Correlation between Jejunal Microbial Diversity and Muscle Fatty Acids Deposition in Broilers Reared at Different Ambient Temperatures

Intestinal Microbiome Profiles in Broiler Chickens Raised with Different Probiotic Strains

The composition of the intestinal microbiota can influence the metabolism and overall functioning of avian organisms. Therefore, the objective of this study was to evaluate the effect of three different probiotics and an antibiotic on the microbiomes of 1.400 male Cobb® broiler raised for 42 days. The experiment was conducted with the following treatments: positive control diet (basal diet + antibiotic); negative control diet (basal diet without antibiotic and without probiotic); basal diet + Normal Avian Gut Flora (NAGF); basal diet + multiple colonizing strain probiotics (MCSPs); and basal diet + non-colonizing single strain probiotics (NCSSPs). The antibiotic (enramycin-antibiotic growth promoter) and probiotics were administered orally during all experiment (1 to 42 days), mixed with broiler feed. To determine the composition of the microbiota, five samples of ileal digesta were collected from 42-day-old chickens of each experimental group. The alpha and beta diversity of the ileal microbiota showed differences between the groups. MCSPs presented greater richness and uniformity compared to the positive control, negative control, and NCSSPs treatments, while the negative control exhibited greater homogeneity among samples than NCSSPs. MCSPs also showed a higher abundance of the genus Enterococcus. There were differences between the groups for low-abundance taxa (<0.5%), with NAGF showing higher levels of Delftia, Brevibacterium, and Bulleidia. In contrast, NCSSPs had a higher abundance of Ochrobactrum, Rhodoplanes, and Nitrospira. It was concluded that the treatments analyzed in this study induced modulations in the ileal microbiota of the chickens examined.

The effects of synbiotics-glyconutrients on growth performance, nutrient digestibility, gas emission, meat quality, and fatty acid profile of finishing pigs

Glyconutrients help in the body's cell communication. Glyconutrients and synbiotics are promising options for improving immune function. Therefore, we hypothesized that combining synbiotics and glyconutrients will enhance pig nutrient utilization. 150 pigs (Landrace × Yorkshire × Duroc), initially weighing 58.85 ± 3.30 kg of live body weight (BW) were utilized to determine the effects of synbiotics-glyconutrients (SGN) on the pigs' performance, feed efficiency, gas emission, pork traits, and composition of fatty acids. The pigs were matched by BW and sex and chosen at random to 1 of 3 diet treatments: control = Basal diet; TRT1 = Basal diet + SGN 0.15%; TRT2 = Basal diet + SGN 0.30%%. The trials were conducted in two phases (weeks 1-5 and weeks 5-10). The average daily gain was increased in pigs fed a basal diet with SGN (p = 0.036) in weeks 5-10. However, the apparent total tract digestibility of dry matter, nitrogen, and gross energy did not differ among the treatments (p > 0.05). Dietary treatments had no effect on NH3, H2S, methyl mercaptans, acetic acids, and CO2 emissions (p > 0.05). Improvement in drip loss on day 7 (p = 0.053) and tendency in the cooking loss were observed (p = 0.070) in a group fed basal diets and SGN at 0.30% inclusion level. The group supplemented with 0.30% of SGN had higher levels of palmitoleic acid (C16:1), margaric acid (C17:0), omega-3 fatty acid, omega-6 fatty acid, and ω-6: ω-3 ratio (p = 0.034, 0.020, 0.025, 0.007, and 0.003, respectively) in the fat of finishing pigs. Furthermore, group supplemented with 0.30% of SGN improved margaric acid (C17:0), linoleic acid (C18:2n6c), arachidic acid (C20:0), omega 6 fatty acid, omega-6 to omega-3 ratio, unsaturated fatty acid, and monounsaturated fatty acid (p = 0.037, 0.05, 0.0142, 0.036, 0.033, 0.020, and 0.045, respectively) in the lean tissues of finishing pigs compared to pigs fed with the control diets. In conclusion, the combination of probiotics, prebiotics, and glyconutrients led to higher average daily gain, improved the quality of pork, and more favorable fatty acid composition. Therefore, these results contributed to a better understanding of the potential of SGN combinations as a feed additive for pigs.

