Influence of mannan oligosaccharide, Ligustrum lucidum and Schisandra chinensis on parameters of antioxidative and immunological status of broilers

The study was conducted to evaluate effects of dietary supplementation with Ligustrum lucidum (LL, 10 g/kg), Schisandra chinensis (SC, 10 g/kg), LL (10 g/kg) + mannan oligosaccharides (MOS, 50 mg/kg), or SC (10 g/kg) + MOS (50 mg/kg) on growth performance and parameters of antioxidative and immunological status of broilers. The results showed that feeding LL, SC, LL + MOS, or SC + MOS had no significant effect on growth performance of broilers relative to the control. However, compared to the control, LL, SC, LL + MOS, or SC + MOS significantly decreased malondialdehyde concentration in serum, thigh, and heart of broilers. In addition, glutathione reductase activity of heart and sera of the birds were significantly elevated by supplementation LL, SC, LK + MOS, or SC + MOS. Furthermore, LL, SC, LL + MOS, or SC + MOS significantly improved antibody titres against Newcastle disease virus and lymphocyte proliferation of broilers (p < 0.05). Whereas, no cooperating effect between LL (or SC) and MOS on antioxidant status and immunity of broilers were found.     

Influence of an aqueous extract of Ligustrum lucidum and an ethanol extract of Schisandra chinensis on parameters of antioxidative metabolism and spleen lymphocyte proliferation of broilers

The study was conducted to evaluate the effects of dietary supplementation with different levels of two extracts, an aqueous extract of Ligustrum lucidum (AELL), and an ethanol extract of Schisandra chinensis (EESC) on growth performance, parameters of antioxidative status and spleen lymphocyte proliferation of broilers, respectively. The results showed that neither AELL nor EESC had significant effects on growth performance of broilers. However, malondialdehyde concentration in heart and liver of the broilers were significantly decreased by feeding AELL or EESC. Superoxide dismutase activity in heart, liver, and kidney of broilers were improved by feeding different dosages of AELL or EESC. In contrast, glutathione reductase activity in serum, heart and kidney of broilers was not affected by experimental treatment. In addition, spleen lymphocyte proliferation of broilers was significantly enhanced by feeding different dosages of AELL or EESC. In conclusion, the results suggested that either AELL or EESC may improve antioxidant status and immune function of broilers.     

Effect of Ligustrum lucidum and Schisandra chinensis on the egg production,antioxidant status and immunity of laying hens during heat stress

Abstract

The experiment was conducted to evaluate the effect of two plants belonging to Chinese herbal medicines, Ligustrum lucidum (LL) and Schisandra chinensis (SC), on the laying performance, antioxidant status and immunity of hens during heat stress. The results showed that diets supplement with 1% of either LL or SC had beneficial effects on egg production and FCR of hens during heat stress (p < 0.05), compared with the control group. Either LL or SC significantly reduced malondialdehyde (MDA) concentration of heart, liver, sera and egg yolk. In addition, glutathione reductase (GR) activity of tissues and sera of the birds was significantly elevated by supplementation LL or SC. Furthermore, LL or SC supplementation significantly elevated lymphoblastogenese of the birds and the antibody values against Newcastle disease virus (NDV). The results suggest that diets supplement with 1% of either LL or SC may enhance egg production, immune function, and antioxidant status of hens during heat stress.     

Effect of Ligustrum lucidum and Schisandra chinensis on the egg production, antioxidant status and immunity of laying hens during heat stress

The experiment was conducted to evaluate the effect of two plants belonging to Chinese herbal medicines, Ligustrum lucidum (LL) and Schisandra chinensis (SC), on the laying performance, antioxidant status and immunity of hens during heat stress. The results showed that diets supplement with 1% of either LL or SC had beneficial effects on egg production and FCR of hens during heat stress (p < 0.05), compared with the control group. Either LL or SC significantly reduced malondialdehyde (MDA) concentration of heart, liver, sera and egg yolk. In addition, glutathione reductase (GR) activity of tissues and sera of the birds was significantly elevated by supplementation LL or SC. Furthermore, LL or SC supplementation significantly elevated lymphoblastogenese of the birds and the antibody values against Newcastle disease virus (NDV). The results suggest that diets supplement with 1% of either LL or SC may enhance egg production, immune function, and antioxidant status of hens during heat stress.     

