Effects of oxygen levels and a Lactobacillus plantarum strain on mortality and immune response of chickens at high altitude

Metagenomic profiling uncovers microbiota and antibiotic resistance patterns across human, chicken, pig fecal, and soil environments

The ongoing and progressive evolution of antibiotic resistance presents escalating challenges for the clinical management and prevention of bacterial infections. Understanding the makeup of resistance genomes and accurately quantifying the current abundance of antibiotic resistance genes (ARGs) are crucial for assessing the threat of antimicrobial resistance (AMR) to public health. This comprehensive study investigated the distribution and diversity of bacterial community composition, ARGs, and virulence factors (VFs) across human, chicken, pig fecal, and soil microbiomes in various provinces of China. As a result, multidrug resistance was identified across all samples. Core ARGs primarily related to multidrug, MLS (Macrolides-Lincosamide-Streptogramins), and tetracycline resistance were characterized. A significant correlation between ARGs and bacterial taxa was observed, especially in soil samples. Probiotic strains such as Lactobacillus harbored ARGs, potentially contributing to the dissemination of antibiotic resistance. We screened subsets of ARGs from samples from different sources as indicators to assess the level of ARGs contamination in samples, with high accuracy. These results underline the complex relationship between microbial communities, resistance mechanisms, and environmental factors, emphasizing the importance of continued research and monitoring to better understand these dynamics.

Effects of different addition levels of CHM-JM113 on growth performance, antioxidant capacity, organ index, and intestinal health of AA broilers

The purpose of the present study was to investigate the effects of different levels of a Chinese herbal medicine formulation combined with JM113 (CHM-JM113) on growth performance, antioxidant capacity, organ index, and intestinal health of AA broilers. The AA broiler chicks were randomly allocated to 5 treatments as follows: a basic diet for the control group, the basic diet supplemented with 0.25% CHM-JM113, 0.5% CHM-JM113, 1% CHM-JM113 and 2% CHM-JM113 for the treatment group, respectively. The results showed that the addition of CHM-JM113 to the diet significantly reduced the mortality (p < 0.01) and improved the European Broiler Index (EBI) (p < 0.05), whereas it had no significance on growth performance of AA broilers (p > 0.05). Comparing the control group, 0.5 and 1% CHM-JM113 group significantly improved the organ index of liver, spleen and bursa (p < 0.05). In terms of intestinal morphology and structure, the addition of different levels of CHM-JM113 increased VH and VH/CD ratio, decreased CD in the small intestine compared to the control group, with 1 and 2% of the additive dose being more effective (p < 0.05). Chinese herbal medicine and probiotics as natural antioxidants also significantly increased the content of SOD in serum of 21-day-old broilers (p < 0.01), and significantly decreased the content of MDA in serum (p < 0.01). At 42 days of age, the addition of 1 and 2% CHM-JM113 significantly increased the content of SOD (p < 0.01) and significantly decreased the content of MDA in the organism (p < 0.01), accompanied by a significant increase in T-AOC and CAT content. In the study of the effect of CHM-JM113 on intestinal immunity, compared with the control group, we found that 1% or 2% CHM-JM113 had a better effect on the expression of occludin and claudin-1 in the intestinal segments of broilers (p < 0.05). For the expression of GATA-3, 0.5% CHM-JM113 may have a better effect (p < 0.05). CHM-JM113 may be used as an antibiotic alternative in broiler production.

Impact of high-altitude acclimatization and de-acclimatization on the intestinal microbiota of rats in a natural high-altitude environment

Introduction

Intestinal microorganisms play an important role in the health of both humans and animals, with their composition being influenced by changes in the host's environment.

Methods

We evaluated the longitudinal changes in the fecal microbial community of rats at different altitudes across various time points. Rats were airlifted to high altitude (3,650 m) and acclimatized for 42 days (HAC), before being by airlifted back to low altitude (500 m) and de-acclimatized for 28 days (HADA); meanwhile, the control group included rats living at low altitude (500 m; LA). We investigated changes in the gut microbiota at 12 time points during high-altitude acclimatization and de-acclimatization, employing 16S rRNA gene sequencing technology alongside physiological indices, such as weight and daily autonomous activity time.

