High-throughput sequencing reveals the effect of Bacillus subtilis CGMCC 1.921 on the cecal microbiota and gene expression in ileum mucosa of laying hens

Anaerobic fermentation of soybean meal by Bacillus subtilis ED-3-7 and its effect on the intestinal microbial community of chicken

A strain named ED-3-7 with a high protease-producing ability was screened in a previous study. This strain can be used for the anaerobic fermentation of soybean meal (SBM) to degrade macromolecular antigen proteins and antinutritional factors. We here evaluated the nutritional quality of the anaerobic fermented SBM and its effects on the chicken intestinal microbial community. Crude protein and acid-soluble protein contents increased by 11.68% and 342.61%, glycinin and β-conglycinin decreased by 82.04% and 88.42%, urease content decreased by 90.10%, and the trypsin inhibitor content was lower than the range specified in the detection kit. After being fed with the fermented SBM, the average daily gain, nutrient digestibility of the chickens increased, and their intestinal bacterial community exhibited significant changes. The richness and diversity of bacterial species decreased, and Lactobacillus became the dominant genus, which was conducive to the health of chicken intestines. The experimental results revealed that ED-3-7 anaerobic fermentation improved the nutritional quality of SBM and had beneficial effects on chicken intestines. Thus, the strain could be used for large-scale industrial production.

Metabolic modelling uncovers the complex interplay between fungal probiotics, poultry microbiomes, and diet

BACKGROUND

The search for alternatives to antibiotic growth promoters in poultry production has increased interest in probiotics. However, the complexity of the interactions between probiotics, gut microbiome, and the host hinders the development of effective probiotic interventions. This study explores metabolic modelling to examine the possibility of designing informed probiotic interventions within poultry production.

RESULTS

Genomic metabolic models of fungi were generated and simulated in the context of poultry gut microbial communities. The modelling approach correlated with short-chain fatty acid production, particularly in the caecum. Introducing fungi to poultry microbiomes resulted in strain-specific and diet-dependent effects on the gut microbiome. The impact of fungal probiotics on microbiome diversity and pathogen inhibition varied depending on the specific strain, resident microbiome composition, and host diet. This context-dependency highlights the need for tailored probiotic interventions that consider the unique characteristics of each poultry production environment.

CONCLUSIONS

This study demonstrates the potential of metabolic modelling to elucidate the complex interactions between probiotics, the gut microbiome, and diet in poultry. While the effects of specific fungal strains were found to be context-dependent, the approach itself provides a valuable tool for designing targeted probiotic interventions. By considering the specific characteristics of the host microbiome and dietary factors, this methodology could guide the deployment of effective probiotics in poultry production. However, the current work relies on computational predictions, and further in vivo validation studies are needed to confirm the efficacy of the identified probiotic candidates. Nonetheless, this study represents a significant step in using metabolic models to inform probiotic interventions in the poultry industry. Video Abstract.

The Influence of Dietary n-3 Highly Unsaturated Fatty Acids on Growth, Fatty Acid Profile, Lipid Metabolism, Inflammatory Response, and Intestinal Microflora in F2 Generation Female Yangtze Sturgeon (Acipenser dabryanus)

DHA and EPA, as indispensable n-3 highly unsaturated fatty acids (HUFAs), exert a fundamental influence on regulating fish growth, lipid metabolism, and overall well-being. However, there is a notable lack of data concerning their effects on the F2 female generation of Yangtze sturgeon. Over a ten-month period, this study assessed the impacts of various dietary concentrations of n-3 HUFAs (0.5%, 1.0%, 1.5%, 2.0%, and 2.4%) on growth, fatty acid composition, lipid metabolism, inflammatory response, and intestinal microbiota in the F2 female generation of Yangtze sturgeon. Seventy-five test fish, with an average body weight of 3.60 ± 0.83 kg, were housed in 15 ponds, with each dietary group being assigned to three ponds. The results indicated that the 1.0%~1.5% n-3 HUFA group was characterized by the highest values of weight gain rate; serum triglyceride levels peaked in the 0.5% n-3 HUFA group. The fatty acid profiles of the fish tissues closely mirrored those of the diets. Specifically, compared to the 1.5% and 2.0% n-3 HUFA groups, the diet containing 2.4% n-3 HUFA down-regulated the mRNA expression of transforming growth factor beta, and, compared to the 0.5% and 1.0% n-3 HUFA groups, the 2.0% n-3 HUFA diet up-regulated the mRNA expression of nuclear factor kappa B. Conversely, compared to the 0.5% n-3 HUFA group, 2.0% n-3 HUFA in the diet up-regulated the gene mRNA expression of fatty acid binding protein 1 and fatty acid synthase. Compared to the 0.5% n-3 HUFA group, 1.0% n-3 HUFA in the diet up-regulated the gene mRNA expression of lipoprotein lipase. The α-diversity indices (ACE, PD_whole tree, Richness, and Chao1) exhibited an upward trend with increasing dietary n-3 HUFA levels, and the 2.4% n-3 HUFA group reached the highest values. At the phylum level, Fusobacteriota, Proteobacteria, Firmicutes, and Bacteroidota were the primary dominant phyla. Cetobacterium was the dominant genus in all groups. Collectively, these findings underscore that moderate dietary supplementation of n-3 HUFA (1.3%) is optimal and does not impair growth. The deposition of fatty acids in muscle and ovarian tissues, as well as the mRNA expression of lipid-metabolism genes, are closely associated with the dietary n-3 HUFA content. High levels of n-3 HUFA did not suppress intestinal α-diversity. These discoveries provide novel insights into the regulation of growth, lipid metabolism, and health in the F2 female generation of Yangtze sturgeon and offer a nutritional strategy for the artificial conservation of this endangered species.

The causality between gut microbiota and functional dyspepsia: A two-sample Mendelian randomization analysis

To investigate the potential link between gut microbiota and functional dyspepsia (FD). Genome-wide association studies (GWAS) of gut microbiota and FD were used in Mendelian randomization (MR) research. Using the GWAS of 18,340 people, instrumental variables related to gut microbiota as an exposure factor were identified. In a GWAS investigation, 189,695 control individuals and 4376 FD patients were included as outcome variables. The primary analysis technique was inverse variance weighted analysis. The reliability of MR analysis results is tested using sensitivity analysis. Two-sample Mendelian randomization analysis revealed the presence of 7 gut microbiota associated to FD. In the inverse variance weighted analysis method, Order Erysipelotrichales (odds ratio (OR): 1.301; 95% confidence interval (CI): 1.016, 1.665; P = .037), Family Erysipelotrichales (OR: 1.301; 95% CI: 1.016, 1.665; P = .037), Genus Haemophilus (OR: 1.236; 95% CI 1.059, 1.442; P = .007), Genus Ruminiclostridium 9 (OR: 1.422; 95% CI: 1.078, 1.877; P = .013), Genus Lachnospiraceae NK4A 136 group (OR: 1.297; 95% CI: 1.059, 1.589; P = .012) was positively associated with FD. Class Gammaproteobacteria (OR: 0.705; 95% CI: 0.522, 0.952; P = .022) and Genus Erysipelatoclostridium (OR: 0.747; 95% CI: 0.628, 0.888; P = .001) were found to be inversely related to FD. There was no evidence of pleiotropy or heterogeneity in the sensitivity analysis. Our research provides evidence for a possible link between FD and a number of gut microbiota. The role that gut microbiota plays in the development of FD requires more investigation.