Dietary novel alkaline protease from Bacillus licheniformis improves broiler meat nutritional value and modulates intestinal microbiota and metabolites

BACKGROUND

Different types of exogenous protease supplements have a positive impact on animal performance, but their effects on the nutritional value of meat and the gut microbial community of broilers have not been extensively studied. The objective of this investigation was to determine the impact of supplementation with a novel alkaline protease derived from Bacillus licheniformis (at doses of 0, 100, 200, 300, and 400 g/t) on the fatty acid and amino acid profiles, inosine monophosphate (IMP) levels, total volatile basic nitrogen (TVB-N) content found within the breast muscle, as well as the impact on the cecal microbiota and metabolites.

RESULTS

Supplementation with 200-400 g/t of the novel protease resulted in a significant elevation in the concentration of essential amino acids (P < 0.001), flavor amino acids (P < 0.001), and total protein (P = 0.013) within the breast muscle. Results derived from the 16S rRNA sequencing and untargeted metabolomics analysis of the cecal content revealed that the novel protease reshaped the cecal microbial and metabolite profiles. In particular, it led to increased relative abundances of Bacteroides, Lactobacillus, Alistipes, and Eubacterium, while simultaneously causing a reduction in the metabolites of D-lactic acid and malonic acid. Moreover, correlation analyses unveiled significant relationships between distinct microbes and metabolites with the contents of IMP, fatty acids, and amino acids in the broiler's breast muscle.

CONCLUSION

In summary, the novel protease regulated the intestinal microbial community and metabolism, thereby inducing changes in the compositions of fatty acids and amino acids profiles, as well as IMP levels in broiler meat. These alterations significantly contributed to the enhancement of the nutritional value and flavor of the meat.

Probiotics and Synbiotics Addition to Bama Mini-Pigs' Diet Improve Carcass Traits and Meat Quality by Altering Plasma Metabolites and Related Gene Expression of Offspring

This study evaluated the effects of maternal probiotics and synbiotics addition on several traits and parameters in offspring. A total of 64 Bama mini pigs were randomly allocated into the control (basal diet), antibiotic (50 g/t virginiamycin), probiotics (200 mL/day probiotics), or synbiotics (500 g/t xylo-oligosaccharides and 200 mL/day probiotics) group and fed with experimental diets during pregnancy and lactation. After weaning, two piglets per litter and eight piglets per group were selected and fed with a basal diet. Eight pigs per group were selected for analysis at 65, 95, and 125 days of age. The results showed that the addition of probiotics increased the average daily feed intake of the pigs during the 66- to 95-day-old periods and backfat thickness at 65 and 125 days of age, and that the addition of synbiotics increased backfat thickness and decreased muscle percentage and loin-eye area at 125 days of age. The addition of maternal probiotics increased the cooking yield and pH45min value at 65 and 95 days of age, respectively, the addition of synbiotics increased the meat color at 95 days of age, and the addition of probiotics and synbiotics decreased drip loss and shear force in 65- and 125-day-old pigs, respectively. However, maternal antibiotic addition increased shear force in 125-day-old pigs. Dietary probiotics and synbiotics addition in sows' diets increased several amino acids (AAs), including total AAs, histidine, methionine, asparagine, arginine, and leucine, and decreased glycine, proline, isoleucine, α-aminoadipic acid, α-amino-n-butyric acid, β-alanine, and γ-amino-n-butyric acid in the plasma and longissimus thoracis (LT) muscle of offspring at different stages. In the LT muscle fatty acid (FA) analysis, saturated FA (including C16:0, C17:0, and C20:0) and C18:1n9t contents were lower, and C18:2n6c, C16:1, C20:1, and unsaturated FA contents were higher in the probiotics group. C10:0, C12:0, and C14:0 contents were higher in 65-day-old pigs, and C20:1 and C18:1n9t contents were lower in the synbiotics group in 95- and 125-day-old pigs, respectively. The plasma biochemical analysis revealed that the addition of maternal probiotics and synbiotics decreased plasma cholinesterase, urea nitrogen, and glucose levels in 95-day-old pigs, and that the addition of synbiotics increased plasma high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and total cholesterol concentrations in 65-day-old pigs and triglyceride concentration in 125-day-old pigs. The addition of maternal probiotics and synbiotics regulated muscle fiber type, myogenic regulation, and lipid metabolism-related gene expression of LT muscle in offspring. In conclusion, the addition of maternal probiotics and synbiotics improved the piglet feed intake and altered the meat quality parameters, plasma metabolites, and gene expression related to meat quality.