胚乳和外源赤霉素对五味子[Schisandra chinensis(Turcz.)Baill]种子发芽的影响

以组织培养和土壤播种的未经层积处理的五味子种子为材料,检测胚乳和外源赤霉素(GA3)对发芽影响的结果表明,在不加生长调节物质的MS培养基上,去掉外种皮带全胚乳的种子发芽率只有2.7%,而带1/2和1/3胚乳的种子发芽率则分别为46%和70.6%;培养基中添加GA3,可提高去掉外种皮带全胚乳和带1/2胚乳种子的发芽率,而对带1/3胚乳的种子则无效果.土壤播种时,用10～1000mg·L-1GA3对去掉外种皮种子进行1～10d前处理,其中100mg·L-1GA3前处理10d的发芽率最高,达到38.7%.     

Influence of pre-storage incubation on hatchability traits,thyroid hormones,antioxidative status and immunity of newly hatched chicks at two chicken breeder flock ages

Egg storage longer than 7 days is associated with negative effects on hatchability traits. Pre-storage incubation has been a suggested method to reduce the negative effects of long-term storage times by enhancing the developmental stage of the embryo and probably reducing the embryonic stress. The objective of the present study was to investigate the effects of pre-storage incubation and storage time on hatchability characteristics, chick quality and serum thyroid hormones, antioxidative properties and immunoglobulin Y (IgY) concentrations of newly hatched chicks at two breeder flock ages. A total of 8000 fertile eggs were obtained from two different ages of chicken breeder hens (Egyptian local cross, Inshas). Half of the eggs were collected from young breeder hens (28 weeks old) and the other half from old breeder hens (50 weeks old). In each breeder flock age, eggs were distributed in a completely randomized experimental design in a 2×4 factorial arrangement, with two storage periods (4 or 14 days) and four pre-storage incubation durations (0, 4, 6 or 8 h at 37.5°C). At 28 and 50 weeks of age, pre-storage incubation and its interaction with storage period influenced significantly the apparent fertility, hatchability of set eggs and hatchability of fertile eggs and this improvement in hatchability is attributed to the reduction in embryonic mortality (early, intermediate and late). Pre-storage incubation for 6 or 8 h elevated significantly the grade A chicks and reduced the grade B chicks in comparison with non-heated controls. Interestingly, for eggs stored for 14 days, pre-storage incubation for 6 or 8 h enhanced serum triiodothyronine, thyroxine, glutathione peroxidase activity, total antioxidant capacity and IgY concentrations significantly and decreased serum malondialdehyde concentration significantly in the newly hatched chicks. It could be concluded that pre-storage incubation enhanced the hatching results, improved the antioxidative properties, reduced lipid peroxidation and elevated the humoral immunity in the newly hatched chicks. Hence, several benefits might be gained by pre-storage incubation when fertilized eggs will be stored for long periods.     

Effects of dietary pyrroloquinoline quinone disodium on growth performance,carcass yield and antioxidant status of broiler chicks

