Effects of a Lactobacillus salivarius mixture on performance, intestinal health and serum lipids of broiler chickens

Lactobacillus salivarius Ameliorates AFB1-induced hepatotoxicity via PINK1/Parkin-mediated mitophagy in Geese

Aflatoxin B1 (AFB1) is commonly found in feed ingredients and foods all over the world, posing a significant threat to food safety and public health in animals and humans. Lactobacillus salivarius (L. salivarius) was recorded to improve the intestinal health and performance of chickens. However, whether L. salivarius can alleviate AFB1-induced hepatotoxicity in geese was unknown. A total of 300 Lande geese were randomly assigned to five groups: control group, AFB1 low-dose group (L), L. salivarius+AFB1 low-dose group (LL), AFB1 high dosage groups (H), L. salivarius+AFB1 high dosage groups (LH), respectively. The results showed that the concentrations of ALT, AST, and GGT significantly increased after exposure to AFB1. Similarly, severe damage of hepatic morphology was observed including the hepatic structure injury and inflammatory cell infiltration. The oxidative stress was evidenced by the elevated concentrations of MDA, and decreased activities of GSH-Px, GSH and SOD. The observation of immunofluorescence, real-time PCR, and western blotting showed that the expression of PINK1 and the value of LC3II/LC3I were increased, but that of p62 significantly decreased after AFB1 exposure. Moreover, the supplementation of L. salivarius effectively improved the geese performance, ameliorated AFB1-induced oxidative stress, inhibited mitochondrial mitophagy and enhanced the liver restoration to normal level. The present study demonstrated that L. salivarius ameliorated AFB1-induced the hepatotoxicity by decreasing the oxidative stress, and regulating the expression of PINK1/Parkin-mediated mitophagy in the mitochondria of the geese liver. Furthermore, this investigation suggested that L. salivarius might serve as a novel and safe additive for preventing AFB1 contamination in poultry feed.

Effects of probiotics on productive performances and serum lipid profile of broiler as substitute of antibiotics

OBJECTIVES

The present research was accomplished to characterize probiotics from broiler gastrointestinal tract (GIT) by profiling biochemical, antimicrobial, and antibiotic sensitivity properties. Eventually, probiotic potentiality was evaluated as a substitute for antibiotic supplements in broiler focusing growth performance, carcass characteristics, and serum lipid profile.

METHODS

Probiotic bacteria were characterized based on morphological, physiological, and several biochemical tests. Antibacterial activity against a broad spectrum of antibiotics and bacterial pathogens was detected. An in vivo trial was conducted on 40-day-old Ross 308 broiler strains during 21 days in an in vivo trial. The chicks were divided into total of five groups, a control group and four experimental groups (Antibiotic1, Antibiotic2, Probiotic1, and Probiotic2) in a completely randomized design. Probiotic was supplemented in broiler feed (2× 109 CFU/g feed) or by direct oral gavage (1× 109 CFU/chick). The variables of production performance like body weight (BW), average daily gain (ADG), feed intake (FI), and feed conversion ratio (FCR), carcass characteristics and serum lipid profile were measured.

RESULTS

10 probiotic bacteria were presumptively identified as Lactobacillus sp. based on the morphological, physiological, and strong resistance properties in several biochemical tests. The mixture of Lactobacillus had favorable effects on productive performance of broilers regarding BW, ADG, and FCR (p < .05) compared with chickens that had no additive or had antibiotic during overall period of in vivo trial. Additionally, noteworthy efficacy on carcass characteristics and serum lipid profile were found (p < .05) in Lactobacillus mixture fed chicken groups of in vivo trial.

CONCLUSION

Mixed Lactobacillus sp. can be considered as a potential additive for broiler diet attributable to noteworthy efficacy on growth performance, carcass characteristics, and serum lipid profile. Accordingly, the research highlights the need for suitable alteration of antibiotics through probiotic characterization and proper inclusion in broiler diet.

Influence of Pediococcus pentosaceus GT001 on Performance, Meat Quality, Immune Function, Antioxidant and Cecum Microbial in Broiler Chickens Challenged by Salmonella typhimurium

This study evaluated the effects of Pediococcus pentosaceus GT001 on Salmonella typhimurium (S. typhimurium)-challenged broiler chickens. Two hundred Ross 708 broiler day-old chicks with comparable weight were distributed at random into four treatments with five replicates and ten chicks per replicate. The following were the treatment groups: (B) basal diet (control); (B + S) basal diet and birds were challenged with S. typhimurium at 1.0 × 107 cfu/g; (B + P) basal diet + Pediococcus pentosaceus GT001 at 4.0 × 108 cfu/g; (B + P + S) basal diet + P. pentosaceus GT001 at 4.0 × 108 cfu/g and birds were challenged with S. typhimurium at 1.0 × 107 cfu/g. There was a significant reduction (p < 0.05) in the body weight of the Salmonella-infected birds compared to the other treatment groups. However, the FCRs of the broilers were comparable among the different treatment groups (p > 0.05). The lipid profile and liver function indices measured were significantly enhanced in the P. pentosaceus GT001-supplemented groups (B + P and B + P + S) compared to the group that was Salmonella-challenged (p < 0.05) but were similar to those in the control group. The serum antioxidant activities, such as the T-AOC, SOD, CAT, GHS-Px and MDA, were significantly improved in the P. pentosaceus GT001-supplemented groups (B + P and B + P + S) (p < 0.05). The MDA was similar in the B + P and B + P + S groups, but both were significantly lower than the control and the Salmonella groups. The administration of P. pentosaceus GT001 enhanced the lipase and amylase levels in both the serum and intestine of the broilers (p < 0.05). The immunoglobin (IgA, IgG, IgM) and cytokine (IL-10 and IL-6) levels in the serum were significantly higher in the B, B + P and B + P + S treatment groups (p < 0.05). The immune-related organs (bursa and spleen) were significantly influenced in the birds fed with P. pentosaceus GT001. No significant variation was noted among all the dietary treatments in terms of the measured meat quality indices. The small intestinal digesta content of the Salmonella load was below a detectable range after 14 days of infection (p < 0.05). No significant differences were observed among the different treatment groups in terms of the breast pH, drip loss and meat color (p > 0.05). The inclusion of P. pentosaceus GT001 also modified the community structure in the cecum. This indicates that it has health benefits and could be incorporated in the broiler diet.

Systematic review on microbiome-related nutritional interventions interfering with the colonization of foodborne pathogens in broiler gut to prevent contamination of poultry meat

This systematic review aimed to compile the available body of knowledge about microbiome-related nutritional interventions contributing to improve the chicken health and having an impact on the reduction of colonization by foodborne pathogens in the gut. Original research articles published between 2012 and 2022 were systematically searched in Scopus and PubMed. A total of 1,948 articles were retrieved and 140 fulfilled the inclusion criteria. Overall, 73 papers described 99 interventions against colonization by Escherichia coli and related organisms; 10 papers described 15 interventions against Campylobacter spp.; 36 papers described 54 interventions against Salmonella; 40 papers described 54 interventions against Clostridium perfringens. A total of 197 microbiome-related interventions were identified as effective against one or more of the listed pathogens and included probiotics (n = 80), prebiotics (n = 23), phytobiotics (n = 25), synbiotics (n = 12), organic acids (n = 12), enzymes (n = 4), essential oils (n = 14) and combination of these (n = 27). The identified interventions were mostly administered in the feed (173/197) or through oral gavage (11/197), in the drinking water (7/197), in ovo (2/197), intra amniotic (2/197), in fresh or reused litter (1/197) or both in the feed and water (1/197). The interventions enhanced the beneficial microbial communities in the broiler gut as Lactic acid bacteria, mostly Lactobacillus spp., or modulated multiple microbial populations. The mechanisms promoting the fighting against colonization by foodborne pathogens included competitive exclusion, production of short chain fatty acids, decrease of gut pH, restoration of the microbiome after dysbiosis events, promotion of a more stable microbial ecology, expression of genes improving the integrity of intestinal mucosa, enhancing of mucin production and improvement of host immune response. All the studies extracted from the literature described in vivo trials but performed on a limited number of animals under experimental settings. Moreover, they detailed the effect of the intervention on the chicken gut without details on further impact on poultry meat safety.

Isolation and Identification of Chicken-Derived Lactic Acid Bacteria: In Vitro Probiotic Properties and Antagonistic Effects against Salmonella pullorum, Staphylococcus aureus, and Escherichia coli

The development of probiotics capable of quickly colonizing the intestines of animals is important in promoting the healthy growth of livestock. The aim of this study was to screen lactic acid bacteria (LAB) from the intestinal microbiota of chickens with potential applications, and to evaluate their probiotic properties and antagonistic abilities against Salmonella pullorum, Staphylococcus aureus, and Escherichia coli. The results showed that a total of 79 strains with the characteristics of LAB were isolated from the chicken cecum microbiota, of which 7 strains exhibited strong inhibitory activity against S. pullorum, S. aureus, and E. coli. Performing 16s rDNA sequencing revealed that these seven strains were Lactiplantibacillus pentosus (n = 1), Lactiplantibacillus plantarum (n = 3), Lactiplantibacillus paraplantarum (n = 1), Lactiplantibacillus argentoratensis (n = 1), and Lactiplantibacillus fabifermentans (n = 1). Among them, L. pentosus R26 and L. plantarum R32 exhibited superior antibacterial activity. These two strains demonstrated high lactic acid production ability, with survival rates of 86.29% and 87.99% after 3 h of treatment at pH 1.5, 86.66% and 85.52% after 3 h of treatment with 0.5% bile salts, 90.03% and 88.16% after 2 h of treatment with simulated gastric fluid, and 98.92% and 98.22% after 2 h of treatment with simulated intestinal fluid, respectively. Co-cultivation with L. pentosus R26 for 24 h resulted in 50% of the pathogens being antagonized, while almost complete inhibition was observed following 72 h of co-cultivation. In conclusion, L. pentosus R26 and L. plantarum R32 exhibited high antibacterial activity and acid production capability, while also demonstrating satisfactory tolerance to low pH values and high concentrations of bile salts and digestive fluid. The probiotic characteristics and stress resistance of L. pentosus R26 were slightly superior to those of L. plantarum R32, indicating its potential for development as a probiotic.

