Effect of Bacillus subtilis CGMCC 1.1086 on the growth performance and intestinal microbiota of broilers

Microbiome-based precision nutrition: Prebiotics, probiotics and postbiotics

Microorganisms have been used in nutrition and medicine for thousands of years worldwide, long before humanity knew of their existence. It is now known that the gut microbiota plays a key role in regulating inflammatory, metabolic, immune and neurobiological processes. This text discusses the importance of microbiota-based precision nutrition in gut permeability, as well as the main advances and current limitations of traditional probiotics, new-generation probiotics, psychobiotic probiotics with an effect on emotional health, probiotic foods, prebiotics, and postbiotics such as short-chain fatty acids, neurotransmitters and vitamins. The aim is to provide a theoretical context built on current scientific evidence for the practical application of microbiota-based precision nutrition in specific health fields and in improving health, quality of life and physiological performance.

Investigating antibiotic free feed additives for growth promotion in poultry: effects on performance and microbiota

The poultry industry is evolving towards antibiotic-free production to meet market demands and decelerate the increasing spread of the antimicrobial resistance. The growing need for antibiotic free products has challenged producers to decrease or completely stop using antimicrobials as feed supplements in broiler diet to improve feed efficiency, growth rate, and intestinal health. Natural feed additives (e.g., probiotics and phytobiotics) are promising alternatives to substitute antimicrobial growth promoters. The goal of our study was to characterize the effects of a Probiotic and an Essential Oils blend on broilers' performance and perform a time-series analysis to describe their excreta microbiome. A total of 320 Cobb 500 (1-day-old) chicks were raised for 21 d in 32 randomly allocated cages. Treatments consisted of 4 experimental diets: a basal diet, and a basal diet mixed with an Antibiotic (bacitracin methylene disalicylate), an essential oils blend (oregano oil, rosemary, and red pepper), or a Probiotic (Bacillus subtilis). Body weight (on 1, 10, and 21d), and feed intake (10d and 21d) were recorded and feed conversion ratio was calculated. Droppings were collected daily (1-21d) to characterize broilers' excreta microbiota by targeted sequencing of the bacterial 16S rRNA gene. The Probiotic significantly improved feed conversion ratio for starter phase 1 to 10d (P = 0.03), grower phase 10 to 21d (P = 0.05), and total period 1 to 21d (P = 0.01) compared to the Antibiotic. Feed supplements did not affect alpha diversity but did impact microbial beta diversity (P < 0.01). Age also impacted microbiome turnover as differences in alpha and beta diversity were detected. Furthermore, when compared to the basal diet, the probiotic and antibiotic significantly impacted relative abundance of Bifidobacterium (log2 fold change -1.44, P = 0.03), Intestinimonas (log2 fold change 0.560, P < 0.01) and Ligilactobacillus (log2 fold change -1.600, P < 0.01). Overall, Probiotic supplementation but not essential oils supplementation positively impacted broilers' growth performance by directly causing directional shifts in broilers' excreta microbiota structure.

Dietary probiotic Lacticaseibacillus paracasei NSMJ56 modulates gut immunity and microbiota in laying hens

This study was performed to investigate supplementary effects of probiotic Lacticaseibacillus paracasei NSMJ56 strain on laying performance, egg quality, intestinal histology, antioxidant status, gut immunity and microbiota in laying hens. A total of ninety-six 21-wk-old Hy-Line Brown laying hens were randomly subjected to one of 2 dietary treatments: a control group fed a non-supplemented diet, or a probiotic group fed with a diet supplemented with 1 g of Lacticaseibacillus paracasei NSMJ56 (5 × 108 CFU/kg of diet). The trial lasted for 4 wk. Egg weight was increased (P < 0.05) in laying hens fed probiotic-fed diet compared with the control group. Dietary probiotics did not affect egg quality except for Haugh unit, which was improved (P < 0.05) in the probiotic-fed group. Neither jejunal histology nor cecal short-chain fatty acids were affected by dietary treatments. Dietary probiotics increased the activity of catalase compared with the control group. Flow cytometry analysis revealed that dietary probiotics elevated the CD4+ T cells, but not CD8+ T cells, in jejunal lamina propria. Based on the LEfSe analysis at the phylum and genus levels, Erysipelotrichales, Erysipelotrichia, Flintibater, Dielma, Hespellia, Coprobacter, Roseburia, Anaerotignum, and Coprococcus were enriched in the probiotic group compared with the control group. Taken together, our study showed that dietary probiotics could be used to improve some parameters associated with egg freshness and antioxidant capacity, and to partially alter T cell population and microbial community in laying hens.

Bacillus amyloliquefaciens SC06 alleviated intestinal damage induced by inflammatory via modulating intestinal microbiota and intestinal stem cell proliferation and differentiation

The aim of our research was to investigate the effects of Bacillus amyloliquefaciens SC06 on growth performance, immune status, intestinal stem cells (ISC) proliferation and differentiation, and gut microbiota in weaned piglets. Twelve piglets (male, 21 days old, 6.11 ± 0.12 kg) were randomly allocated to CON and SC06 (1 × 108 cfu/kg to diet) groups. This experiment lasted three weeks. Our results showed that SC06 increased (P < 0.05) growth performance and reduced the diarrhea rate in weaned piglets. In addition, SC06 increased intestinal morphology and interleukin (IL)-10 levels, and decreased (P < 0.01) necrosis factor (TNF-α) levels in jejunum and serum. Moreover, weaning piglets fed SC06 had a better balance of colonic microbiota, with an increase in the abundance of Lactobacillus. Furthermore, SC06 enhanced ISCs proliferation and induced its differentiation to goblet cells via activating wnt/β-catenin pathway in weaned piglets and intestinal organoid. Taken together, SC06 supplementation improved the growth performance and decreased inflammatory response of piglets by modulating intestinal microbiota, thereby accelerating ISC proliferation and differentiation and promoting epithelial barrier healing.

The Mechanism of Pyroptosis and Its Application Prospect in Diabetic Wound Healing

Pyroptosis defines a form of pro-inflammatory-dependent programmed cell death triggered by gasdermin proteins, which creates cytoplasmic pores and promotes the activation and accumulation of immune cells by releasing several pro-inflammatory mediators and immunogenic substances upon cell rupture. Pyroptosis comprises canonical (mediated by Caspase-1) and non-canonical (mediated by Caspase-4/5/11) molecular signaling pathways. Numerous studies have explored the contributory roles of inflammasome and pyroptosis in the progression of multiple pathological conditions such as tumors, nerve injury, inflammatory diseases and metabolic disorders. Accumulating evidence indicates that the activation of the NOD-like receptor thermal protein domain associated protein 3 (NLRP3) inflammasome results in the activation of pyroptosis and inflammation. Current evidence suggests that pyroptosis-dependent cell death plays a progressive role in the development of diabetic complications including diabetic wound healing (DWH) and diabetic foot ulcers (DFUs). This review presents a brief overview of the molecular mechanisms underlying pyroptosis and addresses the current research on pyroptosis-dependent signaling pathways in the context of DWH. In this review, we also present some prospective therapeutic compounds/agents that can target pyroptotic signaling pathways, which may serve as new strategies for the effective treatment and management of diabetic wounds.

Effects of dietary supplementation with tea polyphenols and probiotics on laying performance, biochemical parameters intestinal morphology and microflora of laying hens

This study was conducted to investigate the effects of tea polyphenols (TP) and probiotics (PB) on the production performance, biochemical indices, and gut health of laying hens. A total of 400 Hy-line Brown layers (45 weeks old) were randomly assigned to 8 diet groups for 8-week feeding trial. Compared with the control basal diet (CT), dietary high dosage of TP and PB (HTP-PB) increased egg mass (P < 0.05). Supplementation with HTP-PB improved the levels of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) and decreased the malonic dialdehyde (MDA) content (P < 0.05) without affecting the contents of immunoglobulins in the serum. The combination of HTP and PB supplementation promoted the secretion of estradiol (E2) and progesterone (PROG) compared with treatment with TP or PB alone (P < 0.05). The combined use of HTP and PB induced higher jejunal villus height (VH) than the CT group (P < 0.05). Dietary TP and PB could optimize the functional network of intestinal microflora and the interactions between the intestinal microflora and the host. Therefore, the combined use of the high dosage of TP and PB affected laying performance, improved antioxidant capacity, and promoted intestinal health, which may be associated with regulation of the intestinal microbiota.

Effects of dietary Astragalus membranaceus and Codonopsis pilosula extracts on growth performance, antioxidant capacity, immune status, and intestinal health in broilers

The objective of this study was to examine the effects of dietary Chinese herbal medicine (CHM) consisting of Astragalus membranaceus (Fisch.) Bunge (AMT) and Codonopsis pilosula (Franch.) Nannf (CPO) extracts on growth performance, antioxidant capacity, immune status, and intestinal health of broiler chickens. Two groups were formed, each consisting of six replicates of 12 one-day-old healthy male 817 white feather broilers. Broilers were fed either a basal diet (CON group) or a basal diet supplemented with 500 mg/kg CHM. The trial lasted 50 days. The results showed that CHM supplementation resulted in enhanced feed efficiency and antioxidant capacity in both the serum and liver, while it reduced uric acid and endotoxin levels, as well as diamine oxidase activity (p < 0.05). Additionally, CHM treatment increased the height of jejunum villi and upregulated Claudin-1 expression in the jejunal mucosa accompanied by an increase in the mRNA levels of interleukin-6 (IL-6), interferon-γ (IFN-γ), interferon-β (IFN-β), tumor necrosis factor-α (TNF-α), and anti-inflammatory cytokine interleukin-10 (IL-10) (p < 0.05). The presence of dietary CHM caused an increase in the proportions of Bacteroidetes and unclassified Bacteroidales but led to a decrease in those of Firmicutes and Alistipes (p < 0.05). The composition of the jejunal mucosa microbiota was correlated with the feed conversion ratio, serum metabolites, and gene expression based on Spearman correlation analysis. The findings indicated that the consumption of dietary CHM improved the utilization of feed, increased the mRNA expression of pro-inflammatory cytokines in the jejunal mucosa, and decreased the endotoxin level and activities of diamine oxidase and lactate dehydrogenase in the serum, which could potentially be linked to changes in the gut microbiota of broiler chickens.

