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This study aimed to assess the influence of dietary supplementation of ε-polylysine on the gut microbiota and host nutrient metabolism, which is not systematically discussed by multi-omics analysis. A total of 40 mice were randomly divided into two groups exposed to either a basal diet (AIN-76A) or a basal diet with 150 ppm ε-polylysine. Fecal samples were collected for gut bacteria identification. Liver and plasma samples were collected for metabolomic and proteomic analyses. The results showed that ε-polylysine decreased the body weight of mice and affected the presence of certain types of intestinal microorganisms. The richness of the microbiota and number of phyla increased with age. ε-Polylysine affected the presence of genera and species, and either regulated or took part in the metabolism of energy, nitrogen, amino acids, lipids, carbohydrates, glycans, cofactors, and vitamins. The metabolite profiling showed that lipid and lipid-like molecules metabolites occupied the majority percent of plasma and liver metabolites. Additionally, ε-polylysine regulated the key role of metabolites and related metabolic enzymes in the metabolic pathways, especially phospholipid metabolism. In conclusion, dietary ε-polylysine improved the immunity of growing mice, and had a greater effect on the anabolism of nutrients in adult mice.

The study aimed to investigate the nutritional value of ramie (Boehmeria nivea) silage, and its consequences for chewing activity, rumen fermentation, and enteric methane (CH4) emissions in goats, by comparing it with corn stover (CS) silage. An in vitro ruminal experiment was firstly performed to investigate the substrate degradation and fermentation of CS and ramie silage. The ramie silage diet was formulated by replacing 60% of CS silage with ramie silage (dry matter (DM) basis). Eight female Xiangdong Black goats (a local breed in Southern China, 1 to 1.2 years of age) with BW of 21.0 ± 1.05 kg were used for this experiment and were randomly assigned to either one of the two dietary treatments in a cross-over design. The ramie silage had higher crude protein (CP) and ash content and lower hemicellulose content, together with decreased (p < 0.05) nutrient degradation and methane production and increased (p < 0.05) acetate molar percentage and acetate to propionate ratio through in vitro ruminal fermentation. Feeding the ramie silage diet did not alter feed intake (p > 0.05), decreased (p < 0.05) nutrient digestibility, and increased (p < 0.05) chewing activity and rumination activity, with reductions (p < 0.05) in eating activity and idle activity. Although feeding the ramie silage diet caused a greater (p < 0.05) molar percentage of acetate and lower molar percentage of propionate, it decreased the rumen-dissolved CH4 concentration and enteric CH4 emissions (p < 0.05). Feeding the ramie silage diet did not alter (p > 0.05) the population of bacteria, protozoa, and fungi; it increased the 16S rRNA gene copies of Ruminococcus flavefaciens (p < 0.05). Further 16SrRNA gene amplicon analysis indicated a distinct bacterial composition between the two treatments (p < 0.05). Feeding the ramie silage diet led to a lower abundance of genera Lawsonibacter, Sedimentibacter, Saccharofermentans, Sediminibacterium, and Bifidobacterium (p < 0.05). Ramie can be an alternative forage resource to stimulate chewing activity and reduce CH4 emissions in ruminants.

Ramie (Boehmeria nivea) is noted for the production of a large biomass that has a high protein content and is rich in antioxidants. It may thus serve as a high-quality forage material to replace alfalfa and improve the meat quality of farmed animals. In this study, we evaluated the carcass characteristics and meat quality of goats when 0, 35%, 75%, and 100% of dietary alfalfa was replaced with ramie. Crude protein content (linear, P

