Distinctive roles of unsaturated and saturated fatty acids in hyperlipidemic pancreatitis

AIM: To investigate how the saturated and unsaturated fatty acid composition influences the susceptibility of developing acute pancreatitis. METHODS: Primary pancreatic acinar cells were treated with low and high concentrations of different saturated and unsaturated fatty acids, and changes in the cytosolic Ca2+ signal and the expression of protein kinase C(PKC) were measured after treatment. RESULTS: Unsaturated fatty acids at high concentrations, including oleic acid, linoleic acid, palmitoleic acid, docosahexaenoic acid, and arachidonic acid, induced a persistent rise in cytosolic Ca2+ concentrations in acinar cells. Unsaturated fatty acids at low concentrations and saturated fatty acids, including palmitic acid, stearic acid, and triglycerides, at low and high concentrations were unable to induce a rise in Ca2+ concentrations in acinar cells. Unsaturated fatty acids at high concentrations but not saturated fatty acids induced intra-acinar cell trypsin activation and cell damage and increased PKC expression.CONCLUSION: At sufficiently high concentrations, unsaturated fatty acids were able to induce acinar cells injury and promote the development of pancreatitis. Unsaturated fatty acids may play a distinctive role in the pathogenesis of pancreatitis through the activation of PKC family members.

Biosynthesis of Unsaturated Fatty Acids via Mortierella Isabellina Cultivated in a Medium Containing Butanol

Mortierella isabellina was found to accumulate large amounts of unsaturated fatty acids when it was grown in a medium containing butanol(5 g/L) and yeast extract(10 g/L) and cultivated at 25 ℃ for 5 d during which additional feeding butanol of 2 g/L was fed after being cultivated for 48 h . The resultant mycelial lipids accounted for 40 1% of the dry mycelia, while about 34% of butanol in the medium was converted. The mycelial lipids contained four kinds of unsaturated fatty acids, i.e ., palmitoleic(4 9%), oleic(54 1%), linoleic(10 4%) and linolenic(5 4%) acids. Those accounted for 74 8% of the total fatty acids. The effects of the culture conditions, such as cultivation temperature, initial pH of the medium and additional feeding butanol in the course of cultivation, on the production of mycelial lipids by M. isabellina were studied.

Effects of unsaturated fatty acids on calcium-activated potassium current in gastric myocytes of guinea pigs

AIM: To investigate the effects of exogenous unsaturated fatty acids on calcium-activated potassium current [Ik(Ca)]in gastric antral circular myocytes of guinea pigs.METHODS: Gastric myocytes were isolated by collagenase from the antral circular layer of guinea pig stomach. The whole-cell patch clamp technique was used to record Ik(Ca)in the isolated single smooth muscle cells with or without different concentrations of arachidonic acid (AA), linoleic acid (LA), and oleic acid (OA).RESULTS: AA at concentrations of 2,5 and 10 μmol/L markedly increased IK(ca)in a dose-dependent manner. LA at concentrations of 5, 10 and 20 μmol/L also enhanced IK(Ca)in a dose-dependent manner. The increasing potency of AA, LA, and oleic acid (OA) on Ik(Ca) at the same concentration(10 μmol/L) was in the order of AA＞LA＞OA. AA (10 μmol/L)-induced increase of Ik(Ca) was not blocked by H-7 (10 μmol/L), an inhibitor of protein kinase C (PKC), or indomethacin (10 μmol/L),an inhibitor of the cyclooxygenase pathway, and 17-octadecynoic acid (10 μmol/L), an inhibitor of the cytochrome P450 pathway, but weakened by nordihydroguaiaretic acid(10 μmol/L), an inhibitor of the lipoxygenase pathway.CONCLUSION: Unsaturated fatty acids markedly increase Ik(Ca), and the enhancing potencies are related to the number of double bonds in the fatty acid chain. The lipoxygenase pathway of unsaturated fatty acid metabolism is involved in the unsaturated fatty acid-induced increase of IK(Ca) in gastric antral circular myocytes of guinea pigs.

