Evaluation of probiotic properties of a Brevibacillus laterosporus strain.

Brevibacillus laterosporus is a strain of probiotic bacteria that has been widely used in pest control, cash crop, and other production areas. However, few studies have been conducted on its use as a feed additive in animals. Therefore, the probiotic potential of B. laterosporus PBC01 was evaluated by characterizing hydrophobicity, auto-aggregation activity, bile salt and simulated gastrointestinal fluid tolerance, bienzymatic, and antibacterial activity. Antibiotic susceptibility, hemolysis assays, and supplemental feeding of mice were also performed to evaluate safety features. Our results showed that B. laterosporus PBC01 had moderate hydrophobicity, high auto-agglutination ability. Meanwhile, B. laterosporus PBC01 had good tolerance to bile salt and simulated gastrointestinal fluid. It had the ability to secrete protease, cellulase, and to inhibit various pathogens. In addition, B. laterosporus PBC01 was sensitive to many antibiotics, and did not produce hemolysin. In the safety assessment of mice, it did not cause any deaths, nor did it affect the cell components of blood, antioxidant capacity, and reproductive health. The study indicated the great probiotic characteristics and safety of B. laterosporus PBC01. This may provide a theoretical basis for the clinical application and development of probiotic-based feed additives.

Fluoride exposure-induced gut microbiota alteration mediates colonic ferroptosis through N6-methyladenosine (m6A) mediated silencing of SLC7A11.

Fluoride exposure is widespread worldwide and poses a significant threat to organisms, particularly to their gastrointestinal tracts. However, due to limited knowledge of the mechanism of fluoride induced intestinal injury, it has been challenging to develop an effective treatment. To address this issue, we used a series of molecular biology in vitro and in vivo experiments. NaF triggered m6A mediated ferroptosis to cause intestinal damage. Mechanistically, NaF exposure increased the m6A level of SLC7A11 mRNA, promoted YTHDF2 binding to m6A-modified SLC7A11 mRNA, drove the degradation of SLC7A11 mRNA, and led to a decrease in its protein expression, which eventually triggers ferroptosis. Moreover, NaF aggravated ferroptosis of the colon after antibiotics destroyed the composition of gut microbiota. 16 S rRNA sequencing and SPEC-OCCU plots, Zi-Pi relationships, and Spearman correlation coefficients verified that Lactobacillus murinus (ASV54, ASV58, and ASV82) plays a key role in the response to NaF-induced ferroptosis. Collectively, NaF-induced gut microbiota alteration mediates severe intestinal cell injury by inducing m6A modification-mediated ferroptosis. Our results highlight a key mechanism of the gut in response to NaF exposure and suggest a valuable theoretical basis for its prevention and treatment.

The panda-derived Lactiplantibacillus plantarum BSG201683 improves LPS-induced intestinal inflammation and epithelial barrier disruption in vitro.

Captive pandas are suffering from intestinal infection due to intestinal microbiota characterized by a high abundance of Enterobacteriaceae induced by long-term captivity. Probiotic supplements showed improvement in intestinal barrier function and inflammation. However, the effects of panda-derived probiotics on the intestinal epithelium and inflammation have not been elucidated. In the present study, lipopolysaccharide (LPS) impaired Caco-2 and RAW264.7 inflammatory models were applied to assess the protection of Lactiplantibacillus plantarum BSG201683 (L. plantarum G83) on barrier disruption and inflammation. The results showed that treatment with L. plantarum G83 significantly decreased the paracellular permeability to fluorescein isothiocyanate conjugated dextran (MW 4000, FITC-D4) after LPS induction. Meanwhile, L. plantarum G83 alleviated the reduction in tight junction (TJ) proteins and downregulated proinflammatory cytokines caused by LPS in Caco-2 cells. L. plantarum G83 also significantly decreased the expression and secretion of pro-inflammatory cytokines in LPS-induced RAW264.7 cells. In addition, the IL-10 increased in both Caco-2 and RAW264.7 cells after L. plantarum G83 treatment. The phagocytosis activity of RAW264.7 cells was significantly increased after L. plantarum G83 treatment. Toll-like receptor 4/ nuclear factor kappa-B (TLR4/NF-κB) signaling pathways were significantly down-regulated after L. plantarum G83 intervention, and the phosphorylation of NF-κB/p65 was consistent with this result. Our findings suggest that L. plantarum G83 improves intestinal inflammation and epithelial barrier disruption in vitro.

