Targeted screening of an anti-inflammatory polypeptide from Rhopilema esculentum Kishinouye cnidoblasts and elucidation of its mechanism in alleviating ulcerative colitis based on an analysis of the gut microbiota and metabolites

Ulcerative colitis(UC)is a recurrent inflammatory bowel disease that imposes a severe burden on families and society.In recent years,exploiting the potential of marine bioactive peptides for the treatment of diseases has become a topic of intense research interest.This study revealed the mechanism underlying the protective effect of the dominant polypeptide PKKVV(Pro-Lys-Lys-Val-Val)of Rhopilema esculentum cnidoblasts against DSS-induced UC through a combined analysis of the metagenome and serum metabolome.Specifically,the polypeptide composition of R.esculentum cnidoblasts was determined by matrix-assisted laser desorption ionization time-of-flight mass spectrometry(MALDI-TOF/TOF-MS).Molecular docking showed that the dominant peptide PKKVV could bind better with tumor necrosis factor-α(TNF-α)than the original ligand.Subsequent animal experiments suggested that PKKVV could modulate disorganized gut microorganisms in mice with UC;affect serum metabolites through the arachidonic acid,glycerophospholipid and linoleic acid metabolism pathways;and further alleviate UC symptoms.This study provides a reference for the comprehensive development of marine bioactive substances and nonpharmaceutical treatments for UC.

Integrated mass spectrometry imaging reveals spatial-metabolic alteration in diabetic cardiomyopathy and the intervention effects of ferulic acid

Diabetic cardiomyopathy(DCM)is a metabolic disease and a leading cause of heart failure among people with diabetes.Mass spectrometry imaging(MSI)is a versatile technique capable of combining the molecular specificity of mass spectrometry(MS)with the spatial information of imaging.In this study,we used MSI to visualize metabolites in the rat heart with high spatial resolution and sensitivity.We optimized the air flow-assisted desorption electrospray ionization(AFADESI)-MSI platform to detect a wide range of metabolites,and then used matrix-assisted laser desorption ionization(MALDI)-MSI for increasing metabolic coverage and improving localization resolution.AFADESI-MSI detected 214 and 149 metabolites in positive and negative analyses of rat heart sections,respectively,while MALDI-MSI detected 61 metabolites in negative analysis.Our study revealed the heterogenous metabolic profile of the heart in a DCM model,with over 105 region-specific changes in the levels of a wide range of metabolite classes,including carbohydrates,amino acids,nucleotides,and their derivatives,fatty acids,glycerol phospholipids,carnitines,and metal ions.The repeated oral administration of ferulic acid during 20 weeks significantly improved most of the metabolic disorders in the DCM model.Our findings provide novel insights into the molecular mechanisms underlying DCM and the potential of ferulic acid as a therapeutic agent for treating this condition.

Single nucleotide polymorphisms linked to quantitative trait loci for grain quality traits in wheat

Wheat(Triticum aestivum L.) grain quality traits that are controlled by quantitative traits loci(QTL) define suitable growing areas and potential end-use products of a wheat cultivar. To dissect QTL for these traits including protein content(GPC); test weight(TW); single kernel characterization system(SKCS)-estimated kernel weight(SKW); kernel diameter(KD);kernel hardness measured by near-infrared reflectance spectroscopy(NIRS) hardness index(NHI); and SKCS-hardness index(SHI), a high-density genetic map with single nucleotide polymorphism(SNP) and simple sequence repeat(SSR) markers was developed using recombinant inbred lines(RILs) derived from Ning7840 × Clark. The RILs were evaluated for these quality traits in seven Oklahoma environments from 2001 to 2003. A total of 41 QTL with additive effects on different traits were mapped on most wheat chromosomes,excluding 1A, 2A, 3D, 4D, 6D, and 7B. Seven chromosome regions showed either tightly linked QTL or QTL with pleiotropic effects on two to four traits. Ten pairs of QTL showed additive × additive effects(AA), four QTL were involved in additive × environment(AE)effects, and one was involved in AAE effects. Two to eleven QTL for each of the six traits and139 tightly linked markers to these QTL were identified. The findings shed light on the inheritance of wheat grain quality traits and provide DNA markers for manipulating these important traits to improve quality of new wheat cultivars.