Effect of urbanization and parasitism on the gut microbiota of Darwin's finch nestlings

Host-associated microbiota can be affected by factors related to environmental change, such as urbanization and invasive species. For example, urban areas often affect food availability for animals, which can change their gut microbiota. Invasive parasites can also influence microbiota through competition or indirectly through a change in the host immune response. These interacting factors can have complex effects on host fitness, but few studies have disentangled the relationship between urbanization and parasitism on an organism's gut microbiota. To address this gap in knowledge, we investigated the effects of urbanization and parasitism by the invasive avian vampire fly (Philornis downsi) on the gut microbiota of nestling small ground finches (Geospiza fuliginosa) on San Cristóbal Island, Galápagos. We conducted a factorial study in which we experimentally manipulated parasite presence in an urban and nonurban area. Faeces were then collected from nestlings to characterize the gut microbiota (i.e. bacterial diversity and community composition). Although we did not find an interactive effect of urbanization and parasitism on the microbiota, we did find main effects of each variable. We found that urban nestlings had lower bacterial diversity and different relative abundances of taxa compared to nonurban nestlings, which could be mediated by introduction of the microbiota of the food items or changes in host physiology. Additionally, parasitized nestlings had lower bacterial richness than nonparasitized nestlings, which could be mediated by a change in the immune system. Overall, this study advances our understanding of the complex effects of anthropogenic stressors on the gut microbiota of birds.

Efficacy of Bacillus subtilis to replace in-feed antibiotics of broiler chickens under necrotic enteritis-challenged experiments: a systematic review and meta-analysis

Necrotic enteritis (NE) and coccidiosis are among the most prevalent infectious diseases in broiler chickens, contributing to large profitability losses. Bacillus subtilis is a promising direct-fed probiotic to counter various pathogens infection in broiler chickens. Here, we performed a meta-analysis to investigate the effects of B. subtilis on broiler chickens performance. A total of 28 studies were selected according to a PRISMA checklist. Random-effect model and mixed-effect model of meta-analysis were fitted to estimate the overall effects of B. subtilis (BS) treatment compared to either the control group (CON) or NE-infected group (NEinf) as a baseline. Hedges' g effect size and its variance were used as estimators of standardized mean difference (SMD) calculation where the results were presented at a 95% confidence interval (95% CI) of the SMD. Overall, NEinf broiler chickens depressed (P < 0.01) body weight (BW), average daily gain (ADG), and feed intake, and elevated (P < 0.01) feed conversion ratio (FCR). Treatment with BS improved ADG and final BW of NEinf with no difference (P = 0.15) between BS and antibiotics (AB), indicating that they had comparable efficacy to treat NE in broiler chickens. BS supplemented to uninfected CON (BSS) improved (P < 0.01) final BW, ADG, and FCR. Compared to CON, BS, and AB failed to recover the FCR but these treatments decreased (P < 0.01) FCR when compared to the NEinf group with similar efficacy (P = 0.97). As expected, NEinf birds had a higher mortality rate (P < 0.01) and higher lesion score (P < 0.01) compared to CON, and treatment using AB and BS successfully decreased (P < 0.01) the mortality rate and lesion score. Compared to BS, AB was more effective to lower (P = 0.01) mortality rate, but comparable (P = 0.65) to minimize lesion score. To conclude, B. subtilis could be an effective natural additive to replace in-feed antibiotics in broiler chickens challenged with C. perfringens. However, the efficacy to reduce mortality rate was better with antibiotics treatment.

Metabolic and inflammatory linkage of the chicken cecal microbiome to growth performance

Introduction

Chinese indigenous chicken breeds are widely used as food in China but their slow growth rate and long farming cycle has limited their industrial production.

Methods

In the current study we examined whether the market weights of native chicken breeds were related to specific cecal bacteria, serum metabolites and inflammatory cytokines. We examined cecal bacterial taxa using 16S rDNA analysis along with untargeted serum metabolites and serum inflammatory cytokines.

Results

We found that the cecal microbiota could explain 10.1% of the individual differences in chicken weights and identified key cecal bacterial genera that influenced this phenotype. The presence of Sphaerochaeta spp. improved growth performance via bovinic acid metabolism. In contrast, Synergistes and norank_f_Desulfovibrionaceae had a negative effect on growth by inducing expression of the inflammatory cytokine IL-6.

Discussion

We were able to link specific bacterial genera with growth promotion in chickens and this study will allow further development of their use as probiotics in these animals.

Fermented Black Tea and Its Relationship with Gut Microbiota and Obesity: A Mini Review

Fermentation is one of the world’s oldest techniques for food preservation, nutrient enhancement, and alcohol manufacturing. During fermentation, carbohydrates such as glucose and starch are converted into other molecules, such as alcohol and acid, anaerobically through enzymatic action while generating energy for the microorganism or cells involved. Black tea is among the most popular fermented beverages; it is made from the dried tea leaves of the evergreen shrub plant known as Camellia sinensis. The adequate consumption of black tea is beneficial to health as it contains high levels of flavanols, also known as catechins, which act as effective antioxidants and are responsible for protecting the body against the development of illnesses, such as inflammation, diabetes, hypertension, cancer, and obesity. The prevalence of obesity is a severe public health concern associated with the incidence of various serious diseases and is now increasing, including in Malaysia. Advances in ‘omic’ research have allowed researchers to identify the pivotal role of the gut microbiota in the development of obesity. This review explores fermented black tea and its correlation with the regulation of the gut microbiota and obesity.

Dietary Oregano Essential Oil Supplementation Influences Production Performance and Gut Microbiota in Late-Phase Laying Hens Fed Wheat-Based Diets

This study aimed to investigate the potential effects of OEO on production performance, egg quality, fatty acid composition in yolk, and cecum microbiota of hens in the late phase of production. A total of 350 58-week-old Jing Tint Six laying hens were randomly divided into five groups: (1) fed a basal diet (control); (2) fed a basal diet + 5 mg/kg flavomycin (AGP); (3) fed a basal diet + 100 mg/kg oregano essential oil + 20 mg/kg cinnamaldehyde (EO1); (4) fed a basal diet + 200 mg/kg oregano essential oil + 20 mg/kg cinnamaldehyde (EO2); (5) fed a basal diet + 300 mg/kg oregano essential oil + 20 mg/kg cinnamaldehyde (EO3). Compared to the control group, group EO2 exhibited higher (p < 0.05) egg production during weeks 5−8 and 1−8. EO2 had a lower feed conversion ratio than the control group during weeks 1−8. The content of monounsaturated fatty acid (MUFA) in EO2 was higher (p < 0.05) than that of the control and AGP groups. EO2 increased (p < 0.05) the abundance of Actinobacteriota and decreased the abundance of Desulfovibri in the cecum. The abundances of Anaerofilum, Fournierella, Fusobacterium, and Sutterella were positively correlated with egg production, feed conversion ratio, and average daily feed intake, while the abundances of Bacteroides, Desulfovibrio, Lactobacillus, Methanobrevibacter, and Rikenellaceae_RC9_gut_group were negatively correlated with egg production, feed conversion ratio, and average daily feed intake. Dietary supplementation with 200 mg/kg OEO and 20 mg/kg cinnamaldehyde could improve egg-production performance, decrease feed conversion ratio, and alter the fatty acid and microbial composition of eggs from late-phase laying hens.

Modified Montmorillonite Improved Growth Performance of Broilers by Modulating Intestinal Microbiota and Enhancing Intestinal Barriers, Anti-Inflammatory Response, and Antioxidative Capacity

This study aims to explore the effects of modified montmorillonite (MMT, copper loading) on the growth performance, gut microbiota, intestinal barrier, antioxidative capacity and immune function of broilers. Yellow-feathered broilers were randomly divided into control (CTR), modified montmorillonite (MMT), and antibiotic (ANTI) groups. Results revealed that MMT supplementation increased the BW and ADG and decreased the F/R during the 63-day experiment period. 16S rRNA sequencing showed that MMT modulated the cecal microbiota composition of broilers by increasing the relative abundance of two phyla (Firmicutes and Bacteroidetes) and two genera (Bacteroides and Faecalibacterium) and decreasing the abundance of genus Olsenella. MMT also improved the intestinal epithelial barrier indicated by the up-regulated mRNA expression of claudin-1, occludin, and ZO-1 and the increased length of microvilli in jejunum and the decreased levels of DAO and D-LA in serum. In addition, MMT enhanced the immune function indicated by the increased levels of immunoglobulins, the decreased levels of MPO and NO, the down-regulated mRNA expression of IL-1β, IL-6, and TNF-α, and the up-regulated mRNA expression of IL-4 and IL-10. Moreover, MMT down-regulated the expression of jejunal TLRs/MAPK/NF-κB signaling pathway-related genes (TLR2, TLR4, Myd88, TRAF6, NF-κB, and iNOS) and related proteins (TRAF6, p38, ERK, NF-κB, and iNOS). In addition, MMT increased the antioxidant enzyme activities and the expression of Nrf2/HO-1 signaling pathway-related genes and thereby decreased the apoptosis-related genes expression. Spearman’s correlation analysis revealed that Bacteroides, Faecalibacterium, and Olsenella were related to the inflammatory index (MPO and NO), oxidative stress (T-AOC, T-SOD, and CAT) and intestinal integrity (D-LA and DAO). Taken together, MMT supplementation improved the growth performance of broilers by modulating intestinal microbiota, enhancing the intestinal barrier function, and improving inflammatory response, which might be mediated by inhibiting the TLRs/MAPK/NF-κB signaling pathway, and antioxidative capacity mediated by the Nrf2/HO-1 signaling pathway.