Autophagy-mediated ferroptosis involved in nickel-induced nephrotoxicity in the mice.

Nickel, as a widely polluted metal, has been shown nephrotoxicity. Ferroptosis is a new type of cell death driven by iron-dependent lipid peroxidation. Our study found that nickel chloride (NiCl2) induced ferroptosis in mouse kidney and TCMK-1 cells. The iron content was significantly increased in the kidney and TCMK-1 cells after NiCl2 treatment. Lipid peroxidation and MDA content were significantly increased, and GSH content and T-SOD activity were significantly decreased after exposure to NiCl2. Moreover, NiCl2 increased COX-2 protein levels, decreased SLC7A11 and GPX4 protein levels, and elevated Ptgs2 mRNA levels. Next, the mechanism of Ni-induced ferroptosis was investigated. The results showed that NiCl2 induced autophagy in TCMK-1 cells, which promoted ferroptosis induced by NiCl2. Furthermore, the data of autophagy activation or inhibition experiment showed that autophagy facilitated ferroptosis through the degradation of the iron regulation protein NCOA4 and FTH1. Otherwise, iron chelator DFOM treatment inhibited ferroptosis induced by NiCl2. Finally, ferroptosis inhibitor Fer-1 treatment significantly alleviated cytotoxicity induced by NiCl2. To sum up, our above results showed that ferroptosis is involved in NiCl2-induced nephrotoxicity, and NiCl2 induces autophagy-dependent ferritin degradation, releases iron ions, leads to iron overload, and induces ferroptosis. This study supplies a new theoretical foundation for the study of nickel and renal toxicity.

Disrupted gut microbiota aggravates spatial memory dysfunction induced by high altitude exposure: A link between plateau environment and microbiome-gut-brain axis.

Approximately 400 million people work and live in high-altitude areas and suffer from memory dysfunction worldwide. Until now, the role of the intestinal flora in plateau-induced brain damage has rarely been reported. To address this, we investigated the effect of intestinal flora on spatial memory impairment induced by high altitudes based on the microbiome-gut-brain axis theory. C57BL/6 mice were divided into three groups: control, high-altitude (HA), and high-altitude antibiotic treatment (HAA) group. The HA and HAA groups were exposed to a low-pressure oxygen chamber that simulated an altitude of 4000 m above sea level (m. a. s.l.) for 14 days, with the air pressure in the chamber set at 60-65 kPa. The results showed that spatial memory dysfunction induced by the high-altitude environment was aggravated by antibiotic treatment, manifesting as lowered escape latency and hippocampal memory-related proteins (BDNF and PSD-95). 16 S rRNA sequencing showed a remarkable separation of the ileal microbiota among the three groups. Antibiotic treatment exacerbated the reduced richness and diversity of the ileal microbiota in mice in the HA group. Lactobacillaceae were the main target bacteria and were significantly reduced in the HA group, which was exacerbated by antibiotic treatment. Meanwhile, reduced intestinal permeability and ileal immune function in mice exposed high-altitude environment was also aggravated by antibiotic treatment, as indicated by the lowered tight junction proteins and IL-1ß and IFN-γ levels. Furthermore, indicator species analysis and Netshift co-analysis revealed that Lactobacillaceae (ASV11) and Corynebacteriaceae (ASV78, ASV25, and ASV47) play important roles in high-altitude exposure-induced memory dysfunction. Interestingly, ASV78 was negatively correlated with IL-1ß and IFN-γ levels, indicating that ASV78 may be induced by reduced ileal immune function, which mediates high-altitude environment exposure-induced memory dysfunction. This study provides evidence that the intestinal flora is effective in preventing brain dysfunction caused by exposure to high-altitude environments, suggesting a relationship between the microbiome-gut-brain axis and altitude exposure.

Fluoride disrupts intestinal epithelial tight junction integrity through intracellular calcium-mediated RhoA/ROCK signaling and myosin light chain kinase.