Effect of caffeic acid grafted chitosan loaded quercetin lyophilized powder formulation on avian colibacillosis and tissue distribution

Quercetin (QR), recognized as a natural antibacterial ingredient, has found widespread application in the poultry industry. This study investigated the bacteriostatic mechanism and evaluated the in vivo inhibitory impact of caffeic acid-grafted chitosan self-assembled micelles loaded quercetin (CA-g-CS/QR) on avian Escherichia coli (E. coli). The findings indicate that the bactericidal mechanism of CA-g-CS/QR exhibits enhanced efficacy compared to QR alone, disrupting bacterial cell walls, disassembling biofilm structures, and impeding essential components necessary for bacterial growth. Following an avian E. coli attack in broilers, CA-g-CS/QR demonstrated the capacity to enhance the population of beneficial bacteria while concurrently decreasing harmful bacteria within the intestinal tract. Moreover, within 3 days of oral administration of CA-g-CS/QR, a significant decrease in Escherichia spp. count was evident, resulting in the restoration of broilers to a healthy state. CA-g-CS/QR proved to be a significant and more efficacious solution than QR alone for avian E. coli disease. Furthermore, CA-g-CS/QR displayed a broader distribution range and higher concentration within the body. Ten metabolites have been identified in the liver for both QR and CA-g-CS/QR. In conclusion, CA-g-CS/QR has demonstrated a notable capacity to enhance in vitro and in vivo bacterial inhibitory effects, providing foundation for the clinical application of QR in combating avian E. coli infections in broilers.

Standardized ileal amino acid digestibility and performance indices in pullets and laying hens fed expeller-pressed Canadian prairie soybean meal

Soybean meals (SBM) from different locations differ in their protein content, subsequently influencing their amino acid (AA) profile. In this study, standardized ileal digestibility (SID) of AA and growth or production performance were evaluated in pullets and hens fed SBM derived from soybean grown in Western Canada, primarily Manitoba (MB) labelled as A-, B- and C-SBM compared with that from Eastern Canada (Ontario, ON-SBM) and contained 38.3 ± 0.44, 38.6 ± 0.61, 39.4 ± 0.49, or 44.0 ± 0.87% CP, respectively. A N-free diet was used to determine basal ileal endogenous losses of AA. The study included the grower, developer, and layer phases (9-12, 13-16, and 44/59-64-wk old birds, respectively). Although a lower (P = 0.029) SID for cysteine was noted in the grower phase for the C-SBM compared with other SBM, the developer phase had higher (P < 0.05) SID for methionine, phenylalanine, cysteine (more by 4.4, 2.4 and 7.2% units, respectively) on average for SBM samples from MB compared with the ON-SBM. Regardless the source of the SBM, no difference in SID of AA was noted in the layer phase. Overall, in all phases the SID values of most AA in the SBM from MB were comparable with the ON-SBM, which may be linked to higher values of these AA per unit of protein content in the former source. In addition, the growth performance including feed intake, BW gain and feed conversion ratio in pullets, and egg production/quality in layers were similar between treatments. These findings show that the MB-SBM have a comparable feeding value with the ON-SBM, hence represent a suitable alternative protein source for poultry.

Feeding Broiler Chicks with Bacillus subtilis, Clostridium butyricum, and Enterococcus faecalis Mixture Improves Growth Performance and Regulates Cecal Microbiota

A total of 300 day-old Arbor Acres Plus broiler chicks (mixed sex) was used to evaluate the effects of dietary supplementation of Bacillus subtilis, Clostridium butyricum, and Enterococcus faecalis mixture (PB) on growth performance, ileal morphology, and cecal microbiota. All birds were randomly assigned into 3 groups based on the initial body weight. There were 5 replicate cages per group and 20 birds per cage. The experimental period was 42 days. Dietary treatments were based on a basal diet and supplemented with 0, 0.05, or 0.10% PB. The results indicated that broiler chicks fed with the diet supplemented with graded levels of PB have quadratically improved their body weight gain and feed intake; the highest value was presented in 0.05% PB-containing group. In addition, villus to crypt ratio linearly increased with the concentration of PB increased in the diet. The alpha diversity linearly increased by PB supplementation, and the highest value was presented in 0.10% PB-containing group. In terms of growth performance, the suitable dose of PB used in the diet was 0.05%. However, ternary plot showed that the harmful bacteria, Escherichia-Shigella, was enriched in 0.05% PB-containing group. In brief, we considered that dietary supplementation of graded levels of PB improved growth performance and regulated cecal microbiota in broiler chicks.

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.

Multi-omics analysis reveals the molecular regulatory network underlying the prevention of Lactiplantibacillus plantarum against LPS-induced salpingitis in laying hens

BACKGROUND

Salpingitis is one of the common diseases in laying hen production, which greatly decreases the economic outcome of laying hen farming. Lactiplantibacillus plantarum was effective in preventing local or systemic inflammation, however rare studies were reported on its prevention against salpingitis. This study aimed to investigate the preventive molecular regulatory network of microencapsulated Lactiplantibacillus plantarum (MLP) against salpingitis through multi-omics analysis, including microbiome, transcriptome and metabolome analyses.

RESULTS

The results revealed that supplementation of MLP in diet significantly alleviated the inflammation and atrophy of uterus caused by lipopolysaccharide (LPS) in hens (P < 0.05). The concentrations of plasma IL-2 and IL-10 in hens of MLP-LPS group were higher than those in hens of LPS-stimulation group (CN-LPS group) (P < 0.05). The expression levels of TLR2, MYD88, NF-κB, COX2, and TNF-α were significantly decreased in the hens fed diet supplemented with MLP and suffered with LPS stimulation (MLP-LPS group) compared with those in the hens of CN-LPS group (P < 0.05). Differentially expressed genes (DEGs) induced by  MLP were involved in inflammation, reproduction, and calcium ion transport. At the genus level, the MLP supplementation significantly increased  the abundance of Phascolarctobacterium, whereas decreased the abundance of Candidatus_Saccharimonas in LPS challenged hens (P < 0.05). The metabolites altered by dietary supplementation with MLP were mainly involved in galactose, uronic acid, histidine, pyruvate and primary bile acid metabolism. Dietary supplementation with MLP inversely regulates LPS-induced differential metabolites such as LysoPA (24:0/0:0) (P < 0.05).

CONCLUSIONS

In summary, dietary supplementation with microencapsulated Lactiplantibacillus plantarum prevented salpingitis by modulating the abundances of Candidatus_Saccharimonas, Phascolarctobacterium, Ruminococcus_torques_group and Eubacterium_hallii_group while downregulating the levels of plasma metabolites, p-tolyl sulfate, o-cresol and N-acetylhistamine and upregulating S-lactoylglutathione, simultaneously increasing the expressions of CPNE4, CNTN3 and ACAN genes in the uterus, and ultimately inhibiting oviducal inflammation.

Effects of fermented feed on growth performance, serum biochemical indexes, antioxidant capacity, and intestinal health of lion-head goslings

Introduction

The aim of this study was to evaluate the effects of fermented feed on growth performance, antioxidant indexes and intestinal health in lion-head goslings.

Methods

288 male lion-head goslings (one-day-old) were randomly divided into four groups (6 replicates per group, 12 samples per replicate): control group (basal diet) and fermented feed (FF) groups (basal diet supplemented with 2.5, 5.0 and 7.5% FF, respectively). The experimental period lasted 28 days.