Effects of dietary palygorskite supplementation on the growth performance, oxidative status, immune function, intestinal barrier and cecal microbial community of broilers

The present study aimed to investigate the effects of palygorskite (PAL) as an alternative to antibiotic on the growth performance, oxidative status, immune function, intestinal barrier and cecal microbial community of broilers. A total of 360 1-day-old male Ross-308 broilers were randomly allotted to three treatments with eight replicates. Broilers in the three groups were designated as follows: basal diet (CON group), basal diet+50 mg/kg chlorotetracycline (ANT group), and basal diet+ 10 g/kg PAL (PAL group). Supplementing PAL reduced feed to gain ratio in broilers during 22 to 42 days of age (P &lt; 0.05), with its value being similar to that of the ANT group (P &gt; 0.05). Broilers fed a PAL-supplemented diet exerted decreased contents of interferon-γ (IFN-γ) and interleukin-1β in serum, and the same reduction was found in jejunal IFN-γ level, when compared to the CON group (P &lt; 0.05). Moreover, compared with the CON group, broilers after PAL treatment had a lower malondialdehyde content in jejunal mucosa (P &lt; 0.05). Supplementing PAL elevated jejunal villus height (VH) and ratio of VH to crypt depth compared with the ANT group (P &lt; 0.05). Cecal microbiota communities among the three groups were significant different, as demonstrated by distinct clusters from partial least squares discriminant analysis, although dietary treatments had no significant effects on the bacterial richness and diversity indices (P &gt; 0.05). At genus level, the addition of PAL increased the relative abundance of norank_f__Barnesiellaceae and decreased that of unclassified_f__Oscillospiraceae in cecal digesta compared with those in the CON group (P &lt; 0.05); the proportion of genus norank_f__Barnesiellaceae was increased by PAL treatment when compared with the ANT group (P &lt; 0.05). Moreover, spearman's correlations showed that the modulation of cecal microflora composition by PAL supplementation was closely correlated with the promotion of growth performance (feed to gain ratio) and intestinal health-related (contents of malondialdehyde and IFN-γ, and VH value in jejunum) variables of broilers (P &lt; 0.05). Taken together, dietary PAL could improve the growth performance, antioxidant capacity, and immune status, as well as intestinal barrier function in broilers, which might be partially associated with the alteration of cecal microbiota. Moreover, dietary PAL may be a promising alternative to antibiotic growth promoter for broilers.

Chicken jejunal microbiota improves growth performance by mitigating intestinal inflammation

Background

Intestinal inflammation is prevalent in chicken, which results in decreased growth performance and considerable economic losses. Accumulated findings established the close relationship between gut microbiota and chicken growth performance. However, whether gut microbiota impacts chicken growth performance by lessening intestinal inflammation remains elusive.

Results

Seven-weeks-old male and female chickens with the highest or lowest body weights were significantly different in breast and leg muscle indices and average cross-sectional area of muscle cells. 16S rRNA gene sequencing indicated Gram-positive bacteria, such as Lactobacilli, were the predominant species in high body weight chickens. Conversely, Gram-negative bacteria, such as Comamonas, Acinetobacter, Brucella, Escherichia-Shigella, Thermus, Undibacterium, and Allorhizobium-Neorhizobium-Pararhizobium-Rhizobium were significantly abundant in low body weight chickens. Serum lipopolysaccharide (LPS) level was significantly higher in low body weight chickens (101.58 ± 5.78 ng/mL) compared with high body weight chickens (85.12 ± 4.79 ng/mL). The expression of TLR4, NF-κB, MyD88, and related inflammatory cytokines in the jejunum was significantly upregulated in low body weight chickens, which led to the damage of gut barrier integrity. Furthermore, transferring fecal microbiota from adult chickens with high body weight into 1-day-old chicks reshaped the jejunal microbiota, mitigated inflammatory response, and improved chicken growth performance.

Conclusions

Our findings suggested that jejunal microbiota could affect chicken growth performance by mitigating intestinal inflammation.

In ovo Inoculation of Bacillus subtilis and Raffinose Affects Growth Performance, Cecal Microbiota, Volatile Fatty Acid, Ileal Morphology and Gene Expression, and Sustainability of Broiler Chickens (Gallus gallus)

Banning antibiotic growth promoters has negatively impacted poultry production and sustainability, which led to exploring efficient alternatives such as probiotics, probiotics, and synbiotics. Effect of in ovo injection of Bacillus subtilis, raffinose, and their synbiotics on growth performance, cecal microbial population and volatile fatty acid concentration, ileal histomorphology, and ileal gene expression was investigated in broilers (Gallus gallus) raised for 21 days. On 300 h of incubation, a total of 1,500 embryonated eggs were equally allotted into 10 groups. The first was non-injected (NC) and the remaining in ovo injected with sterile distilled water (PC), B. subtilis 4 × 10⁵ and 4 × 10⁶ CFU (BS1 and BS2), Raffinose 2 and 3 mg (R1 and R2), B. subtilis 4 × 10⁵ CFU + raffinose 2 mg (BS1R1), B. subtilis 4 × 10⁵ CFU + raffinose 3 mg (BS1R2), B. subtilis 4 × 10⁶ CFU + raffinose 2 mg (BS2R1), and B. subtilis 4 × 10⁶ CFU + raffinose 3 mg (BS2R2). At hatch, 60 chicks from each group were randomly chosen, divided into groups of 6 replicates (10 birds/replicate), and fed with a corn–soybean-based diet. In ovo inoculation of B. subtilis and raffinose alone or combinations significantly improved body weight, feed intake, and feed conversion ratio of 21-day-old broilers compared to NC. Cecal concentrations of butyric, pentanoic, propionic, and isobutyric acids were significantly elevated in R1, R2, BS2R1, and BS2R2, whereas isovaleric and acetic acids were significantly increased in R1 and BS2R1 compared to NC. Cecal microbial population was significantly altered in treated groups. Ileal villus height was increased (p < 0.001) in BS1, R2, and BS2R2 compared to NC. The mRNA expression of mucin-2 was upregulated (p < 0.05) in synbiotic groups except for BS1R1. Vascular endothelial growth factor (VEGF) expression was increased (p < 0.05) in BS2, R1, BS1R1, and BS1R2 compared to NC. SGLT-1 expression was upregulated (p < 0.05) in all treated birds except those of R1 group compared to NC. The mRNA expressions of interleukin (IL)-2 and toll-like receptor (TLR)-4 were downregulated (p < 0.05) in BS2 and R1 for IL-2 and BS1R1 and BS2R2 for TLR-4. It was concluded that in ovo B. subtilis, raffinose, and synbiotics positively affected growth performance, cecal microbiota, gut health, immune responses, and thus the sustainability of production in 21-day-old broilers.

The Microbiota and It’s Correlation With Metabolites in the Gut of Mice With Nonalcoholic Fatty Liver Disease

In recent years, nonalcoholic fatty liver disease (NAFLD) has become the most common liver disease in the world. As an important model animal, the characteristics of gut microbiota alteration in mice with NAFLD have been studied but the changes in metabolite abundance in NAFLD mice and how the gut microbiota affects these intestinal metabolites remain unclear. In this experiment, a mouse model for NAFLD was established by a high-fat diet. The use of 16S rDNA technology showed that while there were no significant changes in the alpha diversity in the cecum of NAFLD mice, the beta diversity changed significantly. The abundance of Blautia, Unidentified-Lachnospiraceae, Romboutsia, Faecalibaculum, and Ileibacterium increased significantly in NAFLD mice, while Allobaculum and Enterorhabdus decreased significantly. Amino acids, lipids, bile acids and nucleotide metabolites were among the 167 significantly different metabolites selected. The metabolic pathways of amino acids, SFAs, and bile acids were significantly enhanced, while the metabolic pathways of PUFAs, vitamins, and nucleotides were significantly inhibited. Through correlation and MIMOSA2 analysis, it is suggested that gut microbiota does not affect the changes of lipids and bile acids but can reduce thiamine, pyridoxine, and promote L-phenylalanine and tyramine production. The findings of this study will help us to better understand the relationship between gut microbiota and metabolites in NAFLD.

Bacillus subtilis WB800N alleviates diabetic wounds in mice by regulating gut microbiota homeostasis and TLR2

OBJECTIVE

This study aims to investigate the effect of Bacillus subtilis WB800N on diabetic wounds.

METHODS

Hematoxylin & eosin (H&E) staining was used to observe the healing of skin wounds. Collagen deposition was assessed by Masson staining. Western blotting and qRT-PCR were used to detect vascular endothelial-related factors (VWF), CD31, TLR2, NLRP3, ASC, and Caspase-1 expression. 16S rDNA sequencing detected microbiota distribution. The concentrations of IL-1β and IL-37 were measured by ELISA. Apoptosis was measured by the TUNEL assay.

RESULTS

Compared with the control group, the wound healing was delayed in diabetic mice. The wound area in the Bacillus subtilis group decreased more significantly than the diabetic wounds group. H&E staining showed that Bacillus subtilis WB800N promoted wound healing and increased re-epithelialization. Masson staining showed that Bacillus subtilis WB800N increased collagen deposition in diabetic wounds mice. Bacillus subtilis WB800N upregulated VWF and CD31 protein expression in diabetic wounds mice. The 16S rDNA results showed that Bacillus subtilis WB800N reduced the diversity of the gut microbiota of diabetic wounds mice and regulated the microbial composition. At the genus level, Bacillus subtilis WB800N reduced the relative abundance of Muribaculaceae and CG-005 in diabetic wounds mice, while increasing the relative abundance of Lactobacillus. Bacillus subtilis WB800N increased the expression of TLR2, NLRP3, ASC, and Caspase-1. Bacillus subtilis WB800N increased the concentrations of IL-1β and IL-37 in serum. Bacillus subtilis WB800N upregulated cell apoptosis. The TLR2 antagonist Sparstolonin B (SsnB) reduced the expression of TLR2, NLRP3, ASC, Caspase-1, IL-1β, and IL-37 and the apoptosis in diabetic wounds mice, while the combined intervention of Bacillus subtilis and SsnB reversed the effect of SsnB treatment alone.

CONCLUSION

Bacillus subtilis WB800N alleviated diabetic wounds healing by regulating gut microbiota homeostasis and TLR2.

SIGNIFICANCE AND IMPACT OF RESEARCH

Our findings might provide potential therapeutic targets for diabetic wounds.