Effects of Supplemental Dietary Energy Source on Feed Intake, Lactation Performance, and Serum Indices of Early-Lactating Holstein Cows in a Positive Energy Balance

The present study investigated the effects of the supplemental dietary energy source on early lactating cows in a positive energy balance. Cows in the control group were fed a basal total mixed ration containing high-quality hay as forage, and the dietary concentrate to forage ratio was 45:65. The corn supplementation resulted in a significant decrease in the milk fat content (P P = 0.15), whereas the fat supplementation resulted in a decreasing trend of the milk protein and lactose content (P ≤ 0.1). Additionally, the corn supplementation significantly decreased the serum 5-hydroxytryptamine level (P < 0.05). The results support the proposal that the source of supplemental dietary energy has varying effects on feed intake, lactation performance, and the intermediate metabolism of early lactating cows in a positive energy balance. 5-Hydroxytryptamine secretion may be associated with the varying effects of the source of supplemental dietary energy.

Identification of traits and genes associated with lodging resistance in maize

Lodging is a major problem limiting maize yield worldwide. However, the mechanisms of lodging resistance remain incompletely understood for maize. Here, we evaluated 443 maize accessions for lodging resistance in the field. Five lodging-resistant accessions and five lodging-sensitive accessions were selected for further research. The leaf number, plant height, stem diameter, and rind penetrometer resistance were similar between lodging-resistant and-sensitive inbred lines. The average thickness of sclerenchymatous hypodermis layer was thicker and the vascular area was larger in the lodging-resistant lines compared with lodging-sensitive lines. Although total lignin content in stem tissue did not significantly differ between lodging-resistant and-sensitive lines, phloroglucinol staining revealed that the lignin content of the cell wall in the stem cortex and in the stem vascular tissue near the cortex was higher in the lodging-resistant lines than in the lodging-sensitive lines. Analysis of strand-specific RNA-seq transcriptome showed that a total of 793 genes were up-regulated and 713 genes were down-regulated in lodging-resistant lines relative to lodging-sensitive lines. The up-regulated genes in lodging-resistant lines were enriched in cell wall biogenesis. These results indicated that modification of cell wall biosynthesis would contribute to lodging resistance of maize.

Platinum is essential in neoadjuvant treatment of triple-negative breast cancer: a network meta-analysis

Objective:This study aimed to assess the efficacy and safety of various neoadjuvant regimens for patients diagnosed with early-stage or locally advanced triple-negative breast cancer(TNBC).Methods:Medline,EMBASE,Cochrane Library,and Web of Science were searched in May 2020 to identify randomized controlled trials(RCTs).Bayesian network meta-analysis(NMA)was performed(Registration:PROSPERO CRD42020223012).Results:A total of 35 RCTs involving 8,424 participants were reviewed,of which 22 RCTs with 5,203 patients were included in this NMA focusing on pathologic complete response(pCR).An anthracycline-taxane-based(AT)regimen combined with a platinum(ATPt)[odds ratio(OR)=2.04,95%credible interval(CrI):1.69,2.48]regimen,and a docetaxel regimen combined with a carboplatin(TCb;OR=2.16,95%CrI:1.20,3.91)regimen improved pCR beyond that with AT only.AT and ATPt combined with targeted therapy[including bevacizumab(Bev),veliparib,atezolizumab,or pembrolizumab]also improved pCR.Five RCTs included in this NMA reported serious adverse events(SAEs)or grade≥3 AEs.TCb was associated with fewer grade≥3 AEs than was AT(OR=0.66,95%CrI:0.23,1.72)alone.In contrast,ATPt,AT+Bev,ATPt+Bev,ATPt+veliparib,and ATPt+pembrolizumab were associated with more SAEs than was AT alone.Conclusions:In patients with TNBC,platinum-based neoadjuvant regimens ATPt and TCb increase pCR beyond that with AT alone,but TCb appears to be better tolerated than either AT or ATPt.Platinum-based regimens combined with targeted therapies(Bev,PARPi,and PD-1/PD-L1 inhibitor)also improve the pCR rate beyond that with AT alone,but this benefit is accompanied by greater toxicity.