Pyrroloquinoline quinone (PQQ), a putative essential nutrient and redox modulator in microorganisms, cell and animal models, has been recognized as a growth promoter in rodents. Growth performance, carcass yield and antioxidant status were evaluated on broiler chickens fed different levels of PQQ disodium (PQQ.Na₂). A total of 784 day-old male Arbor Acres (AA) broilers were randomly allotted into seven dietary groups: negative control group (NC) fed a basal diet without virginiamycin (VIR) or PQQ.Na₂; a positive control group (PC) fed a diet with 15 mg of VIR/kg diet; and PQQ.Na₂ groups fed with 0.05, 0.10, 0.20, 0.40 or 0.80 mg PQQ.Na₂/kg diet. Each treatment contained eight replicates with 14 birds each. The feeding trial lasted for 6 weeks. The results showed that chicks fed 0.2 mg PQQ.Na₂/kg diet significantly improved growth performance comparable to those in PC group, and the feed efficiency enhancement effects of dietary PQQ.Na₂ was more apparent in grower phase. Dietary addition of PQQ.Na₂ had the potential to stimulate immune organs development, and low level dietary addition (<0.1 mg/kg) increased plasma lysozyme level. Broilers fed 0.2 mg PQQ.Na₂/kg diet gained more carcasses at day 42, and had lower lipid peroxide malondialdehyde content and higher total antioxidant power in plasma. The results indicated that dietary PQQ.Na₂ (0.2 mg/kg diet) had the potential to act as a growth promoter comparable to antibiotic in broiler chicks.     

The impact of incorporation of n-3 fatty acids into eggs on ovarian follicular development, immune response, antioxidative status and tibial bone characteristics in aged laying hens

The objectives of this study were to investigate the effects of different dietary sources of unsaturated fatty acids (fish oil (FO) and/or linseed oil (LO)) on laying performance, egg yolk fatty acid composition, ovarian follicular development, antioxidative properties, immune response and tibial bone characteristics in aged laying hens. A total of 100 Hisex Brown hens at 56 weeks of age were housed individually in laying cages in an open-sided building under a 16 h light:8 h dark lighting schedule. Hens were randomly divided into four experimental treatments (n=25 each). Birds were fed ad libitum diets containing 2.5% vegetable oil (C, control), 2.5% FO, 2.5% LO and a mixture of 1.25% LO+1.25% FO (LO+FO) from 56 to 68 weeks of age. Egg production, egg quality characteristics and yolk lipid profile were analyzed. At 68 weeks of age, ovarian follicles were classified and tibial bone characteristics were determined. Serum thiobarbituric acid reactive substance (TBARS), glutathione peroxidase (GSH-Px) activity and total antioxidant capacity were measured. Incorporation of n-3 polyunsaturated fatty acids (n-3PUFA) into the egg yolks has been successful by using dietary FO and/or LO. There were no significant effects of treatments on hen-day egg production, feed intake, egg weight, egg shape index, albumen height, Haugh units and yolk height. However, dietary FO and/or LO supplementation had a significantly positive effect on eggshell percentage, eggshell thickness and yolk color. At 68 weeks of age, there was no significant difference among dietary treatments for tibial bone measurements. Also, no negative effects were detected in ovarian follicular development and weights of the ovary and oviduct, expressed in both absolute terms and relative to body weight. Dietary 2.5% LO, 2.5% FO and a mixture of 1.25% FO+1.25% LO enhanced GSH-Px activity, total antioxidant capacity and antibody titers significantly in comparison with control. It could be concluded that inclusion of mixed sources of n-3PUFA in diets at moderate levels (2.5%) increased the n-3PUFA content and decreased the n-6/n-3 ratio content in the yolk, improved the antioxidative status, reduced lipid peroxidation, enhanced the antibody response and did not have any negative influence on ovarian follicular development and tibial bone characteristics in aged laying hens.     

The effect of Boswellia serrata resin diet supplementation on production,hematological, biochemical and immunological parameters in broiler chickens