The effects of the unsaturated degree of long-chain fatty acids on the rumen microbial protein content and the activities of transaminases and dehydrogenase in vitro

This study investigated the effects of the degree of unsaturation（unsaturity） of long-chain fatty acids on microbial protein content and the activities of transaminases and dehydrogenase in vitro using goat rumen fluid as the cultural medium.Six types of fatty acids,stearic acid（C18：0,group A,control group）,oleic acid（C18：1,n-9,group B）,linoleic acid（C18：2,n-6,group C）,α-linolenic acid（C18：3,n-3,group D）,arachidonic acid（C20：4,n-6,group E）,and eicosapentaenoic acid（C20：5,n-3,group F）,were tested,and the inclusion ratio of each fatty acid was 3%（w/w） in total of culture substrate.Samples were taken at 0,3,6,9,12,18 and 24 h,respectively,during culture for analyses.Compared with stearic acid,linoleic acid,a-linolenic acid,and arachidonic acid increased the bacterial protein content,while oleic acid and eicosapentaenoic acid had no significant effects;the protozoal protein content was reduced for all the unsaturated fatty acids,and the magnitude of the reduction appeared to be associated with the degree of unsaturity of fatty acids.The total microbial protein content was dominantly accounted by the protozoal protein content（about 4-9 folds of the bacterial protein）,and only increased by linoleic acid,but reduced by oleic acid,arachidonic acid and eicosapentaenoic acid.There were no significant effects in the activities of both glutamic oxaloacetic transaminase（GOT） and glutamic-pyruvic transaminase（GPT） for all the other fatty acids,except for arachidonic acid which enhanced GOT activity and oleic acid which enhanced GPT activity.The total dehydrogenase activity was positively correlated with the degree of unsaturation of fatty acids.In conclusion,the inclusion of 3%of long-chain unsaturated fatty acids increased bacterial protein content,whereas reduced protozoal protein content and enhanced dehydrogenase activity.The fatty acids with more than three double bonds had detrimental effects on the microbial protein content.This work demonstrates for the first time the effect rule of the unsaturation degree of long-chain fatty acids on the rumen microbial protein in vitro.

Expression and clinical significance of short-chain fatty acids in patients with intrahepatic cholestasis of pregnancy

BACKGROUND Intrahepatic cholestasis of pregnancy(ICP)is a pregnancy-specific liver condition that typically arises in the middle and late stages of pregnancy.Short-chain fatty acids(SCFAs),prominent metabolites of the gut microbiota,have significant connections with various pregnancy complications,and some SCFAs hold potential for treating such complications.However,the metabolic profile of SCFAs in patients with ICP remains unclear.AIM To investigate the metabolic profiles and differences in SCFAs present in the maternal and cord blood of patients with ICP and determine the clinical significance of these findings.METHODS Maternal serum and cord blood samples were collected from both patients with ICP(ICP group)and normal pregnant women(NP group).Targeted metabolomics was used to assess the SCFA levels in these samples.RESULTS Significant differences in maternal SCFAs were observed between the ICP and NP groups.Most SCFAs exhibited a consistent declining trend in cord blood samples from the ICP group,mirroring the pattern seen in maternal serum.Correlation analysis revealed a positive correlation between maternal serum SCFAs and cord blood SCFAs[r(Pearson)=0.88,P=7.93e-95].In both maternal serum and cord blood,acetic and caproic acids were identified as key metabolites contributing to the differences in SCFAs between the two groups(variable importance for the projection>1).Receiver operating characteristic analysis demonstrated that multiple SCFAs in maternal blood have excellent diagnostic capabilities for ICP,with caproic acid exhibiting the highest diagnostic efficacy(area under the curve=0.97).CONCLUSION Compared with the NP group,significant alterations were observed in the SCFAs of maternal serum and cord blood in the ICP group,although they displayed distinct patterns of change.Furthermore,the SCFA levels in maternal serum and cord blood were significantly positively correlated.Notably,certain maternal serum SCFAs,specifically caproic and acetic acids,demonstrated excellent diagnostic efficiency for ICP.

Novel Lipase from Golden Pompano(Trachinotus ovatus)Viscera:Purification,Characterization,and Application in the Concentrating of n-3 Polyunsaturated Fatty Acids

Lipases have been widely applied in a variety of industrial fields,such as food,pharmaceuticals,biofuels,and biotechnology.Recent years have witnessed a great interest in modifying lipids for the production of triacylglycerols enriched with n-3 polyunsaturated fatty acids(PUFAs).Here,a novel salt-tolerant,organic solvent-stable,and bile salt-activated lipase was purified from golden pompano(Trachinotus ovatus)viscera,which was named as golden pompano lipase(GPL).GPL had a specific activity of 57.2U mg^(-1)with an estimated molecular weight of 14 k Da,exhibited optimal activity at 40℃a nd pH 8.0,and showed K_(m)and V_(max)of 40.16μmol L^(-1)and 769.23μmol L^(-1)min^(-1),respectively.GPL activity was enhanced by Mn^(2+)and sodium deoxycholate.It was active in organic solvents,including methanol,ethanol,chloroform,and hexane.GPL also showed a good salinity tolerance of up to 1 mol L^(-1).n-3PUFA enrichment in the glyceride fraction of golden pompano oil was performed by GPL-catalyzed hydrolysis and yielded a total PUFA concentration of 56.99%.EPA,DHA,and DPA were enriched by 10.4-,3.2-,and 1.8-fold of their initial levels,respectively.This study recognized the industrial applicability of GPL to prepare enriched C_(20-22)n-3 PUFA.