Fluoride is a common contaminant of groundwater and agricultural commodity, which poses challenges to animal and human health. A wealth of research has demonstrated its detrimental effects on intestinal mucosal integrity; however, the underlying mechanisms remain obscure. This study aimed to investigate the role of the cytoskeleton in fluoride-induced barrier dysfunction. After sodium fluoride (NaF) treatment of the cultured Caco-2 cells, both cytotoxicity and cytomorphological changes (internal vacuoles or massive ablation) were observed. NaF lowered transepithelial electrical resistance (TEER) and enhanced paracellular permeation of fluorescein isothiocyanate dextran 4 (FD-4), indicating Caco-2 monolayers hyperpermeability. In the meantime, NaF treatment altered both the expression and distribution of the tight junction protein ZO-1. Fluoride exposure increased myosin light chain II (MLC2) phosphorylation and triggered actin filament (F-actin) remodeling. While inhibition of myosin II by Blebbistatin blocked NaF-induced barrier failure and ZO-1 discontinuity, the corresponding agonist Ionomycin had effects comparable to those of fluoride, suggesting that MLC2 serves as an effector. Given the mechanisms upstream of p-MLC2 regulation, further studies demonstrated that NaF activated RhoA/ROCK signaling pathway and myosin light chain kinase (MLCK), strikingly increasing the expression of both. Pharmacological inhibitors (Rhosin, Y-27632 and ML-7) reversed NaF-induced barrier breakdown and stress fiber formation. The role of intracellular calcium ions ([Ca2+]i) in NaF effects on Rho/ROCK pathway and MLCK was investigated. We found that NaF elevated [Ca2+]i, whereas chelator BAPTA-AM attenuated increased RhoA and MLCK expression as well as ZO-1 rupture, thus, restoring barrier function. Collectively, abovementioned results suggest that NaF induces barrier impairment via Ca2+-dependent RhoA/ROCK pathway and MLCK, which in turn triggers MLC2 phosphorylation and rearrangement of ZO-1 and F-actin. These results provide potential therapeutic targets for fluoride-induced intestinal injury.

Nickel induces hepatotoxicity by mitochondrial biogenesis, mitochondrial dynamics, and mitophagy dysfunction.

Nickel (Ni) is an important and widely hazardous chemical industrial waste. Excessive Ni exposure could cause multi-organs toxicity in human and animals. Liver is the major target organ of Ni accumulation and toxicity, however, the precise mechanism is still unclear. In this study, nickel chloride (NiCl2 )-treatment induced hepatic histopathological changes in the mice, and, transmission electron microscopy results showed mitochondrial swollen and deformed of hepatocyte. Next, the mitochondrial damages including mitochondrial biogenesis, mitochondrial dynamics, and mitophagy were measured after NiCl2 administration. The results showed that NiCl2 suppressed mitochondrial biogenesis by decreasing PGC-1α, TFAM, and NRF1 protein and mRNA expression levels. Meanwhile, the proteins involved in mitochondrial fusion were reduced by NiCl2 , such as Mfn1 and Mfn2, however, mitochondrial fission proteins Drip1 and Fis1 were significantly increased. The up-regulation of mitochondrial p62 and LC3II expression indicated that NiCl2 increased mitophagy in the liver. Moreover, the receptor-mediated mitophagy and ubiquitin (Ub)-dependent mitophagy were detected. NiCl2 promoted PINK1 accumulation and Parkin recruitment on mitochondria. And, the receptor proteins of mitophagy Bnip3 and FUNDC1 were increased in the NiCl2 -treated mice liver. Overall, these results show that NiCl2 could induce mitochondria damage in the liver of mice, and, dysfunction of mitochondrial biogenesis, mitochondrial dynamics and mitophagy involved in the molecular mechanism of NiCl2 -induced hepatotoxicity.

Assessment the role of some Bacillus strains in improvement rex rabbits resistance against ETEC challenge.

Increasing reports have indicated that specific strains of probiotic Bacillus have the potential to prevent diseases. The purpose of this study was to explore the effects of three Bacillus strains (Bacillus subtilis BSWJ2017001, Bacillus pumilus BSWJ2017002, and B. subtilis BSWJ2017003) mixture dietary supplementation on rex rabbits infected with enterotoxigenic Escherichia coli (ETEC). In this study, 60 35-day-old weaning rex rabbits were separated into two groups randomly: control group (fed basal diet with no antibiotics) and Bacillus strains group (fed basal diet containing 1.0 × 106 CFU/g Bacillus strains mixture). After 8 weeks of feeding, the rex rabbits were inoculated orally with 5.0 mL of ETEC (1.0 × 109 CFU/mL) and assessed at 0, 12, and 24 h. The Bacillus strains mixture attenuated the oxidative damage, diarrhea severity, and intestinal damage of ETEC infected rabbits. It also significantly increased the population of Lactobacillus spp., and Bifidobacterium spp., and decreased the population of Enterococcus spp.. Moreover, Bacillus strains group exhibited higher levels of toll-like receptor (TLR) 2, anti-inflammatory cytokines, secretory immunoglobulin A, and intestinal barrier-related genes than control group, as well as lower levels of TLR-4 and pro-inflammatory cytokines. These results demonstrated that Bacillus strains mixture could attenuate injury caused by ETEC and enhance disease resistance by improving specific intestinal microbiota members and immunity in weaning rex rabbits.