Stachyose in combination with L. rhamnosus GG ameliorates acute hypobaric hypoxia-induced intestinal barrier dysfunction through alleviating inflammatory response and oxidative stress

High altitude is closely related to intestinal mucosal damage and intestinal microbiota imbalance, and there is currently no effective prevention and treatment measures. In this study, the effects of stachyose (STA), L. rhamnosus GG (LGG) and their combination on inflammatory response, oxidatve stress and intestinal barrier function in mice exposed to acute hypobaric hypoxia were investigated. Our results indicated the combination of STA and LGG could more effectively regulate intestinal microbiota disorders caused by hypobaric hypoxia than STA or LGG alone. When mice were administered with STA + LGG, the content of short chain fatty acids (SCFAs) especially butyric acid significantly increased, which helped intestinal cells to form tight connections, improve the level of anti-inflammatory cytokine (TGF-β) and antioxidant enzymes (SOD, CAT, GSH-Px), and decrease the expression of pro-inlammatory cytokines and hypoxia-inducing factors (IFN-γ, IL-1β, IL-6, TNF-α and HIF-1α), thereby enhance the strong intestinal barrier function. Furthermore, the synbiotics significantly reduced the ratio of Firmicutes to Bacteroidetes, while significantly increased the relative abundance of Rikenella, Bacteroides, Odoribacter, Ruminiclostridium_5 and Gordonibacter, which were correlated with production of SCFAs and anti-inflammatory role. Correlation analysis showed that the protective effect of synbiotics on intestinal barrier function was associated with its anti-inflammatory activity and antioxidant capacity. It provided a strong foundation for further research on the role of STA and LGG in maintaining normal intestinal function at high altitude. Our study has identified and demonstrated a new synbiotic that may be one of the ideal intervention measures for preventing and treating intestinal dysfunction at high altitude.

Effect of Lactobacillus salivarius SNK-6 on egg quality, intestinal morphology, and cecal microbial community of laying hens

The objective of this study was to investigate the effect of Lactobacillus salivarius (L. salivarius) SNK-6 supple-mentation on the laying performance, egg quality, blood parameters, intestinal morphology, and cecal microbial community of laying hens. A total of 432 healthy 30-wk-age laying hens were randomly divided into 3 groups with 6 replicates under the same husbandry and dietary regimes: control (CON); 2.0 × 108 CFU/kg L. salivarius supplementation (T1); 2.0 × 109 CFU/kg L. salivarius supplementation (T2). The experiment lasted for 10 wk. The results indicated that the supplementation resulted in a significant reduction in the broken egg and unqualified egg ratios, and a significant increase in the eggshell strength, eggshell relative weight, albumen height, and Haugh units (P < 0.05). The L. salivarius-treated hens exhibited significantly reduced serum malondialdehyde levels (P < 0.05); significantly increased total protein, phosphorus, calcitonin, and immunoglobulin M (P < 0.05); significantly increased cecal secretory immunoglobulin A concentration (P < 0.05); significantly improved villus height (VH) in the duodenum and VH to crypt depth ratio in the jejunum (P < 0.05). The serum globulin and interleukin-1β, immunoglobulin G concentrations, and catalase activity significantly increased in T2 (P < 0.05). Furthermore, the serum interferon-α level in T1 was significantly higher than that of the CON (P < 0.05). The intestinal barrier-related mRNA gene ZO-1, CLDN1, and MUC2 expression in the jejunum was significantly upregulated in the T1 and T2 groups (P < 0.05). The Firmicutes/Bacteroidetes ratio was higher and the relative abundances of Flavonifractor and Clostridiales_noname were significantly higher in the T1 group (P < 0.05). In conclusion, dietary supplementation with L. salivarius SNK-6 may improve hen egg quality, serum antioxidant capacity, immune function, and intestinal health.

Integrated multi-omics reveals the roles of cecal microbiota and its derived bacterial consortium in promoting chicken growth

IMPORTANCE

The improvement of chicken growth performance is one of the major concerns for the poultry industry. Gut microbes are increasingly evidenced to be associated with chicken physiology and metabolism, thereby influencing chicken growth and development. Here, through integrated multi-omics analyses, we showed that chickens from the same line differing in their body weight were very different in their gut microbiota structure and host-microbiota crosstalk; microbes in high body weight (HBW) chickens contributed to chicken growth by regulating the gut function and homeostasis. We also verified that a specific bacterial consortium consisting of isolates from the HBW chickens has the potential to be used as chicken growth promoters. These findings provide new insights into the potential links between gut microbiota and chicken phenotypes, shedding light on future manipulation of chicken gut microbiota to improve chicken growth performance.

Assessing the effects of microencapsulated Lactobacillus salivarius and cowpea seed supplementation on broiler chicken growth and health status

This study aimed to assess the nutritional quality of cowpea seeds (cv. Doljana - CSD) and the impact of partially replacing soybean meal with CSD, along with the supplementation of microencapsulated Lactobacillus salivarius (LS), on the growth performance, selected carcass traits, biochemical plasma profile, tibia bone quality, and microbial populations in the ceca and excreta of broiler chickens aged 1 to 35 days. A total of 432 mixed-sex Ross 308 broiler chickens, aged one day, were randomly allocated to four groups, with 108 birds in each group, further divided into 6 pens containing 18 birds each. The experimental design featured a 2 × 2 factorial arrangement, with two cowpea seed levels (CSD0 and CSD15%) and the presence or absence (Yes/No) of microencapsulated LS probiotic (0 and 1 g/kg feed). The experimental diets did not significantly influenced (p > 0.05) production performances. However, the production efficiency factor was notably higher in the CSD0 (336.8%) and CSD15 (332.2%) groups with LS compared to CSD0 (322.4%) and CSD15 (320.6%) groups without LS supplementation. Regarding carcass traits, the CSD15 group with LS supplementation exhibited higher dressing (70.69%) and liver (2.47%) percentages compared to the other groups. Plasma profile analysis revealed significant reductions (p < 0.05) in total cholesterol (from 115 mg/dL to 105 mg/dL) and triglycerides (from 54.80 mg/dL to 46.80 mg/dL) in the CSD15 group with LS supplementation compared to the CSD0 group, with or without LS supplementation. Moreover, the CSD15 group with LS had significantly higher total protein, albumin, and calcium levels and significantly lower (p < 0.05) uric acid levels compared to the CSD0 group, irrespective of LS supplementation. Tibia bone traits and minerals showed no significant effects. However, the pH exhibited a linear decrease from 6.90 in the CSD0 group without LS to 6.69 in the CSD15 group with LS supplementation. In terms of cecal microbial populations, Coliforms decreased from 7.14 CFU/g in the CSD15 group without LS to 5.48 CFU/g in the CSD15 group with LS. Significant alterations were also observed in Clostridium spp., E. coli, Enterococcus spp., and Staphylococcus spp. in the ceca and excreta of the CSD15 group with LS supplementation compared to the CSD0 group, with or without LS supplementation. Beneficial bacteria, specifically Lactobacillus spp., significantly increased in the cecal content of CSD0 (9.06 CFU/g) and CSD15 (9.01 CFU/g) groups with LS compared to CSD0 (8.41 CFU/g) and CSD15 (8.11 CFU/g) groups without LS. In summary, this study suggests that cowpea seeds can be used as a partial replacement for soybean meal in broiler chicken diets, and microencapsulated Lactobacillus salivarius can be employed as a probiotic supplement.

Significance of Limosilactobacillus fermentum and Saccharomyces cerevisiae on the Growth Performance, Haematological Traits, Serum Biochemistry, Faecal and Caeca Microbiota of Broiler Chickens

OBJECTIVE

The aim of the study was to supplement Lactobacillus and yeast in broiler feed by replacing immunomodulators to develop antibiotic free meat and egg production by analyzing broiler performance, haematological traits, serum biochemistry, histopathology, fecal bacterial count, and metagenomic analysis of broiler ceca.

METHOD

Two cultures i.e. KGL4 (Limosilactobacillus fermentum MTCC 25515) and WBS2A (Saccharomyces cerevisiae GI: MG101828) were considered for the evaluation of Broiler chicken's health and growth during 42 days study without supplementing immunomodulators and commercial probiotics in poultry feeds. The 96-day-old broiler chickens were grouped into: T1 [Control: basal diet + immunomodulatory factor and commercial probiotic], T2 [Basal diet without immunomodulatory factor and commercial probiotic + KGL4 (108 CFU/mL), T3 [Basal diet without immunomodulatory factor and commercial probiotic + WBS2A (107 CFU/mL), and T4 [Basal diet without immunomodulatory factor and commercial probiotic + KGL4 + WBS2A in a 1:1 ratio] (Institutional Animal Ethics Committee (IAEC) No. 365/PRS/2022). The following parameters, i.e., body weight gain, feed consumption ratio (FCR), white blood cell count (WBC), red blood cell count (RBC), hemoglobin content, platelet count, cholesterol content, triglycerides, high density lipoprotein (HDL), very low-density lipoprotein (VLDL), fecal counts and metagenomic analysis of broiler ceca samples, were measured.

RESULTS

In the study, amongst various traits, the overall performance of the group treated along with Limosilactobacillus fermentum (KGL4) showed improved results as compared to control group. Limosilactobacillus fermentum (KGL4) treated group had higher body weight gain (2583.04 ± 35.421 g), FCR (1.60 ± 0.019), WBC (235.60 ± 2.562 × 103/µL), hemoglobin content (14.10 ± 0.442 g/dl), and HDL (131.40 ± 11.400 mg/dl). The investigation did not show significant variations in the relative proportions of genus or phylum among various groups during metagenomic analysis of ceca samples. There was also an improvement in haematological traits; no evidence of necrosis in heart, intestine and liver tissues.