Gastrointestinal Tract Development in Unweaned Calves Feeding Different Amounts of Milk and Different Starters

This study was conducted to determine the effect of different starter diets and different amounts of milk on growth performance and gastrointestinal tract development in unweaned calves. 16 calves were assigned to 4 groups, 4 calves in each group. These four groups received the following treatments respectively: 1) high milk (6 L) + low starch (21%), high NDF (28%), high molasses (10%) starter (HMLS group);2) high milk (6L) + high starch (40%), low NDF (14%), low molasses (5%) starter (HMHS group);3) low milk (3 L) + low starch (21%), high NDF (28%), high molasses (10%) starter (LMLS group);4) low milk (3 L) + high starch (40%), low NDF (14%), low molasses (5%) starter (LMHS group). The trial was of 2 × 2 factorial design. All calves had free access to hay and water. Results showed that the low milk allowance increased calf concentrate dry matter intake (DMI) and total DMI, reduced body height at 4 weeks of age, reduced heart girth at 6 weeks of age (P < 0.05). The low milk allowance increased complex stomach full weight, reticulorumen full weight, and the percentages of stomach full weight and reticulorumen full weight over body weight (P < 0.05). The low starch, high fiber, high molasses starters reduced the complex stomach full weight, the proportion of the complex stomach empty weight over body weight, reticulorumen empty weight, abomasum full weight, the proportion of abomasum empty weight over body weight and reticulorumen volume (P < 0.05). The low milk allowance increased calf intestine length, small intestine full weight, the proportion of small intestine full weight over body weight, but reduced the jejunum villus width (P < 0.05), increased ruminal pH (P < 0.05). The low milk allowance reduced papilla length in rumen anterior ventral blind sac, but increased papilla length in the posterior ventral sac

Effects of Supplemental Feeding of Probiotics during Lactation on Rumen Microflora of Calves after Weaning

For the experiment, 8 newborn male Holstein calves were selected that had the same feeding environment, and were of similar ages. They were randomly divided into 2 groups, with 4 in each group. The treatments consisted of feeding active probiotics (Group P) and a normal fed control group (Group C). The growth performance and blood indices were measured;rumen fluid samples were collected after weaning, and 16SrDNA sequencing and LC-MS metabolome detection were performed. Compared with the control group, relative abundances of Deltaproteobacteria, Desulfovibrionales, Bacteroidales_ BS11_gut_group, Desulfovibrionaceae, Bacteroidales_S24-7_group, Acetobacteraceae, Ruminococcaceae_NK4A214_group, Asaia, [Ruminococcus] gauvreauii_group, Desulfovibrio, Kingella, Selenomonas, Lachnoclostridium in group P were significantly different (P < 0.05). In group P, the metabolite of 2-methylbenzoic acid and myo-inositol were significantly increased (P < 0.05). These results showed that compared with normally fed calves, the growth performance and blood indices of probiotic-fed calves were changed, but the differences were not significant. Probiotic-fed calves showed significant differences in rumen fluid and a small number of metabolites, which were mainly involved in the pathway of carbohydrate metabolism. It proves that the supplemental active probiotics had an effect on the rumen microflora.

A PICARD-TYPE THEOREM AND A UNIQUENESS THEOREM OF NON-ARCHIMEDEAN ANALYTIC CURVES IN PROJECTIVE SPACE

In this article, we prove a Picard-type Theorem and a uniqueness theorem for non-Archimedean analytic curves in the projective space Pn(F), where the characteristic of F is 0 or positive. In the main results of this article, we ignore the zeros with large multiplicities.