Multi-Omics Revealed the Protective Effects of Rhamnolipids in Lipopolysaccharide Challenged Broilers

Rhamnolipid (RL) is a glycolipid biosurfactant and exhibits the following outstanding characteristics: strong antibacterial properties, low toxicity, and high biodegradability. The present research was conducted to explore the protective effects and mechanisms of rhamnolipids as an alternative to antibiotics in LPS (lipopolysaccharide)-challenged broilers. 16S rRNA gene sequencing and metabolomics were used for analyzing the cecal microbial composition and serum metabolites. Dietary antibiotics and RLS supplementation decreased the weight loss rate, enhanced serum immunoglobulin levels, reduced serum diamine oxidase and D-lactate acid concentration, and improved the symptoms of intestinal bleeding and villus height, when broilers were challenged with LPS. The addition of RLS in the diet enhanced serum interleukin-4 and interleukin-10 contents and reduced serum interleukin-6 and tumor necrosis factor-α levels in LPS-challenged broilers compared with the antibiotics group. Spearman’s correlation analysis revealed that RLS may alleviate LPS-induced inflammatory responses through altering the 6-methoxymellein level in broilers. The genus Bacteroides may contribute to the decreased weight loss rate via regulating the serum lysoPC [20:5(5Z,8Z,11Z,14Z,17Z)] secretion. RLS alleviates LPS-induced intestinal injury, enhances the growth and immunity, ameliorates intestinal microflora, and improves serum metabolites in LPS-challenged broilers. RLS exhibited better protective effect than antibiotic supplementation in the diet of LPS-challenged broilers. These findings provide potential regulation strategies and novel insights for RLS enhancing its protective effect in LPS-challenged broilers.

Rhamnolipids enhance growth performance by improving the immunity, intestinal barrier function, and metabolome composition in broilers

BACKGROUND

Rhamnolipids (RLS), well known as glycolipid biosurfactants, display low toxicity, high biodegradability, and strong antibacterial properties. This study was carried out to evaluate the use of RLS supplementation as a substitute for antibiotics, and particularly to evaluate its effects on growth performance, immunity, intestinal barrier function, and metabolome composition in broilers.

RESULTS

The RLS treatment improved the growth performance, immunity, and intestinal barrier function in broilers. The 16S rRNA sequencing revealed that the genus Alistipes was the dominant genus in broilers treated by RLS. An ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS)-based metabolomic analysis indicated that the sphingolipid metabolism, glycine, serine, and threonine metabolism, the gycerophospholipid metabolism, and the tryptophan metabolism were changed in broilers that were treated with RLS.

CONCLUSION

l-Tryptophan may be the medium for RLS to regulate the growth and physiological metabolism. Rhamnolipids can be used as a potential alternative to antibiotics, with similar functions to antibiotics in the diet of broilers. The optimal level of supplemented RLS in the diet was 1000 mg kg^-1 . © 2021 Society of Chemical Industry.

Effects of zinc and Bacillus subtilis on the reproductive performance, egg quality, nutrient digestion, intestinal morphology, and serum antioxidant capacity of geese breeders

The effects of zinc (Zn) and Bacillus subtilis (B. subtilis) on reproductive performance, egg quality, nutrient digestion, intestine morphology, and antioxidant capacity were explored in geese breeders. Geese breeders (n = 120, 46-wk of age) were randomly assigned into 6 groups with 4 replicates of 5 birds each (1 male and 4 female). Breeders were fed diets with 2 levels of B. subtilis (2.5 × 10⁹ and 5 × 10⁹ CFU/kg) crossed with three levels of Zn (25, 45, and 65 mg/kg) for duration of 10-wk. The results showed that the egg laying rate (P < 0.05), fertility rate (P < 0.01), hatchability rate (P < 0.05), yolk color (P < 0.05), and the retentions of crude protein (P < 0.05), ether extract (P < 0.05) and phosphorus of geese breeders were improved by dietary supplementation of 5 × 10⁹ CFU/kg B. subtilis and 25 mg or 45 mg/kg Zn. The serum T-SOD (P < 0.05) was increased by 45 mg/kg Zn supplementation. The serum T-AOC (P < 0.05) and retention of Zn (P < 0.05) were increased by 5 × 10⁹ CFU/kg B. subtilis supplementation. The birds fed with 5 × 10⁹ CFU/kg B. subtilis and 25 mg or 45 mg/kg Zn showed improved villus length (P < 0.01) and villus length/ crypt depth (P < 0.01) in both the jejunum and ileum. In conclusion, the combination of B. subtilis and Zn may have synergistic effects on these parameters, and dietary inclusion of 5 × 10⁹ CFU/kg B. subtilis and 45 mg/kg Zn is recommended for improving the reproductive performance of geese breeders.

Dietary Clostridium butyricum and Bacillus subtilis Promote Goose Growth by Improving Intestinal Structure and Function, Antioxidative Capacity and Microbial Composition

Simple Summary

In this study, the effects of dietary supplementation of Clostridium butyricum and/or Bacillus subtilis were determined on growth performance, intestinal antioxidative capacity, intestinal morphology, cytokine production, and intestinal microbial composition in Yangzhou geese. Data showed that probiotics promoted feed intake and growth, improved antioxidative capacity and intestinal morphology, increased the relative abundances of Firmicutes and Lactobacillus in intestinal content, decreased the relative abundances of Proteobacteria and Ralstonia, and altered α-diversity and the predicted functions of intestinal microflora, but did not induce the expression of genes related to intestinal inflammation and tight junction.

Abstract

Probiotics are a substitute for antibiotics in the sense of intestinal health maintenance. Clostridium butyricum and Bacillus subtilis, as probiotic bacteria, have been widely used in animal production. The aim of this study was to investigate the effects of the two probiotic bacteria in geese. A total of 288 1-day old, healthy Yangzhou geese were randomly assigned into 4 groups (A, B, C and D) with 6 replicates of 12 birds each. Group A, as control, was fed a basal diet, and the treatment groups (B, C and D) were fed the basal diet supplemented with 250 mg/kg Clostridium butyricum (the viable count was 3.0 × 10⁶ CFU/g), 250 mg/kg Bacillus subtilis (the viable count was 2.0 × 10⁷ CFU/g), or a combination of the two probiotic bacteria for 70 days, respectively. The results indicated that: compared with the control group, dietary probiotics (1) promoted the growth and feed intake of the geese, (2) increased the absolute weight of duodenum, (3) increased the antioxidative capacity (total antioxidative capacity (T-AOC), total superoxide dismutase (T-SOD) and glutathione peroxidase (GSH-PX)) of intestinal mucosa, (4) improved intestinal morphology (the ratio of villus height to crypt depth), (5) but did not induce inflammation and changes of tight junction in the intestine, which was indicated by no induction of pro/inflammatory cytokines (IL-1β, IL-6, IL-10, TNFAIP3) and tight junction related genes (TJP1 and OCLN). Moreover, dietary probiotics increased the relative abundances of Firmicutes phylum and Lactobacillus genus and decreased the relative abundances of Proteobacteria phylum or Ralstonia genus in the intestinal content. In addition, the alpha diversity (observed species, Chao1, and estimate the number of OTUs in the community(ACE)) was reduced and the predicted functions of intestinal microflora, including peptidases, carbon fixation and metabolic function of starch and sugar, were enhanced by dietary probiotics. In conclusion, dietary probiotics promote the growth of geese by their positive effects on intestinal structure and function, the composition and functions of gut microflora, and intestinal antioxidative capacity.

Analysis of the Microbial Intestinal Tract in Broiler Chickens during the Rearing Period

Gut microbiota contributes to animal health. However, identifying which microorganisms or associated functions are involved remains, still, difficult to assess. In the present study, the microbiota of healthy broiler chickens, under controlled diet and farm conditions, was investigated by 16S rRNA gene sequencing in four intestine segments and at four ages. In detail, 210 Ross-308 male chickens were raised according to the EU guidelines and fed on a commercial diet. The duodenum, jejunum, ileum, and caecum microbiota were analyzed at 11, 24, 35, and 46 days of life. Although the microbial composition was revealed as homogeneous 11 days after chicks hatched, it was found to be similar in the proximal intestine segments and different in ileum and caecum, where almost the same genera and species were detected with different relative abundances. Although changes during the later growth stage were revealed, each genus remained relatively unchanged. Lactobacillus mostly colonized the upper tract of the intestine, whereas the Escherichia/Shigella genus the ileum. Clostridium and Bacteroides genera were predominant in the caecum, where the highest richness of bacterial taxa was observed. We also analyze and discuss the predicted role of the microbiota for each intestine segment and its potential involvement in nutrient digestion and absorption.

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.

Transcriptome Analysis Revealed Ameliorative Effects of Bacillus Based Probiotic on Immunity, Gut Barrier System, and Metabolism of Chicken under an Experimentally Induced Eimeria tenella Infection

In this study, we performed transcriptome analysis in the cecum tissues of negative control untreated non-challenged (NC), positive control untreated challenged (PC), and Bacillus subtilis (B. subtilis) fed challenged chickens (BS + ET) in order to examine the underlying potential therapeutic mechanisms of Bacillus based probiotic feeding under an experimental Eimeria tenella (E. tenella) infection. Our results for clinical parameters showed that birds in probiotic diet decreased the bloody diarrhea scores, oocyst shedding, and lesion scores compared to positive control birds. RNA-sequencing (RNA-seq) analysis revealed that in total, 2509 up-regulated and 2465 down-regulated differentially expressed genes (DEGs) were detected in the PC group versus NC group comparison. In the comparison of BS + ET group versus PC group, a total of 784 up-regulated and 493 down-regulated DEGs were found. Among them, several DEGs encoding proteins involved in immunity, gut barrier integrity, homeostasis, and metabolism were up-regulated by the treatment of probiotic. Functional analysis of DEGs also revealed that some gene ontology (GO) terms related with immunity, metabolism and cellular development were significantly affected by the exposure of probiotic. Kyoto encyclopedia of genes and genomes (KEGG) pathway analysis showed that the DEGs in the cecum of B. subtilis-fed challenged group were mainly participated in the pathways related with immunity and gut barrier integrity, included mitogen-activated protein kinase (MAPK) signaling pathway, toll-like receptor (TLR) signaling pathway, extracellular matrix (ECM)–receptor interaction, tight junction, and so on. Taken together, these results suggest that Bacillus based probiotic modulate the immunity, maintain gut homeostasis as well as barrier system and improve chicken metabolism during E. tenella infection.