CONCLUSIONS

The present study conclude that it is safe to feed Limosilactobacillus fermentum and Saccharomyces cerevisiae to broilers as feed supplements and also supports the current knowledge regarding the use of yeast and lactic acid bacteria as an effective alternative stimulant for maintaining health and growth of broiler chickens.

Effect of Different Feed Particle Size on Gastrointestinal Tract Morphology, Ileal Digesta Viscosity, and Blood Biochemical Parameters as Markers of Health Status in Broiler Chickens

The study is focused on how the physical structure of the feed affects the health status of broiler chickens. The aim of this study was to evaluate the influence of feed particle size in broiler diets on gastrointestinal tract morphology, digesta viscosity, and blood biochemical parameters. A total of 90 one-day-old male Ross 308 broiler chickens were randomly divided into three different experimental groups (with five replicates per pen), with 6 birds per cage. The first experimental group (Coarse) was fed with the coarsest particle size, with feed with a geometric mean diameter (GMD) of 1111.26 µm, the next group (Medium) was fed with a less coarse feed size of GMD 959.89 µm, and the last group (Fine) was fed a diet with a fine feed particle size of GMD 730.48 µm. The use of coarse feed particle size in the diet had a positive effect on the gizzard weight and small intestinal villi height and crypt depth, which increased the surface area intended for digesting nutrients. The use of finely ground particles in the feed increased the level of gamma-glutamyl transferase and at the same time, decreased the level of urea, which could indicate adverse changes in the liver.

Dietary Lactobacillus reuteri SL001 Improves Growth Performance, Health-Related Parameters, Intestinal Morphology and Microbiota of Broiler Chickens

It was assumed that dietary inclusion of Lactobacillus reuteri SL001 isolated from the gastric contents of rabbits could act as an alternative to feed antibiotics to improve the growth performance of broiler chickens. We randomly assigned 360 one-day-old AA white-feathered chicks in three treatments: basal diet (control), basal diet plus zinc bacitracin (antibiotic), and basal diet plus L. reuteri SL001 (SL001) treatment. The results showed the total BW gain and average daily gain (ADG) of broilers in SL001 treatment increased significantly (p < 0.05, respectively) compared with the control group from day 0 to 42. Moreover, we observed higher levels of immune globulins in both the SL001 group and the antibiotic group. Total antioxidant capacity and levels of antioxidant factors were also significantly increased (p ≤ 0.05, respectively) in the SL001 treatment group, while the interleukin 6, interleukin 4, creatinine, uric acid, total cholesterol, triglyceride, VLDL, LDL and malondialdehyde were remarkably decreased (p < 0.05, respectively). In the ileum of SL001 treatment broilers, the height of villi and the ratio of villi height to crypt depth were significantly increased (p < 0.05). Meanwhile, the crypt depth reduced (p < 0.01) and the ratio of villi height to crypt depth increased (p < 0.05) in the jejunum compared to the control. The abundance of microbiota increased in the gut of broilers supplemented with SL001. Dietary SL001 significantly increased the relative abundance of Actinobacteria in the cecal contents of broilers (p < 0.01) at the phylum level. In conclusion, L. reuteri SL001 supplementation promotes the growth performance of broiler chickens and exhibits the potential application value in the industry of broiler feeding.

Effects of dietary supplementation of probiotic and Spirulina platensis microalgae powder on growth performance immune response, carcass characteristics, gastrointestinal microflora and meat quality in broilers chick

BACKGROUND

With the potential development of human pathogenic bacteria resistant to antibiotics, the use of antibiotics as growth promoter in poultry production was banned in different countries, and it has forced the poultry industry to consider 'Biologically safer' alternatives to antibiotics, among which the probiotics and microalgae can be mentioned.

OBJECTIVE

Present study aimed to compare Spirulina platensis microalgae in combination with a native probiotic as an alternative to antibiotics.

METHODS

336 male broiler chicks were allotted into 7 treatments and 4 repetitions in a completely randomised design to evaluate chick's performance and immune response to different treatment based on indexes as feed intake, weight gain, feed conversion ratio, humoral immunity, carcass characteristics, thigh and breast pH, intestinal morphology and microbial population. European production efficiency coefficient was also reported.

RESULTS

No significant difference was appeared in the pH of thigh and breast meat (p > 0.05). Supplementation of diets with SP_0.3 revealed better villi height, villi length to crypt depth ratio and villi surface. With significant difference (p < 0.05), the highest and lowest colonies of Lactobacillus and E. coli were recorded for PR_0.5 SP_0.3 treatments.

CONCLUSIONS

Supplementation of broilers diets either with probiotic prepared from the microorganism isolated of native birds (1 g/kg) or S. platensis (0.2 g/kg) alone and their combination (0.3 g/kg of S. platensis in combination with 0.5 g/kg of native probiotic) are promising and can be a good alternative to antibiotics, lead to progress of broiler's performance.

A randomized pilot trial assessing the reduction of gout episodes in hyperuricemic patients by oral administration of Ligilactobacillus salivarius CECT 30632, a strain with the ability to degrade purines

Introduction

Hyperuricemia and gout are receiving an increasing scientific and medical attention because of their relatively high prevalence and their association with relevant co-morbidities. Recently, it has been suggested that gout patients have an altered gut microbiota. The first objective of this study was to investigate the potential of some Ligilactobacillus salivarius strains to metabolize purine-related metabolites. The second objective was to evaluate the effect of administering a selected potential probiotic strain in individuals with a history of hyperuricemia.

Methods

Inosine, guanosine, hypoxanthine, guanine, xanthine, and uric acid were identified and quantified by high-performance liquid chromatography analysis. The uptake and biotransformation of these compounds by a selection of L. salivarius strains were assessed using bacterial whole cells and cell-free extracts, respectively. The efficacy of L. salivarius CECT 30632 to prevent gout was assessed in a pilot randomized controlled clinical trial involving 30 patients with hyperuricemia and a history of recurrent gout episodes. Half of the patients consumed L. salivarius CECT 30632 (9 log₁₀ CFU/day; probiotic group; n = 15) for 6 months while the remaining patients consumed allopurinol (100-300 mg/daily; control group; n = 15) for the same period. The clinical evolution and medical treatment received by the participants were followed, as well as the changes in several blood biochemical parameters.

Results

L. salivarius CECT 30632 was the most efficient strain for inosine (100%), guanosine (100%) and uric acid (50%) conversion and, therefore, it was selected for the pilot clinical trial. In comparison with the control group, administration of L. salivarius CECT 30632 resulted in a significant reduction in the number of gout episodes and in the use of gout-related drugs as well as an improvement in some blood parameters related to oxidative stress, liver damage or metabolic syndrome.

Conclusion

Regular administration of L. salivarius CECT 30632 reduced serum urate levels, the number of gout episodes and the pharmacological therapy required to control both hyperuricemia and gout episodes in individuals with a history of hyperuricemia and suffering from repeated episodes of gout.

Effects of Lactobacillus plantarum and its Fermentation Products on Growth Performance, Immune Function, Intestinal pH and Cecal Microorganisms of Lingnan Yellow Chicken

The present research was conducted to investigate the effects of dietary supplementation of Lactobacillus plantarum and its fermentation products on growth performance, specific immune function, intestinal pH, and cecal microorganisms in yellow-feather broilers. A total of 1,200 yellow-feather broilers of similar weight and good health condition at 1 d of age were selected and randomly divided into 5 groups. The CK group was fed the basal diet, and the experimental group (I, II, III, IV) were supplemented with 0.1, 0.15% L. plantarum and 3, 4% L. plantarum fermentation products. The results showed that each treatment could improve the growth performance (P < 0.05) and feed conversion rate of yellow-feather broilers. Besides, the pH value of the gastrointestinal tract of yellow-feather broilers (P < 0.05) was significantly reduced through the use of L. plantarum and its fermentation products as additives, which also facilitated the animals to regulate the balance of cecal microorganisms. The immune function assay showed that the bursal index (P < 0.05), spleen index (P < 0.05), and the content of serum immunoglobulins IgA and IgG (P < 0.05) were significantly increased in yellow-finned broilers aged 1 to 21 d by supplementing the diet with L. plantarum. In conclusion, adding L. plantarum or its fermentation products to the diet can improve the growth performance of yellow-feather broilers, and the direct addition of L. plantarum is better than adding fermentation products.

Addition of a Blend Based on Zinc Chloride and Lignans of Magnolia in the Diet of Broilers to Substitute for a Conventional Antibiotic: Effects on Intestinal Health, Meat Quality, and Performance

This study aimed to determine whether adding a blend based on zinc chloride and lignans from magnolia to the diet of broilers could replace conventional performance enhancers. For this study, 360 chickens were divided into four groups, with six repetitions per group (n = 15), as follows: CN, without promoter; GPC, control, 50 mg/kg of enramycin growth promoter; T-50, additive blend at a dose of 50 g/ton; and T-100, additive blend at a dose of 100 g/ton. Chickens fed with the additive blend at 50 g/ton showed a production efficiency index equal to that in the GPC group (p < 0.05). At 42 days, the lowest total bacterial count (TBC) was found in the T-100 group, followed by that in the GPC group (p < 0.001). For E. coli, the lowest count was observed in the T-100 group, followed by that in the CP and T-50 groups (p < 0.001). Higher villus/crypt ratios were observed in birds belonging to the T-100 and T-50 groups than in the GPC and NC groups (p < 0.001). Greater water retention was found in the T-50 group than in NC and T-100 groups (p < 0.048). The lowest water loss during cooking was also noted in the T-50 group (p < 0.033). We concluded that adding the antimicrobial blend, primarily at 50 g/ton, maintains the efficiency of the index of production and improves the intestinal health and meat quality of the birds.