The LXRB-SREBP1 network regulates lipogenic homeostasis by controlling the synthesis of polyunsaturated fatty acids in goat mammary epithelial cells

Background:In rodents,research has revealed a role of liver X receptors(LXR) in controlling lipid homeostasis and regulating the synthesis of polyunsaturated fatty acids(PUFA).Recent data suggest that LXRB is the predominant LXR subtype in ruminant mammary cells,but its role in lipid metabolism is unknown.It was hypothesized that LXRB plays a role in lipid homeostasis via altering the synthesis of PUFA in the ruminant mammary gland.We used overexpression and knockdown of LXRB in goat primary mammary epithelial cells(GMEC) to evaluate abundance of lipogenic enzymes,fatty acid profiles,content of lipid stores and activity of the stearoyl-Co A desaturase(SCD1) promoter.Results:Overexpression of LXRB markedly upregulated the protein abundance of LXRB while incubation with si RNA targeting LXRB markedly decreased abundance of LXRB protein.Overexpression of LXRB plus T0901317(T09,a ligand for LXR) dramatically upregulated SCD1 and elongation of very long chain fatty acid-like fatty acid elongases 5–7(ELOVL 5–7),which are related to PUFA synthesis.Compared with the control,cells overexpressing LXRB and stimulated with T09 had greater concentrations of C16:0,16:1,18:1n7,18:1n9 and C18:2 as well as desaturation and elongation indices of C16:0.Furthermore,LXRB-overexpressing cells incubated with T09 had greater levels of triacylglycerol and cholesterol.Knockdown of LXRB in cells incubated with T09 led to downregulation of genes encoding elongases and desaturases.Knockdown of LXRB attenuated the increase in triacylglycerol and cholesterol that was induced by T09.In cells treated with dimethylsulfoxide,knockdown of LXRB increased the concentration of C16:0 at the expense of C18:0,while a significant decrease in C18:2 was observed in cells incubated with both si LXRB and T09.The abundance of sterol regulatory element binding transcription factor 1 precursor(p SREBP1) and its mature fragment(n SREBP1) was upregulated by T09,but not LXRB overexpression.In the cells cultured with T09,knockdown of LXRB downregulated the abundance for p SREBP1 and n SREBP1.Luciferase reporter assays revealed that the activities of wild type SCD1 promoter or fragment with SREBP1 response element(SRE) mutation were decreased markedly when LXRB was knocked down.Activity of the SCD1 promoter that was induced by T09 was blocked when the SRE mutation was introduced.Conclusion:The current study provides evidence of a physiological link between the LXRB and SREBP1 in the ruminant mammary cell.An important role was revealed for the LXRB-SREBP1 network in the synthesis of PUFA via the regulation of genes encoding elongases and desaturases.Thus,targeting this network might elicit broad effects on lipid homeostasis in ruminant mammary gland.

Milk fat globule membrane supplementation protects againstβ-lactoglobul-ininduced food allergy in mice via upregulation of regulatory T cells and enhancement of intestinal barrier in a microbiota-derived short-chain fatty acids manner

Milk fat globule membrane(MFGM),which contains abundant glycoproteins and phospholipids,exerts beneficial effects on intestinal health and immunomodulation.The aim of this study was to evaluate the protective effects and possible underlying mechanisms of MFGM on cow’s milk allergy(CMA)in aβ-lactoglobulin(BLG)-induced allergic mice model.MFGM was supplemented to allergic mice induced by BLG at a dose of 400 mg/kg body weight.Results demonstrated that MFGM alleviated food allergy symptoms,decreased serum levels of lipopolysaccharide,pro-inflammatory cytokines,immunoglobulin(Ig)E,Ig G1,and Th2 cytokines including interleukin(IL)-4,while increased serum levels of Th1 cytokines including interferon-γand regulatory T cells(Tregs)cytokines including IL-10 and transforming growth factor-β.MFGM modulated gut microbiota and enhanced intestinal barrier of BLG-allergic mice,as evidenced by decreased relative abundance of Desulfobacterota,Rikenellaceae,Lachnospiraceae,and Desulfovibrionaceae,while increased relative abundance of Bacteroidetes,Lactobacillaceae and Muribaculaceae,and enhanced expressions of tight junction proteins including Occludin,Claudin-1 and zonula occludens-1.Furthermore,MFGM increased fecal short-chain fatty acids(SCFAs)levels,which elevated G protein-coupled receptor(GPR)43 and GPR109A expressions.The increased expressions of GPR43 and GPR109A induced CD103+dendritic cells accumulation and promoted Tregs differentiation in mesenteric lymph node to a certain extent.In summary,MFGM alleviated CMA in a BLG-induced allergic mice model through enhancing intestinal barrier and promoting Tregs differentiation,which may be correlated with SCFAs-mediated activation of GPRs.These findings suggest that MFGM may be useful as a promising functional ingredient against CMA.