Results

The results showed that 5.0 and 7.5% FF groups decreased feed conversion rate (FCR) when compared with the control group (p < 0.05). The 5.0% FF group reduced the activity of alkaline phosphatase (ALP) and lactate dehydrogenase (LDH) in serum; while the 7.5% FF group decreased the concentration of total cholesterol (TC), ALP and LDH activity (p < 0.05). Furthermore, the 7.5% FF group significantly increased total antioxidant capacity (T-AOC) in serum (p < 0.05); 2.5% and 5.0% FF groups significantly increased glutathione peroxidase (GSH-Px) in serum (p < 0.05); all FF groups increased the activity of superoxide dismutase (T-SOD) in serum (p < 0.05). For intestinal health, the villous height and villi/crypt ratio in jejunum were increased in all FF groups, but crypt depth was decreased (p < 0.05); The 5.0% FF groups enhanced T-AOC activity in jejunum (p < 0.05); The 2.5% and 5.0% FF groups enhanced GSH-Px activity (p < 0.05) in jejunum; All FF groups reduced malondialdehyde (MDA) level in jejunum (p < 0.05). LEfSe analysis showed that the cecum microbiota was significantly dominant in the 2.5% FF group compared to the control group including Firmicutes, Lactobacillales, Lactobacillus, and Prevotella; the flora that were significantly dominant in the 5.0% FF group compared to the control group included Bacteroidaceae, Bacteroides, Megamonas, and Prevotella; and the groups that were significantly dominant in the 7.5% FF group compared to the control group included Bacteroidota, Bacteroides, Bacteroidaceae, and Ruminococcaceae.

Discussion

In summary, dietary FF supplementation improved growth performance, serum biochemical parameters and antioxidant capacity of lion-head goslings, as well as improved jejunal tissue morphology and optimized intestinal flora structure. In particular, the FF addition at a dose of 7.5% was relatively more effective for lion- head goslings.

Shaoyao-Gancao-Tang regulates the T-helper-type 1/T-helper-type 2 ratio in the lung and gut and alters gut microbiota in rats with ovalbumin-induced asthma

ETHNOPHARMACOLOGICAL RELEVANCE

Shaoyao-Gancao Tang (SGT) is a traditional Chinese medicine formulation. It has been used to treat kinds of pain and to alleviate asthma in clinic. However, the mechanism of action is not known.

AIM OF THE STUDY

To investigate the anti-asthma effect of SGT involving modulation of the T-helper type 1 (Th1) Th1/Th2 ratio in the gut-lung axis and alteration of the gut microbiota (GM) in rats with ovalbumin (OVA)-induced asthma.

MATERIALS AND METHODS

The main constituents of SGT were analyzed by high-performance liquid chromatography (HPLC). A model of asthma was established in rats by OVA-induced allergen challenge. Rats suffering from asthma (RSAs) were treated with SGT (2.5, 5.0 and 10.0 g/kg), dexamethasone (1 mg/kg) or physiologic saline for 4 weeks. The level of immunoglobulin (Ig)E in bronchoalveolar lavage fluid (BALF) and serum was determined by enzyme-linked immunosorbent assay. Histology of lung and colon tissues was investigated using staining (hematoxylin and eosin and periodic acid-Schiff). The Th1/Th2 ratio and levels of cytokines (interferon (IFN)-γ and interleukin (IL)-4) in the lung and colon were detected by immunohistochemistry. The GM in fresh feces was analyzed by 16 S rRNA gene sequencing.

RESULTS

Twelve main constituents (gallic acid, albiflorin, paeoniflorin, liquiritin apioside, liquiritin, benzoic acid, isoliquiritin apioside, isoliquiritin, liquiritigenin, glycyrrhizic acid, isoliquiritigenin and glycyrrhetinic acid) of SGT were simultaneously determined by HPLC. SGT treatment (5.0 and 10.0 g/kg) was found to reduce the IgE level (a vital marker of hyper-responsiveness) in BALF and serum, improve typical morphological changes (inflammatory-cell infiltration and goblet cell metaplasia) in the lung and colon, alleviate airway remodeling (including bronchiostenosis and basement membrane-thickening) in the lung, significantly decrease the IL-4 level and increase the IFN-γ level in the lung and colon, which led to restoration of the IFN-γ/IL-4 ratio. The dysbiosis and dysfunction of GM in RSAs were modulated by SGT. The abundance of bacteria of the genera Ethanoligenens and Harryflintia was increased in RSAs and was decreased upon SGT treatment. The abundance of Family_XIII_AD3011_group was decreased in RSAs and increased upon SGT treatment. Moreover, SGT therapy increased the abundance of bacteria of the genera Ruminococcaceae_UCG-005 and Candidatus_Sacchrimonas, and decreased that of Ruminococcus_2 and Alistipes.

CONCLUSIONS

SGT ameliorated rats with OVA-induced asthma via regulation of the Th1/Th2 ratio in the lung and gut, and modulated the GM.

Exploring the effects of palm kernel meal feeding on the meat quality and rumen microorganisms of Qinghai Tibetan sheep

Palm kernel meal (PKM) has been shown to be a high-quality protein source in ruminant feeds. This study focused on the effects of feed, supplemented with different amounts of PKM (ZL-0 as blank group, and ZL-15, ZL-18, and ZL-21 as treatment group), on the quality and flavor profile of Tibetan sheep meat. Furthermore, the deposition of beneficial metabolites in Tibetan sheep and the composition of rumen microorganisms on underlying regulatory mechanisms of meat quality were studied based on ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry as well as 16S rDNA sequencing. The results of the study showed that Tibetan sheep in the ZL-18 group exhibited superior eating quality and flavor profile while depositing more protein and fat relative to the other groups. The ZL-18 group also changed significantly in terms of the concentration and metabolic pathways of meat metabolites, as revealed by metabolomics. Metabolomics and correlation analyses finally showed that PKM feed mainly affected carbohydrate metabolism in muscle, which in turn affects meat pH, tenderness, and flavor. In addition, 18% of PKM increased the abundance of Christensenellaceae R-7 group, Ruminococcaceae UCG-013, Lachnospiraceae UCG-002, and Family XIII AD3011 group in the rumen but decreased the abundance of Prevotella 1; the above bacteria groups regulate meat quality by regulating rumen metabolites (succinic acid, DL-glutamic acid, etc.). Overall, the addition of PKM may improve the quality and flavor of the meat by affecting muscle metabolism and microorganisms in the rumen.

Microbial diversity and community composition of fecal microbiota in dual-purpose and egg type ducks

Introduction

Ducks are important agricultural animals, which can be divided into egg and dual-purpose type ducks according to economic use. The gut microbiota of ducks plays an important role in their metabolism, immune regulation, and health maintenance.

Methods

Here, we use 16S rDNA V4 hypervariable amplicon sequencing to investigate the compositions and community structures of fecal microbiota between egg (five breeds, 96 individuals) and dual-purpose type ducks (four breeds, 73 individuals) that were reared under the same conditions.

Results

The alpha diversity of fecal microflora in egg type ducks was significantly higher than that in dual-type ducks. In contrast, there is no significant difference in the fecal microbial community richness between the two groups. MetaStat analysis showed that the abundance of Peptostreptococcaceae, Streptococcaceae, Lactobacillus, Romboutsia, and Campylobacter were significantly different between the two groups. The biomarkers associated with the egg and dual-purpose type ducks were identified using LEfSe analysis and IndVal index. Function prediction of the gut microbiota indicated significant differences between the two groups. The functions of environmental information processing, carbohydrate metabolism, lipid metabolism, xenobiotic biodegradation and metabolism, and metabolism of terpenoids and polyketides were more abundant in egg type ducks. Conversely, the genetic information processing, nucleotide metabolism, biosynthesis of amino acids and secondary metabolites, glycan biosynthesis and metabolism, fatty acid elongation, and insulin resistance were significantly enriched in dual-purpose type ducks.

Discussion

This study explored the structure and diversity of the gut microbiota of ducks from different economic-use groups, and provides a reference for improving duck performance by using related probiotics in production.