Preventive effects of Lactobacillus johnsonii on the renal injury of mice induced by high fluoride exposure: Insights from colonic microbiota and co-occurrence network analysis.

Fluoride (F) exposure was widely reported to be associated with renal diseases. Since absorbed F enters the organism from drinking water mostly through the gastrointestinal tract, investigating changes of gut microbes may have profound implications for the prevention of chronic F exposure because increasing evidence supported the existence of the gut-kidney axis. In the present study, we aimed to explore the potential positive effects of probiotics on high F exposure-induced renal lesions and dysfunction in mice by the modulation of the colonic microbiota. Mice were fed with normal (Ctrl group) or sodium-fluoride (F and Prob groups; 100 mg/L sodium fluoride (NaF)) drinking water with or without Lactobaillus johnsonii BS15, a probiotic strain proven to be preventive for F exposure. Mice fed with sodium-fluoride drinking water alone exhibited renal tissue damages, decreased the renal antioxidant capability and dysfunction. In contrast, L. johnsonii BS15 reversed these F-induced renal changes. 16S rRNA gene sequencing shows that L. johnsonii BS15 alleviated the increased community diversity (Shannon diversity) and richness index (number of observed features) as well as the distured structure of colon microbiota in F-exposed mice. A total of 13 OTUs with increased relative abundance were identified as the keystone OTUs in F-exposed mice based on the analysis of degree of co-occurrence and abundance of OTUs. Moreover, Spearman's rank correlation shows that the 13 keystone OTUs had negative effect on renal health and intestinal integrity. L. johnsonii BS15 reversed four of keystone OTUs (OTU 5, OTU 794, OTU 1035, and OTU 868) changes which might be related to the underlying protected mechanism of L. johnsonii BS15 against F-induced renal damages.

Probiotic alleviate fluoride-induced memory impairment by reconstructing gut microbiota in mice.

Fluoride which is widespread in our environment and food due to its geological origin and industrial pollution has been identified as a developmental neurotoxicant. Gut-brain axis provides new insight into brain-derived injury. We previously found the psychoactive effects of a probiotic strain, Lactobacillus johnsonii BS15 against fluoride-induced memory dysfunction in mice by modulating the gut-brain axis. In this study, we aimed to detect the link between the reconstruction of gut microbiota and gut-brain axis through which probiotic alleviate fluoride-induced memory impairment. We also added an hour of water avoidance stress (WAS) before behavioral tests and sampling, aiming to demonstrate the preventive effects of the probiotic on fluoride-induced memory impairment after psychological stress. Mice were given fluoridated drinking water (sodium fluoride 100 ppm, corresponding to 37.8 ± 2.4 ppm F¯) for 70 days and administered with PBS or a probiotic strain, Lactobacillus johnsonii BS15 for 28 days prior to and throughout a 70 day exposure to sodium fluoride. Results showed that fluoride increases the hyperactivity of hypothalamic-pituitary-adrenal (HPA) axis and reduces the exploration ratio in novel object recognition (NOR) test and the spontaneous exploration during the T-maze test in mice following WAS, which were significantly improved by the probiotic. 16S rRNA sequencing showed a significant separation in ileal microbiota between the fluoride-treated mice and control mice. Lactobacillus was the main targeting bacteria and significantly reduced in fluoride-treated mice. BS15 reconstructed the fluoride-post microbiota and increased the relative abundance of Lactobacillus. D-lactate content and diamine oxidase (DAO) activity, two biomarkers of gut permeability were reduced in the serum of probiotic-inoculated mice. ZO-1, an intestinal tight junction protein was reduced by fluoride in mRNA, and its protein levels were increased by the probiotic treatment. Moreover, the hippocampus which is essential to learning and memory, down-regulated mRNA level of both the myelin-associated glycoprotein (MAG), and protein levels of brain-derived neurotrophic factor (BDNF), including the improvement of cAMP response element-binding protein (CREB) by BS15 in fluoride-exposed mice after WAS. Via spearman correlation analysis, Lactobacillus displayed significantly positive associations with the behavioral tests, levels of nerve development related factors, and intestinal tight junction proteins ZO-1, and negative association with TNF-α of the hippocampus, highlighting regulatory effects of gut bacteria on memory potential and gut barrier. These results suggested the psychoactive effects of BS15 on fluoride-induced memory dysfunction after psychological stress. In addition, there may be some correlations between fluoride-induced memory dysfunction and reconstruction of gut microbiota. AVAILABILITY OF DATA AND MATERIALS: 16S rRNA sequencing reads have uploaded to NCBI. The accession code of 16S rRNA sequencing reads in the National Center for Biotechnology Information (NCBI) BioProject database: PRJNA660154.

