Microbiota Composition of Mucosa and Interactions between the Microbes of the Different Gut Segments Could Be a Factor to Modulate the Growth Rate of Broiler Chickens

Multi-trajectories of body mass index, waist circumference, gut microbiota, and incident dyslipidemia: a 27-year prospective study

Background

Evidence is insufficient to establish a longitudinal association between combined trajectories of body mass index (BMI) and waist circumference (WC) and dyslipidemia. Our study aimed to explore the association between multi-trajectories of BMI and WC and incident dyslipidemia and identify microbiota and metabolite signatures of these trajectories.

Methods

Stratified by sex, we used a group-based trajectory modeling approach to identify distinct multi-trajectories of BMI and WC among 10,678 participants from the China Health and Nutrition Survey over a 24-year period. For each sex, we examined the associations between these multi-trajectories (1991-2015) and the onset dyslipidemia (2018) using multivariable logistic regression adjusting for sociodemographic and lifestyles factors. We characterized the gut microbial composition and performed LASSO and logistic regression to identify gut microbial signatures associated with these multi-trajectories in males and females, respectively.

Results

We identified four multi-trajectories of BMI and WC among both males and females: Normal (Group 1), BMI&WC normal increasing (Group 2), BMI&WC overweight increasing (Group 3), and BMI&WC obesity increasing (Group 4). Among males, Group 2 (OR: 2.10, 95% CI: 1.28-3.46), Group 3 (OR: 2.69, 95% CI: 1.56-4.63) and Group 4 (OR: 3.56, 95% CI: 1.85-6.83) had higher odds of developing dyslipidemia. However, among females, only those in Group 2 (OR: 1.54, 95% CI: 1.03-2.30) were more likely to develop dyslipidemia. In males, compared with Group 1, we observed lower alpha-diversity within Groups 2,3, and 4, and significant beta-diversity differences within Groups 3 and 4 (p 0.001). We also identified 3, 8, and 4 characteristic bacterial genera in male Groups 2, 3 and 4, and 2 genera in female Group 2. A total of 23, 25 and 10 differential metabolites were significantly associated with the above genera, except for Group 2 in males.

Conclusions

The ascending combined trajectories of BMI and WC are associated with a higher risk of dyslipidemia, even with normal baseline levels, especially in males. Shared and unique gut microbial and metabolic signatures among these high-risk trajectories could enhance our understanding of the mechanisms connecting obesity to dyslipidemia.

Exploring the modulatory effects of brown seaweed meal and extracts on intestinal microbiota and morphology of broiler chickens challenged with heat stress

Brown seaweed (Ascophyllum nodosum) is known for its prebiotic roles and can improve animal intestinal health by enhancing the growth of beneficial microbes and inhibiting pathogenic ones. However, the gut health-modulatory roles of brown seaweed on chickens challenged with heat stress (HS) are rarely studied. The current study examined the effects of brown seaweed meal (SWM) and extract (SWE) on the ceca microbiota and small intestinal morphology of chickens challenged or unchallenged with HS. Three hundred and thirty-six 1-day-old Ross 308 broiler chicks were randomly assigned to either a thermoneutral (TN; 24 ± 1°C); or HS room (HS; 32-34°C, 8 h/d from d 21 to 27). All birds in each room were randomly allotted to 4 treatments - control (CON), CON + 1 mL/L seaweed extract (SWE) in drinking water, CON + 2 mL/L SWE in drinking water, and CON + 2% seaweed meal (SWM) in feed and raised for 28 d. On d 14 and 28, 12 and 24 birds per treatment group, respectively, were euthanized to collect the ceca content for gut microbiota analysis and small intestinal tissues for morphological examination. On d 14, 2% SWM increased (P = 0.047) the relative abundance of cecal Fecalibacterium and all brown seaweed treatments improved jejunal villus height (VH) and VH:CD compared to the CON diet. On d 28, HS significantly reduced (P < 0.05) ileal VH, VW, and VH:CD, and duodenal VH and VH:CD. Among the HS group, 2% SWM and 2 mL/L SWE significantly increased (P < 0.05) the relative abundance of Lactobacillus, Sellimonas, and Fournierella, compared to the CON diet. HS birds fed with 2% SWM had higher ileal VH and VH:CD compared to other treatments. In summary, SWM and SWE enhanced the abundance of beneficial microbes and improved small intestinal morphology among HS chickens. This implies that seaweed could potentially alleviate HS-induced intestinal impairment in chickens.