The effects of a Bacillus licheniformis and phytase mixture added to broiler diets on growth performance, nutrient digestibility, and cecal microecosystem

This study aims to evaluate the effects of Bacillus licheniformis and 6-phytase added alone or in combination to broiler chicken diets on the growth performance, apparent ileal digestibility coefficient (AID) of nutrients, microbial activity, and cecal bacterial communities. In total, 400 one-day-old female Ross 308 chicks were randomly allocated to 4 dietary treatments (10 replicate pens, 10 birds each). The following groups were defined: NC (negative control), basal diet without any feed additive supplementation; NC+Pro, basal diet with addition of the B. licheniformis preparation (500 g/t of diet); NC+Phy, basal diet with addition of phytase (200 g/t of diet); and NC+Pro+Phy, basal diet combined with both studied additives. B. licheniformis positively affected (P<0.05) the feed intake (FI) and feed conversion ratio (FCR) in the first 10 d of bird rearing. Moreover, phytase supplementation elevated the FCR from 21 to 35 d. In the entire experiment, an interaction between phytase and probiotic was observed only in terms of decreasing the bird FI (P=0.005) without a negative effect on the FCR (P>0.05). Furthermore, the AID of ether extract was improved by phytase supplementation. In terms of the cecal microecology, both separately administered factors promoted Lactobacillaceae in the ceca. Interactions between probiotic preparation and phytase were noted that indicated a decreased Clostridiales population and favored Ruminococcaceae proliferation. It can be concluded that for the first time in the available literature, the favorable interactions between B. licheniformis and phytase resulted in improved performance and cecal microbiota changes in broilers.

Low Ca diet leads to increased Ca retention by changing the gut flora and ileal pH value in laying hens

Osteoporosis is a common degenerative metabolic bone disease in caged laying hens. Intensive egg production mobilizing large amounts of Ca from bone for eggshell formation, consequently leading to Ca deficiency, has been recognized as a critical factor causing osteoporosis in commercial laying hens. The aim of this study was to examine the effect of Ca deficiency on the function of the gut microbiota-bone axis and related egg production traits and bone health in laying hens. Twenty-four 48-week-old laying hens were fed a control diet (Control, 3.72%) or a low Ca diet (LC, 2.04%) for 60 d (n = 12). Compared to the Control hens, the LC hens had higher levels of alkaline phosphatase and tartrate resistant acid phosphatase (P < 0.05) with lower bone strength, eggshell thickness, and eggshell strength (P < 0.05). In addition, the LC hens had higher plasma estradiol concentrations, while having lower concentrations of interleukin-1 (IL-1) and IL-6. The LC hens also had a lower pH value in the ileum with an increased Ca retention. The principal co-ordinates analysis showed significantly separate cecal microbiota populations between the Control and LC hens. The Prevotellaceae_UCG-001, Subdoligranulum, Peptococcus, and Eubacterium_hallii_group (P < 0.05) were higher, while the CHKC1001 and Sutterella (P < 0.05) were lower at the genus level in the LC hens. In addition, Prevotellaceae_UCG-001, Subdoligranulum and Eubacterium_hallii_group had a negative correlation, while Sutterella was positively correlated with ileal pH values. The transcriptome analysis revealed that the low Ca diet caused 20 and 31 genes to be significantly up- and down-regulated, respectively. The gene expressions of cystic fibrosis transmembrane conductance regulator, solute carrier family 26 member 3 of the anion exchangers, and mitogen-activated protein kinase 12 of pro-inflammatory factors were lower in the LC birds, which was correlated with the lower ileal pH values. These results suggest that the hens with low Ca diet-induced osteoporosis have an increased intestinal Ca retention with a decreased ileal pH value, correlated with the changes in Prevotellaceae_UCG-001, Subdoligranulum, and Eubacterium_hallii_group of beneficial genera. The results provide insights for further understanding and preventing osteoporosis in laying hens.

Sodium humate alters the intestinal microbiome, short-chain fatty acids, eggshell ultrastructure, and egg performance of old laying hens

This study investigated the effect of sodium humate supplementation on changes in the intestinal microbiome, intestinal short-chain fatty acids production, and trace element absorption in older laying hens, with consequent effects on egg performance and shell quality. We used the same hens as their own control; a total of 720 laying hens aged 422 days were randomly divided into three replicates, with the CON group fed a commercial diet at 422–441 days of age and the HANa group fed a commercial diet supplemented with 0.05% sodium humate at 442–461 days of age. Compared with the CON group, in the HANa group, Bacteroidetes and Actinobacteria were significantly increased, whereas, Firmicutes was significantly decreased. Further, Veillonella, Enterococcus, Lactobacillus, and Turricibacter significantly decreased, and Peptoniphilus, Helcococcus, GW-34, Psychrobacter, Anaerococcus, Corynebacterium, Facklamia, Trichococcus, Gallicola, Clostridium, and Oscillospira were significantly increased. The results showed that sodium humate significantly altered the alpha and beta diversity and changed the structure of the intestinal microbiome. Acetic acid, isovaleric acid, and isobutyric acid, among short-chain fatty acids were significantly increased in the HANa group, whereas trace elements such as Mn, Zn, and Fe were significantly reduced. The eggshell strength and ultrastructure were significantly altered. In this study, sodium humate was found to alter the intestinal microbiome structure of aged hens, change the production of short-chain fatty acids, and promote the absorption of trace elements to keep aged hens from experiencing a decrease in egg production performance.

Microbiota from patients with ulcerative colitis promote colorectal carcinogenesis in mice

OBJECTIVES

Long-term ulcerative colitis (UC) is associated with both dysbiosis in intestinal microbiota and predisposition to colorectal cancer. In this study, we investigated whether microbiota from patients with UC could increase colorectal carcinogenesis in mice, generated by azoxymethane through intraperitoneal injection.

METHODS

Mice were gavaged twice per week with intestinal microbiota from patients with UC or healthy individuals. Intestinal tissues were collected from mice and compared by histology, immunohistochemistry, expression microarray, quantitative polymerase chain reaction, Western blot, and flow cytometry analyses. Quantification of bacteria in feces was performed using 16 S ribosomal RNA gene selective quantitative polymerase chain reaction.

RESULTS

Compared with mice fed microbiota from healthy controls, increased tumorigenesis was observed in mice gavaged with microbiota from patients with UC, including a higher number of colon adenoma and a significantly higher proportion of grade dysplasia. Consistent with tumorigenesis, mice gavaged with microbiota from patients with UC showed an increased expression of Ki67 and proliferating cell nuclear antigen. In addition, an increased expression of cytokines and more abundant presence of T helper cells types 1 and 17 was observed in mice receiving microbiota from patients with UC. Moreover, a decrease in the abundance of short-chain fatty acids was detected in the feces, as well as an altered intestinal microbial composition in mice fed with microbiota from patients with UC.

CONCLUSIONS

Fecal microbiota from patients with UC exacerbate tumorigenesis in mice. The disturbance of intestinal microbiota and activation of T helper cells types 1 and 17 cytokines caused by gavaging microbiota from patients with UC both contributed to intestinal carcinogenesis.

Alleviating effects of gut micro-ecologically regulatory treatments on mice with constipation

Treatments targeted for gut microbial regulation are newly developed strategies in constipation management. In this study, the alleviating effects of gut micro-ecologically regulatory treatments on constipation in mice were investigated. Male BALB/c mice were treated with loperamide to induce constipation, and then the corresponding intervention was administered in each group, respectively. The results showed that administration of mixed probiotics (MP), a 5-fold dose of postbiotics (P5), both synbiotics (S and S2), as well as mixed probiotics and postbiotics (MPP) blend for 8 days shortened the time to the first black stool, raised fecal water content, promoted intestinal motility, and increased serum motilin level in loperamide-treated mice. Furthermore, these treatments altered gut microbial composition and metabolism of short-chain fatty acids (SCFA). Based on linear regression analysis, SCFA was positively correlated with serum motilin except for isobutyrate. It suggested gut microbial metabolites affected secretion of motilin to increase gastrointestinal movement and transportation function and thus improved pathological symptoms of mice with constipation. In conclusion, the alteration of gut micro-ecology is closely associated with gastrointestinal function, and it is an effective way to improve constipation via probiotic, prebiotic, and postbiotic treatment.