Results

A significant increase in the Chao1 index was observed on day 14 in the HAC and HADA groups compared to that in the LA group, indicating clear differences in species richness. Moreover, the principal coordinate analysis revealed that the bacterial community structures of HAC and HADA differed from those in LA. Long-term high-altitude acclimatization and de- acclimatization resulted in the reduced abundance of the probiotic Lactobacillus. Altitude and age significantly influenced intestinal microbiota composition, with changes in ambient oxygen content and atmospheric partial pressure being considered key causal factors of altitude-dependent alterations in microbiota composition. High-altitude may be linked to an increase in anaerobic bacterial abundance and a decrease in non-anaerobic bacterial abundance.

Discussion

In this study, the hypobaric hypoxic conditions at high-altitude increased the abundance of anaerobes, while reducing the abundance of probiotics; these changes in bacterial community structure may, ultimately, affect host health. Overall, gaining a comprehensive understanding of the intestinal microbiota alterations during high-altitude acclimatization and de-acclimatization is essential for the development of effective prevention and treatment strategies to better protect the health of individuals traveling between high- and low-altitude areas.

Lactobacillus plantarum Decreased Ammonia Emissions through Modulating Cecal Microbiotain Broilers Challenged with Ammonia

Probiotic supplementation has become a prominent method of decreasing ammonia emissions in poultry production. The present study was conducted to investigate the influence of Lactobacillus plantarum on ammonia emission, immune responses, antioxidant capacity, cecal microflora and short chain fatty acids, and serum metabolites in broilers challenged with ammonia. A total of 360 1-day-old yellow-feathered broilers were randomly divided into three treatment groups: birds fed with a basal diet (CON), a basal diet supplemented with ammonia (AN), and a basal diet supplemented with 2.5 × 108 CFU L. plantarum kg-1 and challenged with ammonia (LP). Data showed that L. plantarum supplementation decreased ammonia more than 30% from day 48, and significantly reduced the levels of serum urea nitrogen and ammonia, fecal urease, and ammonium nitrogen compared with those on CON. Compared with AN and CON treatments, LP administration increased (p < 0.05) the concentration of serum immunoglobulin Y (IgY), IgM, and IL-10, as well as the serum total-antioxidant capacity (T-AOC) and GSH-Px, and decreased (p < 0.05) IL-1β, IL-6, and TNF-α. Furthermore, birds supplemented with LP had higher (p < 0.05) cecal contents of short chain fatty acids (SCFAs) than AN birds and had more butyrate than CON birds. Data from 16s high throughput sequencing showed that LP supplementation significantly increased (p < 0.05) the Shannon and Simpson indices of bird cecal microflora, and Alloprevotella dominated the LP birds. The function prediction of cecal microflora indicated that LP treatment significantly increased alanine aspartate and glutamate metabolism, starch and sucrose metabolism, exosome, mismatch repair, homologous recombination, DNA repair and recombination proteins, and amino acid-related enzymes. The serum metabolome showed that LP supplementation significantly changed the aminoacyl-tRNA, pantothenate and acetyl-coenzyme A, arginine, phenylalanine, tyrosine and tryptophan, valine, leucine, and isoleucine biosynthesis; purine, beta-alanine, galactose, histidine, alanine, aspartate and glutamate, glyoxylate and dicarboxylate, pyruvate and thiamine metabolism, melanogenesis, and citrate cycle.