Boswellia serrata resin (BSR), exhibiting a variety of therapeutic properties, is applied in Asian traditional medicine. These properties can be used in poultry production as well. Application of the resin as a phytobiotic in broiler chicken rearing can increase the productivity and improve meat quality. However, the optimum and maximum levels of BSR in broiler diets need to be assessed. The study determined the effect of different levels of supplementation of BSR (directly derived, unprocessed) in diets for broiler chickens on the production traits, selected slaughter analysis parameters, nutrient digestibility and selected hematological, biochemical and immunological parameters. In total, 200 1-day-old broiler chickens were assigned randomly to four treatments with five replicate cages of 10 broiler chickens/cage (five females and five males). The experiment lasted 6 weeks, and the broiler chickens were fed diets containing 0% (control), 3% (BSR3), 4% (BSR4) or 5% (BSR5). In the broiler chickens receiving diets with addition of resin BSR3 and BSR4, there was an increase in (P<0.05) BW gain, ether extract, ADF, organic matter and energy digestibility of the diets. Moreover, the best carcass quality with a high proportion of muscles and low abdominal fat content (P<0.05) was noted in these groups. The content of uric acid (P<0.01) and the activity of aspartate aminotransferase (P<0.001) and alkaline phosphatase (P<0.05) in blood plasma decreased upon the BSR supplementation. Globulin content increased in blood plasma (P<0.05) along the increasing level of BSR. The blood immunoglobulin A concentration was only affected by the BSR treatments (P<0.05). It may be concluded that BSR can be regarded as a safe and effective dietary additive for broiler chicken.     

复合噬菌体裂解酶对白羽肉鸡肠道菌群结构和肝脏抗氧化酶指标的影响

【背景】噬菌体裂解酶具有良好的安全性与抑菌特性,有望替代抗生素作为一种饲料添加剂应用于改善畜禽肠道菌群和预防动物疾病。【目的】以白羽肉鸡为饲喂对象,分别饲喂复合噬菌体裂解酶与抗生素制剂,评估噬菌体裂解酶对畜禽肠道菌群的影响及其作为替抗饲料添加剂的应用潜能。【方法】以3日龄健康白羽肉鸡为饲喂对象,在基础饲粮上添加由噬菌体裂解酶TSPphg和噬菌体裂解酶MMPphg获得的复合噬菌体裂解酶制剂(200 mg/kg)与50μg/g的金霉素制剂,分别进行比较饲喂管理。利用第三代测序技术对28 d时白羽肉鸡肠道菌群进行高通量测序,借助生物信息学分析肠道菌群多样性和优势菌群(丰度前10)相对丰度,揭示各分组组间与组内差异,并对肝脏主要氧化酶活性进一步比较。【结果】饲喂复合噬菌体裂解酶和金霉素制剂对白羽肉鸡肠道菌群有一定影响,均降低了肠道菌群相对丰度与多样性,而且Shannon指数与空白组相比存在显著差异(P<0.05)。优势菌群中,复合噬菌体裂解酶组相较于金霉素组和空白组,拟杆菌门的相对丰度发生了显著上升,而厚壁菌门的相对丰度发生了显著下降(P<0.05)。同时,在属水平上,粪杆菌属的相...     

Effect of zinc supplementation on the antioxidant,copper, and iron status of physically active adolescents

Puberty associated with intense physical activity results in oxidation stress. Zinc supplementation may benefit antioxidant capacity although it may also affect iron and copper status. This study evaluated the effect of zinc supplementation on antioxidant, zinc and copper status of physically active male football players (13 years ± 0.4 years), divided in two groups and studied during 12 weeks: Zn‐supplemented (Zn‐SUP, 22 mg Zn d^?1 as zinc gluconate, n = 21) and placebo (PLA, n = 26). At baseline, there was no significant difference in biochemical indices between the two groups. After treatment, plasma zinc and erythrocyte iron increased in both groups (p < 0.001); urinary zinc increased (p < 0.001) only in Zn‐SUP, and erythrocyte zinc decreased (p = 0.002) only in PLA. Plasma iron and copper decreased (p = 0.01 and p = 0.015, respectively) only in Zn‐SUP. Plasma ferric‐reducing ability and plasma conjugated dienes increased, and erythrocyte osmotic fragility decrease in both groups, although the latter two were significantly lower in Zn‐SUP compared to PLA (p < 0.01). In conclusion, our study indicates that the use of 22 mg d^?1 of supplemental zinc during 12 week in adolescent athletes did not affect growth, improved markers of antioxidant status but reduced plasma iron and copper. Therefore, it appears that the use of zinc supplementation by healthy adolescent athletes benefits their antioxidant capacity but impairs copper and iron nutritional status. Copyright © 2009 John Wiley & Sons, Ltd.     