Effects of Dietary Energy Density in the Dry Period on the Production Performance and Metabolism of Dairy Cows

Thirty healthy Holstein dairy cows in the dry period were randomly divided into three groups and fed diets with different net energy for lactation (group A: 1.2 Mcal/kg DM, group B: 1.3 Mcal/kg DM, and group C: 1.4 Mcal/kg DM) for 8 weeks prepartum. Thereafter, dairy cows were fed a diet of the same formulation (1.66 Mcal/kg DM) for 12 weeks postpartum. The effects of different dietary energy densities in the dry period on postpartum performance and metabolic parameters of dairy cows were observed. Milk yield was reduced by 14.5% in the low-energy diet group;however, there were no differences in milk composition between the three groups. Postpartum plasma β-hydroxybutyrate, non-esterified fatty acid, growth hormone, and glucagon levels were significantly decreased whereas leptin and neuropeptide levels were elevated in the low-energy diet group. Moreover, body fat mobilization was attenuated, and the decline in postpartum body condition was reduced in the low-energy diet group, thus effectively reducing the postpartum negative energy balance.

Research Progress on Rapid Breeding Technology of Anoectochilus roxburghii Seedlings

As a traditional precious Chinese herbal medicine,Anoectochilus roxburghii has the cooling and detoxifying effects,and can nourish yin to reduce pathogenic fire,and has anti-inflammatory and analgesic effects. In this paper,we summarized the research progress in detail about the biological characteristics,resource distribution,composition,medicinal value and rapid seedling breeding technology concerning the rare Chinese herbal medicine A. roxburghii,in order to provide a reference for the in-depth study and rational development and utilization of A.roxburghii.

The Effects of Amino Acid Nutritional Deficiency on the Expression of Protein Metabolism-Related Genes in the Mammary Gland and Muscle Tissues of Lactating Mice

The mammary gland tissue exhibits a series of responses that are different from those of muscle and other peripheral tissues under amino acid deficiency. So, this present study was designed to investigate the effects of amino acid nutritional deficiency on the expression of protein metabolism-related genes in the mammary gland and muscle tissues of lactating mice. A total of 60 postpartum, lactating Kunming white mice were selected and randomly divided into 5 groups;each group contained 12 mice. Group A was the control group. The mice in group A were maintained on a normal diet after the initiation of lactation. Group B (starved) was given normal saline via intragastric administration. Group C (energy) was given glucose solution via intragastric administration. Groups D and E received a sodium caseinate solution via intragastric administration, which provided 0.5 g protein/d and 1.5 g protein/d, respectively. The results showed the following. 1) When the mice were exposed to nutritional stress caused by dietary amino acid deficiency, the β-casein mRNA expression level was increased in the mammary gland tissue. The increase in β-casein expression was the most significant in the energy-supplemented group, followed by the starved group (P P 14k and C2 (P P P < 0.05). 5) The phosphorylation level of p70S6K was elevated in the muscle tissues collected from the treatment groups. However, the magnitude of the increase was far smaller compared to that in the mammary gland tissues.

Preparation of a polyclonal antibody against immunogenic fragment of bovine intestinal peptide transporter I (<i>b</i>PepTI)

The goal of the current study is to prepare polyclonal antibody against bovine intestinal peptide transporter I (bPepTI) in order to develop assay for immunological assessment of protein levels. Antigenicity of the entire bPepTI was analyzed with DNAStar, and a fragment with high antigenicity (bPepTI ORF 1369 - 1695) was selected, cloned in pGEX-6p-1 vector, resulting in a recombinant plasmid GST-BP, which verified by double enzyme digestion and sequenced, the recombinant plasmid was introduced to BL21. Exogenous expression was induced by IPTG and validated by Western blot analysis. The recombinant protein was isolated, purified and used for production of antiserum in mice. The specificity of antiserum was evaluated with immunobloting and titer was estimated with ELISA. Results indicate that the antibody against bPepTI was produced. The optimal GST-BP antigen embedding concentration was 0.5 μg/ml. The optimal dilution was 1:400. An indirect ELISA assay indicates the effective dilution was 1:102400.