Evaluation of the lactic acid bacteria based formulated probiotic product for poultry

This study evaluated the effectiveness of a new probiotic product developed to reduce the effect of Salmonella infections and compared it to the efficacy of commercial probiotics in broiler chicken. Based on the in vitro assessment of the growth characteristics and safety to human health, four bacterial isolates were isolated, characterized, and identified as excellent candidates for the development of commercial probiotic feed additives for poultry. Compatibility and interactions among the four selected strains were investigated. After that, a preliminary study was conducted in which the selected isolates were evaluated individually in vivo with three different methods of application (water, feed, and oral gavage). The cycle included N = 312 chicks, which were divided into 13 groups, including control, distributed into four batteries, with 78 broiler chickens in each battery. There were eight replicates with 24 chicks in each replicate, and the analysis was randomly done in triplicate. The intentional parameters were growth performance, microbial analysis and humoral immune response. The results of the preliminary study assisted in formulating the new probiotic product. Then In vivo evaluations for the newly formulated product were performed with the comparison with two imported commercial products (Alterion and Galli pro fit) used in poultry farms in Kuwait. The second cycle included N = 96 chicks that were divided into four groups, including control. Each group has three replicates and each replicate has eight chicks, and the analysis was randomly done in triplicate. The results showed that although antibiotics were not used, all the growth parameters were similar and sometimes better than the control. The new product inhibited the growth of salmonella as a control and all chickens in different treatment gained a high mass of meat. The statistical analysis showed that no differences were observed in bird weight, weight gain, feed consumption, and feed efficiency between bacterial strains p&gt;0.05. Also, the different probiotic treatments did not affect the total antibody IgM titers significantly in the broilers (P &gt; 0.05). Thus, the newly formulated product was effective in reducing the salmonella.

Supplementation of Paraformic Acid as a Substitute for Antibiotics in the Diet Improves Growth Performance and Liver Health in Broiler Chickens

The current study aimed to explore the effects of supplementing paraformic acid (PFA) into broilers’ diet on growth performance, inflammatory responses, and liver protection. A total of 567 healthy one-day-old broilers were used in a 42-d study, and they were randomized into three groups. Broilers were fed a basal diet (CON group) or the basal diet supplemented with either 50 mg/kg aureomycin (AB group) or 1000 mg/kg PFA (PFA group). The results showed that the PFA and AB groups had a higher feed conversion rate than the CON group from day 21 to 42 (p < 0.05). Dietary PFA or aureomycin supplementation decreased serum levels of interleukin (IL)-1β, IL-6, IL-10, alanine transaminase, diamine oxidase, and D-lactate, and significantly increased serum concentrations of immunoglobulin (Ig) A, IgM, and complement C4 (p < 0.05). Moreover, dietary PFA or aureomycin supplementation decreased hepatic levels of caspase-1, NOD-like receptor family pyrin domain containing 3 (NLRP3), tumor necrosis factor-alpha, IL-6, and IL-18, as well as NF-κB mRNA expression (p < 0.05). Above all, PFA supplementation into the broilers’ diet improved growth performance, inhibited inflammatory responses, and benefited liver protection. The protective effects of PFA on the liver might be related to inhibition of caspase-1-induced pyroptosis via inactivating the NF-κB/NLRP3 inflammasome axis in broiler chickens.

Effects of Dietary Macleaya cordata Extract Containing Isoquinoline Alkaloids Supplementation as an Alternative to Antibiotics in the Diets on Growth Performance and Liver Health of Broiler Chickens