Comparative Analyses of Antibiotic Resistance Genes in Jejunum Microbiota of Pigs in Different Areas

Antibiotic resistance genes (ARGs) are emerging environmental contaminants that threaten human and animal health. Intestinal microbiota may be an important ARGs repository, and intensive animal farming is a likely contributor to the environmental burden of ARGs. Using metagenomic sequencing, we investigated the structure, function, and drug resistance of the jejunal microbial community in Landrace (LA, Kunming), Saba (SB, Kunming), Dahe (DH, Qujing), and Diannan small-ear piglets (DS, Xishuangbanna) from different areas in Yunnan Province, China. Remarkable differences in jejunal microbial diversity among the different pig breeds, while the microbial composition of pig breeds in close areas tends to be similar. Functional analysis showed that there were abundant metabolic pathways and carbohydrate enzymes in all samples. In total, 32,487 ARGs were detected in all samples, which showed resistance to 38 categories of drugs. The abundance of ARGs in jejunum was not significantly different between LA and SB from the same area, but significantly different between DS, DH and LA or SB from different areas. Therefore, the abundance of ARGs was little affected by pig breeds and microorganism community structure, but it was closely related to geographical location. In addition, as a probiotic, Lactobacillus amylovorus is also an important ARGs producing bacterium. Our results revealed the antibiotic exposure and intestinal microbial resistance of farms in the study areas, which could provide basic knowledge and potential strategies for rational use of antibiotics and reducing the risk of ARGs transmission in animal husbandry.

Heat Stress Affects Jejunal Immunity of Yellow-Feathered Broilers and Is Potentially Mediated by the Microbiome

In the perspective of the global climate change leading to increasing temperature, heat stress (HS) has become a severe issue in broiler production, including the indigenous yellow-feathered broilers. The present study aimed to investigate the effects of HS on jejunal immune response, microbiota structure and their correlation in yellow-feathered broilers. A total of forty female broilers (56-days-old) were randomly and equally divided into normal treatment group (NT group, 21.3 ± 1.2°C, 24 h/day) and HS group (32.5 ± 1.4°C, 8 h/day) with five replicates of each for 4 weeks feeding trial. The results showed that HS exposure increased the contents of TNF-α, IL-1β, and IL-6 in jejunal mucosa (p < 0.05). The HS exposure up-regulated the relative fold changes of NF-κB, TNF-α, IL-1β, and IL-6 (p < 0.01) while down-regulated the relative fold change of IFN-γ in jejunal mucosa (p < 0.05). Meanwhile, HS had no significant impacts on alpha diversity of jejunal microbiota such as Simpson, Chao1 richness estimator (Chao 1), abundance-based coverage estimators (ACE), and Shannon index (p > 0.10). Broilers exposed to HS reduced the jejunal microbial species number at the class and order level (p < 0.05). Moreover, HS decreased the relative abundance of Ruminococcus, Bdellovibrio, and Serratia at the genus level in jejunum (p < 0.05). At the phylum level, four species of bacteria (Bacteroidetes, Cyanobacteria, Thermi, and TM7) were significantly associated with immune-related genes expression (p < 0.05). At the genus level, ten species of bacteria were significantly correlated with the expression of immune-related genes (p < 0.05), including Caulobacteraceae, Actinomyces, Ruminococcaceae, Thermus, Bdellovibrio, Clostridiales, Sediminibacterium, Bacteroides, Sphingomonadales and Ruminococcus. In particular, the microbial with significantly different abundances, Ruminococcus and Bdellovibrio, were negatively associated with pro-inflammatory cytokines expression (p < 0.05). These findings demonstrated that HS exposure promoted the production of pro-inflammatory cytokines in yellow-feathered broilers’ jejunum. The detrimental effects of HS on jejunal immune response might be related to dysbiosis, especially the reduced levels of Ruminococcus and Bdellovibrio.