Effect of Substituting Alfalfa by Wheat Straw Powder on Rumen Digestion, Metabolism and Production Performance in Lactating Dairy Cows

China has abundant straw resources. However, the straw has high levels of crude fiber, low levels of crude protein and fat, poor palatability and low digestibility and a large volume. This study explored the feasibility of using wheat straw powder to replace some of alfalfa and the suitable replacement ratio for lactating dairy cows. In this trial, cows in the mid-lactation stage were fed with rations in which alfalfa hay was replaced isocalorically and isonitrogenously at 0%, 20%, 40% and 60% by wheat straw powder to explore the rumen metabolism and production performance of lactating dairy cows. Using a large randomized block design, 60 cows were selected and divided into 4 groups: the positive control group CG (0% replacement), and groups AL (20% replacement), AM (40% replacement), and AH (60% replacement). The pre-feeding period was 2 weeks and the trial period was 8 weeks. Milk yield, milk protein yield, milk protein percentage, lactose yield, lactose percentage, milk fat yield, and milk fat percentage were not affected by the diets, and the differences among the groups were not significant (P > 0.05). The results show that replacing 20% alfalfa with wheat straw powder is most beneficial to production. When only the feed costs were considered, without considering other costs (such as labor, machinery, etc.) in the economic benefit calculation process, and assume that other costs are the same among the groups, and the economic benefits obtained by the AL group were the largest. The experimental results provide a basis for the further development of straw feed.

Evaluation of Feeding Dairy Cow with Whole Wheat Hay and Alfalfa

The preliminary results of this laboratory (unpublished) indicate that the nutritional value of whole wheat hay (wheat hay, for short) is very high, and the milk stage is the best period of wheat hay harvest. In this study, we investigated the feeding effect and economic benefits using wheat hay instead of alfalfa diet for dairy cows under the condition of the same energy and crude protein levels. Three types of diets were used: alfalfa diet, wheat hay diet and alfalfa + wheat hay diet. The results showed that the dry matter digestibility of alfalfa diet and alfalfa + wheat hay diet did not differ significantly (P > 0.1), but was significantly higher than that of wheat hay diet (P < 0.05). The wheat hay diet could produce more propionic acid and ammonia nitrogen (P < 0.05) in the rumen, and reduce the ratio of acetic/propionic and nitrogen utilization. There was no significant difference in milk production among the three diets (P > 0.1). There was no significant difference in milk somatic cell count and body condition score among the three groups (P > 0.1). The wheat hay diet could significantly increase milk protein and lactose (P contents of interleukin-6 in cows fed alfalfa diet and alfalfa + wheat diet were significantly higher than that in cows fed wheat hay diet (P < 0.05). There was no significant difference in interleukinm-6 between in cows fed alfalfa diet and alfalfa + wheat diet (P > 0.05). The use of wheat hay to replace imported alfalfa in whole or in part could save feed costs. Full substitution of alfalfa with wheat hay could have a daily economic benefit of 13.74 yuan.

Choice for host-specific high-adhesive <i>Lactobacillus</i>strains

Adhesive ability was tested in seven Lactobacillus solated from the chicken digestive tract after cultivation with CaCo-2 cells (intestinal epithelial cells), MDCK (dog kidney) cells and CEF (chicken embryo fiber) cells. We noted the following important observations regarding the adhesive ability between different Lactobacillus strains and three cell types: the adhesive interaction between the SDnB7, SDnE1 and SDnA3 lactobacillus strains and CaCo-2cells was greater compared to controls, the adhesive effect between SDnB1 and CEF cells was also greater than controls and Lactobacillus showed only minimal adherence to MDCK cells. Incubation time also affected Lactobacillus adherence to CaCo-2cells: adhesive ability was optimal at 37°C when incubated for 2 days and this was confirmed by a local increase in the concentration of Lactobacillus around CaCo-2 cells when incubated for 24 h as opposed to 3 h. Adherence ability in lactobacillus was also tested at various concentrations (108, 107, 106, 105 and 104 ). The number of Lactobacillus that adhered around the cells was significantly increased in the treatment with 108 bacterial cells. Transmission electron microscopy revealed that the cellularity of the junction between CaCo-2cells and Lactobacillus was not compromised. Transmission electron microscopy also revealed that the thalli fabric structure remained intact.