Effect of dietary supplementation of grape seed extract on the growth performance,lipid profile,antioxidant status and immune response of broiler chickens

Grape seed extracts (GSE) contain several beneficial bioactive constituents; therefore, can be utilized as a potential feed additive in broiler chickens. An experiment was conducted to investigate the effect of supplementation of broiler chicken diets with GSE as a natural antioxidant at levels of 125, 250, 500, 1000 and 2000 ppm on the growth performance, serum lipid profile, liver glutathione-reduced, thigh muscle malondialdehyde and humoral immune response against Newcastle disease virus vaccines. This experiment was performed during the life-span of chickens from 0 to 42 days of age. The results of broilers fed on diet supplemented by GSE were compared with those fed on the basal diet (control) or the basal diet supplemented by butylated hydroxytoluene as a synthetic antioxidant (BHT, 125 ppm). No significant differences were observed in the growth performance, percent livability, total lipid, high and very low-density lipoprotein cholesterols when the use of GSE or BHT were compared with the control. Total cholesterol and low-density lipoprotein cholesterol were significantly decreased after intake of GSE compared with BHT in the feed diet. The glutathione-reduced level in liver tissues was significantly increased by inclusion of GSE, but not by BHT. Inclusion of GSE or BHT decreased significantly the malondialdehyde level found in meat tissue. The antibody titer against Newcastle disease virus vaccines was significantly elevated in 28 and 35-day-old broiler chickens fed with a diet supplemented with GSE or BHT, the former providing a higher response. It can be concluded that GSE can be used as an effective natural antioxidant and immunostimulant agent in broiler chicken diets, and that 125 to 250 ppm can be considered as the optimum dosage.     

Effects of dietary 25-hydroxyvitamin D3 supplementation on growth performance,immune function and antioxidative capacity in weaned piglets

The study evaluated the effects of different doses of 25-hydroxyvitamin D₃ (25(OH)D₃) on growth performance, immune function and antioxidative capacity in piglets. In a 21-d trial, 35 weaned pigs were divided into five groups and diets were supplemented with 5.5 (control), 43.0, 80.5, 118.0 and 155.5 μg 25(OH)D₃/kg, respectively. No treatment effects were observed for average daily gain, average daily feed intake and feed to gain ratio. Increasing dietary 25(OH)D₃ levels increased serum 25(OH)D₃ concentrations linearly (p < 0.01), decreased the frequency of CD3+CD4+ and CD3+CD8+ T cells (p < 0.01), and the serum level of complement component 3 (p < 0.05). Supplementation of 80.5 and 118.0 μg 25(OH)D₃/kg enhanced the activity of serum glutathione peroxidase (p < 0.05) and addition of 43.0 μg 25(OH)D₃/kg increased the malondialdehyde concentration (p < 0.05). Overall, feeding high-dose 25(OH)D₃ to weaned pigs partly improved immune functions and the antioxidative capacity.     

Effect of dietary supplementation of Ligustrum lucidum on performance,egg quality and blood biochemical parameters of Hy-Line Brown hens during the late laying period