Efficacy of Bacillus methylotrophicus SY200 strain as feed additive against experimental Salmonella typhimurium infection in mice.

To investigate the effects of Bacillus methylotrophicus SY200 on Salmonella typhimurium (STM) infection in mice, a total of 36 three-week-old male mice were selected and randomly divided into 3 equal groups (N = 12). Group A and group B were fed with basal diet while group C was fed the basal diet supplemented with 0.1% (w/w) B. methylotrophicus SY200 during the 21 days experimental period. On the 14th day of the experiment, mice of group A were intragastrically administered with 0.5 ml of normal saline, group B and C were orally administered with 0.5 ml of STM suspension. On the first day and seventh day after STM challenge, the number of total white blood cells (WBCs) and neutrophils, relative weight of visceral organs, the number of Salmonella spp., Escherichia coli, Lactobacillus spp. and Bifidobacterium spp. in ileum and cecum, and diversity of cecal microflora were measured. The results showed that: on the first day and seventh day after STM challenge, the number of WBCs and neutrophils in the blood of the mice was the highest in group B, then followed by group C, and group A. On the first day after STM challenge, the relative weight of spleen in group C was significantly higher than that in group B (p < 0.05), moreover, compared with group B, B. methylotrophicus SY200 significantly reduced the number of Salmonella spp. and E. coli (p < 0.05), and increased the number of Lactobacillus spp. and Bifidobacterium spp. (p < 0.05) in the intestines of mice, and improved the Shannon-Wiener diversity (H), Simpson (E) and richness (S) indices of cecal flora of mice (p < 0.05). The results indicated that B. methylotrophicus SY200 could alleviate the inflammatory reaction after STM infection and resist the adverse effects of STM infection on mice intestinal flora.

Bacillus strains improve growth performance via enhancing digestive function and anti-disease ability in young and weaning rex rabbits.

Numerous studies have shown that probiotic Bacillus could promote growth and enhance anti-disease ability in animal. In present study, the mixture of three Bacillus strains, which were isolated from rex rabbits and showed high cellulose, protease, and amylase activities, was added into the diet for investigating its effects on young and weaning rex rabbits. For experiment 1, 40 young rex rabbits (9 weeks old) were randomly divided into four groups and fed with diets containing 0 (NC), 1.0 × 105 cfu/g (LC), 1.0 × 106 cfu/g (MC), and 1.0 × 107 cfu/g (HC) Bacillus strains for 4 weeks. For experiment 2, 80 weaning rex rabbits (5 weeks old) were randomly divided into four groups and fed with diet containing 0 (control), 1.0 × 105 cfu/g (T-1), 1.0 × 106 cfu/g (T-2), and 1.0 × 107 cfu/g (T-3) Bacillus strains for 8 weeks. The results showed that Bacillus strains at a dose of 1.0 × 106 cfu/g significantly enhanced growth performance, increased immune organ indexes, improved serum biochemical parameters, and heightened antioxidant capacity. It also markedly improved the intestinal microbiota by increasing Lactobacillus spp., Bacillus spp. counts, and decreased Escherichia coli count. In addition, the Bacillus mixture raised the concentrations of acetic acid, propionic acid, and butyric acid as well as protease, amylase, and cellulase activities of young and weaning rex rabbits. Moreover, for weaning rex rabbits, the inclusion of Bacillus strains also upregulated the abundance of cellulolytic bacteria and improved intestinal morphology. Therefore, our results indicated that Bacillus strains could facilitate the growth of young and weaning rex rabbits by improving digestive function and anti-disease ability. KEY POINTS: • Bacillus with high extracellular enzyme activity were isolated from rex rabbits. • Bacillus could improve growth performance of young and weaning rex rabbits. • The digestive function of young and weaning rex rabbits could be improved by Bacillus.