Intestinal microbiota of layer hens and its association with egg quality and safety

The intestinal microbiota has attracted tremendous attention in the field of the poultry industry due to its critical role in the modulation of nutrient utilization, immune system, and consequently the improvement of the host health and production performance. Accumulating evidence implies intestinal microbiota of laying hens is a potential mediator to improve the prevalent issues in terms of egg quality decline in the late phase of laying production. However, the regulatory effect of intestinal microbiota on egg quality in laying hens remains elusive, which requires consideration of microbial baseline composition and succession during their long lifespans. Notable, although Firmicutes, Bacteroidetes, and Proteobacteria form the vast majority of intestinal microbiota in layer hens, dynamic intestinal microbiota succession occurs throughout all laying periods. In addition to the direct effects on egg safety, intestinal microbiota and its metabolites such as short-chain fatty acids, bile acids, and tryptophan derivatives, are suggested to indirectly modulate egg quality through the microbiota-gut-liver/brain-reproductive tract axis. These findings can extend our understanding of the crosstalk between intestinal microbiota and the host to improve egg quality and safety. This paper reviews the compositions of intestinal microbiota in different physiological stages of laying hens and their effects on egg quality and proposes that intestinal microbiota may become a potential target for modulating egg quality and safety by nutritional strategies in the future.

Bacillus subtilis inhibits intestinal inflammation and oxidative stress by regulating gut flora and related metabolites in laying hens

Bacillus subtilis is one of the most popular commercial probiotics used in farm animal production. However, its potential mechanisms are not very clear. The aim of this study was to investigate the effects of dietary Bacillus subtilis on intestinal histomorphology, innate immunity, microbiota composition, transcriptomics, and related metabolomics. Twenty-four 48-week-old Lohman Pink-shell laying hens were randomly divided into two groups: a basic diet and the basic diet supplemented with Bacillus subtilis (0.5 g/kg) for a 9-week experiment. At the end of the experiment, tissues of the duodenum, ileum, and jejunum as well as cecal content of each bird were collected for microstructure, PCR, transcriptome, metabolome, and 16S rRNA analyses. The results showed that dietary Bacillus subtilis supplement had no effect on the intestinal microstructure. However, Bacillus subtilis increased mRNA expression of tight junction protein occludin (P < 0.05), while reduced mRNA expression of lipopolysaccharide-induced TNF factor (P < 0.01) in the duodenum. Moreover, transcriptomic results indicated that most of Bacillus subtilis supplement-induced differential genes were associated with inflammation and immunity, including cytochrome b-245 beta chain, transferrin, and purinergic receptor P2X 7, resulting in a decrease in Malondialdehyde level (P < 0.05) in the duodenum. In addition, at the genus level, Bacillus subtilis supplement enriched the potential beneficial bacteria, Candidatus_Soleaferrea (P = 0.02) but inhibited the harmful bacteria including Lachnospiraceae_FCS020_group, Ruminiclostridium, Lachnospiraceae_UCG-010, and Oxalobacter. Metabolomic results revealed that N-Acetylneuraminic acid and ADP were increased by fed Bacillus subtilis. These results suggest that dietary Bacillus subtilis could inhibit gut inflammation and improve antioxidative status and barrier integrity of the duodenum via regulating gut microbial composition in laying hens.

Effects of Different Fermented Feeds on Production Performance, Cecal Microorganisms, and Intestinal Immunity of Laying Hens

Simple Summary

Fermented feed exerts beneficial effects on intestinal microorganisms, host health, and production performance. However, the effect of fermented feed on laying hens is uncertain due to the different types of inoculated probiotics, fermentation substrates, and fermentation technology. Hence, this experiment was conducted to investigate the effects of fermented feed with different compound strains on the performance and intestinal health of laying hens. Supplement fermented feed reduced the feed conversion ratio and promoted egg quality. Both dietary treatment (fermented feed A produced Bacillus subtilis, Lactobacillus, and Yeast and fermented feed B produced by C. butyricum and L. salivarius) influenced intestinal immunity and regulated cecal microbial structure. This may be because the metabolites of microorganisms in fermented feed and the reduced pH value inhibited the colonization of harmful bacteria, improved the intestinal morphology, and then had a positive impact on the production performance and albumen quality of laying hens.

Abstract

This experiment was conducted to investigate the effects of different compound probiotics on the performance, cecal microflora, and intestinal immunity of laying hens. A total of 270 Jing Fen No.6 (22-week-old) were randomly divided into 3 groups: basal diet (CON); basal diet supplemented with 6% fermented feed A by Bacillussubtilis,Lactobacillus, and Yeast (FA); and with 6% fermented feed B by C. butyricum and L. salivarius (FB). Phytic acid, trypsin inhibitor, β-glucan concentrations, and pH value in fermented feed were lower than the CON group (p < 0.05). The feed conversion ratio (FCR) in the experimental groups was decreased, while albumen height and Haugh unit were increased, compared with the CON group (p < 0.05). Fermented feed could upregulate the expression of the signal pathway (TLR4/MyD88/NF-κB) to inhibit mRNA expression of pro-inflammatory cytokines (p < 0.05). Fermented feed promoted the level of Romboutsia (in the FA group) Butyricicoccus (in the FB group), and other beneficial bacteria, and reduced opportunistic pathogens, such as Enterocooccus (p < 0.05). Spearman’s correlations showed that the above bacteria were closely related to albumen height and intestinal immunity. In summary, fermented feed can decrease the feed conversion ratio, and improve the performance and intestinal immunity of laying hens, which may be related to the improvement of the cecal microflora structure.

Shifts in diversity and function of bacterial community during manufacture of Rushan

Rushan is a traditional dairy product consumed by the Bai people in the Yunnan Province of China, and its production still follows the traditional procedure of backslopping. However, how the microbial composition of raw materials and processing shape the microorganisms in Rushan have not been systemically reported. In this study, high-throughput sequencing technique was applied to analyze the microbial compositions of raw milk, fresh Rushan, curd whey, acid whey, and dry Rushan at the phylum, family, genus, and Lactobacillus species levels. The results indicated that Lactobacillus, Lactococcus, and Streptococcus were dominant genera in Rushan, whereas Lactobacillus kefiranofaciens and Lactobacillus helveticus were the 2 abundant species at the Lactobacillus species level. The network analysis indicated that raw milk mainly contributed to the microbial diversity of Rushan, whereas acid whey made a great contribution to shaping the relative abundance of microbes in Rushan and dramatically increased acid-producing genera, such as Lactobacillus and Acetobacter. The variation in microbial composition led to an increase in the relative abundance of pathways related to energy supply, acid production, fatty acid accumulation, cysteine, methionine, and lysine accumulation. The volatile profile of Rushan was rich in esters and acids, and the high relative abundance of Lactobacillus might be associated with reduction of amino acid metabolism, degradation of unpleasant flavored xylene, and accumulation of decanoic, dodecanoic, and tetradecanoic acids in the products. The accumulation of medium long-chain fatty acids might result from the relative abundance of FabF, FabZ, and FabI, particularly from Lactobacillus amylolyticus and Lacticaseibacillus paracasei.