The fruit of Ligustrum lucidum (FLL, Nuzhenzi in Chinese) is an important traditional medicine, and have attracted significant research attention because of their various biological activities. However, there are few research reports available on the use of FLL as a feed additive in livestock nutrition, particularly in layers. This study was conducted to determine the effects of supplementation of the diet of laying hens with FLL on laying performance, egg quality and blood metabolites. A total of 360 72-week-old hens were allocated to three dietary treatments (eight replications of 15 hens/treatment group) and were fed either a control diet or a diet supplemented with an inclusion level of 0.25% or 0.50% of FLL powder in the final feed, until 78 weeks of age. Hens were housed in a three-tier cage system. Feed and water were provided ad libitum. Blood samples and eggs were collected at the end of the experiment. The results showed that dietary supplementation with FLL did not affect egg weight, feed conversion ratio, eggshell thickness, albumen height, egg yolk color, eggshell breaking strength or egg shape index. However, FLL supplementation significantly decreased (P<0.001) mortality, cracked-egg rate and blood serum levels of cholesterol, low-density lipoprotein cholesterol, triglycerides and alanine aminotransferase, and increased (P<0.001) blood serum levels of high-density lipoprotein cholesterol. No differences in serum levels of total protein, albumin, glucose, calcium, aspartate aminotransferase or alkaline phosphatase were observed in hens fed FLL compared with the control group. It can be concluded that FLL, at a supplementation level of 0.25% final feed, can be used as an effective feed additive to improve the performance of laying hens during the late laying period.     

Comparative effects of n-hexane and methanol extracts of elecampane (Inula helenium L.) rhizome on growth performance,carcass traits,feed digestibility,intestinal antioxidant status and ileal microbiota in broiler chickens

In this study, the effects of dietary methanol and n-hexane extracts of elecampane rhizome (MEER and HEER, respectively) on growth performance, apparent ileal nutrient digestibility (AID), ileal microbiota, intestinal morphology and antioxidant status of the intestinal mucosa were compared in broiler chickens. In total, 450 1-d-old male chicks were allotted into five groups in six replicates of 15 chicks each. Dietary treatments included: a control, control plus 500 or 1000 mg MEER per kg diet (MEER₅₀₀ and MEER₁₀₀₀) and control plus 500 or 1000 mg HEER per kg diet (HEER₅₀₀ and HEER₁₀₀₀). Broiler performance was not affected by dietary treatments during the starter and grower periods. However, in the finisher (25–42 d) and entire (1–42 d) periods, an increase in body weight gain and a corresponding decrease in feed conversion ratio was noticed when birds received Diets MEER₁₀₀₀ or HEER₁₀₀₀. Also, considering the entire trial, the growth-promoting action of MEER was found to be greater than HEER. When compared with the control, AID of dry matter, organic matter, ether extract (EE) and gross energy (GE) were increased by all treatments, while the AID of EE and GE were also improved by increased extract level. Additionally, HEER groups had significantly increased AID of crude protein. The counts of Escherichia coli and Clostridium spp. were suppressed while the number of Lactobacillus spp. increased in response to an elevated extract level. Meanwhile, the ileum of MEER groups contained lower numbers of Clostridium spp. and greater numbers of Lactobacillus spp. when compared with HEER groups. The duodenal and jejunal structures were not associated with dietary treatments. However, a decreased ileal crypt depth and an increased villus to crypt ratio were observed with addition of extracts, which was more intense with MEER. A lower malondialdehyde content and a higher activity of superoxide dismutase, catalase and glutathione peroxidase were detected in duodenal and jejunal mucosa with increased extract level, and in jejunum, the antioxidant capability of MEER was found to be stronger than HEER. The antioxidant properties of the ileal mucosa were also improved in response to MEER, which was not observed after HEER inclusion. Overall, MEER seems to be a better choice of treatment owing to its more effective benefits on broiler performance, ileal microbiota, gut morphology and antioxidant ability of the intestinal mucosa.     

