Genome-wide mining of gpx gene family provides new insights into cadmium stress responses in common carp (Cyprinus carpio).

Glutathione peroxidase (Gpx) is an important member of antioxidant enzymes, which can play a vital role in metabolizing reactive oxygen species (ROS) and in maintaining cell homeostasis. In order to study the evolutionary dynamics of gpx gene family in allotetraploid fish species, we identified a total of 14 gpx genes in common carp Cyprinus carpio, while 9 gpx genes were discovered in the diploid progenitor-like species Poropuntius huangchuchieni. Comparative genomic analysis and phylogenetic analysis revealed that the common carp gpx genes had significant expansion and were divided into five distinct subclades. Exon-intron distribution patterns and conserved motif analysis revealed highly conserved evolutionary patterns. Transcript profiles suggested that different gpx genes had specific patterns of regulation during early embryonic development. In adult tissues, gpx genes had a relatively broad expression distribution, most of which were highly expressed in the gills, intestines, and gonads. RT-qPCR studies showed that most gpx genes were downregulated during the initial cd2+ treatment stage. Dietary supplementation of Bacillus coagulans at different concentrations (Group 2 of 1.0 × 107 cfu/g, Group 3 of 1.0 × 108 cfu/g, and Group 4 of 1.0 × 109 cfu/g) induced different regulatory responses of gpx subclades. This result suggested that the appropriate concentration of B. coagulans can improve gpx gene expression when exposed to heavy metal cadmium treatment, which may play a vital role in the resistance to oxidative stress and immune responses. This study has expanded our understanding of the functional evolution of the gpx gene family in common carp.

ARTP mutation and adaptive laboratory evolution improve probiotic performance of Bacillus coagulans.

Bacillus coagulans is a thermophilic, facultative anaerobic, spore-forming Gram-positive bacterium, which is used as a probiotic in animal feed and human dietary supplements. In the present study, a bile-resistant thermophilic B. coagulans WT-03 strain was isolated and genetically identified. Atmospheric pressure room temperature plasma (ARTP)-induced mutation combined with adaptive laboratory evolution (ALE) was used to improve the probiotic performance of B. coagulans WT-03. After 15 s of ARTP mutation and 40 days of ALE culture, a mutant artp-aleBC15 was obtained and showed the improved tolerance to pH 2.5 and 0.3% bile salt with a survival rate of 22.4%. Further studies showed that the artp-aleBC15 mutant exhibited a relatively stable morphology, lower permeability, and higher hydrophobicity of cell membrane compared with the parent strain of B. coagulans. Additionally, artp-aleBC15 could maintain homeostasis with an intracellular pH of over 4.5 and had the altered contents of saturated fatty acids/unsaturated fatty acids in the cell membrane at pH 2.5. Our study proved that ARTP mutation combined with ALE is an efficient mutagenesis strategy to improve the probiotic performance of B. coagulans for potential industrial use.Key Points• A B. coagulans strain that can grow at 80 °C and 0.3% bile salt was screened.• ARTP combined with ALE effectively mutated B. coagulans WT-03.• B. coagulans artp-aleBC15 mutant showed an improved probiotic performance.• The mutant exhibited the lower permeability and altered fatty acid contents in the cell membrane.

Protective Effects of Benzoic Acid, Bacillus Coagulans, and Oregano Oil on Intestinal Injury Caused by Enterotoxigenic Escherichia coli in Weaned Piglets.

The use of antibiotics as growth promoters in feed has been fully or partially banned in several countries. The objective of this study was to investigate the effects of benzoic acid (A), bacillus coagulans (B) and oregano oil (O) combined supplementation on growth performance and intestinal barrier in piglets challenged with enterotoxigenic Escherichia coli (ETEC). Thirty piglets were randomly assigned to 6 treatments: (1) nonchallenged control (CON); (2) ETEC-challenged control (ETEC); (3) antibiotics + ETEC (AT); (4) A + B + ETEC (AB); (5) A + O + ETEC (AO); (6) A + B + O + ETEC (ABO). On day 22, piglets were orally challenged with ETEC or saline. The trial lasted 26 days. Dietary AO and ABO inhibited the reduction of growth performance and the elevation of diarrhoea incidence in piglets induced by ETEC (P<0.05). AB, AO, and ABO prevented the elevation of serum TNF-α and LPS concentrations in piglets induced by ETEC (P<0.05). ABO alleviated the elevation of TNF-α and IL-1ß concentrations and the reduction of sIgA level in jejunal mucosa induced by ETEC (P<0.05). Furthermore, ABO upregulated mRNA expressions of Claudin-1 and Mucin2 (P<0.05), downregulated mRNA abundances of TLR4 and NOD2 signaling pathways related genes in jejunal mucosa (P<0.05), and improved the microbiota in jejunal and cecal digesta (P<0.05) compared with ETEC group. These results indicated that benzoic acid, bacillus coagulans, and oregano oil combined supplementation could improve growth performance and alleviate diarrhoea of piglets challenged with ETEC via improving intestinal mucosal barrier integrity, which was possibly associated with the improvement of intestinal microbiota and immune status. The combination of 3000 g/t benzoic acid + 400 g/t bacillus coagulans + 400 g/t oregano oil showed better effects than other treatments in improving growth performance and intestinal health of piglets, which could be used as a viable substitute for antibiotic.