Supplementation of Bacillus subtilis GM5 enhances broiler body weight gain and modulates cecal microbiota

We investigated the effect of the strain Bacillus subtilis GM5 on growth, feed conversion, and the composition of cecum microbiota in broiler chickens. Half of which received a control diet, while the other half was fed a diet supplemented with GM5 spores. Cecal contents on days 1, 10, and 42 were subjected to metataxonomic analysis. Principal Component Analysis showed that the control and probiotic groups formed three separate clusters, indicating changes, which occurred gradually in microbial communities. On day 1, Firmicutes (53.87-57.61%) and Proteobacteria (43.77-38.93%) were prevalent in both groups, whereas samples of days 10 and 42 were predominantly occupied by Firmicutes (54.55-81.79%) and Bacteroidetes (26.94-30.45%). In the group of chickens treated with probiotic, the average daily gain in body weight was higher, while feed conversion decreased by 1.44%. A surge in the presence of beneficial bacteria of the Ruminococcaceae family was observed. The introduction of the probiotic led to an elevated Firmicutes/Bacteroidetes ratio, which positively correlated with chickens' bodyweight (Spearman ρ = 1.0, P < 0.05). Supplementing broiler feed with B. subtilis GM5 spores leads to improved feed intake and digestibility, which is paramount in reducing the cost of the final product. Thus, the probiotic strain GM5 modulates the cecal microbiota of broiler chickens and increases microbial diversity, which is well exhibited on the 42nd day.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s13205-020-02634-2.

Effects of Flaxseed and Multi-Carbohydrase Enzymes on the Cecal Microbiota and Liver Inflammation of Laying Hens

Simple Summary

Wheat and flaxseed are used worldwide to produce omega-3 (ω-3) enriched poultry meat and eggs, however, wheat and flaxseed contain some anti-nutritional factors (ANFs). In addition, the supplementation of feed additive including enzymes usually alleviate the deleterious influence of ANFs. Therefore, we conducted the current study of laying hens fed with two diets (corn/flaxseed and wheat/flaxseed, supplemented with three enzymes), for a period of 10 weeks. Here, we found a clear increase in the fat weight of birds fed with corn diet as compared with wheat diet. Moreover, a high level of secretory IL-1β, IL-6, and IL-10 and comparatively higher inflammatory changes in the liver tissue were found in birds fed with corn diet as compared with wheat diet. The gut microbial composition of hens fed with corn diet was clearly different than that of birds fed a wheat diet. In conclusion, our findings suggest that inflammatory changes in laying birds were mediated by a corn diet with flaxseed and enzymes instead of a wheat diet. Additionally, in the wheat-fed group, enzyme-b and -c showed more encouraging results as compared to enzyme-a indicating that wheat diet might be a preferable diet for commercial layers poultry farms.

Abstract

Background: The use of wheat and flaxseed to produce omega-3 (ω-3) enriched poultry meat and eggs is very popular in the world. However, wheat and flaxseed contain some anti-nutritional factors (ANFs), and enzymes are usually used to alleviate the deleterious influence of ANFs. Method: A 2 × 3 two factors design was used in the experiment. A total of 540 twenty-week-old Nongda-3 laying hens were randomly allocated to six dietary treatments, two diets (corn/flaxseed and wheat/flaxseed), and three enzymes (enzyme-a contains neutral protease 10,000, xylanase 35,000, β-mannanase 1500, β-glucanase 2000, cellulose 500, amylase 100, and pectinase 10,000 (U g⁻¹); enzyme-b contains alkaline protease 40,000 and neutral protease 10,000 (U g⁻¹); enzyme-c contains alkaline protease 40,000, neutral protease 10,000, and cellulase 4000 (U g⁻¹). Results: There was an interaction between dietary treatment and supplemental enzymes for liver weight and liver inflammatory cytokines of broilers. A significant increase was observed in the fat weight of birds fed a corn diet as compared with a wheat diet. A corn diet and wheat diet with the addition of enzyme-a (p < 0.001) showed the highest level of liver fat followed by enzyme-c (p < 0.01) and enzyme-b. Moreover, a high level of secretory IL-1β, IL-6, and IL-10 and comparatively higher inflammatory changes in the liver tissue were found in birds fed a corn diet as compared with a wheat diet, and enzyme-b showed more beneficial effects as compared with enzyme-a and -c. The gut microbial composition of hens fed a corn diet was significantly different than that of birds fed a wheat diet. Bacteroides were significantly (p < 0.05) abundant in the corn-fed birds as compared with wheat-fed birds. However, Firmicutes were less abundant in the wheat-fed birds than the corn-fed birds (16.99 vs. 31.80%, respectively). The microbial community at the genus level differed significantly in the dietary groups and we observed that Bacteroides are the predominant cecal microbiota. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways of co-factors, carbohydrates, vitamins, protein, and energy were expressed at slightly higher levels in the microbiota of the wheat-fed birds, whereas, metabolic pathways for nucleotides, lipids, and glycine were expressed at higher levels in the wheat-fed birds. Furthermore, expression of the growth and cellular processes pathway and endocrine system pathway levels were predicted to be higher for the wheat-fed group as compared with the corn-fed group. Conclusions: In conclusion, our findings suggest that inflammatory changes in laying birds were mediated by a corn diet with flaxseed and enzymes instead of a wheat diet. Additionally, in the wheat-fed group, enzyme-b and -c showed more encouraging results as compared to enzyme-a.

The storage stability of Bacillus subtilis spore displaying cysteine protease of Clonorchis sinensis and its effect on improving the gut microbiota of mice

Bacillus subtilis (B. subtilis) spore can serve as an ideal vehicle for expressing heterologous antigens, and elicit specific immune responses by oral administration. In previous studies, we successfully constructed the recombinant B. subtilis spores expressing cysteine protease of Clonorchis sinensis (C. sinensis, B.s-CsCP), and confirmed that oral administration of B.s-CsCP could elicit good protective immune responses in mice. In this study, Gram staining was used to observe the morphology of B.s-CsCP in different form, and the storage of liquid spores and lyophilized spores at different temperatures was compared. The mice were orally immunized with three different doses of spores (2×10⁸, 1×10⁹, and 5×10⁹ CFU/day) for three times in total at biweekly interval. Then, antibody levels of mice were measured, the safety of spores was evaluated, and the changes of gut microbiota after oral gavage of spores (1×10⁹ dose) were investigated. Results showed that B. subtilis was a typical Gram-positive bacterium, and its spore had good resistance to chemical dye. Liquid B. subtilis spores resuspended in sterile water could be stored for a long time at 4 °C or below, while lyophilized spores could be well stored even at RT and better at lower temperatures. Oral administration of B. subtilis spores to mice could stimulate both local mucosal and systemic immune responses in a dose-dependent manner without toxic side effects. Besides, beneficial bacteria producing butyrate such as Odoribacter were increased, while potential pathogens such as Escherichia-Shigella were decreased in mice intestine. Therefore, our work further confirmed that B. subtilis spores expressing CsCP could be a promising oral vaccine against C. sinensis with the advantages of stability, safety, easy storage, and promotion of intestinal health.Key Points• Recombinant CsCP B. subtilis spores could be easily preserved in either liquid or freeze-dried state.• Oral immunization of recombinant spores in mice could increase both local and system immune levels in a dose-dependent manner.• Oral administration of recombinant spores increased the number of beneficial bacteria and reduced the number of harmful bacteria in the intestinal tract of mice.

Bacterial meta-analysis of chicken cecal microbiota

Poultry production is an industry that generates 90,000 metric tons of chicken meat worldwide. Thus, optimizing chicken growth and sustainable production is of great importance. A central factor determining not only production parameters, but also stability of the immune system and chicken health, is the diversity and variability of the microbiota present throughout the gastrointestinal tract. To date, several studies have investigated the relationship between bacterial communities and the gut microbiome, with limited data to compare. This study aims to create a bacterial meta-analysis based on studies using amplicon sequencing with Illumina sequencing technologies in order to build a baseline for comparison in future analyses of the cecal bacterial composition in chicken. A systematic literature review was performed (SYRF ID: e84f0468-e418-4eec-9da4-b517f1b4809d. Full project URL: https://app.syrf.org.uk/projects/e84f0468-e418-4eec-9da4-b517f1b4809d/detail). From all the available and analyzed manuscripts only nine contained full raw-sequence data available and the corresponding metadata. A total of 324 samples, comprising three different regions within the 16S rRNA gene, were analyzed. Due to the heterogeneity of the data, each region was analyzed independently and an effort for a joint analysis was performed as well. Taxonomic profiling revealed 11 phyla, with Firmicutes as the most prevalent phylum, followed by Bacteroidetes and Proteobacteria. At genus level, 109 genera were found. Shannon metric for alpha diversity showed that factors like type of chickens (Commercial or experimental) and 16S rRNA gene subregion have negligible effect on diversity. Despite the large number of parameters that were taken into account, the identification of common bacteria showed five genera to be common for all sets in at least 50% of the samples. These genera are highly associated to cellulose degradation and short chain fatty acids synthesis. In general, it was possible to identify some commonalities in the bacterial cecal microbial community despite the extensive variability and factors differing from one study to another.

Sex differences in growth performance are related to cecal microbiota in chicken

In poultry industry, male chickens have a better growth performance than female ones under the same genetic background and diet. Emerging evidences proposed an important role of intestinal microbiota in chicken's growth performance. This study aimed to determine gut microbiota related gender based differences in the growth performance of chickens. Therefore, male and female chickens (n = 20) at 7-week age were used to carry out histomorphological, molecular, gene expression analysis with their liver, chest and leg muscle, as well as 16S rRNA sequencing analysis for gut microbiota. The results revealed that Bacteroides and Megamonas genera were more prominently colonized in the cecum of male chickens. The male chicken's cecal microbiota indicated a closer relation with glycan metabolism, while in the female chickens it was more related with lipid metabolism. Gene expression levels associated with glycan and lipid metabolism were different between male and female chickens. Further, using Spearman correlation analysis, we found a positive correlation between glycan and lipid metabolism, and the relative abundance of Bacteroides, Megamona and Lactobacillus in male chickens. Similarly, we also found a positive correlation between the lipid metabolism and the relative abundance of Ruminococcaceae and Enterococcus in female chickens. These findings revealed the association of chicken growth performance with cecal microbiota that contributed to the metabolism of glycan and lipid in a sex-dependent manner.