The nature of adhesion factors which lie on the surfaces of <i>Lactobacillus</i>adhering to cells

Lactobacillus adheres to intestinal epithelial cells and yeast fungus cells with the aid of adhesion factors expressed on its cell surface. To identify adhesion factors nature on the surface of Lactobacillus, an adhesion experiment was carried out by pre-treating the Lactobacillus supernatant with different concentrations of bovine serum albumin, trypsin and 100°C for 10min. Additionally, intestinal epithelial cells were treated with sodium iodate, trypsin and sugar inhibition tests to characterize the receptors in Lactobacillus that interact with intestinal epithelial cells. It was demonstrated that Lactobacillus adhesion ability was decreased (P Lactobacillus cells was identified as a D-mannose glycoprotein. This observation was confirmed after treating intestinal epithelial cells with sodium iodate and trypsin, and sugar inhibition tests. Wild type Lactobacillus can agglutinate yeast fungus cells but after being exposured to mannose, agglutination to yeast fungus cells is lost or reduced. Results from this study we also got that inactivated and live bacteria that similarly adhere to intestinal epithelial cells.

A Study on the Mechanism Regulating Acetate to Propionate Ratio in Rumen Fermentation by Dietary Carbohydrate Type

The research direction of our team is nutrition and physiology of ruminants, including dietary nutrition metabolism and rumen microorganisms. Previous research has shown that ruminal acetate-to-propionate ratio is related to diet utilization efficiency. At present, it is believed that the main factors affecting the ruminal acetate-to-propionate ratio are the degradation rate of the diet and the rumen microbial structure, but the main mechanism is unclear. This study found that the effect of ruminal acetate-to-propionate ratio was not affected by the concentration of the fermentation substrate, but was affected by the structure of the rumen microbiota. We believe that changes in the rumen microflora structure are the main mechanism for regulating the ruminal acetate-to-propionate ratio. This will help people to further understand the rumen physiology, thereby gradually improving feed conversion efficiency and reducing production costs. Abstract: In order to explore the mechanism by which diet regulates the acetate-to-propionate molar ratio (A: P ratio), we compared the effect on rumen fermentation parameters and the microbiome by altering the ratio of dietary concentrates to roughage ratio and calcium pyruvate infusion. The test animals were Laoshan dairy goats, and were fed continuously through an automatic feeder. The test groups were fed a base diet of low concentrates, and intraruminally infused with calcium pyruvate at two concentrations. The infusion concentrations were derived from the difference in the rate of carbohydrate degradation of the high and low concentrate diets, and they were artificially set such that the high concentration infusion group was infused with twice the concentration as the low concentration infusion group. The control groups were fed high concentrate (6:4) and low concentrate (3:7) diets, respectively. The following results were obtained by measuring rumen fermentation parameters and microbial composition: the rumen A: P ratio was significantly lower in the high-concentrate diet group than in the low concentrate diet group (P < 0.05). Infusion of low concentration calcium pyruvate had no significant effect on rumen A: P ratio (P > 0.05), while infusion of high concentration calcium pyruvate significantly increased the rumen A: P ratio (P < 0.05). Relative to goats fed the low concentrate diet, those fed the high concentrate diet had a greater abundance of microbes related to propionate production and a reduced abundance of microbes related to fiber degradation. Infusion of pyruvate had no significant effect on rumen microbial structure. The above results indicate that increasing the concentration of the fermentation substrate without affecting the composition of the microflora does not reduce the A: P ratio. Microbiological results showed that the A: P ratio was more closely related to the rumen microflora structure. Therefore, it is believed that rumen microflora structure is the main mechanism regulating A: P ratio in rumen fermentation.