Given the antibacterial effects of ε-polylysine acting on cell membranes, and that glycerol phospholipids are important components of the cell membrane, we hypothesized that ε-polylysine may regulate glycerophospholipid metabolism by modifying the gut microbiota. To test this hypothesis, we treated post-weaning C57 mice with different levels of ε-polylysine (0, 300, 600, and 1,200 ppm) in their basic diet. The growth performance and morphology of intestine were then determined. Modification of the gut microbiota and their function were analyzed using 16S rDNA sequencing. Metabolite identification was performed using the LC-MS method. The results showed that body weight decreased with an increasing supplemental level of ε-polylysine from 5 to 7 weeks (P < 0.05), but no significant difference was observed after 8 weeks (P > 0.05). Supplementation with 1,200 ppm ε-polylysine changed the morphology of the jejunum and ileum, increased the villus length, decreased the crypt depth of the jejunum, and decreased the villus length and crypt depth of the ileum (P < 0.05). ε-Polylysine shifted the intestine microbiota by changing alpha diversity (Chao 1, observed species, Shannon, and Simpson indices) and varied at different times. ε-polylysine decreased Firmicutes and increased Bacteroidetes at 4 week, but increased Firmicutes and decreased Bacteroidetes at 10 week. ε-Polylysine regulated genera associated with lipid metabolism such as Parabacteroides, Odoribacter, Akkermansia, Alistipes, Lachnospiraceae UCG-001, Collinsella, Ruminococcaceae, and Intestinimonas. During the adult period, the genera Alistipes, Lachnospiraceae UCG-001, and Streptomyces were positively associated with PC, PE, LysoPC, LysoPE, 1-Arachidonoylglycerophosphoinositol and OHOHA-PS (R > 0.6, P < 0.001), but changes in Blautia, Christensenellaceae R-7 group, Odoribacter, Allobaculum, Ruminococcaceae UCG-004, Ruminococcaceae UCG-005, and Lachnospiraceae UCG-010 were negatively correlated with glycerophospholipid metabolites (R < −0.6, P < 0.001). The abundance of glycerophospholipid metabolites, including PC, PE, lysoPC, and lysoPE, were decreased by ε-polylysine. Furthermore, ε-polylysine reduced the incidence of the genera including Ruminococcus, Prevotella, Prevotellaceae, Butyricimonas, and Escherichia-Shigella and reduced the abundance of Faecalibaculum, Christensenellaceae R-7 group, Coriobacteriaceae UCG-002. In conclusion, ε-polylysine modified gut microbiota composition and function while also restraining pathogenic bacteria. The glycerophospholipid metabolism pathway and associated metabolites may be regulated by intestinal bacteria.

Alfalfa silage is one of the main roughages in the production of dairy cow, which can provide nutrition with high quality to improve milk quality and production. Sucrose additions have been widely used to improve the silage quality. In this study, the effects of sucrose on the fermentation quality and bacterial communities of alfalfa silage were investigated here using 0, 0.5, and 1% sucrose ensiling treatments for 15, 30, and 60 days. The ensiling time significantly decreased the crude fiber content and increased the ammonia nitrogen, acetic acid content, and the relative abundance of Enterococcus in the silages. The 1% sucrose-treated silage at 60 days had the lowest neutral detergent fiber acid, acid detergent fiber, and crude fiber content and the highest relative feed value. Moreover, sucrose-treated silage contained less acetic acid, propionic acid, and butyric acid, and had a lower pH than the controls for each duration. Enterobacteriaceae, Klebsiella, and Enterococcus were the dominant genera in all groups, and the relative abundance of Enterococcus and Lactobacillus was higher in the 1% sucrose-treated group than in the control. These results suggested that sucrose supplementation could improve alfalfa silage quality and increase its beneficial bacterial content.

Intestinal microbiota plays an important role in the health of animals. However, little is known about the gut microbiota in Ningxiang pigs. Thus, we investigated how dietary supplementation with different ε-polylysine concentrations (0, 20, 40, 80, and 160 ppm) affected the ileal microbiota in Ningxiang pigs using a replicated 5 × 5 Latin square method. Each experimental period included 10 days for diet adaptation, 3 days for feces collection and 2 days for digesta collection. The ileal contents were collected and used for sequencing of the V3–V4 hypervariable region of the 16S rRNA gene. The results revealed that ε-polylysine significantly decreased the digestibility of crude protein and crude fiber, as well as the utilization of metabolizable energy (P < 0.05). The relative abundances of 19 bacterial genera significantly increased, while those of 26 genera significantly decreased (P < 0.05). In addition, ε-polylysine increased the abundance of some bacteria (e.g., Faecalibacterium, Bifidobacterium, and lactic acid bacteria) and inhibited some other bacteria (e.g., Micrococcaceae, Acinetobacter, Anaerococcus, Peptoniphilus, Dehalobacterium, Finegoldia, Treponema, and Brevundimonas). Furthermore, based on the 16S rRNA gene data and data from the precalculated GreenGenes database, bacterial communities in the ileal contents exhibited enhanced functional maturation, including changes in the metabolism of carbohydrates, amino acids (e.g., alanine, lysine, tryptophan, cysteine, and methionine), cofactors, and vitamins (e.g., biotin, thiamine, and folate), as well as in the activity of the insulin signaling pathway. This study suggests that ε-polylysine may influence the utilization of feed nutrients by Ningxiang pigs, including proteins, lipids, metabolizable energy, and fiber, by regulating the gut microbiota.