Bacillus subtilis-fermented products ameliorate the growth performance and alter cecal microbiota community in broilers under lipopolysaccharide challenge

In this study, the effects of Bacillus subtilis–fermented products on the growth performance and cecal microbiota of broilers were investigated in response to lipopolysaccharide (LPS) challenge. A total of 120 one-day-old male broiler chicks (Ross 308) were randomly assigned to 4 dietary treatments, with 5 replicate cages per treatment and 6 birds per cage. The dietary treatments comprised a basal diet as the control, basal diet plus 5 mg/kg of LPS, and basal diet plus 5 mg/kg of LPS in combination with 1 and 3 g/kg of B. subtilis–fermented products. The results indicated that B. subtilis–fermented product supplementation increased (linear, P < 0.05) the body weight of broilers relative to LPS treatment alone at 21 d of age. At 15 to 21 d and 1 to 21 d of age, B. subtilis–fermented product supplementation improved (linear, P < 0.05) the average daily gain in broilers compared with LPS challenge alone. The inflammation-associated gene expression was decreased (P < 0.05), and intestinal barrier–associated gene expression was increased (P < 0.05) in the small intestine of the group treated with 3 g/kg of B. subtilis–fermented products in combination with LPS challenge. In cecal microbiota analysis, the richness of bacterial species was lower (P < 0.05) in the groups treated with 1 and 3 g/kg of B. subtilis–fermented products in combination with LPS challenge than in the control group. Principal coordinates analysis indicated distinct clusters between the groups treated with LPS alone and B. subtilis–fermented products in combination with LPS challenge. The abundance of the genera Erysipelatoclostridium and Ruminococcaceae_unclassified in the cecal digesta decreased (P < 0.05) in broilers fed with B. subtilis–fermented products compared with the control group. The average abundance of the genera Bacteroides and Romboutsia in the cecal digesta was positively correlated with the body weight and average daily gain of broilers in response to LPS challenge. Furthermore, the average abundance of the genera Bacteroides and Romboutsia in the cecal digesta was positively correlated with the concentration of B. subtilis–fermented products under LPS challenge. These results demonstrate that B. subtilis–fermented products can improve the growth performance and modulate the gut microflora composition of broilers under immune stress.

Bacillus subtilis delivery route: effect on growth performance, intestinal morphology, cecal short-chain fatty acid concentration, and cecal microbiota in broiler chickens

As the poultry industry recedes from the use of antibiotic growth promoters, the need to evaluate the efficacy of possible alternatives and the delivery method that maximizes their effectiveness arises. This study aimed at expounding knowledge on the effect of the delivery method of a probiotic product (Bacillus subtilis fermentation extract) on performance and gut parameters in broiler chickens. A total of 450 fertile eggs sourced from Cobb 500 broiler breeders were randomly allotted to 3 groups: in ovo probiotic (n = 66), in ovo saline (n = 66), and noninjection (n = 200) and incubated for 21 d. On day 18.5 of incubation, 200 μL of either probiotic (10 × 10⁶ cfu) or saline was injected into the amnion. At hatch, chicks were reallotted to 6 new treatment groups: in ovo probiotic, in ovo saline, in-feed antibiotics, in-water probiotic, in-feed probiotics, and control (corn-wheat-soybean diet) in 6 replicate cages and raised for 28 d. Of all hatch parameters evaluated, only percentage pipped eggs was found significant (P < 0.05) with the noninjection group having higher percentage pipped eggs than the other groups. Treatments did not affect the incidence of necrotic enteritis on day 28 (P > 0.05). Irrespective of the delivery method, the probiotic treatments had no significant effect on growth performance. The ileum villus width of the in ovo probiotic treatment was 18% higher than the in ovo saline group (P = 0.05) but not statistically higher than other groups. The jejunum villus height was 23% higher (P = 0.000) in the in ovo probiotic group than in the control group. There was no effect of treatment on total cecal short-chain fatty acid concentration and cecal gut microbiota composition and diversity (P > 0.05), although few unique bacteria differential abundance were recorded per treatment. Conclusively, although probiotic treatments (irrespective of the delivery route) did not affect growth performance, in ovo delivery of the probiotic product enhanced intestinal morphology, without compromising hatch performance and gut homeostasis.

Effects of manganese and Bacillus subtilis on the reproductive performance, egg quality, antioxidant capacity, and gut microbiota of breeding geese during laying period

This experiment was conducted to investigate the effects of manganese (Mn) and Bacillus subtilis (BS) on the production performance, egg quality, antioxidant capacity, and gut microbiota of breeding geese during laying period. A total of 120 forty-six-week-old breeding geese (Wulong) were randomly assigned to 1 of 6 treatment diets formulated to supply 10, 20, and 30 mg/kg Mn with 5 × 109 CFU/kg or 2.5 × 109 CFU/kg BS for a 10-wk trial. Results showed that dietary supplementation with 20 and 30 mg/kg Mn could decrease the daily feed intake (DFI) of geese. Moreover, 30 mg/kg Mn significantly increased the laying rate. Besides, although Mn addition had no obvious effect on egg quality, 5 × 109 CFU/kg BS was found to elevate the hatching egg hatching rate and eggshell thickness. For the serum hormones, 30 mg/kg Mn promoted estradiol secretion, while 5 × 109 CFU/kg BS increased the level of follicle-stimulating hormone. Furthermore, 20 and 30 mg/kg Mn and 5 × 109 CFU/kg BS significantly enhanced the total antioxidant capacity by increasing the activity of total superoxide dismutases or decreasing the content of malondialdehyde. Dietary supplementation with 5 × 109 CFU/kg BS also increased the intestinal villus height and upregulated the abundance of Fusobacteria, Fusobacteriaceae, Fusobacterium, and Faecalibacterium in cecal content. In addition, 20 and 30 mg/kg Mn elevated the levels of Bacteroidetes, Bacteroidaceae, Bacteroides, and Ruminococcaceae but decreased Streptococcaceae. Importantly, an interaction effect was observed between Mn and BS on the DFI, egg mass, average egg size, and the abundance of Bacteroides as well as Faecalibacterium. In conclusion, dietary inclusion of Mn and BS could improve the production performance, egg quality, antioxidant capacity, intestinal structure, as well as gut microbiota. Supplementation of 30 mg/kg Mn and 5.0 × 109 CFU/kg BS provided the optimal effect.

Effects of Rearing Conditions and Sex on Cecal Microbiota in Ducks

The intestinal microbiome influences the health of animals. However, little is known about the impact of indoor conditions and sex on intestinal microbiome diversity and composition in ducks. The present study aimed to investigate differences in the cecal microbiome between male and female ducks reared on the floor (PY group) or in cages (LY group). We also determined the relationships between cecal microbiota composition and slaughter traits, and the expression levels of mucosal and intestinal structural genes in ducks. There was a slight difference in slaughter traits among the groups, with cecum weight being significantly lighter in the LY compared with the PY group, especially in females (p < 0.05). Analysis of the alpha diversity of the cecal microbiota between males and females in the LY and PY groups showed that LY males had significantly lower diversity and richness. Beta diversity analysis demonstrated differences in the microbiota composition in relation to rearing conditions, and a significant difference between the sexes in the PY groups. The dominant bacterial phyla in duck cecum were Bacteroidetes, Firmicutes, Proteobacteria, and Fusobacteria. The relative abundances of the most common bacteria revealed that the intestinal microbiota diversity and composition were affected by both feeding conditions and sex. Several bacterial genera were detected differentially among the groups. These genera were correlated with slaughter traits and expression levels of mucosal and cecal structural genes in ducks. In conclusion, rearing conditions, sex, and associated changes in the cecal microbiota are thus associated with gut barrier functions in ducks.

Medium-chain α-monoglycerides improves productive performance and egg quality in aged hens associated with gut microbiota modulation

The present study aimed to evaluate the effects of medium-chain α-monoglycerides (MG) on productive performance, egg quality, serum biochemical indices, and gut microbiota in laying hens. A total of 252 40-wk-old Hy-Line Brown laying hens were randomly allotted into two groups (21 hens per replicate, 6 replicates per group) and fed with a basal diet (CON group) or a basal diet containing 300 mg/kg of MG (MG300 group). The eggs laid were recorded daily on a replicate basis, and egg quality was measured at 48, 56, and 64 wk of age. At the end of this trial, three randomly selected hens from each replicate were slaughtered, and the serum and cecal digesta were collected for analysis of serum biochemical indices and sex hormones and gut microbiota composition determination. The results revealed that the laying rate was significantly (P < 0.05) increased in the MG300 group, and the feed conversion ratio was decreased (P < 0.01) during 40–64 wk of age. The eggshell strength at 56 wk of age and eggshell thickness at 56 and 64 wk of age were significantly (P < 0.05) increased in the MG300 group. In addition, dietary MG significantly (P < 0.05) increased levels of serum follicle-stimulating hormone, luteinizing hormone, estradiol, glucose, Ca, serum total cholesterol, triglycerides, and high-density lipoprotein cholesterol, but decreased the lipopolysaccharide level. Notably, MG supplementation increased (P < 0.05) the relative abundance of genera Lachnospiraceae_NK4A136_group, Romboutsia, Syntrophomonas, Victivallis, Ruminiclostridium_6, and Family_XIII_UCG_001 (P < 0.01) and simultaneously decreased the abundances of Proteobacteria, Faecalibacterium, Alistipes, Cerasicoccus, Schlegelella, and Treponema_2. Spearman's correlation analysis indicated that the differentiated genera were significantly associated with the serum biochemical indices and sex hormone. In summary, the present study revealed that dietary supplementation with MG can improve productive performance and egg quality by modulating gut microbiota, suggested that MG may act as an efficient feed supplement in aged hens.