Stevia as a natural additive on gut health and cecal microbiota in broilers

Stevia mash (SM), leaves of Stevia rebaudiana Bertoni plant, is an additive used in poultry that enhances growth and health. Objective: to determine the effect of 1 % SM on productive parameters, gut health, and the cecal microbiome in broilers between the first 15 and 21 days old. One hundred sixty male, 1-day-old broilers (48.5 ± 2.5 g) were divided into Control (C) without SM and Treated (T) with 1 % SM on diet, during 15/21 days. Each subgroup had eight broilers/five repetitions/treatment. At day 15 or 21, all broilers were dissected, Fabricius Bursa and Gut removed and processed for histomorphometry, followed by Villi Height/Crypt Deep (VH/CD) ratio. Conversion Index (CI) was determined. The V3-V4 region of 16S rRNA gene was amplified from DNA obtained from pooled cecal contents and sequenced on Illumina Miseq PE 2 × 250 platform. Sequence processing and taxonomic assignments were performed using the SHAMAN pipeline. Both T groups have better VH/CD Ratios than C groups (p ≤ 0.05). In guts, increased plasmatic and goblet cells number and thicker mucus layer were found in T15 and T21. All groups received SM showed early immunological maturity in Fabricius Bursa. IC was similar between all treatments. Faecalibacterium, Ruminococcus torques group, and Bacteroides were the major genera modulated by SM addition. At 15 and 21 days old, SM exerts a impact on diversity and evenness of the cecal microbiome.  Conclusion: SM (1 %) produced early immunologic maturity on Fabricius Bursa, increased intestinal functionality, and modified the microbiota, increasing beneficial microbial genera and microbial diversity.

Effects of melittin on production performance, antioxidant function, immune function, heat shock protein, intestinal morphology, and cecal microbiota in heat-stressed quails

The purpose of this study was to investigate the effects of melittin on production performance, antioxidant function, immune function, heat shock protein, intestinal morphology, and cecal microbiota of heat-stressed quails. A total of 120 (30-day-old) male quails were randomly divided into 3 groups. Each group consisted of 4 replicates with 10 birds per replicate. The ambient temperature of the control group (group W) was 24°C ± 2°C. The heat stress group (group WH) and the heat stress + melittin group (group WHA2) were subjected to heat stress for 4 h from 12:00 to 16:00 every day, and the temperature was 36°C ± 2°C for 10 d. The results showed that compared with the group W, heat stress significantly decreased growth performance, serum and liver antioxidative function, immune function, intestinal villus height (VH) and villus height-to-crypt depth ratio (VH/CD), and cecal microbiota Chao and ACE index (P < 0.05). The crypt depth (CD) in the small intestine, and HSP70 and HSP90 mRNA levels in the heart, liver, spleen, and kidney were significantly increased (P < 0.05). Dietary melittin significantly increased growth performance, serum and liver antioxidative function, immune function, intestinal VH and VH/CD, and cecal microbiota Shannon index in heat-stressed quails (P < 0.05). Melittin significantly decreased small intestinal CD, and HSP70 and HSP90 mRNA levels in the viscera (P < 0.05). Furthermore, dietary melittin could have balanced the disorder of cecal microbiota caused by heat stress and increased the abundance and diversity of beneficial microbiota (e.g., Firmicutes were significantly increased). PICRUSt2 functional prediction revealed that most of the KEGG pathways with differential abundance caused by high temperature were related to metabolism, and melittin could have restored them close to normal levels. Spearman correlation analysis showed that the beneficial intestinal bacteria Anaerotruncus, Bacteroidales_S24-7_group_norank, Lachnospiraceae_unclassified, Shuttleworthia, and Ruminococcaceae_UCG-014 increased by melittin were positively correlated with average daily feed intake, the average daily gain, serum and liver superoxide dismutase, IgG, IgA, bursa of Fabricius index, and ileum VH and VH/CD. In sum, our results demonstrate for the first time that dietary melittin could improve the adverse effects of heat stress on antioxidant function, immune function, heat shock protein, intestinal morphology, and cecal microbiota in quails, consequently improving their production performance under heat stress.