This study aimed to investigate the effects of dietary supplementation with Macleaya cordata extract (MCE) containing protopine and allotypotopine on the growth performance and liver health in broiler chickens. A total of 486 1-day-old male AA broiler chickens were randomly assigned to the following three groups: (1) control (CON) group, broiler chickens fed a basal diet; (2) AGP group (positive control), broiler chickens fed a basal diet supplemented with 50 mg/kg aureomycin; (3) MCE group, broiler chickens fed a basal diet supplemented with 0.6 mg/kg MCE including 0.4 mg/kg protopine and 0.2 mg/kg allotypotopine. The results showed that the MCE group had significantly higher final body weight and average daily gain from d 0 to 42 than the other groups (p < 0.05), and groups MCE and AGP both had significantly lower feed-to-gain ratio from d 0 to 42 than the CON group (p < 0.05). Serum total protein, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, total cholesterol, glucose, immunoglobulin A, immunoglobulin M, and complements (C3, C4) concentrations in the MCE group were significantly higher than in the CON group (p < 0.05). Dietary MCE or aureomycin supplementation significantly reduced the hepatic contents of 8-hydroxy-2'-deoxyguanosine, malondialdehyde, interleukin (IL)-1β, IL-6, NLRs family pyrin domain containing 3 (NLRP3), and caspase-1 in the liver (p < 0.05). Moreover, MCE or aureomycin supplementation significantly inhibited mRNA expressions of Toll-like receptor 4, myeloid differentiation factor 88, nuclear factor-κB, and NLRP3, as well as the expression ratio of Bax to Bcl-2 mRNA (p < 0.05). Therefore, our study suggested that dietary supplementation with 0.6 mg/kg MCE containing protopine and allocryptopine improved growth performance and benefited liver health in broiler chickens possibly through inhibiting caspase-1-induced pyroptosis by inactivating TLR4/MyD88/NF-κB/NLRP3 signaling pathway, and provided support for the application of MCE containing protopine and allocryptopine as an alternative to antibiotics in the feed industry.

Effects of synbiotic on growth, digestibility, immune and antioxidant performance in broilers

The overuse of in-feed antibiotics has been associated with serious issues, including the developing of antibiotic-resistant pathogens and causing drug residues in poultry products. To date, many countries have restricted the use of growth-promoting antibiotics in food animals, resulting in the increased need for effective alternatives to in-feed antibiotic. Synbiotics, which are composed of probiotics and prebiotics, have been shown to act synergistically when applied simultaneously. Thus, this study investigated the effects of a synbiotic, composed of microencapsulated Lactobacillus plantarum (MLP) and fructooligosaccharide (FOS), on growth, immune and antioxidant parameters, and digestibility of calcium and phosphorus in broilers. A total of 168 newly hatched male broilers were randomly allotted to three dietary groups (n = 7): (1) a corn-soybean meal basal diet (CON); (2) basal diet + synbiotic (SYN); and (3) basal diet + aureomycin (ANT). Compared with the CON, chickens had greater average daily gain and digestibility of calcium and phosphorus in the SYN group (P < 0.05). In the SYN and ANT group, serum IgA, IgG, and IL-10 levels were higher, while the serum TNF-α, IL-2, and IL-6 levels were reduced (P < 0.05) compared to CON. Compared with CON, the level of serum malondialdehyde was lower (P < 0.05) and SOD level was higher (P < 0.05) in either SYN or ANT group. No significant differences in populations of Escherichia coli were seen in chickens among the three groups, whereas, the populations of Lactobacillus were higher (P < 0.05) in chickens in the SYN group compared with those in CON and ANT groups. Taken together, the addition of SYN, consisting of MLP and FOS, had benefits on growth, immune and antioxidant parameters, and digestibility of calcium and phosphorus, indicating its potential to serve as a substitute for antibiotics in broiler feeding.

Comparative N-glycoproteomic analysis of Tibetan and lowland chicken fertilized eggs: Implications on proteins biofunction and species evolution

The characterization and functionality of protein glycosylation among different related species are of common interest. Herein, non-standard quantification and N-glycosylation enrichment technology combined with ultra-high liquid chromatography-tandem mass spectrometry were used to establish detailed N-glycoproteomics of fertilized eggs, and quantitatively compared between Tibetan and lowland chicken. A total of 396N-glycosites from 143 glycoproteins were found. Specifically, compared with lowland chicken egg white, 32N-glycosites of 22 glycoproteins were up-regulated and 57N-glycosites of 25 glycoproteins were down-regulated in Tibetan chicken egg white. Also, 137N-glycosites in 72 glycoproteins showed much higher-degree glycosylation and 36N-glycosites in 15 glycoproteins displayed lower-degree glycosylation in Tibetan chicken egg yolk than those in lowland chicken egg yolk. Through bioinformatic analysis, these varied glycoproteins were highly associated with antifreeze activity, hypoxia adaptation, coagulation cascade, and binding/immunity activities, which may be related to plateau hypoxia and cold stress. PRACTICAL APPLICATIONS: These findings provide a new insight on the role of biological egg N-glycoproteins related to environmental adaptation and evolution, which may be further applied in improving egg processing and human health, by developing biomolecules for food and medical industry.