Association Among the Gut Microbiome, the Serum Metabolomic Profile and RNA m6A Methylation in Sepsis-Associated Encephalopathy

Objective: To investigate the relationship among the gut microbiome, serum metabolomic profile and RNA m6A methylation in patients with sepsis-associated encephalopathy (SAE), 16S rDNA technology, metabolomics and gene expression validation were applied.

Methods: Serum and feces were collected from patients with and without (SAE group and non-SAE group, respectively, n = 20). The expression of serum markers and IL-6 was detected by enzyme-linked immunosorbent assay (ELISA), and blood clinical indicators were detected using a double antibody sandwich immunochemiluminescence method. The expression of RNA m⁶A regulator were checked by Q-RTPCR. The gut microbiome was analyzed by 16S rDNA sequencing and the metabolite profile was revealed by liquid chromatography-mass spectrometry (LC-MS/MS).

Results: In the SAE group, the IL-6, ICAM-5 and METTL3 levels were significantly more than those in the non-SAE group, while the FTO levels were significantly decreased in the SAE group. The diversity was decreased in the SAE gut microbiome, as characterized by a profound increase in commensals of the Acinetobacter, Methanobrevibacter, and Syner-01 genera, a decrease in [Eubacterium]_hallii_group, while depletion of opportunistic organisms of the Anaerofilum, Catenibacterium, and Senegalimassilia genera were observed in both groups. The abundance of Acinetobacter was positively correlated with the expression of METTL3. The changes between the intestinal flora and the metabolite profile showed a significant correlation. Sphingorhabdus was negatively correlated with 2-ketobutyric acid, 9-decenoic acid, and l-leucine, and positively correlated with Glycyl-Valine [Eubacterium]_hallii_group was positively correlated with 2-methoxy-3-methylpyazine, acetaminophen, and synephrine acetonide.

Conclusion: The gut microbiota diversity was decreased. The serum metabolites and expression of RNA m6A regulators in PBMC were significantly changed in the SAE group compared to the non-SAE group. The results revealed that serum and fecal biomarkers could be used for SAE screening.

The Correlation between Gut Microbiota and Serum Metabolomic in Elderly Patients with Chronic Heart Failure

OBJECTIVE

Chronic heart failure (CHF) refers to a state of persistent heart failure that can be stable, deteriorated, or decompensated. The mechanism and pathogenesis of myocardial remodeling remain unknown. Based on 16S rDNA sequencing and metabolomics technology, this study analyzed the gut microbiota and serum metabolome in elderly patients with CHF to provide new insights into the microbiota and metabolic phenotypes of CHF.

METHODS

Blood and fecal samples were collected from 25 elderly patients with CHF and 25 healthy subjects. The expression of inflammatory factors in blood was detected by ELISA. 16S rDNA sequencing was used to analyze the changes in microorganisms in the samples. The changes of small molecular metabolites in serum samples were analyzed by LC-MS/MS. Spearman correlation coefficients were used to analyze the correlation between gut microbiota and serum metabolites.

RESULTS

Our results showed that the IL-6, IL-8, and TNF-α levels were significantly increased, and the IL-10 level was significantly decreased in the elderly patients with CHF compared with the healthy subjects. The diversity of the gut microbiota was decreased in the elderly patients with CHF. Moreover, Escherichia Shigella was negatively correlated with biocytin and RIBOFLAVIN. Haemophilus was negatively correlated with alpha-lactose, cellobiose, isomaltose, lactose, melibiose, sucrose, trehalose, and turanose. Klebsiella was positively correlated with bilirubin and ethylsalicylate. Klebsiella was negatively correlated with citramalate, hexanoylcarnitine, inosine, isovalerylcarnitine, methylmalonate, and riboflavin.

CONCLUSION

The gut microbiota is simplified by the disease, and serum small-molecule metabolites evidently change in elderly patients with CHF. Serum and fecal biomarkers could be used for elderly patients with CHF screening.