The Supplementation of FloraMax-B11 Did Not Affect the Bile Acid Neosynthesis and the Enterohepatic Circulation in Broiler Chickens

Most probiotics possess bile salt hydrolase enzymes and may increase bile acid excretion and negatively affect fat digestion and absorption. Therefore, the study objective was to determine the time course effects of a commercial probiotic (P) FloraMax-B11 (FM) supplementation on bile acid neosynthesis and enterohepatic circulation in broiler chickens. Fertile Ross 708 eggs were incubated under standard commercial conditions. At hatch, chicks (n = 550) were randomly assigned to 5 treatment groups (n = 5 replicates per treatment group) with 22 birds per pen. The 5 treatment groups consisted of: control group (C, normal water from hatch to 35 days of age without supplements); P3, water supplemented with FM for the first 3 days post-hatch followed by normal water until day 35; P10, water supplemented with FM for the first 10 days post-hatch followed by normal water until day 35; P35, water supplemented with FM from hatch to day 35; and AGP, water supplemented with antibiotic growth promoter (AGP) from hatch until day 35. Ileum, liver, and plasma were collected at hatch, days 3, 10, 21, and 35 post-hatch. The relative mRNA expression of genes involved in bile acid synthesis (CYP7A1, CYP8B1, FXR, FGFR4, and FGF19) and transport (ASBT, I-BABP, OSTα, OSTβ, and BSEP) as well as ileal deoxycholic acid and plasma cholic acid were determined. There was no FM and AGP interaction for any of the response criteria. No FM or AGP effects were observed (p > 0.05) for any genes, except FGF19, which expression was increased (p < 0.0001) in AGP compared to P35. No FM or AGP effects were observed (p > 0.05) for levels of deoxycholic and cholic acids. However, all the genes, deoxycholic acid, and plasma cholic acid were affected by age (p < 0.0001). In general, the data indicate that FM did not negatively impact bile acid metabolism and enterohepatic circulation, which appeared to be age dependent. However, more research should be conducted to confirm these results and investigate the effects of FM on bile acid metabolism, fat digestion, and intestinal microbiota in broiler chickens.

L-serine improves lipid profile, performance, carcass weight and intestinal parameters in feed restricted broiler chickens during the hot-dry season

The study evaluated effects of L-serine on lipid profile, performance, carcass weight and small intestinal parameters in heat-stressed broiler chickens subjected to feed restriction. Broiler chickens were divided into four groups, comprising 30 each. Group 1, feed restriction (FR); Group 2, feed restriction + L-serine (200 mg/kg) (FR + L-serine); Group 3, ad libitum (AL); Group 4, ad libitum + L-serine (200 mg/kg) (AL + L-serine). L-serine was administered orally from days 1 to 14, and feed restriction was performed on days 7-14. Serum harvested from blood samples on days 21, 28 and 35 was evaluated for lipid profile. Feed and water intake, live weight gain, organ and carcass weight were measured. At 35 days old, broiler chickens (n = 7) per group were sacrificed to evaluate small intestinal morphology. Temperature-humidity index in the pen (30.88 ± 0.81) was above thermoneutral zone, indicating that chickens were subjected to heat stress. Concentrations of low-density lipoprotein, total cholesterol and total triglycerides were lower (p < 0.05), while higher concentration of high-density lipoprotein was recorded in L-serine groups than in the controls. Feed intake and live weight gain on day 35 in L-serine groups were higher (p < 0.05) than in controls. In L-serine groups, liver, spleen, pancreas and heart weight were higher, but abdominal fat was lower than in FR and AL groups. Villus height:crypt height ratio and area of villus surface were highest in L-serine groups than any other group. In conclusion, L-serine decreased low-density lipoprotein, increased feed intake, live weight, organ and carcass weight, villus height:crypt height ratio and villus surface area.

Lactobacillus salivarius SNK-6 Activates Intestinal Mucosal Immune System by Regulating Cecal Microbial Community Structure in Laying Hens

The production performance and disease resistance of laying hens decrease obviously with age. This study aimed to investigate the effects of supplementary Lactobacillus salivarius (L. salivarius) SNK-6 on laying performance, the immune-related gene expression in cecal tonsil, and the cecal microbial composition of laying hens. Here, 384 Xinyang black commercial hens (55 weeks old) were randomly allocated to three groups under the same husbandry and dietary regimes: basal diet (Con), the low L. salivarius SNK-6 group (T1: 1.0 × 106 CFU/g), and the high L. salivarius SNK-6 group (T2: 1.0 × 107 CFU/g). The results showed that the feed intake and broken-egg rate in the T1 group were significantly higher than the Con group (p < 0.05). Meanwhile, expressions of intestinal mucosal immune-related genes were significantly upregulated. The 16S rRNA gene sequencing indicated that supplementary L. salivarius SNK-6 had no significant difference in α -diversity and only displayed a trend difference in the β-diversity of cecal microbiota (p = 0.07). LEfSe and random forest were further used to identify bacteria family Enterobacteriaceae, order RF39, genera Ochrobactrum, and Eubacterium as biomarkers between the Con and T1 groups. Genera Ochrobactrum, which had high relative abundance and nodal degree in the T1 and T2 groups, showed a significant positive correlation with the expression of TLR-6, IL-10, MHC-II, and CD40 in cecal tonsils and might play a critical role in activating the host intestinal mucosal immune responses. Overall, dietary supplementary L. salivarius SNK-6 can display an immunomodulatory function, possibly by regulating cecal microbial composition. However, the changes in immune responses may be at the expenditure of corresponding production performance, which needs to be weighed up in practical application.

Effect of Dietary Supplementation of Bacillus subtilis on Growth Performance, Organ Weight, Digestive Enzyme Activities, and Serum Biochemical Indices in Broiler

This study was conducted to investigate the effects of supplementing Bacillus subtilis and an antibiotic (Zinc bacitracin) in the diet of broilers on growth performance, organ weight, blood metabolites, and digestive enzymes of broiler chickens. A total of 600 1-d Arbor Acres broilers were randomly allotted to five treatments. Each treatment consisted of six replicates with four pens, and each pen had five birds. The chicks were fed (1) the basal diet (control), (2) the basal diet with 500 mg/kg Zinc bacitracin (APZ), (3) the basal diet with B. subtilis at 1 × 108 CFU/g (B.Sut-1), (4) the basal diet with B. subtilis at 3 × 108 CFU/g (B.Sut-3), and (5) the basal diet with B. subtilis at 5 × 108 CFU/g (B.Sut-5). The experiment lasted for 42 days. In this study, the supplementation of diets with B. subtilis (B.Sut-3 and B.Sut-5 groups) increased body weight gain from 1 to 21 days compared with control (p < 0.05). Additionally, the B.Sut-3 group had a significantly heavier bursa of Fabricius than control at 21 days (p < 0.05). Serum total protein, albumin, and high-density lipoprotein concentrations were increased in B.Sut-5 and APZ groups (p < 0.05) over the whole period. Serum low-density lipoprotein, very low-density lipoprotein, triglyceride, and total cholesterol concentrations were decreased in B.Sut-5 and APZ groups at 21 and 42 days (p < 0.05). Chicks in the B.Sut-5 and APZ groups had higher serum lipase, pepsin, and amylase activities (p < 0.05) at 21 and 42 days. From the results obtained from the study, it can be concluded that Bacillus subtilis ATCC19659 at 5 × 108 CFU/g could be applied as an alternative to antibiotics in poultry diets.

Bifidobacterium animalis ssp. lactis MG741 Reduces Body Weight and Ameliorates Nonalcoholic Fatty Liver Disease via Improving the Gut Permeability and Amelioration of Inflammatory Cytokines

Diet-induced obesity is one of the major causes of the development of metabolic disorders such as insulin resistance and nonalcoholic fatty liver disease (NAFLD). Recently, specific probiotic strains have been found to improve the symptoms of NAFLD. We examined the effects of Bifidobacterium animalis ssp. lactis MG741 (MG741) on NAFLD and weight gain, using a mouse model of high-fat-diet (HFD)-induced obesity. HFD-fed mice were supplemented daily with MG741. After 12 weeks, MG741-administered mice exhibited reduced fat deposition, and serum metabolic alterations, including fasting hyperinsulinemia, were modulated. In addition, MG741 regulated Acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS), sterol regulatory element-binding protein 1 (SREBP-1), and carbohydrate-responsive element-binding protein (ChREBP) expression and lipid accumulation in the liver, thereby reducing the hepatic steatosis score. To determine whether the effects of MG741 were related to improvements in gut health, MG741 improved the HFD-induced deterioration in gut permeability by reducing toxic substances and inflammatory cytokine expression, and upregulating tight junctions. These results collectively demonstrate that the oral administration of MG741 could prevent NAFLD and obesity, thereby improving metabolic health.

Caraway (Carum carvi L.) in Fast-growing and Slow-Growing Broiler Chickens’ Diets and its Effect on Performance, Digestive Tract Morphology and Blood Biochemical Profile

The aim of this study was to evaluate the addition of caraway (1%) in fast-growing and slow-growing broiler chickens’ diet and its effect on performance parameters, blood biochemical profile, and relative organ sizes and ileum morphology in slow-growing broilers. Two separated experiments were performed. On the first day of age, the broilers were divided into 2 equal groups (Control and Caraway) with 6 replicates per treatment in both experiments. Experiment I: The total of 276 male fast-growing Ross 308 broiler chickens were used. The trial lasted from the first day to 35th day of chickens’ age. Experiment II: The total of 216 male slow-growing (Hubbard JA 57) broilers were used. The trial lasted from the first to 50th day of chickens’ age. Mean liveweight, weight gain, feed conversion ratio, blood biochemical parameters, and relative organ sizes were not significantly different in these trials. The group of slow-growing broilers supplemented with 1% of caraway in the diet showed longer villi and deeper crypt in the ileum after 50 d of life. Based on our results, it can be stated that the proportion of 1% caraway in fast-growing and slow-growing broiler chickens’ diet did not influence performance parameters, blood biochemical profile and relative organ sizes. In case of the experiment with the slow-growing broilers supplemented with caraway, a significant difference in the height of the villi and the depth of the crypts was found. Caraway can be included in the broiler chickens’ diets without negative effects, but further study of the effect on the intestinal morphology is necessary.