Horizontally Acquired Polysaccharide-Synthetic Gene Cluster From Weissella cibaria Boosts the Probiotic Property of Lactiplantibacillus plantarum

Lactiplantibacillus plantarum are probiotic bacteria, maintaining the integrity of the gastrointestinal epithelial barrier, and preventing the infection of pathogenic bacteria. Exopolysaccharides (EPSs) are often involved in the probiotic property of L. plantarum. Here, we identified a new EPS-synthetic gene cluster, cpsWc, carrying 13 genes, laid on a large plasmid in a well-characterized probiotic L. plantarum strain LTC-113. The cpsWc gene cluster was horizontally acquired from Weissella cibaria, enhancing the biofilm formation ability of the host strain and its tolerance to harsh environmental stresses, including heat, acid, and bile. Transfer of cpsWc also conferred the probiotic properties to other L. plantarum strains. Moreover, cpsWc strengthened the adhesion of LTC-113 to intestinal epithelial cells. Both the cpsWc-carrying LTC-113 and its EPSs per se effectively attenuated the LPS-induced pro-inflammatory effect of intestinal epithelial cells, and inhibited the adhesion of pathogenic bacteria, such as S. typhimurium and E. coli by exclusion and competition. The newly identified cpsWc gene cluster emphasized the contribution of mobile EPS-synthetic element on the probiotic activity of L. plantarum, and shed a light on the engineering of probiotic bacteria.

Probiotic fermented feed improved the production, health and nutrient utilisation of yellow-feathered broilers reared in high altitude in Tibet

1. Probiotic fermented feed (PFF) has been widely used in poultry production. The current study was designed to investigate whether PPF could alleviate the negative effects of hypoxia on yellow-feathered broilers reared at high altitude on the Tibet Plateau. 2. A total of 480, one-day-old male Lingnan yellow-feathered broilers were divided into four treatment groups with six replicates, each containing 20 broiler chickens. Broilers in the four groups were offered either a basal diet (without antibiotics) or test diets containing 5, 10 and 15% of PFF respectively. The experiment lasted for eight weeks. 3. Birds fed the 10% PFF diet exhibited increased (P < 0.05) average daily gain (ADG) on d 28 and 56, body weight (BW) on d 56, total tract apparent digestibility (TTAD) of dry matter (DM), crude protein (CP) and gross energy (GE). Feeding diets supplemented with 10% PFF increased (P < 0.05) digestive activity and gut development in duodenum and jejunum. Supplementation with 10% or 15% PFF significantly increased (P < 0.05) the caecal populations of Lactobacilli and Bifidobacteria spp. and decreased (P < 0.05) caecal E. coli and Salmonella spp. on d 28 and 56. 4. The ADG and BW on d 56, protease activity in duodenum on d 56 and jejunum on d 28 and 56, villus height and villi absorptive area in duodenum and jejunum and caecal Bifidobacteria spp. showed a quadratic (P < 0.05) dose response as supplemental PFF level increased. The TTAD of DM and CP and caecal Lactobacilli spp. increased linearly with PFF level. The caecal populations of E. coli and Salmonella spp. decreased linearly with PFF level. 5. In conclusion, addition of PFF in broiler diets had the potential to improve production performance, nutrient utilisation, intestinal digestive function and caecal microflora in yellow broiler chickens raised at high altitude.