Effect of High Concentrate Corn Stalk Particle Size on Physical State and Production Performance of Lactating Dairy Cows

In order to realize the application of corn stalk in cow feed, we designed experiments to explore the effect of a certain proportion of corn stalk on the performance of lactating dairy cows. 9 multiparous mid-lactating cows were allocated at random to three groups, each containing 3 intact cows. The trial consisted of three periods and three dietary treatments with a 3 × 3 Latin square design. The diets were normal concentrats plus dried corn stalk chopped to 5 - 8 cm long (N), high concentrates plus dried corn stalks chopped to a length of approximately 5 - 8 cm by a mower (H) while the milled corn stalks were passed through a pulviser with a 2 cm pore size (MH). Each cow was measured for dry matter intake (DMI), ruminal pH, rumen fermentation, selective feeding behavior and production performance. The results showed that MH led to a significantly higher intake of DM, neutral detergent fiber (NDF), forage NDF (FNDF), acid detergent fiber (ADF), crude protein (CP) and organic matter (OM) than N and H (P < 0.05). Cows fed H and MH showed similar selective feeding behavior, while those fed H showed various selectivity for the dietary component. MH resulted in a significantly higher milk production (P < 0.05), and tended to have a higher milk fat production than N (P = 0.055). There were no significant differences in the milk components (P = 0.424) and lactose (P = 0.113) between cows fed N and MH. The high-concentrates plus milled corn stalk diet can increase the milk yield under the premise of normal rumen pH in dairy cows, thereby generating higher economic benefits. And milled corn stalk can effectively inhibit the cow’s selective eating of low-quality roughage.

Effects of Supplementation with <i>Saccharomyces cerevisiae</i>and Its Fermentation Products on Production Performance and Its Mechanism in Perinatal Dairy Cows

The aim of this study was to investigate the effects of Saccharomyces cerevisiae and its fermentation products on performance, blood hormone levels and rumen floral composition in peripartum dairy cows. Sixty perinatal cows were selected and allocated to two groups according to parity and expected date of delivery. Each group was supplemented with Saccharomyces cerevisiae and its fermentation product 0 or 100 g. The results showed that Saccharomyces cerevisiae and its fermentation products could significantly increase the feed intake of peripartum dairy cows (P < 0.01), increase the lactose content after 21 days postpartum (P < 0.01), and tend to increase milk production (P = 0.052). There was no significant effect on other milk components, the apparent digestibility of nutrients. There was a tendency to increase milk production and reduce the number of somatic cells in milk;increase blood levels of glucagon (P < 0.01) and β-hydroxybutyrate (P = 0.01), reducing the insulin content (P = 0.02). Saccharomyces cerevisiae reduced the abundance of rumen microbes in peripartum dairy cows but had no effect on rumen microbial diversity. Compared with the control group, the supplemented group showed reductions in the abundance of genera Bacillus (P = 0.03), Butyrivibrio (P = 0.01), Denitrobacterium (P = 0.01), and Mogibacterium (P < 0.01), Porphyromonas (P = 0.05), Saccharofermentans (P < 0.01), Sphaerochaeta (P = 0.02), Streptococcus (P = 0.04) and other genera. There were significant increase in the content of Acidaminococcus (P = 0.03), Allisonella (P < 0.01), Bulleidia (P < 0.01), Corynebacterium (P = 0.01), Dialister (P < 0.01), Faecalibacterium (P = 0.02), Faekalitalea (P = 0.03), Fibrobacter (P = 0.04), Flavobacterium (P = 0.03), Kandleria (P < 0.01), Paraprevotella (P < 0.01), Pyramidobacter (P = 0.05), Roseburia (P < 0.01), Succinivibrio (P < 0.01) and other genera. The main metabolic pathways such as tryptophan metabolism and steroid hormone biosynthesis in perinatal dairy cows were determined for Saccharomyces cerevisiae and its fermentation products.