Effect of Bacillus subtilis on growth performance, bone mineralization, and bacterial population of broilers fed with different protein sources

The objective of this study was to investigate the impacts of Bacillus subtilis (BS), ATCC 6051a strain, as a probiotic bacterium in broiler diets based of 2 protein sources (soybean meal [SBM] and cowpea seeds [CWP]), on growth performance (GP), carcass traits, bone mineralization, and microflora population (0 to 42 d age). The SBM and CWP starter, grower, and finisher diets were tested in the presence or absence of BS (5.0 × 10¹¹ CFU spores g⁻¹ feed) in a 2 × 2 factorial arrangement of treatments in a completely randomized design. Broilers were randomly assigned to 4 dietary treatments with 6 replicate pens per treatment (20 chicks per pen). The results showed that broilers fed CWP had comparable GP (body weight gain, feed intake, and feed conversion ratio) to the birds fed the SBM diet. Carcass, breast and legs' yield, organ size (i.e., gizzard, liver, pancreas, small intestine, cecum), and bone development were not affected by the protein source. The addition of BS in both types of diet improved BWG (P < 0.001) and feed efficiency, especially in the grower and finisher period (P = 0.047; P = 0.043, respectively). In addition, BS significantly decreased abdominal fat (P = 0.026) and cecum weight (P = 0.034) and increased tibia bone P concentration (P = 0.015). Furthermore, BS decrease cecal pH (P = 0.010) and reduced Escherichia coli and Staphylococcus spp. from cecum and excreta broilers (P < 0.001; P < 0.0001, respectively). It is concluded that the BS significantly improved the GP of broilers and can beneficially affect the gut and excreta bacterial community in both SBM and CWP diets.

Titration of supplemental Bacillus subtilis subsp. subtilis American Type Culture Collection PTA-125135 to broiler chickens fed diets of 2 different metabolizable energy concentrations

Bacillus subtilis subsp. subtilis American Type Culture Collection deposit number PTA-125135 has recently been studied by our laboratory as a potential probiotic strain for avian species. The objective of the present study was to evaluate growth performance and feed efficiency in broiler chickens in response to a dose titration of the Bacillus strain in feed. In addition to a nonsupplemented control, Bacillus spores were supplemented into broiler chicken diets at 4 levels, which were 8.1 × 10⁴, 1.6 × 10⁵, 2.4 × 10⁵, and 3.2 × 10⁵ CFU per g of feed. The titration was applied to two different dietary regimes of standard or low metabolizable energy (ME), which differed in ME by 22, 56, and 110 kcal/kg in starter, grower, and finisher dietary phases, respectively. All diets contained 249 g per metric ton of a previously patented synbiotic feed additive. Performance data were collected at day 14, 26, and 40 of age, and the effects of Bacillus and ME treatments were evaluated by factorial ANOVA. Treatment group means were further examined for significant (P < 0.05) pairwise differences among treatments and for significant (P < 0.05) linear and quadratic effects. At day 14 of age, significant linear effects for decreased feed conversion ratio (FCR) with higher CFU of Bacillus supplementation were observed within the standard ME diet. At day 26, a linear trend was observed for increased mortality with increased dose within the standard ME diet only. Bacillus supplementation at day 26 also significantly affected FCR and mortality-adjusted FCR, where supplementation with 3.2 × 10⁵ CFU per g feed produced lower FCR and mortality-adjusted FCR than supplementation with 1.6 × 10⁵ CFU per g feed. We conclude from linear effects related to feed efficiency observed at day 14 and from the significant separation of Bacillus treatment means within the titrated range of supplementation at day 26 that further evaluation for effects on performance should be made of doses at 2.4 × 10⁵, 3.2 × 10⁵, and greater CFU per g in feed.

Post hatch recovery of a probiotic Enterococcus faecium strain in the yolk sac and intestinal tract of broiler chickens after in ovo injection

Concerns about antibiotic-resistant bacteria and their presence in animal products grow and thus alternatives to use of antibiotics in animal production are being investigated. Probiotics have gained increased focus due to improvements in performance, immune health and pathogen reduction when provided to poultry through feed. These traits may be further improved if probiotics can be provided to the embryo before hatch, before meeting environmental pathogens. The objective was to determine the faith of a probiotic Enterococcus faecium (M74) strain in the yolk sac and intestinal tract of broiler chickens after injection into hatching eggs. E. faecium M74 (1.4 × 107 CFU/egg) was applied in ovo at day 18 of incubation. From 1- and 7-day-old chickens, 20 samples from yolk sac, caecal tonsils and rest of the intestinal tract were subjected to CFU counting. Isolates from a sample subset were typed by pulsed-field gel electrophoresis (PFGE). Enterococci were found in varying numbers: 1.0 × 104-2.2 × 1010 CFU/g. The prevalence of M74 PFGE profiles was high in 1-day-old (88%) and 7-day-old chickens (67%). This demonstrates that the embryos ingested M74 before hatching, that M74 is viable for intestinal colonization through in ovo administration, and that the strain multiplies in the chickens gastrointestinal tract post hatching.

From Maternal Grazing to Barn Feeding During Pre-weaning Period: Altered Gastrointestinal Microbiota Contributes to Change the Development and Function of the Rumen and Intestine of Yak Calves

Understanding the altered gastrointestinal microbiota is important to illuminate effects of maternal grazing (MG: maternally nursed and grazed) and barn feeding (BF: supplied milk replacer, starter feed, and alfalfa hay) on the performance and immune function of yak calves. Compared with the MG group, the significantly increased body weight, body height, body length, chest girth, and organ development of liver, spleen, and thymus were identified in the BF group, which were resulted from the significantly increased dry matter intake, increased concentrations of propionate, butyrate, isobutyrate, and valerate, increased ruminal pectinase, duodenal α-amylase, jejunal α-amylase and trypsin, and ileal trypsin, and promoted gastrointestinal epithelial development. Furthermore, genera of Sharpea, Sphingomonas, Atopobium, Syntrophococcus, Clostridium_XIVb, Acinetobacter, Oscillibacter, Dialister, Desulfovibrio, Bacteroides, Lachnospiracea_incertae_sedis, and Clostridium_sensu_stricto, which were involved in utilization of non-fibrous carbohydrate and further beneficial to improve the gastrointestinal digestion, development, and immune functions, were significantly increased in the BF group. Meanwhile, the significantly enhanced ruminal epithelial immune functions and intestinal immune functions based on enhanced ruminal immune related pathway, duodenal IL-1β, jejunal IL-1β, IL-2, TNF-α, and IFN-γ, and ileal IL-1β were identified in the BF group, which also may induced by the increased abundance of gastrointestinal microbiota. Overall, barn feeding significantly increased the diversity of species and abundance of microbes which used different carbohydrates and further benefit to the growth and immune function of yak calves.

Effect of dietary supplementation of whey powder and Bacillus subtilis on growth performance, gut and hepatic function, and muscle antioxidant capacity of Japanese quail

This experiment was conducted to evaluate the effects of dietary supplementation of whey powder (WP), Bacillus subtilis (BAS), and their combination (MIX) on growth performance, intestinal morphology, caecal microflora, hepatic gene expression, blood metabolites, and skeletal muscle antioxidant capacity in Japanese quails. A total of 400 one-day-old Japanese quails were randomly distributed to 20-floor pens (4 dietary treatments, 5 replications per treatment, 20 birds per pen). The birds were fed a basal diet (control, CON) or the basal diet supplemented with 40 g/kg WP, 1 g/kg BAS probiotic or 40 g/kg WP plus 1 g/kg BAS probiotic for five weeks. Feed intake was not affected by the treatments at any stage of the trial. However, the WP, BAS, and MIX feed had better weight gain and feed conversion ratio compared to the CON during the entire production period (day 1-35; p < .05). Feeding the WP, BAS, and MIX diets caused no significant difference in morphometric measures in the duodenum, jejunum, and ileum other than the villus height to crypt depth ratio in the ileum (p < .05). The expression of insulin-like growth factor-1 (IGF-1) and growth hormone genes was highly upregulated in the liver of the birds fed the MIX diet (p < .05). Feeding birds with the diets containing WP, BAS, and MIX increased the population of caecal lactic acid bacteria and reduced serum cholesterol concentration compared to the CON diet (p < .05). Likewise, the tested feed additives increased superoxide dismutase and glutathione peroxidase enzyme activities in the thigh muscle (p < .05). No synergistic effect was found between WP and BAS in studied parameters other than IGF-1 gene expression. Improved growth performance of Japanese quails by feeding the WP, BAS, and the MIX feed could be linked to improved absorptive capacity of the small intestine as well as over-expression of anabolic growth factors. In conclusion, WP with or without BAS could be considered as a beneficial dietary supplement to enhance productive performance, gut functionality, and antioxidant capacity of Japanese quail.

Effects of Bacillus licheniformis on the growth, antioxidant capacity, intestinal barrier and disease resistance of grass carp (Ctenopharyngodon idella)

To study the effect of dietary supplementation of Bacillus licheniformis FA6 on the growth, survival and intestinal health of grass carp, we assessed the antioxidant capacity, intestinal barrier, expression levels of immune genes, and the resistance to Aeromonas hydrophila AH-1 infection. Experimental setup comprised three groups (90 specimens each; average initial weight = 16.5 g): the control group was fed the basal diet without B. licheniformis, the low-dose (LD) group was supplemented with B. licheniformis at the concentration of 1 × 10⁵ cfu/g, and the high-dose (HD) group with 1 × 10⁶ cfu/g. After 56 days of growth trial, the challenge test with A. hydrophila AH-1 was conducted for 14 days. The results revealed that the grass carp in LD group and HD group had significantly (p < 0.05) improved percent weight gain (PWG) and specific growth rate (SGR) parameters. Additionally, the antioxidant status was improved, which included increased superoxide dismutase (SOD) activity and decreased malondialdehyde (MDA) levels in the serum, and upregulated mRNA levels of antioxidant enzymes MnSOD and catalase (CAT) in the intestine. Meanwhile, B. licheniformis FA6 supplementation groups exhibited a decreased mRNA expression of proinflammatory cytokines (such as IL-1β and TNF-α) and increased the expression of anti-inflammatory cytokine IL-10. Histological (villi length was increased) and gene expression (qPCR: upregulated ZO-1, occludin, and claudin-c) analyses suggested improved functioning of the intestinal barrier. Post-challenge mortality rates in LD and HD groups were significantly lower (56.6% and 70% respectively) than in the control group (100%). Overall, these results indicated that dietary supplementation of B. licheniformis FA6 can improve growth, antioxidant capacity, intestinal barrier functions and disease resistance of grass carp.