Absence of Circadian Rhythm in Fecal Microbiota of Laying Hens under Common Light

The circadian rhythm of gut microbiota is an important biological rhythm that plays a crucial role in host health. However, few studies have determined the associations between the circadian rhythm and gut microbiota in laying hens. The present experiment investigated the circadian rhythm of fecal microbiota in laying hens. Feces samples were collected from 10 laying hens at nine different time points (06:00-12:00-18:00-00:00-06:00-12:00-18:00-00:00-06:00) to demonstrate the circadian rhythm of fecal microbiota. The results showed that the α and β diversity of the fecal microbiota fluctuated significantly at different time points. Beta nearest taxon index analysis suggested that assembly strategies of the abundant and rare amplicon sequence variant (ASV) sub-communities were different. Abundant ASVs preferred dispersal limitation (weak selection), and rare ASVs were randomly formed due to the "non-dominant" fractions. Highly robust fluctuations of fecal microbiota at the phylum level were found. For example, Firmicutes and Proteobacteria fluctuated inversely to each other, but the total ratio remained in a dynamic balance over 48 h. We identified that temporal dynamic changes had a significant effect on the relative abundance of the important bacteria in the feces microbial community using the random forest algorithm. Eight bacteria, Ruminococcus gnavus, Faecalibacterium, Ruminococcaceae, Enterococcus cecorum, Lachnospiraceae, Clostridium, Clostridiales, and Megamonas, showed significant changes over time. One unexpected finding was the fact that these eight bacteria belong to Firmicutes. The pathways showed significant fluctuation, including xenobiotic biodegradation and metabolism, carbohydrate metabolism, and amino acid metabolism, which were consistent with the metabolic functions of amino acids and carbohydrates from the feed. This study showed that the defecation time may be an important factor in the diversity, proportion, and functions of the feces microbial community. However, there was no circadian rhythm of microbial community assembly confirmed by JTK_Cycle analysis. These results might suggest there was no obvious circadian rhythm of fecal microbiota in laying hens under common light.

Association of Broiler Litter Microbiome Composition and Campylobacter Isolation

Infection with Campylobacter species is one of the leading causes of bacterial diarrhea in humans in the US. Chickens, which become colonized on the farm, are important reservoirs of this bacterium. Campylobacter can establish itself in the broiler house via a variety of sources, can survive in the litter of the house, and possibly persist over successive flock cycles. However, the role of the broiler litter microbiome on Campylobacter persistence is not clear. A matched case-control study was conducted to determine whether the broiler litter microbiome composition was associated with Campylobacter isolation within the broiler house. Flocks were classified as cases when either Campylobacter jejuni or Campylobacter coli was isolated in boot sock samples, or as controls otherwise. Case and control flocks were matched at the broiler house level. Composite broiler litter samples were collected and used for DNA extraction and 16S rRNA gene V4 region sequencing. Reads were processed using the DADA2 pipeline to obtain a table of amplicon sequence variants. Alpha diversity and differential bacterial relative abundance were used as predictors of Campylobacter isolation status in conditional logistic regression models adjusting for flock age and sampling season. Beta diversity distances were used as regressors in stratified PERMANOVA with Campylobacter isolation status as predictor, and broiler house as stratum. When Campylobacter was isolated in boot socks, broiler litter microbiome richness and evenness were lower and higher, respectively, without reaching statistical significance. Campylobacter isolation status significantly explained a small proportion of the beta diversity (genus-level Aitchison dissimilarity distance). Clostridium and Anaerostipes were positively associated with Campylobacter isolation status, whereas Bifidobacterium, Anaerosporobacter, and Stenotrophomonas were negatively associated. Our results suggest the presence of bacterial interactions between Campylobacter and the broiler litter microbiome. The negative association of Campylobacter with Bifidobacterium, Anaerosporobacter, and Stenotrophomonas in litter could be potentially exploited as a pre-harvest control strategy.