Effect of different dietary energy and protein sources on antioxidant status,fresh yolk fatty acid profile and microstructure of salted yolks in laying ducks

The study investigated whether different dietary energy and protein sources affect laying performance, antioxidant status, fresh yolk fatty acid profile and quality of salted yolks in laying ducks. In all, 360 19-week-old Longyan ducks were randomly assigned to four diets in a factorial arrangement (2×2). The four diets consisted of two energy sources, corn (CO) or sorghum (SO) and two protein sources, soybean meal (SM) and rapeseed meal with corn distillers dried grains with solubles (RMD), and each treatment contained six replicates of 15 birds each. The experimental diets were isocaloric (metabolizable energy, 10.84 MJ/kg) and isonitrogenous (CP, 17%). The results showed that egg production, average egg weight, egg mass and feed conversion ratio were not affected by diets (P>0.05). Plasma contents of reduced glutathione (GSH), GSH/oxidized glutathione and total antioxidant capacity were lower (P<0.05) in ducks fed the RMD diets compared with those fed SM diets with a substantial increase (P=0.006) in plasma content of malondialdehyde (MDA). Egg yolks from ducks fed SO diets had higher proportions of polyunsaturated fatty acids (PUFA) and lower saturated and monounsaturated fatty acids compared with CO diets (P<0.001). Similarly, ducks fed RMD diets had a higher content of PUFA and n-6/n-3 ratio in fresh yolks (P<0.001), and increased salted yolk MDA, carbonylated proteins content and incidence of hard salted yolks (P<0.05) compared with SM diets. Scanning electron microscopy showed that salted yolks contained rougher polyhedral granules and fewer fat droplets, and were surrounded with a layer of bunchy fibers in ducks fed SO+RMD than those fed CO+SM diet. In conclusion, the current study showed that feeding laying ducks with diets containing SO or RMD reduced antioxidant capacity and increased egg yolk concentrations of PUFA. It appeared that egg yolks from ducks fed these diets were more sensitive to lipid peroxidation and protein oxidation during salting, and reduced the quality of salted yolks.     

The effect of Helicobacter pylori and economic status on growth parameters and leptin, ghrelin, and insulin-like growth factor (IGF)-I concentrations in children

Background: It was suggested that gastric colonization with Helicobacter pylori (H. pylori) was associated with suboptimal nutrition and growth in childhood. Furthermore, several studies indicated a relationship between H. pylori colonization and alterations in the circulating levels of growth‐related molecules (GRM). Accordingly, in this study, we investigate the effect of H. pylori infection on GRMs and on the growth of healthy school children, taking into consideration the effect of their economic status (ES) and anthropometric indices of their parents. Methods: To acquire sociodemographic and anthropometric nutritional parameters and to detect H. pylori‐specific serum IgG antibodies and growth‐related molecules, we evaluated a total of 473 children attending four different primary and secondary schools in Istanbul. Subsequently, we assessed the effect of H. pylori on growth‐related parameters (weight for age SDS, height for age SDS, BMI SDS, TSF, and waist‐to‐hip ratio) and on GRMs (leptin, ghrelin, and insulin‐like growth factor‐1 (IGF‐1)), controlling for age, gender, family income, household crowding (HC), breastfeeding, maternal and paternal BMI SDS, and midparental height SDS with complex statistical models. Results: Of the 473 children (275 F/198 M, age 6–15 years; mean: 10.3 ± 0.1 years), 161 (34%) were H. pylori‐positive. The prevalence of H. pylori was significantly higher in lower economic status (ES) groups, in children living in crowded houses, and in older age groups. Using simple statistical models, we did not find any significant associations between H. pylori infection and the growth parameters. However, in complex models for height for age SDS and for weight for age SDS, there was a significant interaction between H. pylori infection status and ES. Whereas in H. pylori‐positive subjects, mid‐income family children were both taller and heavier than the low‐income group, there was no such an association in H. pylori‐negative subjects. Among biochemical parameters, only ghrelin levels were associated with H. pylori infection in all models. Leptin levels were associated with HC in girls, whereas none of the parameters was significantly associated with leptin levels in boys. For IGF‐1 levels, for boys, age and maternal BMI, and for girls, age and HC were significantly associated with IGF‐1 levels. Conclusion: We suggest that H. pylori may impair growth significantly only in susceptible children where unfavorable socioeconomic conditions facilitate its action, probably through mechanisms, at least in part, involving growth‐related molecules.