibited growth-promoting effect on Pekin duck, improved intestinal morphology, and enhanced the intestinal barrier integrity.

Intestinal microbiome of broiler chickens after use of nanoparticles and metal salts

The research included the study of influence of ultrafine particle preparations (nanoparticles of copper, zinc, iron, CuZn alloy) and metal salts (iron pyrophosphate, copper asparginate, zinc asparginate) on the composition of cecal microbiota of broiler chickens. Before adding the studied nanoparticles and metal salts to the diet, cecal microbiota of broiler chickens was represented by 76% Firmicutes taxon and 16% Bacteroidetes. Numerous among them were the bacteria of the taxa Anaerotruncus spp., Lactobacillus spp., Blautia spp., Alistipes spp., and Bacteroides spp.; they constituted 18, 17, 11, and 6%, respectively. A peculiarity of action of the most analyzed metals in nanoform and in the form of salts was a decrease in the number of phylum Firmicutes bacteria and an increase in the number of microorganisms of the phylum Bacteroidetes. The number of bacteria belonging to the families Ruminococcaceae (III, IV, V, VII, and VIII groups), Bacteroidaceae (in all experimental groups), and Lachnospiraceae (I, IV, V, and VII groups) was registered within the taxa of Firmicutes and Bacteroidetes. At the same time, in some experimental groups, the number of bacteria of the family Lachnospiraceae (II, III, and VIII) decreased in the intestine. The data obtained can be used to assess the possibility of using metal nanoparticles in the poultry diet, as a micronutrient preparation, to correct dysbiosis and to improve the utilization of fodder energy.

Zinc Oxide Nanoparticles Influence Microflora in Ileal Digesta and Correlate Well with Blood Metabolites

Zinc oxide nanoparticles (ZnO NPs) are used widely in consumer and industrial products, however, their influence on gut microbiota and metabolism and their mutual interactions are not fully understood. In this study, the effects of ZnO NPs on ileal bacterial communities, plasma metabolites, and correlations between them were investigated. Hens were fed with different concentrations of ZnO NPs [based on Zn; 0 mg/kg (control), 25 mg/kg, 50 mg/kg, and 100 mg/kg] for 9 weeks. Subsequently, ileal digesta and blood plasma were collected for analysis of microflora and metabolites, respectively. The V3-V4 region of the 16S rRNA gene of ileal digesta microbiota was sequenced using the Illumina HiSeq 2500 platform. The predominant bacterial community in the ileum belongs to the phylum Firmicutes. The richness of the bacterial community was negatively correlated with increasing amounts of ZnO NPs (r = -0.636, P < 0.01); when ZnO NP levels were at 100 mg/kg, microbiota diversity was significantly decreased (P < 0.05). The community structure determined by LEfSe analysis indicated that Bacilli, Fusobacteria, and Proteobacteria were changed, and Lactobacillus was reduced by ZnO NPs. Moreover, metabolism as analyzed by nuclear magnetic resonance (NMR) indicated that glucose, some amino acids, and other metabolites were changed by ZnO NPs. Choline, lactate, and methionine were positively correlated with bacterial richness. In summary, ZnO NPs could influence the levels of microflora in ileal digesta, particularly Lactobacillus. Furthermore, the richness of the microbiota was related to changes in choline, lactate, and methionine metabolism.