Beneficial Impact and Molecular Mechanism of Bacillus coagulans on Piglets' Intestine.

The aim of this research was to investigate the beneficial impact and molecular mechanism of B. coagulans on piglets' intestine. Twenty-four 21 days old weaned piglets were allotted to three treatments: Control group (basal diet), B6 group (basal diet + 2 × 106 CFU/g B. coagulans), and the B7 group (basal diet + 2 × 107 CFU/g B. coagulans). The results showed that, compared with the control group, the B7 group had a reduced cholesterol content and gamma glutamyl transpeptidase (GGT) in plasma (p < 0.05); the B6 and B7 groups had a significantly decreased diarrhea rate and diamine oxidase (DAO) activity in plasma (p < 0.05), increased villus height in ileum and decreased crypt depth in the jejunum (p < 0.05); increased activities of superoxide dismutase (SOD) and catalase (CAT), and decreased the content of malondialdehyde (MDA) and H2O2 in the intestine (p < 0.05). These data suggested that supplementing B. coagulans had beneficial impacts on promoting nutrients' metabolism, maintaining intestinal integrity, and alleviating oxidative stress and diarrhea. Further research of molecular mechanisms showed changing expression levels of related proteins and genes, suggesting that these could be involved in the regulation of the impact. The community composition of the gut microbiota was also found to be altered in several operational taxonomic units within the genus, Prevotella (order Bacteroidales), and the order, Clostridiales.

Protective effects of synbiotic diets of Bacillus coagulans, Lactobacillus plantarum and inulin against acute cadmium toxicity in rats.

BACKGROUND: Cadmium is a heavy metal that causes oxidative stress and has toxic effects in humans. The aim of this study was to investigate the influence of two probiotics along with a prebiotic in preventing the toxic effects of cadmium in rats. METHODS: Twenty-four male Wistar rats were randomly divided into four groups namely control, cadmium only, cadmium along with Lactobacillus plantarum (1 × 109 CFU/day) and inulin (5% of feedstuff) and cadmium along with Bacillus coagulans (1 × 109 spore/day) and inulin (5% of feedstuff). Cadmium treated groups received 200 µg/rat/day CdCl2 administered by gavage. During the 42-day experimental period, they were weighed weekly. For evaluation of changes in oxidative stress, the levels of some biochemicals and enzymes of serum including SOD, GPX, MDA, AST, ALT, total bilirubin, BUN and creatinine, and also SOD level of livers were measured at day 21 and 42 of treatment. The cadmium content of kidney and liver was determined by using atomic absorption mass spectrophotometry. Data were analyzed using analysis of variance (ANOVA) followed by Duncan's post hoc test. RESULTS: Treatment of cadmium induced rats with synbiotic diets significantly improved the liver enzymes and biochemical parameters that decreased AST, ALT, total bilirubin, BUN and metal accumulation in the liver and kidney and increased body weight, serum and liver SOD values in comparison with the cadmium-treated group. No significant differences were observed with MDA and GPX values between all groups (p > 0.05). CONCLUSIONS: This study showed that synbiotic diets containing probiotics (L. plantarum and B. coagulans) in combination with the prebiotic (inulin) can reduce the level of cadmium in the liver and kidney, preventing their damage and recover antioxidant enzymes in acute cadmium poisoning in rat.

Pectin-non-starch nanofibers biocomposites as novel gastrointestinal-resistant prebiotics.

Incorporation of nanofibers of chitin (NC), lignocellulose (NLC) and bacterial cellulose (BNC) in pectin was studied to improve prebiotic activity and gastrointestinal resistance of the pectin-nanofibers biocomposites for protection of probiotics under simulated gastrointestinal conditions. The biocomposites were prepared using various compositions of pectin and nanofibers, which were designed using D-optimal mixture method. The incorporation of the nanofibers in pectin led to a slow degradation of the pectin-nanofibers biocomposites in contrast to their rapid swelling. AFM analysis indicated the homogenous distribution of interconnected nanofibers network structure in the pectin-nanofibers biocomposite. FTIR spectra demonstrated fabrication of the biocomposites based on the inter- and intra-molecular hydrogen bonding and ionic interaction of pectin-Ca2+. XRD patterns revealed the amorphous structures of the biocomposites as compared to the crystalline structures of the nanofibers. Among the compositions, the optimal compositions were as follows: 60% pectin+40% NC, 50% pectin+50% NLC and 60% pectin+40% BNC, where the prebiotic score, probiotic survival under simulated gastric and intestinal conditions were optimum. The optimal biocomposite pectin-NC exhibited the highest survival of the entrapped probiotic bacteria under simulated gastric (97.7%) and intestinal (95.8%) conditions when compared with the corresponding to free cells (76.2 and 73.4%).