Transcriptome analysis revealed ameliorative effect of probiotic Lactobacillus johnsonii BS15 against subclinical necrotic enteritis induced hepatic inflammation in broilers.

Subclinical necrotic enteritis (SNE) broadly occurs in boilers, which reduces the growth performance by causing serious economic and social problems. The following study was conducted to better understand the molecular mechanism of the SNE on liver inflammation and to examine the innovative prevention of Lactobacillus johnsonii BS15 upon SNE. The research was based on the regulatory molecular mechanism of Lactobacillus johnsonii BS15, and its effect on liver inflammatory pathways in the broiler with SNE infection. Day old one hundred and eighty (Cobb 500) broiler chickens were distributed into 3 groups (control, SNE and BS15 group) and reared for 28 days. RNA sequencing was used for the analysis of gene expression extracted from liver samples. Gene expression was detected with the help of quantitative real-time PCR (qRT-PCR). RNA-Seq analysis revealed altered expressions of genes involved in liver inflammatory pathway. A total number of 385 genes were found as differentially expressed (DEGs) in the liver samples that belonged to SNE group as compared with the control liver samples (p < 0.05). Out of those 385 genes, 117 were down-regulated and 268 were up-regulated. The DEGs related to liver inflammation between control group and SNE group or SNE and BS15 groups, included cluster of differentiation 80 (CD80), Interleukin 1 beta (IL1B), Phosphoinositide 3- Kinase regulatory subunit 5 (PIK3R5), Toll-like receptor 4 (TLR4), Toll-like receptor 2 A (TLR2A), and proto-oncogene protein (FOS). The RNA-Seq analysis provided DEGs expression and this result was validated by qRT-PCR. Results confirmed that these genes are essential in the regulation of liver inflammation in the SNE infected chickens. Findings of current research indicated that the hepatic inflammation could be induced by SNE in broilers. Simultaneously, effects of SNE infection on liver could be subsided by improved TLRs signaling pathway with the naturally present prophylactic strategy as BS15.

Surface Display of Antigen Protein VP8* of Porcine Rotavirus on Bacillus Subtilis Spores Using CotB as a Fusion Partner.

Porcine rotavirus is a major cause of acute viral gastroenteritis in suckling piglets, and vaccination is considered to be an effective measure to control these infections. The development of a live mucosal vaccine using Bacillus subtilis spores as an antigen delivery vehicle is a convenient and attractive vaccination strategy against porcine rotavirus. In this study, a shuttle vector was constructed for the spore surface display of the spike protein VP8* from porcine rotavirus (the genotype was G5P[7]). A successful display of the CotB-VP8* fusion protein on the spore surface was confirmed by Western blot and immunofluorescence microscopy analysis. The capacity for immune response generated after immunization with the recombinant strain was evaluated in a mouse model. The intestinal fecal IgA and serum IgG were detected by enzyme-linked-immunosorbent serologic assay (ELISA). Importantly, recombinant strain spores could elicit strong specific mucosal and humoral immune responses. These encouraging results suggest that recombinant B. subtilis BV could provide a strategy for a potential novel application approach to the development of a new and safe mucosal subunit vaccine against porcine rotavirus.

Characterization of Inulin-Type Fructan from Platycodon grandiflorus and Study on Its Prebiotic and Immunomodulating Activity.

Platycodon grandiflorus is a plant widely used in traditional Chinese medicine, of which polysaccharides are reported to be the main components responsible for its bio-functions. In this work, the inulin-type fructan (PGF) was obtained by DEAE anion exchange chromatography from the water extracted from P. grandifloras. Characterization was performed with methanolysis, methylation, and NMR and the results showed that PGF is a ß-(2-1) linked fructan, with terminal glucose and with a degree of polymerization of 2⁻10. In order to study its biofunctions, the prebiotic and immunomodulation properties were assayed. We found that PGF exhibited good prebiotic activity, as shown by a promotion on six strains of lactobacillus proliferation. Additionally, the PGF also displayed direct immunomodulation on intestinal epithelial cells and stimulated the expressions of anti-inflammatory factors. These results indicated that the inulin from P. grandiflorus is a potential natural source of prebiotics as well as a potential intestinal immunomodulator, which will be valuable for further studies and new applications.

Analysis of hepatic transcriptome demonstrates altered lipid metabolism following Lactobacillus johnsonii BS15 prevention in chickens with subclinical necrotic enteritis.