A novel Lactobacillus bulgaricus isolate can maintain the intestinal health, improve the growth performance and reduce the colonization of E. coli O157:H7 in broilers

1. This study aimed at the effects of a novel Lactobacillus bulgaricus (L. bulgaricus) strain and Enterohemorrhagic Escherichia coli (E. coli) O157: H7 on intestinal flora and growth performance of broilers, and the protective effect of L. bulgaricus on broilers in challenged experiment by E. coli O157: H7.2. In vitro bacteriostatic test showed that the cell-free supernatant (CFS) of L. bulgaricus isolate had obvious inhibitory effect on E. coli O157: H7.3. Eighty 1-day-old male broilers were randomly assigned into 4 treatment groups with 4 replicate per treatment. All group received basic diet in addition to the specific treatments: NC group, gavage with normal saline; In LBP group, gavage with L. bulgaricus isolate (1×10⁹ CFU/mL) during the whole process, and challenged with E. coli O157: H7 (3×10⁹ CFU/mL); EC group, gavage with E. coli O157: H7 (3×10⁹ CFU/mL); LB Group, gavage with L. bulgaricus isolate. At the age of 21 days, broilers were weighed and feed conversion ratio (FCR) was calculated. Cecum and cecal contents, ileum and feces samples were taken after slaughter.4. The challenge of E. coli O157: H7 resulted in an increase in TLR-4, NF-κB and IL-8 mRNA in cecal tissue, a decrease in Villus: crypt ratio in ileum, a decrease in overall diversity of intestinal microflora and a poor FCR.5. The L. bulgaricus isolate decreased the mRNA expression of TLR-4, NF-κB and IL-8 induced by E. coli O157: H7, reduced the content of E. coli O157: H7 in the cecum of broilers, increased the Villus: crypt ratio, increased the abundance of beneficial bacteria and overall diversity of intestinal microflora, made good FCR.6. The L. bulgaricus isolate can maintain the intestinal health, improve the growth performance of broilers and reduce the colonization of E. coli O157:H7 in the cecum.

Feeding Bacillus subtilis ATCC19659 to Broiler Chickens Enhances Growth Performance and Immune Function by Modulating Intestinal Morphology and Cecum Microbiota

This study investigated dietary supplementation with Bacillus subtilis (BS) ATCC19659 on growth performance, biochemical indices, intestinal morphology, and cecum microflora in broiler chicks. A total of 600 Arbor 1-day Acres broilers of either sex were allotted to 5 treatments: chicks were fed a corn- and soybean-based diet (CON); chicks were fed basal diet containing 500 mg ZnB/kg (ZnB); chicks were fed basal diet containing 1 × 10⁸ CFU/g feed of BS-ATCC19659 (BS-1); chicks were fed basal diet containing 3 × 10⁸ CFU/g feed of BS-ATCC19659 (BS-3); and chicks were fed basal diet containing 5 × 10⁸ CFU/g feed of BS-ATCC19659 (BS-5). Each treatment comprised 6 replicates with 20 birds for each replicate pen. Chicks in the BS-5 and BS-3 groups had higher body weight at the 21^st and 42^nd days and average daily gain from 1 to 21 days than that in the CON group (p < 0.05). Chicks in the BS-5 and ZnB groups had higher serum antioxidant activities and immunity response than those in the CON group (p < 0.05). Compared with the CON group, the liver mRNA abundance of GHR, TGF-β, IGF-1, IFN-γ, SOD, CAT, and GPX of chicks in three BS groups and the ileum villus length (μm) of chicks in BS-3 and ZnB groups was increased (p < 0.05). Compared with the CON group, the villus height-to-crypt depth ratio of the ileum of chicks in the BS-5 and BS-3 groups and the crypt depth and villus height-to-crypt depth ratio of the jejunum in the BS-5 and ZnB groups were increased (p < 0.05). The abundance of the Cyanobacteria phyla in the cecum decreased in response to treatment with both BS-ATCC19659 and ZnB groups (p < 0.05). Compared with the CON group, the cecum abundance of genera GCA-900066575 (Lachnospiraceae), Anaerofustis, and Papillibacter (Firmicutes phylum) in three BS groups were increased (p < 0.05); The abundance of genus Escherichia–Shigella reduced in the BS-3 group (p < 0.05). Compared with the CON group, the cecum abundance of genus Clostridia_unclassified in ZnB and BS-5 groups was decreased (p < 0.05) of broilers. Generally, Bacillus subtilis ATCC19659 as feed additive positively affected growth performance, immunity response, and cecal microflora of broilers.

Intestinal Microbiota and Host Cooperate for Adaptation as a Hologenome

Multiomic analyses reported here involved two lines of chickens, from a common founder population, that had undergone long-term selection for high (HWS) or low (LWS) 56-day body weight. In these lines that differ by around 15-fold in body weight, we observed different compositions of intestinal microbiota in the holobionts and variation in DNA methylation, mRNA expression, and microRNA profiles in the ceca. Insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1) was the most upregulated gene in HWS ceca with its expression likely affected by the upregulation of expression of gga-miR-2128 and a methylated region near its transcription start site (388 bp). Correlation analysis showed that IGF2BP1 expression was associated with an abundance of microbes, such as Lactobacillus and Methanocorpusculum. These findings suggest that IGF2BP1 was regulated in the hologenome in adapting to long-term artificial selection for body weight. Our study provides evidence that adaptation of the holobiont can occur in the microbiome as well as in the epigenetic profile of the host. IMPORTANCE The hologenome concept has broadened our perspectives for studying host-microbe coevolution. The multiomic analyses reported here involved two lines of chickens, from a common founder population, that had undergone long-term selection for high (HWS) or low (LWS) 56-day body weight. In these lines that differ by around 15-fold in body weight, we observed different compositions of intestinal microbiota in the holobionts, and variation in DNA methylation, mRNA expression, and microRNA profiles in ceca. The insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1) was the most upregulated gene in HWS ceca with its expression likely affected by a methylated region near its transcription start site and the upregulation of expression of gga-miR-2128. Correlation analysis also showed that IGF2BP1 expression was associated with the abundance of microbes, such as Lactobacillus and Methanocorpusculum. These findings suggest that IGF2BP1 was regulated in the hologenome in response to long-term artificial selection for body weight. Our study shows that the holobiont may adapt in both the microbiome and the host's epigenetic profile.

Ameliorative effects of Lactobacillus against Aflatoxin B1

Lactobacilli are probiotics with Aflatoxin (AF) detoxification ability, found in fermented products, GIT of animals and environment. Purpose of this study was to investigate the ability of broiler isolates of Lactobacillus against Aflatoxin B1 (AFB1). For this purpose, 5 isolates of Lactobacillus from broiler gut were incubated with 100 ppb AFB1 in aqueous environment and effect of different parameters (cell fractions, time, temperature, pH) on detoxification was determined by HPLC. The ameliorative effect of Lactobacillus salivarius (LS) against AFB1 was studied in broiler. The results revealed that LS (CR. 4) showed the best results (in vitro) as compared to other isolates (L. salivarius (CR. 3, CR, 4), L. agilis (CE. 2.1, CE. 3.1) and L. crispatus (CE. 28). Cell debris of CR. 4 showed significantly higher detoxification (P<0.05). Maximum amount of AFB1 was detoxified at 30°C (97%), pH 4.0 (99%) and 6 h (99.97%). In vivo study showed that AFB1 decreased weight gain (1,269 ± 0.04 gm/ bird), feed consumed (2,161 ± 0.08 gm/ bird), serum total protein (2.42 ± 0.34 gm/ dl), serum albumin (0.5 ± 0.2 2 gm/dl) and antibody titer (4.2 ± 0.83). Liver function enzymes were found (alanine transaminase (ALT): 32 ± 10.7 U/L) and aspartate transaminase (AST): 314.8 ± 27 U/L) elevated in AFB1 fed broilers. Treatment with 1% LS not only decreased the toxic effects of AFB1 (group D) but also improved the overall health of broilers due to its probiotic effects (p<0.05) as compared to control negative (group A). The detoxification ability of LS was better than commercial binder (CB) (0.2% Protmyc). It was concluded that detoxification of AFB1 by Lactobacillus was strain, temperature, pH and time dependent. LS has detoxification ability against AFB1 in vivo.

Effectiveness of Bacillus licheniformis-Fermented Products and Their Derived Antimicrobial Lipopeptides in Controlling Coccidiosis in Broilers

Simple Summary

Coccidiosis is an important health problem in broilers, caused by infection with a highly contagious intestinal parasite of the genus Eimeria. Anti-coccidial drugs are widely used for the prevention of coccidiosis in broilers. However, multi-resistance coccidia is a potential threat to poultry production. In this study, we evaluated the potential of Bacillus licheniformis-fermented products (BLFP) and their derived antimicrobial lipopeptide, surfactin, on the prevention of coccidiosis in broilers. Results demonstrate that BLFPs and their derived antimicrobial lipopeptide, surfactin, exhibit anti-coccidial activity in vitro and in vivo.

Abstract

This study aimed to investigate the potential of Bacillus licheniformis-fermented products (BLFP) and their derived antimicrobial lipopeptide, surfactin, for the prevention of coccidiosis in broilers. Broilers were fed BLFP at 1.25 and 5 g/kg under Eimeria tenella challenge. At the end of experiment (35 days), the growth performance, survival rate, cecal morphology, cecal lesion scores, oocyst-count index, and anti-coccidial index were analyzed. The effects of the BLFP-derived surfactin on oocyst sporulation and sporozoite morphology in Eimeria species were also investigated in vitro. Results showed that BLFP supplementation at 1.25 and 5 g/kg improved cecal morphology and increased the survival rate of broilers under E. tenella challenge. Supplementation with 1.25 g/kg of BLFP reduced the lesion scores in the cecum of E. tenella-challenged broilers, while the oocyst-count index was reduced in broilers given 5 g/kg of BLFP. The anti-coccidial index of the 1.25 g/kg of BLFP-treated group was greater than 160, compared with the E. tenella-challenge-only group. Furthermore, surfactin inhibited Eimeria oocyst sporulation and disrupted sporozoite morphology. These results demonstrate that BLFPs and their derived antimicrobial lipopeptide, surfactin, exhibit anti-coccidial activity in vitro and in vivo. BLFP may be used as a natural feed additive for the prevention of coccidiosis in broilers, and 1.25 g/kg can be considered the optimum dosage.

