Lactobacillus-derived protoporphyrin IX and SCFAs regulate the fiber size via glucose metabolism in the skeletal muscle of chickens.

The gut microbiota contributes to skeletal muscle energy metabolism and is an indirect factor affecting meat quality. However, the role of specific gut microbes in energy metabolism and fiber size of skeletal muscle in chickens remains largely unknown. In this study, we first performed cecal microbiota transplantation from Chinese indigenous Jingyuan chickens (JY) to Arbor Acres chickens (AA), to determine the effects of microbiota on skeletal muscle fiber and energy metabolism. Then, we used metagenomics, gas chromatography, and metabolomics analysis to identify functional microbes. Finally, we validated the role of these functional microbes in regulating the fiber size via glucose metabolism in the skeletal muscle of chickens through feeding experiments. The results showed that the skeletal muscle characteristics of AA after microbiota transplantation tended to be consistent with that of JY, as the fiber diameter was significantly increased, and glucose metabolism level was significantly enhanced in the pectoralis muscle. L. plantarum, L. ingluviei, L. salivarius, and their mixture could increase the production of the microbial metabolites protoporphyrin IX and short-chain fatty acids, therefore increasing the expression levels of genes related to the oxidative fiber type (MyHC SM and MyHC FRM), mitochondrial function (Tfam and CoxVa), and glucose metabolism (PFK, PK, PDH, IDH, and SDH), thereby increasing the fiber diameter and density. These three Lactobacillus species could be promising probiotics to improve the meat quality of chicken.IMPORTANCEThis study revealed that the L. plantarum, L. ingluviei, and L. salivarius could enhance the production of protoporphyrin IX and short-chain fatty acids in the cecum of chickens, improving glucose metabolism, and finally cause the increase in fiber diameter and density of skeletal muscle. These three microbes could be potential probiotic candidates to regulate glucose metabolism in skeletal muscle to improve the meat quality of chicken in broiler production.

The Mixture of Saccharomyces cerevisiae and Clostridium butyricum Could Promote Rumen Fermentation and Improve the Growth Performance of Goats in Hot Summer.

This study aimed to investigate the effects of multiple mixing ratio pairs of Saccharomyces cerevisiae (SC) and Clostridium butyricum (CB) on rumen fermentation and growth performance of goats in hot summer. Thirty goats were divided into five groups: 0.00% probiotics (control), 0.30% SC and 0.05% CB (P1), 0.30% SC and 0.10% CB (P2), 0.60% SC and 0.05% CB (P3), and 0.60% SC and 0.10% CB (P4) of the dry matter (DM) weight of the basal diet and were assigned to a 5 × 5 Latin square experimental design. The results showed the pH values, the activities of ruminal cellulolytic enzymes, and the concentrations of ammonia nitrogen, acetic acid, propionic acid, total volatile fatty acids, vitamins B1 and B2, and niacin were significantly increased (p < 0.05) by probiotics. Moreover, the DM intake, average daily gain, the digestibilities of DM, neutral detergent fiber, and acid detergent fiber were significantly increased (p < 0.05) in probiotic-supplemented groups. Additionally, among all probiotic supplementation groups, the P3 group had the most beneficial effect on rumen fermentation parameters and the growth performance of goats. These results suggested that the mixture of 0.60% Saccharomyces cerevisiae and 0.05% Clostridium butyricum of the DM concentration was beneficial to improve rumen fermentation and promote the growth of goats in hot summer.

Bacteroides-derived isovaleric acid enhances mucosal immunity by facilitating intestinal IgA response in broilers.