BACKGROUND: Subclinical necrotic enteritis (SNE) widely outbreaks in chickens which inflicted growth-slowing, causing enormous social and economic burdens. To better understand the molecular underpinnings of SNE on lipid metabolism and explore novel preventative strategies against SNE, we studied the regulatory mechanism of a potential probiotic, Lactobacillus johnsonii BS15 on the lipid metabolism pathways involved in chickens with SNE. METHODS: One hundred eighty one-day-old chickens were randomly divided into three groups and arranged with basal diet (control and SNE group). Added with BS15 (1 × 106 cfu/g) or Man Rogosa Sharpe (MRS) liquid medium for 28 days. The hepatic gene expression of each group was then measured using high-throughput analysis methods (RNA-Seq). Quantitative real-time PCR (qRT-PCR) was used to detect the expression changes of the related genes. RESULTS: The results showed that there are eleven lipid metabolic pathways were found during the prevention of BS15 treatment in SNE chickens by RNA-Seq, including the peroxisome proliferator-activated receptor (PPAR) signaling pathway and arachidonic acid metabolism. BS15 notably facilitated the expressions of fatty acid binding protein 2 (FABP2), acyl-CoA synthetase bubblegum family member 1 (ACSBG1), perilipin 1 (PLIN1) and perilipin 2 (PLIN2), which were involved in PPAR signaling pathway of SNE chickens. Besides, suppression of phospholipase A2 group IVA (PLA2G4A) in arachidonic acid metabolism was observed in SNE chickens after BS15 prevention. The expression patterns of FABP2, ACSBG1, PLIN1, PLIN2 and PLA24G in qRT-PCR validation were consistent with RNA-Seq results. CONCLUSIONS: These findings indicate that SNE may affect the hepatic lipid metabolism of chickens. Meanwhile, BS15 pretreatment may provide a prospective natural prophylaxis strategy against SNE through improving the PPAR signaling pathway and arachidonic acid metabolism.

Controlling of growth performance, lipid deposits and fatty acid composition of chicken meat through a probiotic, Lactobacillus johnsonii during subclinical Clostridium perfringens infection.

BACKGROUND: Meat is considered as a major source of polyunsaturated fatty acid (PUFA) which is essential for humans, therefore its lipid level and fatty acid composition have drawn great attention. As no clinical sign can be found in chicks subclinically infected by Clostridium perfringens (CP), the meat may be purchased and eaten. The objective of the present study was to determine whether Lactobacillus johnsonii (LJ) can control the CP-caused impact on growth, lipid levels, fatty acid composition and other flavor or nutritional quality in the meat. METHODS: 480 one-day-old chicks were divided into four groups and fed with basal diet (control and CP group). Supplemented with 1 × 105 (L-LJ) and 1 × 106 (H-LJ) colony-forming unit (cfu), CP diet was fed for 42 days. From day 19 to 22, birds of CP and LJ groups were administered with CP twice per day and the control was administered with liver broth. RESULTS: LJ-treated chickens were free from negative influences on growth performance and significant decrease of abdominal fat deposit., LJ inhibited CP-caused shearing force and drip loss increase and pH 40 min and 24 h decrease after sacrifice. In addition, LJ exhibited a positive effect on muscle lipid peroxidation by significantly increasing SOD, CAT and GSH-Px activity and decreasing MDA level. Besides, LJ attenuated the decrease of intramuscular fat, total cholesterol and triglyceride contents caused by CP infection. However, levels of total protein and most of amino acids were not changed. CP infection decreased C18:3n-3 (α-LA), C20:4n-6, C20:5n-3(EPA), C22:4n-6, C22:5n-3, C22:6n-3(DHA), total PUFA, n-3 PUFA and PUFA:SFA ratio and increased C14:0, total SFA and n-6:n-3 ratio. LJ was found to protect the muscle from these changes. Meanwhile, the 28-day gut permeability level was higher in CP group. CONCLUSIONS: These findings suggest that CP may affect the growth performance of chicks and negatively influence lipid content and fatty acid composition in chicken meat. Meanwhile, LJ treatment may be effective in controlling these changes by reducing the increased gut permeability caused by CP subclinical infection.

Fermented Yupingfeng polysaccharides enhance immunity by improving the foregut microflora and intestinal barrier in weaning rex rabbits.