Investigating the cecal microbiota of broilers raised in extensive and intensive production systems

Intensive broiler production practices are structured to prevent the introduction and spread of pathogens; however, they can potentially minimize the exposure of broilers to beneficial commensal bacteria. In this study, we used 16S rRNA amplicon sequencing to characterize the cecal microbiota of 35-day-old broilers from 22 independent commercial farms rearing broilers under intensive (IPS) or extensive production systems (EPS). We aimed to determine which bacteria are normal inhabitants of the broiler ceca and which bacteria might be missing from broilers in IPS. In addition, we generated a collection of 410 bacterial isolates, including 87 different species, to be used as a resource to further explore the effects of selected isolates on bird physiology and to elucidate the role of individual species within the cecal microbial community. Our results indicated significant differences in the microbiota of broilers between systems: the microbiota of broilers from EPS was dominated by Bacteroidetes {55.2% ± 8.9 [mean ± standard deviation (SD)]}, whereas Firmicutes dominated the microbiota of broilers from IPS (61.7% ± 14.4, mean ± SD). Bacterial taxa found to be core in the EPS microbiota, including Olsenella, Alistipes, Bacteroides, Barnesiella, Parabacteroides, Megamonas, and Parasutterella, were shown to be infrequent or absent from the IPS microbiota, and the EPS microbiota presented higher phylogenetic diversity and greater predicted functional potential than that of broilers in IPS. The bacteria shown to be depleted in broilers from IPS should be further investigated for their effects on bird physiology and potential application as next-generation probiotics. IMPORTANCE Production practices in intensive farming systems significantly reduce the introduction and spread of pathogens; however, they may potentially minimize the exposure of animals to beneficial commensal microorganisms. In this study, we identified core bacteria from the cecal microbiota of broilers raised in extensive production systems that are missing or reduced in birds from intensive systems, including Olsenella, Alistipes, Bacteroides, Barnesiella, Parabacteroides, Megamonas, and Parasutterella. Furthermore, the cecal microbiota of broilers from extensive systems showed higher diversity and greater functional potential than that of broilers from intensive systems. In addition, a collection of bacterial isolates containing 87 different species was generated from the current study, and this important resource can be used to further explore the role of selected commensal bacteria on the microbial community and bird physiology.

Intestinal Immune Cell Populations, Barrier Function, and Microbiomes in Broilers Fed a Diet Supplemented with Chlorella vulgaris

This study aimed to evaluate the effects of dietary Chlorella vulgaris (CV) on the distribution of immune cells, intestinal morphology, intestinal barrier function, antioxidant markers, and the cecal microbiome in 10-day-old broiler chickens. A total of 120 day-old Ross 308 male broiler chicks were assigned to two dietary treatments using a randomized complete block design, with body weight as the blocking factor. Birds fed a diet containing CV showed an increase in CD4⁺ T cells (p < 0.05) compared to those fed the control diet. The relative mRNA expression of intestinal epithelial barrier function-related markers (occludin and avian β-defensin 5) was elevated (p < 0.05) in the CV-supplemented group compared to the control group. The alpha diversity indices (Chao1 and observed features) of the cecal microbiome in 10-day-old birds increased (p < 0.05), indicating higher richness within the cecal bacterial community. In the microbiome analysis, enriched genera abundance of Clostridium ASF356 and Coriobacteriaceae CHKCI002 was observed in birds fed the diet containing CV compared to those fed the control diet. Taken together, dietary CV supplementation might alter intestinal barrier function, immunity, and microbiomes in 10-day-old broiler chickens.

Anaerobutyricum and Subdoligranulum Are Differentially Enriched in Broilers with Disparate Weight Gains

The intestinal microbiota is critically important for animal health and productivity. However, the influence of the intestinal microbiota on animal growth efficiency remains elusive. This current study was aimed at identifying the intestinal bacteria that are associated with the growth rate of broilers in a commercial production setting. Ross 708 broilers with extremely high, medium, and extremely low body weight (BW) were separately selected for each sex from a house of approximately 18,000 chickens on day 42. The cecal content of each animal was subjected to 16S rRNA gene sequencing for microbiota profiling. Our results indicate that a number of bacteria were differentially enriched among different groups of broilers, with several showing a significant correlation (p < 0.05) with BW in both sexes or in a sex-specific manner. Subdoligranulum was drastically diminished in high-BW birds with a strong negative correlation with BW in both males and females. While one Anaerobutyricum strain showed a positive correlation with BW in both sexes, another strain of Anaerobutyricum was positively correlated with BW only in females. These sex-dependent and -independent bacteria could be targeted for improving the growth efficiency and may also be explored as potential biomarkers for the growth rate of broiler chickens.