Effects of Bacillus subtilis on Production Performance, Bone Physiological Property, and Hematology Indexes in Laying Hens

This study was to investigate the effects of Bacillus subtilis on production performance and bone pathophysiological characteristics of layers. Twenty-four 48-week-old Lohmann Pink-shell laying hens were randomly divided into two groups: a basic diet (control) and the basic diet mixed with Bacillus subtilis (0.5 g/kg) for a 60-day trial. Statistically, independent-sample t-test was used to assess the treatment differences. The results showed that Bacillus subtilis supplementation improved the percent of marketable eggs (p < 0.05) with reduced numbers of broken and soft-shelled eggs but had no effects on egg weight, height of albumen, yolk color, and Haugh unit (p > 0.05). Bacillus subtilis supplement also elevated maximum load (p = 0.06), maximum stress (p = 0.01), stiffness (p < 0.01), and Young's modulus (p < 0.01) but suppressed maximum strain (p = 0.06) in the femur. In addition, compared with control birds, phosphorous concentration (p < 0.01) was reduced in serum at day 61 but increased in the femur (p < 0.05) in Bacillus subtilis fed birds. Bacillus subtilis fed birds also had lower magnesium concentrations in both femur (p = 0.04) and feces (p = 0.09). Furthermore, Bacillus subtilis increased plasma estrogen concentration (p = 0.01) and femur TNF receptor superfamily member 11b (OPG) expression (p < 0.05) but reduced plasma IL-1 (p < 0.01) and TNF-α (p < 0.01) concentrations. These results indicate that Bacillus subtilis could be used as a health promotor to reduce overproduction-induced inflammation and associated bone damage and to increase marketable egg production. The data provide evidence for developing a management strategy to use Bacillus subtilis as a feed additive to improve marketable egg production and health and welfare status of laying hens.

Effects of Oral Exposure to Mn-Doped ZnS Quantum Dots on Intestinal Tract and Gut Microbiota in Mice

Mn-doped ZnS quantum dots (QDs) with excellent optical properties have been explored in a wide range of fields. Their potential adverse effects on biological systems and human health should be evaluated before biological application. In the present study, we investigated the effect of Mn-doped ZnS QDs on the intestinal tract and gut microbiota structures at 2 h and 14 days (d) after 14 d repeated oral exposure in mice. Flame atomic absorption spectrophotometry (FAAS), histopathological examination, and transmission electron microscopy (TEM) were used to assess the absorption and toxicity of Mn-doped ZnS QDs on the intestinal tract. The 16S rRNA gene sequencing was used to evaluate the gut microbial communities. Mn-doped ZnS QDs did not accumulate in the duodenum, jejunum, ileum, or colon. The Zn content of feces was not significantly higher than in the control group. No major histological changes were found in these tissues. The intestinal microvilli remained regular, but swelling of mitochondria and endoplasmic reticulum was detected by TEM at 14 d after the last gavage. A total of 2,712 operational taxonomic units (OTUs) were generated. Mn-doped ZnS QDs treatment did not significantly change the α-diversity of Richness, Chao1, Shannon, and Simpson indexes. According to principal component analysis (PCA), Mn-doped ZnS QDs had no effect on the overall structure of the gut microbiota. No significant change occurred at the phylum level, while three genera were downregulated at 2 h and seven changed at 14 d after the last gavage. Our findings revealed that Mn-doped ZnS QDs had a little stimulation of the intestinal tract and gut microbiota, and oral administration may be a safe route for biological application (such as bioimaging and drug delivery).

Benefit of Dietary Supplementation with Bacillus subtilis BYS2 on Growth Performance, Immune Response, and Disease Resistance of Broilers

A strain of Bacillus subtilis (B. subtilis) BYS2 was previously isolated from Mount Tai, which is located in Tai'an City in the Shandong Province of China. The strain was then stored in the Environmental Microbiology Laboratory at Shandong Agricultural University. To evaluate the effect of the bacterium preparation in broiler production, we fed the bacterium (10⁶ CFU/g) to 1-day-old broilers and continued this feeding for 6 weeks to analyze its effect on growth and immune performance. We found that the average weight of the bacterium-fed group increased by 17.19% at weeks 5 compared to the control group (P < 0.05). The height of the villi in the duodenum and jejunum and the ratio of villi to crypt were significantly increased in the bacterium-fed group at weeks 5 (P < 0.05). Also, the IgG in the serum of broilers in the experimental group increased by 31.60% (P < 0.05) and IgM 30.52% (P < 0.05) compared with those in the control group. The expressions of the major pattern recognition receptors (PRRs), antiviral proteins, pro-inflammatory cytokines, and β-defensins were significantly higher than those in the control group (P < 0.05). Meanwhile, the bursa immune organ indices of broilers in the experimental group were significantly higher than those in the control group (P < 0.05). Also, after 5 weeks of continuous feeding, when infected with Escherichia coli (E. coli) O1K1 and Newcastle disease virus (NDV) F48E8, the content of bacteria and virus in tissues and organs of the experimental group decreased significantly, and the survival rate of infected chickens increased by 31.1% and 17.7%, respectively (P < 0.05). These results show that the anti-infective B. subtilis BYS2 could, to some extent, replace antibiotics to promote growth, improve innate immunity, and enhance disease resistance in broilers.

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.

Dietary supplementation with Bacillus subtilis promotes growth performance of broilers by altering the dominant microbial community

The purpose of this study was to investigate the effects of Bacillus subtilis on growth performance, intestinal morphology, and cecal microbial composition of broilers. A total of 270 healthy one-day-old Arbor Acres male broiler chicks were randomly divided into 3 dietary treatment groups, with 6 replicates per group and 15 chickens per replicate. The dietary treatment groups were as follows: 1) basal diet, negative control group; 2) basal diet +250 g/t of zinc bacitracin, positive control group; and 3) basal diet +750 g/t of B. subtilis, B. subtilis group. Results of this experiment showed that compared with the negative control group, body weight at 42 d, average daily gain and European Production Efficiency Factor over the 42 d phase in the B. subtilis group and positive control group were significantly increased (P < 0.05); feed conversion rates in the B. subtilis group and positive control group were significantly decreased (P < 0.05); and average daily feed intake and mortality were not significantly different (P > 0.05). The villus height to crypt depth ratio in the ileum of the B. subtilis group was significantly higher (P < 0.05) than that of the negative control group. The results of cecal microflora at genus level were as follows. As compared with the negative control group, the abundance of Blautia, Faecalibacterium, Flavonifractor, and Hydrogenoanaerobacterium of the B. subtilis group and positive control group was significantly higher (P < 0.05), whereas the abundance of Odoribacter was significantly lower (P < 0.05). Moreover, abundance of the genera Romboutsia in the B. subtilis group was higher (P < 0.05) than that in the positive control group. The abundance of Flavonifractor, Erysipelatoclostridium, and Hydrogenoanaerobacterium were positively correlated with body weight and average daily gain by Spearman correlation analysis. In conclusion, dietary supplementation with B. subtilis improved growth performance of broilers which may be related to the increased abundance of Blautia, Faecalibacterium, Flavonifractor, Hydrogenoanaerobacterium, and Romboutsia, along with the decreased abundance of Odoribacter. In addition, the effect of B. subtilis was superior to zinc bacitracin in improving intestinal microbial composition of broilers. Therefore, B. subtilis may act as an effective antibiotic substitute in broilers.