BACKGROUND: The interaction between nutrition and immunity plays a vital role in nutrient digestion, absorption, and metabolism during poultry production. Recent studies showed that the gut microbiota contributes to the development of intestinal mucosal immunity. However, the mechanisms by which gut microbes regulate this process remain unclear. METHODS: We compared the intestinal mucosal immunity and gut microbiota of Arbor Acre broilers (AA (lower mucosal immunity) and Chinese native Wuliang Mountain Black-bone chickens (WLMB) (higher mucosal immunity) using 16S rDNA sequencing, transcriptomic analysis, and immunoglobulin A (IgA) antibody repertoire sequencing. We then combined 16S rDNA sequencing with transcriptomics to identify the key microbes and found that they were positively correlated with IgA production. Next, we transplanted candidate microbes into 1-day-old broiler to explore their role in intestinal mucosal immunity. Finally, we verified the function of candidate microbial metabolites in regulating the immune function of macrophages and the intestinal-epithelial cells (IECs) using in vitro experiments. RESULTS: WLMB performs stronger mucosal immunity than AA, including higher IgA levels, more diverse IgA antibody repertoire, and higher bacterial affinity. Bacteroides was identified as the key microbes related to the intestinal IgA response. Bacteroides transplantation could increase IgA concentration in the duodenal contents by enhancing the expression of IgA, polymeric immunoglobin receptor (PIgR), B cell-activating factor of the TNF family (BAFF), and activation-induced cytidine deaminase (AID) in the duodenum. Additionally, Bacteroides-derived isovaleric acid promoted M2 macrophage polarization of macrophage via mTOR/PPAR-γ/STAT3 signaling pathways and regulated the immunologic function of IECs to produce cytokines, including interleukin (IL)-10, IL-4, BAFF, and transforming growth factor-beta (TGF-ß), thus promoting IgA production in B cells by facilitating AID expression. CONCLUSION: Our study revealed that Bacteroides modulate the intestinal IgA response and maintain gut health in broilers. Bacteroides may be a promising alternative as an immunomodulatory microbial agent for developing next-generation probiotics for broiler production.

The Low Dose of Saccharomyces cerevisiae Is Beneficial for Rumen Fermentation (Both In Vivo and In Vitro) and the Growth Performance of Heat-Stressed Goats.

This study aimed to investigate the effects of Saccharomyces cerevisiae on rumen fermentation and the growth performance of heat-stressed goats. The fermentation experiment was conducted using Saccharomyces cerevisiae added at 0‱ (HS1), 0.30‱ (SC1), 0.60‱ (SC2), and 1.20‱ (SC3) of the dry matter (DM) weight of the basal diet. The results showed that supplementing with 0.60‱ (SC2) could increase the pH, acetic acid to propionic acid ratio, the concentrations of ammonia nitrogen, total volatile fatty acids, acetic acid, propionic acid, butyric acid, and the degradability of DM, neutral detergent fiber, and acid detergent fiber in rumen fluids of heat-stressed goats. In the feeding experiment, twelve heat-stressed goats were assigned to a 4 × 4 Latin square experimental design, and the Saccharomyces cerevisiae supplement levels are similar to the fermentation experiment above. Similar effects on rumen fermentation and digestibility parameters were obtained with a supplement with 0.60‱ of Saccharomyces cerevisiae (SC2A) compared to the fermentation trial. Moreover, in the SC2A group, the DM intake and average daily gain also increased significantly compared with other groups. These results suggested that a low dose of Saccharomyces cerevisiae can still effectively improve the rumen fermentation and growth performance of heat-stressed goats.

Prophylactic Feeding of Clostridium butyricum and Saccharomyces cerevisiae Were Advantageous in Resisting the Adverse Effects of Heat Stress on Rumen Fermentation and Growth Performance in Goats.

This study aimed to investigate the effect of the prophylactic feeding of Clostridium butyricum (CB), Saccharomyces cerevisiae (SC), and their mixture before the onset of heat stress on the rumen fermentation and growth performance of goats, and subsequently, on heat stress status. Forty-eight male Macheng Black × Boer crossed goats (22.25 ± 4.26 kg) were divided into four groups­the control group (fed the basal diet), and the CB (0.05% CB added to the basal diet), SC (0.60% SC added to the basal diet), and Mix (0.05% CB and 0.60% SC added to the basal diet) groups­and fed for fourteen days. Then, these goats were kept in a heat stress environment (with a temperature−humidity index of 87.04) for fourteen days. Then, the parameters of rumen fermentation and growth performance were measured. The results showed that the pH values, the activities of cellulolytic enzymes (avicelase, CMCaes, cellobiase, and xylanase), and the concentrations of ammonia-N, total volatile fatty acid, acetic acid, propionic acid, and butyric acid were significantly increased (p < 0.05) in the rumens of the CB, SC, and Mix groups compared to those of the control group. Moreover, the average daily gain and the digestibility of dry matter, neutral detergent fiber, and acid detergent fiber were significantly increased (p < 0.05) in the CB, SC, and Mix groups compared to those of the control group. These results suggest that these two probiotics and their mixture effectively alleviate the adverse effects of heat stress on rumen fermentation and growth performance via prophylactic feeding.

Saccharomyces cerevisiae and Clostridium butyricum Could Improve B-Vitamin Production in the Rumen and Growth Performance of Heat-Stressed Goats.