Glucose oxidase as an alternative to antibiotic growth promoters improves the immunity function, antioxidative status, and cecal microbiota environment in white-feathered broilers

This study aimed to demonstrate the effects of glucose oxidase (GOD) on broilers as a potential antibiotic substitute. A total of four hundred twenty 1-day-old male Cobb500 broilers were randomly assigned into five dietary treatments, each with six replicates (12 chicks per replicate). The treatments included two control groups (a basal diet and a basal diet with 50 mg/kg aureomycin) and three GOD-additive groups involving three different concentrations of GOD. Analysis after the t-test showed that, on day 21, the feed:gain ratio significantly decreased in the 1,200 U/kg GOD-supplied group (GOD1200) compared to the antibiotic group (Ant). The same effect was also observed in GOD1200 during days 22-42 and in the 600 U/kg GOD-supplied group (GOD600) when compared to the control group (Ctr). The serum tests indicated that, on day 21, the TGF-β cytokine was significantly decreased in both GOD600 and GOD1200 when compared with Ctr. A decrease in malondialdehyde and an increase in superoxide dismutase in GOD1200 were observed, which is similar to the effects seen in Ant. On day 42, the D-lactate and glutathione peroxidase activity changed remarkably in GOD1200 and surpassed Ant. Furthermore, GOD upregulated the expression of the jejunal barrier genes (MUC-2 and ZO-1) in two phases relative to Ctr. In the aureomycin-supplied group, the secretory immunoglobulin A significantly decreased in the jejunum at 42 days. Changes in microbial genera were also discovered in the cecum by sequencing 16S rRNA genes at 42 days. The biomarkers for GOD supplementation were identified as Colidextribacter, Oscillibacter, Flavonifractor, Oscillospira, and Shuttleworthia. Except for Shuttleworthia, all the abovementioned genera were n-butyrate producers known for imparting their various benefits to broilers. The PICRUSt prediction of microbial communities revealed 11 pathways that were enriched in both the control and GOD-supplied groups. GOD1200 accounted for an increased number of metabolic pathways, demonstrating their potential in aiding nutrient absorption and digestion. In conclusion, a diet containing GOD can be beneficial to broiler health, particularly at a GOD concentration of 1,200 U/kg. The improved feed conversion ratio, immunity, antioxidative capacity, and intestinal condition demonstrated that GOD could be a valuable alternative to antibiotics in broiler breeding.

Effects of fermented Andrographis paniculata on growth performance, carcass traits, immune function, and intestinal health in Muscovy ducks

The study aimed to examine the effects of unfermented and fermented Andrographis paniculata on growth performance, carcass traits, immune function, and intestinal health in Muscovy ducks. A total of 450 (16-day-old) Muscovy ducks weighing 271.44 ± 8.25 g were randomly assigned to 5 dietary treatments (6 replicate pens of 15 ducks per treatment), consisting of one control treatment (basal diet without A. paniculata), one unfermented A. paniculata treatment (basal diet plus 30 g/kg unfermented A. paniculata) and 3 fermented A. paniculata treatments (basal diet plus 10, 30, and 50 g/kg). 30 g/kg unfermented A. paniculata increased the ADG, thymus index, peripheral blood lymphocyte conversion rate, villi height, intestinal thickness, villi surface area, intraepithelial lymphocytes rate, while decreased the FCR. 10 g/kg fermented A. paniculata markedly boosted ADG, bursa of fabricius index, thymus index, serum lysozyme, lymphocyte conversion rate, villi height, vilii width, intestinal thickness, villi surface area, while decreased the FCR. 30 g/kg fermented A. paniculata clearly improved ADG, bursa of fabricius index, thymus index, serum lysozyme, lymphocyte conversion rate, villi height, vilii width, intestinal thickness, villi surface area, intraepithelial lymphocytes, while decreased FCR. 50 g/kg fermented A. paniculata significantly increased villi height, vilii width, and villi surface area, while clearly reduced BW. Additionally, compared to 30 g/kg unfermented A. paniculata, 30 g/kg fermented A. paniculata obviously increased bursa of fabricius indices, lymphocyte conversion rate, vilii width, villi surface area. On top of that, supplementation with unfermented and fermented A. paniculata (30 g/kg each) decreased the relative abundance of harmful bacteria (Succinivibrio, Succinatimonas, Sphaerochaeta, and Mucispirillum) and increase the abundance of beneficial bacteria (Rikenellaceae, Methanocorpusculum, Fournierella, Ruminococcaceae) in the ceca of the ducks. However, fermented A. paniculata had considerable better effects than unfermented A. paniculate on all above measured indices. Overall, these results revealed that supplementation with unfermented and fermented A. paniculata across different treatments improved growth, immune status, intestinal morphology, and intestinal microbiota composition and structure in Muscovy ducks, making it a potential alternative to antibiotics in poultry production.