Effects of Lactobacillus plantarum on growth traits, slaughter performance, serum markers and intestinal bacterial community of Daheng broilers

Probiotics are expected to be an ideal alternative for antibiotics in the poultry industry. This study aimed to investigate the effect of Lactobacillus plantarum on growth traits, slaughter performance, serum markers and intestinal bacterial community of Daheng broilers. A total of 2400 healthy one-day-old Daheng broilers were randomly divided into 5 groups with 6 replicates per group and 40 individuals per replicate. Birds in control group were fed a basal diet, and others were fed basal diets supplemented with 10⁵ , 10⁶ , 10⁷ and 10⁸  CFU/kg Lactobacillus plantarum, respectively. It turned out that adding Lactobacillus plantarum to diet could significantly improve the serum immune performance of broilers (p < 0.05), enhance the antioxidant capacity to a certain extent (p > 0.05), but had no significant effect on growth traits and slaughter performance. Moreover, Lactobacillus plantarum could improve the diversity of intestinal bacterial community, but with the increase of addition concentration, the diversity would gradually decrease. In conclusion, Lactobacillus plantarum can be used as feed additive in broiler production, but whether it is more effective than antibiotics needs further investigation.

Probiotics: an Antibiotic Replacement Strategy for Healthy Broilers and Productive Rearing

Pathogens develop resistance to antibiotics at a rate much faster than the discovery of new antimicrobial compounds. Reports of multidrug-resistant bacteria isolated from broilers, and the possibility that these strains may spread diseases amongst humans, prompted many European countries to ban the inclusion of antibiotics in feed. Probiotics added to broiler feed controlled a number of bacterial infections. A combination of Enterococcus faecium, Pediococcus acidilactici, Bacillus animalis, Lactobacillus salivarius and Lactobacillus reuteri decreased the colonisation of Campylobacter jejuni and Salmonella Enteritidis in the gastro-intestinal tract (GIT) of broilers, whereas Bacillus subtilis improved feed conversion, intestinal morphology, stimulated the immune system and inhibited the colonisation of Campylobacter jejuni, Escherichia coli and Salmonella Minnesota. Lactobacillus salivarius and Pediococcus parvulus improved weight gain, bone characteristics, intestinal morphology and immune response, and decreased the colonisation of S. Enteritidis. Lactobacillus crispatus, L. salivarius, Lactobacillus gallinarum, Lactobacillus johnsonii, Enterococcus faecalis and Bacillus amyloliquefaciens decreased the Salmonella count and led to an increase in lysozyme and T lymphocytes. Probiotics may also improve feed digestion through production of phytases, lipases, amylases and proteases or stimulate the GIT to secrete digestive enzymes. Some strains increase the nutritional value of feed by production of vitamins, exopolysaccharides and antioxidants. Bacteriocins, if produced, regulate pathogen numbers in the GIT and keep pro-inflammatory and anti-inflammatory reactions in balance.

Modulatory Effects of Bacillus subtilis on the Performance, Morphology, Cecal Microbiota and Gut Barrier Function of Laying Hens

We investigated the efficacy of a single bacterium strain, Bacillus subtilis (B. subtilis) YW1, on the performance, morphology, cecal microbiota, and intestinal barrier function of laying hens. A total of 216 28-week-old Hy-line Brown laying hens were divided into three dietary treatment groups, with six replicates of 12 birds each for 4 weeks. The control group (Ctr) was fed a basal diet and the treatment groups, T1 and T2, were fed a basal diet supplemented with B. subtilis at a dose rate of 5 × 108 CFU/kg and 2.5 × 109 CFU/kg, respectively. Dietary supplementation with B. subtilis did not significantly affect overall egg production in both groups, with no obvious changes in average egg weight and intestine morphology. B. subtilis administration also improved the physical barrier function of the intestine by inducing significantly greater expression levels of the tight junction protein occludin in T1 (p = 0.07) and T2 (p < 0.05). Further, supplementation with B. subtilis effectively modulated the cecal microbiota, increasing the relative level of beneficial bacteria at the genus level (e.g., Bifidobacterium p < 0.05, Lactobacillus p = 0.298, Bacillus p = 0.550) and decreasing the level of potential pathogens (e.g., Fusobacterium p < 0.05, Staphylococcus p < 0.05, Campylobacter p = 0.298). Overall, B. subtilis YW1 supplementation cannot significantly improve the egg production; however, it modulated the cecal microbiota towards a healthier pattern and promoted the mRNA expression of the tight junction protein occludin in laying hens, making B. subtilis YW1 a good probiotic candidate for application in the poultry industry, and further expanding the resources of strains of animal probiotics.

Disequilibrium in chicken gut microflora with avian colibacillosis is related to microenvironment damaged by antibiotics

The avian colibacillosis outbreak is a disease that threatens public health, poultry production, and economic interests, even after antibiotic feed addition. It is known that avian pathogenic E. coli is a major pathogenic factor; however, the systemic characteristics of gut flora in disease samples and how pathogens grow remain unknown. To study these issues in depth, we used the whole microbial genome shotgun sequencing technique to compare entire microbes in diseased and healthy broiler chickens. We found that it was not only E. coli that increased substantially, but most pathogenic flora also increased significantly in diseased samples. Subsequently, we proved that aminoglycoside antibiotic resistance genes were mainly found in non-E. coli strains. This suggests that E. coli survival under antibiotic stress was due to the cooperative resistance from non-E. coli strains. Among all these increasing strains, attaching and effacing pathogens could damage host intestinal epithelial cells to release oxygen in the gut to make the microenvironment more adaptable for E. coli strains. Furthermore, we observed that the functions of the T4SS/T6SS secretion system were dramatically enhanced, which could help E. coli to compete and enlarge their living spaces. Ultimately, pathogenic E. coli accumulated to cause avian colibacillosis. This study provides a new insight into intestinal microecology in diseased individuals, which would propose new treatment options for avian colibacillosis from a metagenome perspective.

An appraisal of the gut health modulatory effects of a calf faecal-origin probiotic Lactobacillus salivarius CPN60 using Wistar rats with dextran sulfate sodium-induced colitis

BACKGROUND

Probiotics of varied origins are being developed for augmenting the gut health of human and animals. The present study aimed to evaluate the effect of a calf-origin probiotic supplement on the gut health of Wistar rats for both healthy and colitis conditions.

RESULTS

Forty-eight rats were randomly distributed into four equal groups. The 42-day study involved feeding basal diet alone (CON) or diet supplemented with the calf-origin Lactobacillus salivarius strain CPN60 (PRO). The third (CONc) and fourth (PROc) groups of rats also received the same dietary treatments (CON and PRO, respectively) but were subjected to dextran sulfate sodium (DSS)-induced colitis after 32 days of feeding. The results of a digestion trial conducted after 5 days of DSS administration revealed no influence of probiotic on the digestibility of nutrients. However, the reduced digestibility of protein and fat seen in the CONc rats was improved in the PROc group. The concentrations of lactate and acetate, propionate and butyrate, as well as total short-chain fatty acids (SCFA), were increased (P < 0.05) in the caecal and colonic digesta upon probiotic supplementation, together with significantly reduced colonic ammonia levels. Furthermore, there were reductions (P < 0.05) in acetate, butyrate and total SCFA levels in the caecal contents as a result of colitis. Probiotic supplementation increased (P < 0.05) lactobacilli and bifidobacteria counts in the colon, whereas clostridia and coliform counts were reduced (P < 0.05). These were reversed by the probiotic supplementation.

CONCLUSION

Dietary supplementation of L. salivarius CPN60 had a positive effect with respect to improving the overall gut health of healthy rats, as well as that of rats exposed to experimental colitis. © 2020 Society of Chemical Industry.

Assessment of novel probiotic strains on growth, hematobiochemical parameters, and production costs of commercial broilers in Bangladesh

Background and Aim:

The use of antibiotic growth promoters (AGPs) in the poultry industry has raised concern because of their potential harm to human health. Emerging evidence suggests that probiotics are a safer substitute, although little research has explored this in Bangladesh. We recently isolated local bacterial strains with probiotic properties. We aimed to determine their impact on the growth, hematobiochemical parameters, and production costs of broiler chicks relative to that of a commercial probiotic (CP) and AGP.

Materials and Methods:

Day-old male broiler chicks (Cobb 500, n=63) were divided equally into three experimental groups (three replicates per group and seven chicks per replicate). First group was fed a basal diet supplemented with the AGP, ciprofloxacin (CTL group), second group was fed a basal diet supplemented with the CP, Protexin^® (CP group), and the third group was fed a basal diet supplemented with our isolated bacterial strains (study probiotic [SP] group) for 36 days. Body weight was recorded daily, and relative growth rate (RGR), feed conversion ratio (FCR), and organ weights and carcass yields were calculated at the study’s end. Blood obtained on day 36 was used to determine the number of red blood cell (RBC) and white blood cells (WBCs), hemoglobin (Hb) concentration, packed cell volume, erythrocyte sedimentation rate, as well as levels of serum glucose, total and high-density lipoprotein (HDL) cholesterol, and triglycerides (TGs). Total production costs were estimated by summing the variable and fixed costs.