Heat stress can adversely affect the rumen environment and the growth performance of goats. The present study aimed to investigate the effects of Saccharomyces cerevisiae (SC), Clostridium butyricum (CB), and their mixture on B-vitamin production in the rumen and the growth performance of heat-stressed goats. Firstly, twelve Macheng × Boer crossed goats (24.21 ± 2.05 kg, control) were modeled to become heat-stressed goats (HS1). Then, the B-vitamin concentrations in the rumen and the parameters of growth performance were measured in goats. The results showed that heat stress could cause significantly decreased vitamin B1, B2, B6, B12, and niacin concentrations (p < 0.05). It also could cause a significantly reduced dry matter (DM) intake (DMI) and average daily gain (ADG) (p < 0.05). However, the digestibilities of DM, neutral detergent fiber (NDF), and acid detergent fiber (ADF) were significantly increased (p < 0.05) in HS1 compared to controls. Then, these twelve heat-stressed goats were divided equally into four groups: control group (HS2, no probiotic supplemented), SC group (0.30% SC supplemented to the basal diet), CB group (0.05% CB supplemented to the basal diet), and mix group (0.30% SC and 0.05% CB supplemented to the basal diet). They were used in a 4 × 4 Latin square experimental design. The results showed that the concentrations of vitamins B1, B2, and niacin in the rumen and the DMI, ADG, and the digestibility of DM, NDF, and ADF were significantly increased (p < 0.05) with SC, CB, and their mixture supplementation (p < 0.05). These results suggest that dietary supplementation with SC and CB could improve B-vitamin production in the rumen and the growth performance of heat-stressed goats.

Trans-Species Fecal Transplant Revealed the Role of the Gut Microbiome as a Contributor to Energy Metabolism and Development of Skeletal Muscle.

The aim of this study was to investigate the influence of the exogenous gut microbiome at early life stages on the development of mice skeletal muscle in adulthood. First, the characteristics of skeletal muscle and the gut microbiota composition of the gut microbiota donors­Erhualian (EH) pigs (a native Chinese breed)­were studied. EH pigs had significantly higher fiber densities and thinner fiber diameters than Duroc × Landrace × Yorkshire crossed (DLY) pigs (p < 0.05). The expression levels of genes related to oxidized muscle fibers, mitochondrial function, and glucose metabolism in the skeletal muscle of EH pigs were significantly higher than those in DLY pigs (p < 0.05). Moreover, the abundances of 8 gut microbial phyla and 35 genera correlated with the skeletal muscle fiber diameters and densities exhibited significant differences (p < 0.05) between EH and DLY pigs. Subsequently, newborn mice were treated with saline (CG) and fecal microbiota suspensions collected from EH pigs (AG), respectively, for 15 days, starting from the day of birth. In adulthood (60 days), the relative abundances of Parabacteroides, Sutterella, and Dehalobacterium were significantly higher in the feces of the AG mice than those of the CG mice. The microbes contribute to improved functions related to lipid and carbohydrate metabolism. The weight, density, and gene expression related to the oxidized muscle fibers, mitochondrial function, and glucose metabolism of the AG group were significantly higher than those of the CG group (p < 0.05), whereas the fiber diameters in the skeletal muscle of the AG mice were significantly lower (p < 0.05) than those of the CG mice. These results suggested that intervention with exogenous microbiota at early stages of life can affect the fiber size and energy metabolism of their skeletal muscle.

Clostridium butyricum Improves Rumen Fermentation and Growth Performance of Heat-Stressed Goats In Vitro and In Vivo.

This study aimed to evaluate the effects of Clostridium butyricum on rumen fermentation and the growth performance of heat-stressed goats. The in vitro fermentation was carried out using Clostridium butyricum supplement at 0% (CG), 0.025% (CB1), 0.05% (CB2), 0.10% (CB3), and 0.20% (CB4) of the dry matter (DM) weight of basal diet. Results showed that ruminal pH and the concentrations of ammonia nitrogen, total volatile fatty acids, acetic acid, propionic acid, as well as the acetic acid to propionic acid ratio were significantly increased (p < 0.05) in CB2 and CB3 compared with the CG group. Additionally, significant increases (p < 0.05) in the degradability of DM, neutral detergent fiber, and acid detergent fiber were observed in CB2 and CB3 compared with the CG group. For the in vivo study, 12 heat-stressed goats were divided equally into three groups: the control (HS1) was fed the basal diet, and groups HS2 and HS3 were fed with 0.05% and 0.10% Clostridium butyricum added to the basal diet, respectively. The experiment was designed as a 3 × 3 Latin square. Similar effects on rumen fermentation and digestibility parameters were obtained with 0.05% of Clostridium butyricum supplement compared to the in vitro study. Moreover, the dry matter intake and average daily gain were significantly increased (p < 0.05) in HS2 compared with other groups. These results indicated that an effective dose of Clostridium butyricum supplement (0.05%) could improve the rumen fermentation and growth performance of heat-stressed goats.