Yupingfeng (YPF) is a kind of Astragali radix-based ancient Chinese herbal supplemented with Atractylodis Macrocephalae Rhizoma and Radix Saposhnikoviae. Increasing evidence has proven the beneficial immunomodulating activity of YPF. However, the action mechanism(s) of it is not known. Here, we explored the immunomodulatory activity of unfermented Yupingfeng polysaccharides (UYP) and fermented Yupingfeng polysaccharides (FYP) obtained using Rhizopus oligosporus SH in weaning Rex rabbits. The results showed that both UYP and FYP exhibited notable growth-promoting and immune-enhancing activities, improvement of the intestinal flora homeostasis, and maintenance of intestinal barrier integrity and functionality. Notably, compared with UYP, FYP effectively enhanced average daily gain, organ indices, interleukin-2 (IL-2), IL-4, IL-10, tumor necrosis factor-alpha (TNF-α), TLR2, and TLR4 mRNA levels in spleen, IL-1, IL-2, IL-4, IL-6, IL-10, IL-12, TNF-α, and IFN-γ protein concentrations in serum, and TLR2 and TLR4 mRNA expressions in the gastrointestinal tract (GIT). Moreover, FYP exhibited greater beneficial effects in improving the intestinal flora, including augment flora diversity and the abundance of cellulolytic bacteria, reduction the abundance of Streptococcus spp. and Enterococcus spp. in the GIT, particularly the foregut and maintaining the intestinal barrier integrity and functionality by upregulating zonula occludens 1, claudin, polymeric immunoglobulin receptor, trefoil factor, and epidermal growth factor mRNA levels in the jejunum and ileum. Our results indicated the immunoenhancement effect of FYP is superior over that of UYP, which is probably related with the amelioration of the intestinal microflora and intestinal barrier in the foregut.

Effects of Bacillus licheniformis on the growth performance and expression of lipid metabolism-related genes in broiler chickens challenged with Clostridium perfringens-induced necrotic enteritis.

BACKGROUND: Necrotic enteritis (NE), caused by Clostridium perfringens, has cost the poultry industry $2 billion in losses. This study aimed to investigate the effect of Bacillus licheniformis as dietary supplement on the growth, serum antioxidant status, and expression of lipid-metabolism genes of broiler chickens with C. perfringens-induced NE. METHODS: A total of 240 one-day-old broilers were randomly grouped into four: a negative control, an NE experimental model (PC), chickens fed a diet supplemented with 30 % of fishmeal from day 14 onwards and challenged with coccidiosis vaccine (FC), and NE group supplied with feed containing 1.0 × 10(6) CFU/g B. licheniformis (BL). RESULTS: Body weight gain, feed conversion ratio, serum antioxidant status, and lipid-metabolism-gene expression were analyzed. In the PC group, FCR increased significantly whereas serum catalase and glutathione peroxidase activity decreased compared with NC group. Dietary B. licheniformis supplementation improved FCR and oxidative stress in experimental avian NE. Using Bacillus licheniformis as a direct-fed microbial (DFM) could also significantly upregulate catabolism-related genes, namely, peroxisome proliferator-activated receptor-α and carnitine palmitoyltransferase-1, in livers and changed the expression of lipid-anabolism genes. CONCLUSION: These results suggested that dietary B. licheniformis supplementation can enhance growth and antioxidant ability, as well as change the expression of genes related to fatty-acid synthesis and oxidation in the livers of NE-infected broilers.

Decreased microbial diversity and Lactobacillus group in the intestine of geriatric giant pandas (Ailuropoda melanoleuca).

It has been established beyond doubt that giant panda genome lacks lignin-degrading related enzyme, gastrointestinal microbes may play a vital role in digestion of highly fibrous bamboo diet. However, there is not much information available about the intestinal bacteria composition in captive giant pandas with different ages. In this study, we compared the intestinal bacterial community of 12 captive giant pandas from three different age groups (subadults, adults, and geriatrics) through PCR-denaturing gradient gel electrophoresis (DGGE) and real-time PCR analysis. Results indicated that microbial diversity in the intestine of adults was significantly higher than that of the geriatrics (p < 0.05), but not significant compared to the subadults (p > 0.05). The predominant bands in DGGE patterns shared by the twelve pandas were related to Firmicutes and Proteobacteria. Additionally, in comparison to healthy individuals, antibiotic-treated animals showed partial microbial dysbiosis. Real-time PCR analyses confirmed a significantly higher abundance of the Lactobacillus in the fecal microbiota of adults (p < 0.05), while other bacterial groups and species detected did not significantly differ among the three age groups (p > 0.05). This study revealed that captive giant pandas with different ages showed different intestinal bacteria composition.