Results:

Chicks in both the CP and SP groups experienced significant decreases in blood glucose levels and significant increases in BW, RGR, FCR, levels of RBC and WBC, Hb concentration, and packed cell volume compared with those in the CTL group (p<0.05 for all). Our data suggested a numerical reduction (p>0.05) in levels of total cholesterol, TGs, and HDL in the SP and CP groups when compared to the CTL group. In addition, both CP and SP treatments resulted in significant (p<0.05) gains in net profit compared with the treatment given to the CTL group.

Conclusion:

Administration of probiotics, either from a commercialized or local source, led to greater improvements in growth, hematological parameters, and net profits of broiler chicks when compared with that of an AGP. This suggests that they are suitable alternatives to the AGPs used in poultry feed and that our isolated strains, in particular, are an ideal option for farmers in Bangladesh.

Effects of Mesobiliverdin IXα-Enriched Microalgae Feed on Gut Health and Microbiota of Broilers

Gut inflammatory bowel diseases (IBDs) links to animal medicinal feed and antibiotic-resistance are fueling major economic impacts in the agricultural livestock industry. New animal feeds that promote livestock gut health and control of IBDs without antibiotics are needed. This study investigates the effects of mesobiliverdin IXα (MBV)-enriched microalgae spirulina extracts on the growth performance, blood parameters, intestinal morphology, and gut microbiota of broilers. A total of 288 1-day-old broiler chicks (Arbor Acres) were randomly allotted to six dietary treatments (4 pens/treatment and 12 birds/pen). The dietary treatments comprised a basal diet as control (CON), basal diet plus 0.05 and 0.1% microalgae extract as low and high dose, respectively (SP1 and SP2), basal diet plus 0.05 and 0.1% MBV-enriched microalgae extract as low and high dose, respectively (MBV-SP1 and MBV-SP2), and basal diet plus 0.1% amoxicillin (AMX). All treated animals showed no significant differences in live weight, average daily gain, and feed efficiency compared to control animals. Histological examination showed that AMX treatment decreased the villi lengths of the duodenum and ileum below control villi length (P < 0.05) while MBV-SP1 and particularly MBV-SP2 increased villi lengths in the duodenum, jejunum, and ileum above AMX -treatment lengths (P < 0.05). The Firmicutes/Bacteroidetes ratio increased in the cecum of broilers fed AMX (P < 0.05) while SP2, MBV-SP1, and MBV-SP2-fed animals showed (in order) increasing ratios up to the AMX level. The abundance of bacterial species of the genus Lactobacillus increased in MBV-SP1 and MBV-SP2-fed groups including a striking increase in Lactobacillus salivarius abundance with MBV-SP2 (P < 0.05). Feeding MBV-SP1 and MBV-SP2 decreased the level of pro-inflammatory cytokine IL-6 in plasma of broilers to a greater extent than SP1 and SP2. These results reveal that MBV-enriched microalgae extracts improve the intestinal health and beneficial microflora composition of broilers.

Influence of dietary supplementation of Crassocephalum crepidioides leaf on growth, immune status, caecal microbiota, and meat quality in broiler chickens

The effect of dietary supplementation of Crassocephalum crepidioides leaf powder (CCLP) in comparison with oxytetracycline and butylated hydroxyanisole (BHA) on growth, caecal microbiota, immune status, blood chemistry, carcass traits, meat quality, and oxidative stability in broiler chickens was evaluated. Two hundred and eighty 1-day-old Arbor acre chicks were randomly assigned to a basal diet containing either no additive (control, CON), 400 ppm oxytetracycline + 150 ppm BHA (ANTIBIOX), 1000 ppm CCLP (CCLP-1), or 2000 ppm CCLP (CCLP-2) for 42 days. Each dietary group had seven replicates with ten birds per replicate. Supplemented birds had higher (P < 0.05) feed efficiency, hemoglobin, and hematocrit compared with the CON birds. Diet did not affect feed intake, body weight gain, splenic interleukin-1β, interleukin-6, interleukin-10, and serum IgM. The CCLP-2 birds had lower (P < 0.05) serum total and LDL cholesterol than did birds fed other treatments. Salmonella spp. and Escherichia coli counts and serum IgG were higher in the CON birds than in the supplemented birds. The ANTIBIOX birds had lower (P < 0.05) Lactobacillus spp. count, and higher (P < 0.05) E. coli count compared with the CCLP-supplemented birds. Carcass, muscle pH, and cook loss were not affected by diet. The CON breast meat had higher drip loss and lower redness than did the breast meat of the supplemented birds. Carbonyl content and TBARS value in the thigh and breast meat of the supplemented birds were lower (P < 0.05) than those of the CON birds. These results infer that CCLP exhibited antioxidant and antimicrobial properties that were comparable to those of BHA and oxytetracycline in the diet of broiler chickens.

Inclusion of Lactobacillus salivarius strain revealed a positive effect on improving growth performance, fecal microbiota and immunological responses in chicken

Probiotics are defined as live microorganisms that when administered in an appropriate amount, provide health benefits to the host. This study aimed to evaluate the effect of the oral administration of Lactobacillus salivarius (L. salivarius) on growth performance, immunological responses, fecal microbial flora and intestinal mucosal morphology in chickens. Chickens were fed with 10⁹ colony-forming units (CFUs) of wild-type (WT) L. salivarius or phosphate-buffered saline (PBS) for 5 weeks. Chickens body weight was significantly increased by administration of L. salivarius groups compared than control group. The microbial taxonomy in the small intestine and cecum was identified via the chicken feces sample. A total of 286,331 bacterial species were obtained from the chicken fecal samples in overall experimental group. From these, 145,012 bacterial species were obtained from oral administration of L. salivarius treatment group, while 141,319 bacterial species were obtained from control group. Almost 98% of all 16S rRNA sequences from the chicken fecal sample of the two groups were classified into known phyla. Firmicutes, Cyanobacteria, Proteobacteria, Bacteroidetes and Actinobacteria were highly abundant in both groups. Compared with the control birds, the chickens orally administered L. salivarius showed no significant differences in villus length and crypt length. Serum concentrations of the cytokines IL-8, TNF-α, IFN-γ, and IL-4 were markedly reduced in the L. salivarius group. In summary, our findings reveal that L. salivarius can act as a potential probiotic to improve performance and overall gut health in of chickens.

Administration of L. salivarius expressing 3D8 scFv as a feed additive improved the growth performance, immune homeostasis, and gut microbiota of chickens

Probiotics have been defined as live microorganisms that are administered in an appropriate amount to provide health benefits to the host animal. In this study, we investigated the effect of L. salivarius DJ-sa-01 secreting the 3D8 single-chain variable fragment (3D8 scFv) on the growth performance, cytokine secretion, and intestinal microbial flora of chickens. The experiment was divided into the control group and L. salivarius expressing 3D8 scFv experimental group. Chicken was fed 10⁹ colony-forming units (CFUs) of wild-type (WT) L. salivarius or 3D8 scFv-secreting L. salivarius daily for 35 days. The administration of L. salivarius expressing 3D8 scFv significantly improved the body weight of chickens compared with the administration of WT L. salivarius. A 16S ribosomal RNA metagenomic analysis showed that Firmicutes, Proteobacteria, Actinobacteria, and Bacteroidetes were the dominant phyla in both experimental groups. At the genus level, Lactobacillus was more abundant (22.82%) in the L. salivarius/3D8 group compared with the WT L. salivarius group. The serum levels of cytokines, such as IL-8, TNF-α, IL-1β, IFN-γ, IL-4, and IGF1, were significantly reduced in the L. salivarius/3D8-treated chickens. In summary, our results suggest that L. salivarius expressing 3D8 scFv could be considered a feed additive for improving the growth performance, immune function, and disease resistance of poultry.

The Effect of Using New Synbiotics on the Turkey Performance, the Intestinal Microbiota and the Fecal Enzymes Activity in Turkeys Fed Ochratoxin A Contaminated Feed

The feed supplementation of probiotic microorganisms is a promising method for detoxification of ochratoxin A (OTA) in poultry. The aim of the study was to investigate the effect of newly elaborated synbiotics on the turkey performance, the intestinal microbiota and its enzymatic activity in turkeys (0-15 weeks) fed OTA contaminated feed (198.6-462.0 µg/kg) compared to control group (OTA-free feed). The studies determined the composition of intestinal microorganisms by the culture method and the activity of fecal enzymes by spectrophotometry. It was found that OTA had an adverse effect on the body weight, the intestinal microbiota and the fecal enzymes activity in turkeys. On the other hand, synbiotics resulted in an increase in the count of beneficial bacteria while reducing the number of potential pathogens in the digestive tract. Moreover, synbiotics caused an increase in the activity of α-glucosidase and α-galactosidase, while decreasing the activity of potentially harmful fecal enzymes (β-glucosidase, β-galactosidase, β-glucuronidase) in the turkey's excreta. Results indicate a beneficial effect of elaborated synbiotics on the health of turkeys and a reduction of the negative impact of OTA contaminated feed. These synbiotics can be successfully used as feed additives for turkeys.

Caenorhabditis elegans, a Host to Investigate the Probiotic Properties of Beneficial Microorganisms

Caenorhabditis elegans, a non-parasitic nematode emerges as a relevant and powerful candidate as an in vivo model for microorganisms-microorganisms and microorganisms-host interactions studies. Experiments have demonstrated the probiotic potential of bacteria since they can provide to the worm a longer lifespan, an increased resistance to pathogens and to oxidative or heat stresses. Probiotics are used to prevent or treat microbiota dysbiosis and associated pathologies but the molecular mechanisms underlying their capacities are still unknown. Beyond safety and healthy aspects of probiotics, C. elegans represents a powerful way to design large-scale studies to explore transkingdom interactions and to solve questioning about the molecular aspect of these interactions. Future challenges and opportunities would be to validate C. elegans as an in vivo tool for high-throughput screening of microorganisms for their potential probiotic use on human health and to enlarge the panels of microorganisms studied as well as the human diseases investigated.