Dietary Supplementation with Saccharomyces cerevisiae, Clostridium butyricum and Their Combination Ameliorate Rumen Fermentation and Growth Performance of Heat-Stressed Goats.

This study aimed to evaluate the effects of Saccharomyces cerevisiae, and their combination on rumen fermentation and growth performance of heat-stressed goats. Twelve heat-stressed goats (20.21 ± 2.30 kg) were divided equally into four groups: control group (CG, fed the basal diet, Saccharomyces cerevisiae supplemented group (SC, 0.60% Saccharomyces cerevisiae added to the basal diet), Clostridium butyricum supplemented group (CB, 0.05% Clostridium butyricum added to the basal diet), and their combination supplemented group (COM 0.60% Saccharomyces cerevisiae and 0.05% Clostridium butyricum added to the basal diet) and were assigned to a 4 × 3 incomplete Latin square design. The rumen fluid and feces were collected for fermentation parameters and feed digestibility analysis, and animal growth performance was also assessed during all the experiment periods. The results showed that rumen pH, rumen cellulolytic enzymes (avicelase, CMCaes, cellobiase, and xylanase) activities, and the concentrations of rumen total volatile fatty acid (TVFA), acetic acid, and propionic acid were significantly increased with Saccharomyces cerevisiae, Clostridium butyricum, and their combination supplementation (p < 0.05). Besides, the dry matter intake (DMI), average daily gain (ADG), and the digestibility of dry matter (DM), neutral detergent fiber (NDF), and acidic detergent fiber (ADF) were significantly increased (p < 0.05) with supplemented these probiotics. However, the ammonia nitrogen (NH3-N) concentration only significantly increased in CB and A/P ratio (acetic acid to propionic acid ratio) only significantly increased in SC and CB. These results indicated that the supplementation with these probiotics could ameliorate rumen fermentation and growth performance of heat-stressed goats.

Effects of Thymol Supplementation on Goat Rumen Fermentation and Rumen Microbiota In Vitro.

This study was performed to explore the predominant responses of rumen microbiota with thymol supplementation as well as effective dose of thymol on rumen fermentation. Thymol at different concentrations, i.e., 0, 100 mg/L, 200 mg/L, and 400 mg/L (four groups × five replications) was applied for 24 h of fermentation in a rumen fluid incubation system. Illumina MiSeq sequencing was applied to investigate the ruminal microbes in addition to the examination of rumen fermentation. Thymol doses reached 200 mg/L and significantly decreased (p < 0.05) total gas production (TGP) and methane production; the production of total volatile fatty acids (VFA), propionate, and ammonia nitrogen, and the digestibility of dry matter and organic matter were apparently decreased (p < 0.05) when the thymol dose reached 400 mg/L. A thymol dose of 200 mg/L significantly affected (p < 0.05) the relative abundance of 14 genera of bacteria, three species of archaea, and two genera of protozoa. Network analysis showed that bacteria, archaea, and protozoa significantly correlated with methane production and VFA production. This study indicates an optimal dose of thymol at 200 mg/L to facilitate rumen fermentation, the critical roles of bacteria in rumen fermentation, and their interactions with the archaea and protozoa.

Metabolic changes of Acidithiobacillus caldus under Cu²(+) stress.

Metabolic changes were investigated by measuring the depletion of dissolved oxygen and the enzymatic activities of sulfur metabolism in Acidithiobacillus caldus (A. caldus) before and after copper stress. The results showed that high concentrations of Cu²(+) have an indirect negative effect on the sulfite oxidase and the APS reductase involved in sulfur metabolism when A. caldus is cultured in medium with elemental sulfur as its growth energy. This leads to a decrease in the respiration rate and the growth rate. The changes of activity are negatively correlated with the intracellular Cu²(+) concentration through an indirect interaction mechanism. A. caldus was able to induce an efflux of copper ions by forming an ATPase-dependent pump, which transported copper ions by consuming ATP. The negative effect of Cu²(+) on the bacterial metabolism could be minimized by the copper efflux when the bacteria were adapted in medium containing Cu²(+) for a long time. However, this bacterial rejuvenation became weaker when grown in medium containing higher concentrations of copper ions.