Effect of dietary n-3 polyunsaturated fatty acids on the composition of cecal microbiome of Lohmann hens

Supplementation of n-3 fatty acids to poultry diets is widely acknowledged for its role in enhancing poultry products, however, little is known about the compositional responses of gut microbial communities to type and dosage of these supplements.  Here, we compared the effects of n-3 polyunsaturated fatty acids (PUFA), supplied as alpha-linolenic acid (ALA) or docosahexaenoic acid (DHA), on the composition of bacterial communities in ceca of laying hens.  Corn-soybean basal diets were supplemented with either flaxseed oil (FO, ALA-rich) or marine algal biomass (MA, DHA-rich), and each supplied 0.20 and 0.60% of total n-3 PUFA in the diet.  Lohmann LSL-Classic laying hens (n = 10/treatment) were randomly allocated to one of the 4 diets.  After 8 weeks of feeding, blood, liver and cecal digesta samples were obtained for plasma glucose, fatty acids, and short chain fatty acids analyses, respectively.  The gut bacterial communities were characterized using genomic DNA extracted from cecal contents, whereby the V3-V4 hypervariable region of the 16S rRNA gene was sequenced using the Illumina Miseq® platform.  Firmicutes and Bacteroidetes were the predominant phyla in both the FO- and MA-fed groups.  The relative abundance of Tenericutes, often associated with immunomodulation, was relatively higher (P<0.0001) in the FO than MA group.  Although the relative abundance of Bacteroides was greater for the FO- than the MA-fed group, this genus was negatively correlated (P<0.05) with total n-3 PUFA in the liver at higher dosages of both FO- and MA-fed hens.  Higher dose of FO (0.60%) and both dosages of MA (0.20 and 0.60%) substantially enriched several members of Firmicutes (e.g., Faecalibacterium, Clostridium and Ruminococcus) which are known to produce butyrate.  Moreover, co-occurrence network analysis revealed that, in the FO 0.60- and MA 0.20-fed hens, Ruminococcaceae was the most influential taxon accounting for about 31% of the network complexity.  These findings demonstrate that supplementation of different type and level of n-3 PUFA in hens' diets could enrich microbial communities with potential role in lipid metabolism and health.

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.

Combined Use of Bacillus subtilis yb-114,246 and Bacillus licheniformis yb-214,245 Improves Body Growth Performance of Chinese Huainan Partridge Shank Chickens by Enhancing Intestinal Digestive Profiles

The aim of our study was to unveil the promoting function of compound Bacillus sp. in improving chicken digestion-induced higher body growth performance. Strains of Bacillus subtilis and B. licheniformis were jointly supplemented to the chick diet. Digestive enzyme activities in the digesta improved, development of intestinal villus enhanced, and duodenum and ileum villous height increased, while their crypt depth declined, and the cecum's bacterial composition optimized after 56 days of supplementation. Bacterial composition at the phylum level changed significantly, more Firmicutes, Proteobacteria, Epsilonbacteraeota, and Tenericutes, but fewer Bacteroidetes were detected in cecum digesta in the compound Bacillus supplemented group. Bacterial composition diversity, which improves the abundances of metabolic genes through KEGG pathway classification, became more abundant. Results indicated that the Ruminococcaceae UCG-005, unclassified Ruminococcaceae, and unclassified Lachnospiraceae species are actively correlated with body growth, promoting higher final body weight. In conclusion, owing to digestive enzyme secretion, the development of intestinal villus was stimulated and gastrointestinal bacterial composition optimized, and two combined Bacillus sp. improved chicken body growth. Our findings show the promoting action of Bacillus subtilis and B. licheniformis on digestion, which can be an alternative to antibiotics.

Effects of Fermented Soybean Meal Supplementation on the Growth Performance and Cecal Microbiota Community of Broiler Chickens

Simple Summary

Microbial fermentation is considered an economically viable processing technique to reduce the content of anti-nutritional factors and improve the nutritional quality of soybean meal (SBM). Fermented soybean meal (FSBM) exerts beneficial effects on the growth performance, carcass traits, and meat quality of broilers. However, there is very little information on the effects of FSBM on cecal microbial composition and diversity in broilers. Hence, this trial is conducted to investigate the effects of the partial replacement of SBM with FSBM in the diet on growth performance and cecal microflora of broilers. Replacing 25% of the SBM in the diet of broilers with FSBM promoted average daily gain and feed conversion ratio during the growth and whole phases. Both dietary treatment (25% or 50% of the SBM in the basal diet was replaced with FSBM) influenced the serum immunity, diversity and composition of cecal microbiota in broilers. FSBM supplementation in the diet shifted the cecal microbial community of broilers towards a healthier balance by increasing the abundance of beneficial bacteria and reducing the abundance of potentially harmful bacteria.

Abstract

This study investigated the growth performance, serum immunity, and cecal bacterial microbiota of broilers fed a diet in which soybean meal (SBM) was partially replaced with fermented soybean meal (FSBM) for 36 days. A total of 180 one-day-old male Cobb 500 broilers were randomly divided into three dietary groups (six replicates per group): corn-SBM diet (CC); 25% SBM replaced by FSBM (SC); 50% SBM replaced by FSBM (TC). The average daily gain (ADG) and feed conversion rates (FCR) were higher in SC than CC and TC groups (p < 0.05) during the growth (d 22–36) and whole (d 1–36) phases. No significant difference was observed in ADG and average daily feed intake (ADFI) between CC and TC groups during any phases. Dietary treatments increased serum IgA, IgG, and IgM, Chao 1, observed species, and the abundance of the phylum Fimicutes but decreased the proportion of Proteobacteria (p < 0.05). Dietary treatments increased the abundance of the genera Lachnospiraceae, Lachnoclostridium, Gastranaerophilales, and Lactobacillus but decreased the abundance of Escherichia-Shigella and Clostridiales (p < 0.05). Spearman’s correlations showed that the abundance of Gastranaerophilales was positively correlated with ADG and serum immunity, and the abundance of Lactobacillus was strongly positively with IgM. Thus, replacing 25% of SBM with FSBM improves the growth performance and serum immunity of broilers, possibly due to altered cecal microbial composition.

Effects of Housing Types on Cecal Microbiota of Two Different Strains of Laying Hens During the Late Production Phase

Due to animal welfare issues, European Union has banned the use of conventional cages (CC) and non-EU countries including the US are also under constant public pressure to restrict their use in egg production. Very limited information is available on the composition of the microbial community of hens raised in different housing environments. This study was conducted to determine the effects of CC and enriched colony cages (EC) on cecal microbiota of two commercial laying hen strains, Hy-Line W36 (W36) and Hy-Line Brown (HB) during the late production stage (53, 58, 67, and 72 weeks of age). Cecal microbiota was studied by analyzing 16S rRNA gene sequences with Quantitative Insights Into Microbial Ecology (QIIME) 2 ver. 2018.8. Differentially abundant taxa were identified by Linear discriminant analysis Effect Size (LEfSe) analysis (P < 0.05, LDA score > 2.0). At phylum level, Actinobacteria was significantly enriched in W36 at all time points while Synergistetes (53 weeks), Spirochaetes (58 weeks), and Synergistetes and Spirochaetes (67 weeks) were significantly higher in HB. At genus level, Bifidobacterium (at all time points) and butyric acid producing genera such as Butyricicoccus and Subdoligranulum (58 and 72 weeks) were significantly higher in W36 as compared to HB. Moreover, Proteobacteria (72 weeks) and its associated genus Campylobacter (67 and 72 weeks) were significantly enriched in EC as compared to CC. Alpha diversity was significantly higher in HB (at all time points) and in EC (67 weeks) as compared to W36 and CC, respectively. Similarly, there was a significant difference in community structure (beta diversity) between W36 and HB (all time points) as well as between EC and CC (67 weeks). The effect of housing and strains was not only seen at the bacterial composition and structure but also reflected at their functional level. Notably, KEGG metabolic pathways predicted to be involved in carbohydrates degradation and amino acids biosynthesis by PICRUSt analysis were significantly different between W36 and HB housed at CC and EC. In sum, cecal microbiota composition, diversities, and their functional pathways were affected by housing type which further varied between two commercial laying hen strains, HB and W36. This suggests that both housing and genetic strains of laying hens should be considered for selection of the alternative housing systems such as enriched colony cage.