Effects of Different Ambient Temperatures on Caecal Microbial Composition in Broilers

Short-term or acute temperature stress affect the immune responses and alters the gut microbiota of broilers, but the influences of long-term temperature stress on stress biomarkers and the intestinal microbiota remains largely unknown. Therefore, we examined the effect of three long-term ambient temperatures (high (HC), medium (MC), and low (LC) temperature groups) on the gene expression of broilers’ heat shock proteins (Hsps) and inflammation – related genes, as well as the caecal microbial composition. The results revealed that Hsp70 and Hsp90 levels in HC group significantly increased, and levels of Hsp70, Hsp90, IL-6, TNF-α, and NFKB1 in LC group were significantly higher than in MC group (p < 0.05). In comparison with the MC group, the proportion of Firmicutes increased in HC and LC groups, while that of Bacteroidetes decreased in LC group at phylum level (p < 0.05). At genus level, the proportion of Escherichia/Shigella, Phascolarctobacterium, Parabacteroides,and Enterococcus increased in HC group; the fraction of Faecalibacterium was higher in LC group; and the percentage of Barnesiella and Alistipes decreased in both HC and LC groups (p < 0.05). Functional analysis based on communities’ phylogenetic investigation revealed that the pathways involved in environmental information processing and metabolism were enriched in the HC group. Those involved in cellular processes and signaling, metabolism, and gene regulation were enriched in LC group. Hence, we conclude that the long-term temperature stress can greatly alter the intestinal microbial communities in broilers and may further affect the host’s immunity and health.

Nutraceuticals Induced Changes in the Broiler Gastrointestinal Tract Microbiota

Effects of nutraceuticals on the intestinal microbiota are receiving increased attention; however, there are few studies investigating their effects on broiler meat production. The aim of this study was to implement feeding strategies and carry out a comprehensive trial examining the interplay between natural biologically active compounds such as carotenoids, anthocyanins, fermentable oligosaccharides, and synbiotics and the gastrointestinal tract microbiota. Our feeding program was applied to an intensive production system with a flock of 1,080 Ross 308 broilers. Aging induced significant changes through the feeding experiment. Nutraceuticals were shown to modulate broiler intestinal diversity and differentially enriched Lactobacillus, Enterococcus, Campylobacter, and Streptococcus in the core microbiome during the different stages of broiler rearing. Additionally, they did not remarkably affect animal growth performance; nevertheless, a positive correlation was found between body weight and Corynebacteriales and Pseudomonadales. Furthermore, a diet high in carotenoid, fermentable oligosaccharide, and anthocyanin contents affected the number of beneficial genera such as Faecalibacterium, Lactobacillus, Blautia, and Ruminococcus. With this comprehensive trial, we revealed that nutraceuticals induced modulations in broiler gastrointestinal tract microbiota. We believe that plant-derived immunostimulants, recycled from plant food waste products, can supplement antibiotic-free broiler meat production.

IMPORTANCE In this trial, nutraceuticals were manufactured from waste products of food industry processing of Hungarian red sweet pepper and sour cherry and incorporated into the diet of poultry to investigate their effects on broilers’ growth and the broiler gastrointestinal tract microbiota. To avoid the generation of food waste products, we believe that this approach can be developed into a sustainable, green approach that can be implemented in commercial antibiotic-free poultry to provide safe and high-quality meat.

Comparison of cecal microbiota composition in hybrid pigs from two separate three-way crosses

Objective

The intestinal microbiota plays an important role in host physiology, metabolism, immunity, and behavior. And host genetics could influence the gut microbiota of hybrid animals. The three-way cross model is commonly utilized in commercial pig production; however, the use of this model to analyse the gut microbial composition is rarely reported.

Methods

Two three-way hybrid pigs were selected, with Saba pigs as the starting maternal pig: Duroc× (Berkshire×Saba) (DBS) pig, Berkshire×(Duroc×Saba) (BDS) pig. One hundred pigs of each model were reared from 35 days (d) to 210 d. The body weight or feed consumption of all pigs were recorded and their feed/gain (F/G) ratio was calculated. On day 210, 10 pigs from each three-way cross were selected for slaughter, and cecal chyme samples were collected for 16S rRNA gene sequencing.

Results

The final body weight (FBW) and average daily gain (ADG) of DBS pigs were significantly higher than those of BDS pigs (p<0.05), while the F/G ratios of DBS pigs were significantly lower than those of BDS pigs (p<0.05). The dominant phyla in DBS and BDS pigs were Bacteroidetes (55.23% vs 59%, respectively) and Firmicutes (36.65% vs 34.86%, respectively) (p>0.05). At the genus level, the abundance of Prevotella, Roseburia, and Anaerovibrio in DBS pigs was significantly lower than in BDS pigs (p<0.01). The abundance of Eubacterium, Clostridium XI, Bacteroides, Methanomassiliicoccus, and Parabacteroides in DBS pigs was significantly higher than in BDS pigs (p<0.05). The FBWs and ADGs were positively correlated with Bacteroides, ClostridiumXI, and Parabacteroides but negatively correlated with the Prevotella, Prevotella/Bacteroides (P/B) ratio, Roseburia, and Anaerovibrio.