Five white-rot fungi Pleurotus ostreatus, Lentinus edodes, Hericium erinaceus, Pleurotus eryngii and Flammulina filiformis were studied (solid-state incubation and in vitro gas production) to determine lignin degradation and optimal duration of fermentation of corn straw. All fungi significantly decreased lignin, with optimal reductions after 28 d. Although cellulose also decreased, L. edodes and P. eryngii minimized these losses. In intro dry matter digestibility, total volatile fatty acid concentration and total gas production of fermented corn straw decreased (P 0.001) as fermentation was prolonged, with improved rumen fermentability for all fungal treatments except F. filiformis. Total gas production in L. edodes did not decrease but peaked on day 28, whereas F. filiformis reduced methane emission. In conclusion, fermentation of corn straw with P. eryngii or L. edodes for 28 d degraded lignin and improved nutritional value as ruminant feed.

BACKGROUND Post-ruminal digestion of fiber has received much less attention than its ruminal digestion. Using in vitro incubation techniques, the present study explored whether variations in fiber digestion occurred in different segments of the post-ruminal tract and whether fiber structure could influence its digestibility. A split plot design was conducted with gut segments (jejunum, ileum, cecum and colon) as main plot and substrates (neutral detergent fiber (NDF) and cellulose (CEL)) as subplot. RESULTS With the same substrate, the final asymptotic gas volume (VF), gas production at ti (), digestibility, microbial crude protein (MCP), total bacteria number (TBN), total short-chain fatty acids (TSCFA) and xylanase in incocula from the cecum and colon exceeded (P < 0.01) those in incocula from the jejunum and ileum, while the NH3-N in the former was less (P < 0.01). For the same gut segment, the digestion of CEL was superior to NDF, as reflected in greater VF, , maximum rate of gas production, digestibility, enzyme activities and SCFA but lower pH and NH3-N. CONCLUSION The current results imply that the intestinal contents from the cecum and colon have greater potential to digest fiber than those from the jejunum and ileum, and CEL is more easily digested in the post-ruminal tract than NDF. © 2013 Society of Chemical Industry

A series of batch cultures were conducted to investigate the effects of oleic acid (OA) on in vitro ruminal dry matter degradability (IVDMD), gas production, methane (CH4) and hydrogen (H2) production, and proportion of fatty acids. Rumen fluid was collected from fistulated goats, diluted with incubation buffer, and then incubated with 500 mg Leymus chinensis meal supplemented with different amounts of OA (0, 20, 40, and 60 mg for the CON, OA20, OA40 and OA60 groups, respectively). Incubation was carried out anaerobically at 39°C for 48 h, and the samples were taken at 12, 24 and 48 h and subjected to laboratory analysis. Supplementation of OA decreased IVDMD, the cumulative gas production, theoretical maximum of gas production and CH4 production, but increased H2 production. However, no effect was observed on any parameters of rumen fermentation (pH, ammonia, production of acetate, propionate and butyrate and total volatile fatty acid production). The concentrations of some beneficial fatty acids, such as cis monounsaturated fatty acids and conjugated linoleic acid (CLA) were higher (P < 0.05) from OA groups than those from the control group at 12 h incubation. In summary, these results suggest that the OA supplementation in diet can reduce methane production and increase the amount of some beneficial fatty acids in vitro.