Combination of Bacillus licheniformis and Salinomycin: Effect on the Growth Performance and GIT Microbial Populations of Broiler Chickens

Simple Summary

The beneficial effects of Bacillus spp. probiotic preparations used for poultry are well-documented and characterized by growth performance improvement and positive modulation of gastrointestinal tract (GIT) microbiota. Moreover, the favorable influence of salinomycin has been frequently studied as an ionophore coccidiostat, as well as an antimicrobial agent. However, limited data are available in terms of the parallel usage of both Bacillus licheniformis DSM 28710 and salinomycin in poultry diets. From a practical point of view, evaluating the potential interactions between this species and agent is crucial to assess their parallel usage, and the current study confirmed the positive effect of their mixture on the modulation of pH value in the crop and ceca, as well as the GIT microbiota, especially in the jejunum and ceca. Additionally, the results obtained in this study show positive effects of B. licheniformis on the growth performance, as well as the influence of both experimental factors used separately in the case of GIT microbiota modulations.

Abstract

The aim of the study was to investigate the effect of Bacillus licheniformis and salinomycin supplementation in broiler diets as individual factors or in combination on the growth performance, GIT morphometry, and microbiota populations. Four hundred one-day-old Ross 308 chicks were randomly distributed to four dietary treatments (10 replicates, 10 birds each). The following treatments were applied: NC—no additives; NC + SAL—salinomycin addition (60 mg/kg diet), NC + PRO—B. licheniformis DSM 28710 preparation (1.6 × 10⁹ CFU/kg; 500 mg/kg diet), and NC + SAL + PRO—combination of salinomycin and B. licheniformis. Probiotic administration resulted in improvement (p < 0.05) of the performance parameters, including body weight gain (1–10 d, and 11–22 d) and feed conversion ratio (11–22 d, 1–36 d). An interaction (p < 0.05) between experimental factors was observed in terms of lower pH values in the crop (tendency, p = 0.053) and ceca. Both factors lowered the alpha diversity and Enterobacteriaceae and promoted Bacillaceae communities in the jejunum (p < 0.05). Interactions were also observed in terms of reducing Clostridiaceae in the ceca. In conclusion, the combined use of B. licheniformis and salinomycin in broilers’ diets had beneficial effects.

The effects and combinational effects of Bacillus subtilis and montmorillonite on the intestinal health status in laying hens

This study was conducted to evaluate the effects and combinational effects of Bacillus subtilis (BS) and montmorillonite (MMT) on laying performance, gut mucosal oxidation status, and intestinal immunological and physical barrier functions of laying hens. Three hundred sixty laying hens (29-week-old) were randomly assigned to a 2 × 2 factorial arrangement of treatments (n = 6) for 10 wk as follows: (1) basal diet; (2) the basal diet plus 5 × 10⁸ cfu BS/kg; (3) the basal diet plus 0.5 g MMT/kg; and (4) the basal diet plus 5 × 10⁸ cfu BS/kg and 0.5 g MMT/kg. Dietary supplementation with BS increased egg production and egg mass, the activities of catalase (CAT) and total superoxide dismutase in the intestinal mucosa, and villus height and villus height-to-crypt depth ratio of the jejunum (P < 0.05) but downregulated the mRNA expression levels of toll-like receptor 4 and myeloid differentiation factor 88 (MyD88) in the duodenum and jejunum, interleukin 1 beta in the duodenum, and nuclear factor kappa B P65 (NF-κB P65) and tumor necrosis factor alpha in the jejunum (P < 0.05). Dietary supplementation with MMT increased egg production and egg mass, the concentration of secretory immunoglobulin A in the duodenum, and the occludin mRNA expression level in the jejunum (P < 0.05) but reduced feed conversion ratio, malondialdehyde concentration in the duodenum and jejunum, and the mRNA expression level of MyD88 in the jejunum (P < 0.05). In addition, there was an interaction effect between BS and MMT supplementation on the CAT activity and the MyD88 mRNA expression level in the duodenum and the mRNA expression level of occludin in the jejunum (P < 0.05). In conclusion, dietary BS and MMT and their combination may improve the intestinal health status of laying hens, which may contribute to the increase in hens' laying performance.

Could probiotics be the panacea alternative to the use of antimicrobials in livestock diets?

Probiotics are most frequently derived from the natural microbiota of healthy animals. These bacteria and their metabolic products are viewed as nutritional tools for promoting animal health and productivity, disease prevention and therapy, and food safety in an era defined by increasingly widespread antimicrobial resistance in bacterial pathogens. In contemporary livestock production, antimicrobial usage is indispensable for animal welfare, and employed to enhance growth and feed efficiency. Given the importance of antimicrobials in both human and veterinary medicine, their effective replacement with direct-fed microbials or probiotics could help reduce antimicrobial use, perhaps restoring or extending the usefulness of these precious drugs against serious infections. Thus, probiotic research in livestock is rapidly evolving, aspiring to produce local and systemic health benefits on par with antimicrobials. Although many studies have clearly demonstrated the potential of probiotics to positively affect animal health and inhibit pathogens, experimental evidence suggests that probiotics' successes are modest, conditional, strain-dependent, and transient. Here, we explore current understanding, trends, and emerging applications of probiotic research and usage in major livestock species, and highlight successes in animal health and performance.

Bacillus subtilis Strain DSM 29784 Modulates the Cecal Microbiome, Concentration of Short-Chain Fatty Acids, and Apparent Retention of Dietary Components in Shaver White Chickens during Grower, Developer, and Laying Phases

This study investigated the efficacy of a single strain of Bacillus subtilis (SSB) in modulating the composition of cecal microbiota and its link to the concentration of short-chain fatty acids (SCFA) and apparent retention (AR) of components. A total of 720, 4-week-old Shaver White chicks were allotted to control (CON), 1.1E+08 (low, LSSB), 2.2E+08 (medium, MSSB), or 1.1E+09 (high, HSSB) CFU/kg of diet groups. At grower (10-week), developer (16-week), and laying (28-week) phases, excreta and cecal digesta samples were taken for AR, microbial, and SCFA analyses. Microbial analysis involved high-throughput sequencing of the V3-V4 hypervariable regions of 16S rRNA gene. Bacterial diversity decreased (P < 0.05) at the developer phase as the SSB dose increased; however, a distinct clustering pattern (P < 0.05) of bacterial community was noted. Bacteroides and Faecalibacterium were differentially enriched in the developer for SSB-fed compared to CON-fed birds. Although no differences in microbial diversity were detected in grower and layer phases, different species of Clostridium (XVIII, XIVa, IV, and XIVb)-major butyrate producers-were identified in all phases, with stronger effect sizes for SSB-fed compared to CON-fed birds. Isobutyric acid was elevated in dose response (P = 0.034) in layer phase. In addition, the relative abundances of Alistipes, Lactobacillus, and Bifidobacterium were positively correlated (P < 0.05), with AR of most components for SSB-fed birds in the pullet phase. The results suggested that supplementing chickens' diet with B. subtilis DSM 29784 may selectively enrich beneficial bacterial communities, which in turn are critical in promoting the growth and performance of hens.IMPORTANCE In egg-laying chickens, the trend in the move away from the cage to alternative housing systems and restriction in antimicrobial use requires alternative approaches to maintain health and prevent diseases. There is increased research and commercial interest toward alternative gut health solutions while improving the performance and product safety in poultry production systems. One such approach, in recognition of the importance of the gut microbial community, is the use of microbes as feed supplements (such as probiotics). Unlike meat-type chickens, studies assessing the efficacy of such microbial supplements are limited for egg-laying chickens. Thus, by conducting a comprehensive assessment of the hen microbiota in response to various levels of B. subtilis DSM 29784 during the pullet phase (grower and developer) and the layer phase, the present study demonstrates the importance of direct-fed microbes in modulating gut microbiome, which may relate to improved performance efficiency in the pullet and layer phases.