Conclusion

These results indicated that host genetics affect the cecal microbiota composition and the porcine gut microbiota is associated with growth performance, thereby suggesting that gut microbiota composition may be a useful biomarker in porcine genetics and breeding.

Characteristics of the Jejunal Microbiota in 35-Day-Old Saba and Landrace Piglets

The balanced microbiological system is a significant hallmark of piglet health. One of the crucial factors affecting intestinal microbiota is the host’s genetics. This study explored the difference in the diversity of jejunal microbiota between Saba (SB) and Landrace (LA) piglets. Nine Saba and nine Landrace piglets were fed with sow’s milk until day 35. Jejunal contents were harvested for 16S rRNA sequencing. The birth weight, body weight, and average daily gain of Saba piglets were lower than those of Landrace piglets (p < 0.01). Firmicutes were the main phylum in Saba and Landrace piglets, and the Saba piglets had a higher (p < 0.05) abundance of Bacteroidetes compared with Landrace piglets. The two most abundant genera were Lactobacilli and Clostridium XI in the jejunum of Landrace and Saba piglets. Compared with Landrace piglets, the Saba piglets had significantly lower (p < 0.05) abundance of Veillonella, Streptococcus, and Saccharibacteria genera incertae sedis. The functional prediction showed that “d-glutamine and d-glutamate metabolism” and “one carbon pool by folate” pathways were enriched in Saba piglets, while “limonene and pinene degradation”, “tryptophan metabolism”, and “sulfur relay system” pathways were enriched in Landrace piglets. In summary, the growth performance was higher for Landrace piglets compared with Saba piglets due to their genetic characteristics. The rich diversity and fewer infection-associated taxa were observed in Saba piglets, partially accounting for their higher adaptability to environmental perturbations than Landrace piglets. Furthermore, different pig breeds may regulate their health through different metabolic pathways.

Correlation analysis of muscle amino acid deposition and gut microbiota profile of broilers reared at different ambient temperatures

Objective

Temperature could influence protein and amino acid deposition as well as gut microbiota profile and composition. However, the specific effects of ambient temperature on amino acids deposition and gut microbiota composition remain insufficiently understood.

Methods

A total of 300 one-day-old Avian broilers were randomly divided into three groups and reared at high, medium, and low temperature (HT, MT, and LT), respectively. Breast muscle and fecal samples were collected for amino acid composition analysis and 16S rRNA gene sequence analysis.

Results

Our data showed that compared to the MT group, there was a decrease of muscle leucine and tyrosine (p<0.05), as well as an increase of methionine in the HT group (p<0.05) and a decrease of serine in the LT group. Examination of microbiota shift revealed that at genus level, the relative abundance of Turicibacter and Parabacteroides was increased in the HT group (p<0.05) and that the relative abundances of Pandoraea, Achromobacter, Prevotella, Brevundimonas, and Stenotrophomonas in the LT group were higher than those in the MT group (p<0.05). In addition, there were substantial correlations between microbes and amino acids. In the HT group. Turicibacter was negatively correlated with aspartic acid and tyrosine, whereas Parabacteroides was positively correlated with methionine (p<0.05). In the LT group, there were multiple positive correlations between Achromobacter and arginine, isoleucine or tyrosine; between Prevotella and cysteine or phenylalanine; between Brevundimonas and cysteine; and between Stenotrophomonas and cysteine as well as a negative correlation between Stenotrophomonas and serine.

Conclusion

Our findings demonstrated that amino acid content of breast muscle and intestinal microbiota profile was affected by different ambient temperatures. Under heat exposure, augmented abundance of Parabacteroides was correlated with elevated methionine. Low temperature treatment may affect muscle tyrosine content through the regulation of Achromobacter.