Effects of Gut Microbiome and Short-Chain Fatty Acids (SCFAs) on Finishing Weight of Meat Rabbits

Understanding how the gut microbiome and short-chain fatty acids (SCFAs) affect finishing weight is beneficial to improve meat production in the meat rabbit industry. In this study, we identified 15 OTUs and 23 microbial species associated with finishing weight using 16S rRNA gene and metagenomic sequencing analysis, respectively. Among these, butyrate-producing bacteria of the family Ruminococcaceae were positively associated with finishing weight, whereas the microbial taxa related to intestinal damage and inflammation showed opposite effects. Furthermore, interactions of these microbial taxa were firstly found to be associated with finishing weight. Gut microbial functional capacity analysis revealed that CAZymes, such as galactosidase, xylanase, and glucosidase, could significantly affect finishing weight, given their roles in regulating nutrient digestibility. GOs related to the metabolism of several carbohydrates and amino acids also showed important effects on finishing weight. Additionally, both KOs and KEGG pathways related to the membrane transportation system and involved in aminoacyl-tRNA biosynthesis and butanoate metabolism could act as key factors in modulating finishing weight. Importantly, gut microbiome explained nearly 11% of the variation in finishing weight, and our findings revealed that a subset of metagenomic species could act as predictors of finishing weight. SCFAs levels, especially butyrate level, had critical impacts on finishing weight, and several finishing weight-associated species were potentially contributed to the shift in butyrate level. Thus, our results should give deep insights into how gut microbiome and SCFAs influence finishing weight of meat rabbits and provide essential knowledge for improving finishing weight by manipulating gut microbiome.

Enterococcus faecium Modulates the Gut Microbiota of Broilers and Enhances Phosphorus Absorption and Utilization

Modern broiler chickens have ongoing bone health problems. Phosphorus (P) plays an important role in bone development and increased understanding of P metabolism should improve the skeletal health of broilers. Enterococcus faecium has been widely used as a probiotic in broiler production and is shown to improve skeletal health of rats, but its effect on the bones of broilers remains unclear. This study investigated the effect of E. faecium on P absorption and utilization in broilers and the associated changes in the gut microbiota using 16S rDNA sequencing. Dietary supplementation with E. faecium improved P absorption through upregulation of the expression of intestinal NaP-IIb mRNA and increased the concentration of serum alkaline phosphatase. These actions increased P retention and bone mineralization in E. faecium-treated broilers. The positive effects of E. faecium on P metabolism were associated with changes in the populations of the intestinal microbiota. There was increased relative abundance of the following genera, Alistipes, Eubacterium, Rikenella and Ruminococcaceae and a decrease in the relative abundance of Faecalibacterium and Escherichia-Shigella. Dietary supplementation with E. faecium changed gut microbiota populations of broilers, increased the relative abundance of SCFA (short-chain fatty acid)-producing bacteria, improved intestinal P absorption and bone forming metabolic activities, and decreased P excretion. E. faecium facilitates increased utilisation of P in broilers.

Assessment of Probiotic Properties of Lactobacillus salivarius Isolated From Chickens as Feed Additives

The continued use of sub-therapeutic antibiotics as feed additives in the poultry industry improved health and growth performance. However, the resulting antibiotic resistance increasingly becomes a major threat to public health. Probiotics are promising alternatives for the antibiotics used in poultry industry. The aim of this study was to evaluate the probiotic properties of Lactobacillus salivarius as feed additive in chickens. White leghorn chickens were randomly assigned to experimental groups. Effects of Lactobacillus salivarius supplementation on growth performance, resistance to Escherichia coli O78 challenge and heat-stress, and immune response after vaccinated with attenuated infectious bursal disease virus (IBDV) vaccine were determined. The results showed that Lactobacillus salivarius supplementation improved growth performance, such as weight and longer shank length, increased relative weights of the immune organs and decreased concentrations of odor-causing compounds. In addition, Lactobacillus salivarius supplementation alleviated organ injury caused by Escherichia coli O78 challenge and heat stress. Furthermore, Lactobacillus salivarius results in enhanced immune response after IBDV vaccine immunization, enhanced specific antibody and IFN-γ production, and lymphocyte proliferation. Our results revealed a tremendous potential of Lactobacillus salivarius as antibiotics' substitute in poultry production.

Effects of synbiotics on the gut microbiota, blood and rearing parameters of chickens

The aim of the study was to assess the safety of three newly developed synbiotic preparations in feeding chickens. The study was carried out on 84 Specific Pathogen Free chickens, between 1st and 21st day of their life. Animals were divided into four groups fed ad libitum: three with an addition of synbiotics A, B or C and a control group (feed with no additives). Synbiotics contained Lactobacillus, Saccharomyces cerevisiae and inulin (prebiotic). Rearing parameters were determined taking into account undesirable clinical and sectional symptoms, daily mortality and body weight of birds. In addition, chicken blood parameters were determined based on haematological, biochemical and serological tests. Samples of the intestinal content and of the excreta constituted a material for research aimed at determination of the dominant chicken gut microbiota. On the basis of the conducted investigation, it was found that synbiotics met the basic requirements for this type of formulas regarding the safety of use and had a positive effect on the health of chickens. Therefore, further research is being carried out on the application of these formulas in large-scale production. The next step of the research will be the comparison of effects of synbiotics with commercial probiotics.

Pulicaria gnaphalodes powder in broiler diets: consequences for performance, gut health, antioxidant enzyme activity, and fatty acid profile

The search constantly continues to identify potential alternatives to the use of antimicrobial growth promoters (AGP) in broiler production. This trial was conducted with broiler chicks to investigate the effect of different levels of Pulicaria gnaphalodes powder (PGP) in comparison with AGP, and probiotic (PRO) on growth performance, gut microflora, intestinal morphology, antioxidant enzyme activity, and fatty acid profile of meat. Ross 308 male broiler chicks (n = 576) were randomly assigned into 6 dietary treatments with 8 replicate pens per treatment and 12 birds per pen. The dietary treatments consisted of a basal diet as control (CON, with no additive), CON + 0.1% PGP, CON + 0.2% PGP, CON + 0.3% PGP, CON + 0.1% probiotic mixture (PRO), and CON + 0.05% bacitracin methylene disalicylate (AGP). Higher body weight gain and lower feed conversion ratio were obtained in birds fed AGP and 0.3% PGP compared with those fed CON and 0.1% PGP during grower, finisher, and the entire study (P < 0.05). On day 42, birds on PRO, 0.2 and 0.3% PGP treatments had lower counts of Escherichia coli and higher lactobacillus spp. in ileum and cecal contents compared to the CON and 0.1% PGP (P < 0.05). Villus height and villus height to crypt depth ratio of the duodenum were increased (P < 0.05) in response to dietary AGP, PRO, and 0.3% PGP. The diets containing PRO and different levels of PGP increased superoxide dismutase and glutathione peroxidase activities and decreased malondialdehyde level in serum, liver, and thigh muscle (P < 0.05). Total polyunsaturated fatty acid and n-3 fatty acid of birds fed PRO and PGP diets were higher than birds in CON and AGP groups (P < 0.05). In summary, supplementation of PGP could be a potential alternative to AGP in broiler diets due to its combined positive impacts on performance, serum cholesterol, intestinal health, antioxidant activity, and fatty acid profile in meat. Such effects, however, need to be further verified under compromised health or a disease challenge condition.

Effects of probiotic lactic acid bacteria on growth performance, carcass characteristics, hematological indices, humoral immunity, and IGF-I gene expression in broiler chicken

The effects of screened lactic acid bacteria strains were evaluated on growth performance, humoral immunity, and IGF-1 gene expression in broiler chickens. The three dietary groups of negative control fed basal diet, the native LAB probiotic group (NP), and PrimaLac commercial LAB probiotic (PC) were studied. The results revealed that NP and PC diets significantly improved feed conversion ratio and increased body weight, as well as relative weight of carcass compared with group fed NC diet (P < 0.05). Lymphocyte level was significantly increased in birds fed NP and PC (P < 0.01), while serum triglycerides and total cholesterol levels were significantly decreased compared with the NC (P < 0.05). Significant increases were observed in antibody titers against Newcastle disease virus of vaccinated birds (P < 0.03), and morphological analysis of ileum revealed significant increases (P < 0.05) in the villus height and villus height/crypt depth in birds fed NP and PC compared with the NC. The dietary significantly increased Lactobacillus spp. (P < 0.05), while Escherichia coli (P < 0.04) populations were significantly decreased, and also, the expression of IGF-1 gene in liver tissue of broilers fed NP and PC was significantly increased compared with the NC (P < 0.05). These results indicated that the identified native LAB strains can be used commercially as a low-cost probiotic in poultry industry of Iran.

Properties of potentially probiotic Lactobacillus isolates from poultry intestines

The most commonly used probiotic bacteria belong to the genus Lactobacillus, being regarded as beneficial for poultry health and production. However, commercial probiotics do not always ensure both expected effects. In order to improve the utility properties of new preparations, the selection of new probiotic candidates should be made on the basis of the performance of the species within the poultry digestive tract. The aim of this study was to isolate and identify lactobacilli from poultry intestines, and to select probiotic candidates for subsequent in vivo trials. Digesta from 18 poultry specimens were collected, serially diluted, plated onto Wilkins-Chalgren anaerobe agar supplemented with 30% of rumen fluid and onto De Man, Rogosa and Sharpe agar plates, and incubated at 37 °C for 48 h under anaerobic conditions. Isolated colonies were subjected to Gram staining and catalase reaction. They were then pre-identified using matrix-assisted laser desorption ionization (MALDI) time of flight (TOF) mass spectrometry (MS). Forty-four Lactobacillus strains belonging to 16 species were identified and subjected to evaluations of survival under simulated gastrointestinal conditions, autoaggregation and hydrophobicity. Most of the screened Lactobacillus reuteri strains as well as individual strains of L. acidophilus, L. salivarius, L. saerimneri, and L. vaginalis showed high survival rates under gastrointestinal tract conditions and good surface properties. The results suggest their potential for further testing as probiotic candidates in in vivo trials.