Oral delivery of Bacillus subtilis spores expressing Clonorchis sinensis paramyosin protects grass carp from cercaria infection

Clonorchis sinensis (C. sinensis), an important fishborne zoonotic parasite threatening public health, is of major socioeconomic importance in epidemic areas. Effective strategies are still urgently expected to prevent against C. sinensis infection. In the present study, paramyosin of C. sinensis (CsPmy) was stably and abundantly expressed on the surface of Bacillus subtilis spores. The recombinant spores (B.s-CotC-CsPmy) were incorporated in the basal pellets diet in three different dosages (1 × 10⁵, 1 × 10⁸, 1 × 10¹¹ CFU/g pellets) and orally administrated to grass carp (Ctenopharyngodon idella). The immune responses and intestinal microbiota in the treated grass carp were investigated. Results showed that specific anti-CsPmy IgM levels in sera, skin mucus, bile, and intestinal mucus, as well as mRNA levels of IgM and IgZ in the spleen and head kidney, were significantly increased in B.s-CotC-CsPmy-10¹¹ group. Besides, transcripts levels of IL-8 and TNF-αin the spleen and head kidney were also significantly elevated than the control groups. Moreover, mRNA levels of tight junction proteins in the intestines of B.s-CotC-CsPmy-10¹¹ group increased. Potential pathogenetic bacteria with lower abundance and higher abundances of candidate probiotics and bacteria associated with digestion in 1 × 10¹¹ CFU/g B.s-CotC-CsPmy spores administrated fishes could be detected compared with control group. The amount of metacercaria in per gram fish flesh was statistically decreased in 1 × 10¹¹ CFU/g B.s-CotC-CsPmy spores orally immunized group. Our work demonstrated that B. subtilis spores presenting CsPmy on the surface could be a promising effective, safe, and needle-free candidate vaccine against C. sinensis infection for grass carp.

A novel Bacillus based multi-strain probiotic improves growth performance and intestinal properties of Clostridium perfringens challenged broilers

There is a necessity for the implementation of in-feed probiotics in the poultry production industry, following strict regulations around the use of antibiotic growth promoters (AGP). Bacillus spp. are becoming an attractive alternative because of their functionality and stability. This study aims to evaluate the effect of a novel multi-strain Bacillus based probiotic on growth performance and gut health in male Ross 308 broiler chickens challenged with Clostridium perfringens Type A. Broilers on a 4 phase feeding program were fed diets containing either a standard metabolizable energy (ME) (100%) or a reduced ME (98%) level. The test probiotic was compared to an un-supplemented negative control and a commercial benchmark product as positive control over a 35 D feeding trial, using a 2 × 3 factorial experimental design. Chicks were inoculated with a once-off dose of C. perfringens on day 14. Growth performance was measured weekly to calculate body weight (BW), feed intake (FI) and feed conversion ratio (FCR). Villi histomorphology, gut lesions, and liver weight were assessed at day 35. Broilers fed the reduced ME diet with the test probiotic achieved higher final BWs (P = 0.037) and FCR (P = 0.014) than the negative control. Broilers fed the standard ME diet with the test probiotic showed improved (P = 0.001) FCR than the negative control from day 21 onwards. Increased duodenal villi height (P = 0.012) and villi height to crypt depth ratio in the duodenum (P < 0.0001) and jejunum (P = 0.0004) were observed in broilers fed the reduced ME diet containing the test probiotic. Additionally, the test probiotic resulted in significantly reduced relative liver weights in both ME groups. Consequently, the results suggest that the novel multi-strain Bacillus based probiotic enhanced broiler performance and improved gut health and is thus attractive as an alternative to AGP's in broiler production.

Use of Bacillus subtilis PB6 enriched with choline to improve growth performance, immune status, histological parameters and intestinal microbiota of broiler chickens

Context Probiotics used in poultry nutrition may promote the propagation of beneficial bacteria and limit the growth of pathogens, improving the body’s resistance to disease. Aims The aim of the study was to establish the dose and timing of administration of a probiotic preparation containing live cultures of Bacillus subtilis PB6 and choline that would have the most beneficial effect on histological parameters and microbiological status of the intestine, immune status, and growth performance of broiler chickens. Methods In total, 980 one-day-old Ross 308 male chickens, divided into seven groups of 140 (each group with seven replications of 20 individuals), were used in the experiment. The birds were reared until Day 42 of life. In the control group, birds received water without addition of the probiotic preparation. In three continuous treatments, birds received the probiotic preparation in their water at doses of 0.05, 0.1 or 0.25 g/L from Day 1 to Day 42 of rearing. In three periodic treatments, birds received the same doses of the probiotic preparation, but only during Days 1–7, 15–21 and 29–35 of rearing. Key results Addition of the probiotic preparation to the drinking water of broiler chickens increased the total number of aerobic bacteria as well as the length of the intestinal villi and the depth of the crypts. It also reduced the number of fungi and coliform bacteria. In addition, increases were noted in the lysozyme content, the phagocytic index, and the level of immunoglobulin A. Conclusions The probiotic preparation containing B. subtilis and choline administered continuously at a dose of 0.25 g/L in water throughout the rearing period had the most beneficial effect on the composition of the microbiome, and improved the mucous membrane structure of the intestine (increasing villus length and intestinal crypt depth), immunity, and growth performance of the broiler chickens. Implications The use of probiotics in poultry nutrition improves the health of animals and makes breeding more profitable. Administration of this probiotic improves disease resistance, jejunal histological parameters, and intestinal microflora of broiler chickens.

The effects of dietary Bacillus subtilis supplementation, as an alternative to antibiotics, on growth performance, intestinal immunity, and epithelial barrier integrity in broiler chickens infected with Eimeria maxima

The objective of this study was to investigate the effects of dietary Bacillus subtilis supplementation on growth performance, jejunal lesion scores, oocyst shedding, and cytokine and tight junction protein expression in broiler chickens infected with Eimeria maxima. A total of 196 male day-old Ross 708 broilers were given a nonexperimental diet until 14 D of age. Then, all chickens were randomly assigned to one of seven dietary treatments: 2 basal diets (CON and NC); CON + virginiamycin (AB1); CON + bacitracin methylene disalicylate (BMD; AB2); CON + B. subtilis 1781 (PB1); CON + B. subtilis 747 (PB2); or CON + B. subtilis 1781 + 747 (PB3). At day 21, all chickens except those in the CON group were orally inoculated with E. maxima oocysts. At 7 D after E. maxima infection, the body weight gains of chickens fed PB2 and PB3 increased (P = 0.032) as much as those in chickens fed AB2. The body weight gain and feed efficiency of chickens fed PB2 were significantly increased (P < 0.001), and PB2 chickens showed (P = 0.005) the lowest lesion scores after E. maxima infection. Chickens fed PB2 showed (P < 0.05) lower mRNA expression of IL-1β in infected chicken groups. Chickens in the AB1, AB2, PB1, PB2, and PB3 groups showed (P < 0.05) greater mRNA expression of junctional adhesion molecule 2 in jejunal tissue, whereas occludin expression increased (P < 0.05) in the jejunal tissue of chickens fed AB2 or PB2. Dietary B. subtilis supplementation significantly improved the growth performance of young chickens to a level comparable with that induced by virginiamycin or BMD without E. maxima infection. After infection with E. maxima, dietary virginiamycin and BMD significantly enhanced the epithelial barrier integrity, and the dietary B. subtilis 747 showed significantly enhanced growth performance, intestinal immunity, and epithelial barrier integrity. Together our results indicated that certain strains of B. subtilis provide beneficial effects on the growth of young broiler chickens and have the potential to replace antibiotic growth promoters.

Effects of Bacillus subtilis and coccidial vaccination on cecal microbial diversity and composition of Eimeria-challenged male broilers

In a companion study, the effects of dietary antibiotic alternative and coccidial vaccination on the growth performance of male broilers have been reported. In this paper, the effects of dietary probiotics and coccidial vaccination on diversity and composition of cecal microbiota were investigated using a 3 (diets) × 2 (vaccinated or non-vaccinated) factorial setting of treatments. Three diets, including a corn and soybean-meal control diet, an antibiotic diet (a control diet supplemented with bacitracin and salinomycin), and a probiotic diet (a control diet supplemented with Bacillus subtilis) were provided to broiler chicken from day 0 to 42. To simulate an Eimeria challenge in the field, all chicks were gavaged with a 20× dose of commercial coccidial vaccine containing live Eimeria oocysts on day 14. Cecal contents were collected on day 42. High-throughput sequencing of the 16S rRNA gene was used to determine microbial diversity and composition. Coccidial vaccination to broilers reduced bacterial diversity (Shannon index) of the cecal microbiota. There was a significant interaction between the dietary additive and coccidial vaccination on the observed bacterial species number. Diets supplemented with B. subtilis increased bacterial species of non-vaccinated broilers but decreased bacterial species of vaccinated broilers. In contrast, diets supplemented with antibiotics reduced bacterial species of broilers from both groups. Interactions between dietary additive and coccidial vaccination were also observed on microbial composition. Vaccinated broilers fed the B. subtilis diet exhibited the lowest Firmicutes percentage and highest Bacteroidetes percentage within the microbial community. In addition, vaccinated broilers fed the B. subtilis diet exhibited the highest Rikenella microfusus percentage. From this study, the coccidial vaccination on the day of hatch reduced the microbial diversity of broilers at a later age. The inclusion of B. subtilis-probiotics in the feed of vaccinated broilers may reduce microbial diversity in cecal content by increasing the proportion of a predominant bacterial species, R. microfusus, in the microbial community.