Gut Microbiota, Intestinal Morphometric Characteristics, and Gene Expression in Relation to the Growth Performance of Chickens

this study aimed to investigate the growth mechanism in a local breed of chickens by comparing the highest weight (HW) and the lowest weight in their microbiota, histological characteristics, and gene expression. Golden Montazah chickens, an Egyptian breed, were reared until they were 49 days old. All of the birds were fed ad libitum by a starter diet from day 1 until day 21, followed by a grower diet from day 21 to the end of the study. At 49 days old, the forty-eight birds with the heaviest body weight (HW) and the lightest body weight (LW) were chosen. Blood biochemical and histological morphometric parameters, electron microscopy, and intestinal nutrient transporter gene expression were studied in the sampled jejunum. The microbial composition and functions of the content and mucosa in HW and LW chickens were studied using 16S rRNA gene sequencing. The histological morphometric parameters were all more significantly (p < 0.05) increased in the HW chickens than in the LW chickens. Total protein, albumin, and triglycerides in serum were significantly higher (p < 0.05) in the HW chickens than in the LW chickens. The microbiome profile in the gut showed that Microbacterium and Sphingomonas were positively correlated with the body weights. In the local breed, there were significant differences in the intestinal microstructure which could enhance the growth mechanism and body weight. Our findings showed that some microbial components were significantly associated with body weight and their interactions with the host could be inferred to explain why these interactions might alter the host’s metabolic responses. Further investigation into combining bioinformatics with lab experiments in chickens will help us to understand how gut bacteria can change the host’s metabolism by special metabolic features in the gastrointestinal system.

Dynamic Changes in the Gut Microbial Community and Function during Broiler Growth

During the entire growth process, gut microbiota continues to change and has a certain impact on the performance of broilers. Here, we used 16S rRNA gene sequencing to explore the dynamic changes in the fecal bacterial communities and functions in 120 broilers from 4 to 16 weeks of age. We found that the main phyla (Firmicutes, Fusobacteria, Proteobacteria, and Bacteroides) accounted for more than 93.5% of the total bacteria in the feces. The alpha diversity of the fecal microbiota showed a downward trend with time, and the beta diversity showed significant differences at various time points. Then, the study on the differences of microbiota between high-weight (HW) and low-weight (LW) broilers showed that there were differences in the diversity and composition of microbiota between high- and low-weight broilers. Furthermore, we identified 22 genera that may be related to the weight change of broilers. The analysis of flora function reveals their changes in metabolism, genetic information processing, and environmental information processing. Finally, combined with microbial function and cecal transcriptome results, we speculated that microorganisms may affect the immune level and energy metabolism level of broilers through their own carbohydrate metabolism and lipid metabolism and then affect body weight (BW). Our results will help to expand our understanding of intestinal microbiota and provide guidance for the production of high-quality broilers.

IMPORTANCE The intestinal microbiota has a certain impact on the performance of broilers. However, the change of intestinal microbiota after 4 weeks of age is not clear, and the mechanism of the effect of microorganisms on the weight change of broilers needs more exploration. After 4 weeks of age, the alpha diversity of microorganisms in broiler feces decreased, and the dominant bacteria were Firmicutes, Fusobacteria, Proteobacteria, and Bacteroides. There were differences in microbiota diversity and composition between high- and low-weight broilers. Intestinal microorganisms may affect the immune level and energy metabolism level of broilers through their own carbohydrate metabolism and lipid metabolism and then affect the body weight. The results are helpful to increase the understanding of intestinal microbiota and provide reference for the production of high-quality broilers.