Serum bile acid and unsaturated fatty acid profiles of non-alcoholic fatty liver disease in type 2 diabetic patients

BACKGROUND The understanding of bile acid(BA)and unsaturated fatty acid(UFA)profiles,as well as their dysregulation,remains elusive in individuals with type 2 diabetes mellitus(T2DM)coexisting with non-alcoholic fatty liver disease(NAFLD).Investigating these metabolites could offer valuable insights into the pathophy-siology of NAFLD in T2DM.AIM To identify potential metabolite biomarkers capable of distinguishing between NAFLD and T2DM.METHODS A training model was developed involving 399 participants,comprising 113 healthy controls(HCs),134 individuals with T2DM without NAFLD,and 152 individuals with T2DM and NAFLD.External validation encompassed 172 participants.NAFLD patients were divided based on liver fibrosis scores.The analytical approach employed univariate testing,orthogonal partial least squares-discriminant analysis,logistic regression,receiver operating characteristic curve analysis,and decision curve analysis to pinpoint and assess the diagnostic value of serum biomarkers.RESULTS Compared to HCs,both T2DM and NAFLD groups exhibited diminished levels of specific BAs.In UFAs,particular acids exhibited a positive correlation with NAFLD risk in T2DM,while theω-6:ω-3 UFA ratio demonstrated a negative correlation.Levels ofα-linolenic acid andγ-linolenic acid were linked to significant liver fibrosis in NAFLD.The validation cohort substantiated the predictive efficacy of these biomarkers for assessing NAFLD risk in T2DM patients.CONCLUSION This study underscores the connection between altered BA and UFA profiles and the presence of NAFLD in individuals with T2DM,proposing their potential as biomarkers in the pathogenesis of NAFLD.

Effects of forsythin extract in Forsythia leaves on intestinal microbiota and short-chain fatty acids in rats fed a high-fat diet

Forsythia suspensa,belonging to the deciduous shrubs of the Luteaceae family,a traditional Chinese medicine,has effects of alleviating swelling,clearing heat,detoxification and promoting blood circulation.The leaves of F.suspensa contain multiple chemical components and have a long history of use in folk medicines and health foods.The purpose of this study was to explore the effects of forsythin extract from F.suspensa leaves on intestinal microbiota and short-chain fatty acid(SCFA)content in rats with obesity induced by a high-fat diet.Forsythin extract in F.suspensa leaves increased the abundance of the intestinal microbiota,ameliorated intestinal microbiota disorders and inhibited the increase in total SCFA content in the intestinal tract in rats with obesity induced by a high-fat diet.These results suggested that forsythin extract in F.suspensa leaves may slow the development of obesity induced by a high-fat diet;thus,its active components and efficacy are worthy of further study.

Hatching egg polyunsaturated fatty acids and the broiler chick

Transgenerational effects of certain nutrients such as essential fatty acids are gaining increased attention in the field of human medicine and animal sciences as a new tool to improve health and animal performance during perinatal life.Omega-3(n-3)and omega-6(n-6)fatty acids are denoted by the position of the first double bond from methyl end of the hydrocarbon chain.Alpha-linolenic acid(18:3 n-3)and linoleic acid(18:2 n-6)are essential n-3 and n-6 fatty acids and cannot be synthesized by the vertebrates including chickens.Alpha-linolenic acid and linoleic acid are the parent fatty acids of long chain(>20–22C)n-3 and n-6 polyunsaturated fatty acids(PUFA)such as eicosapentaenoic acid(20:5 n-3,EPA),docosapentaenoic acid(22:5 n-3/or 22:5 n-6,DPA),docosahexaenoic acid(22:6 n-3,DHA)and arachidonic acid(20:4 n-6).As components of cell membrane phospholipids,PUFA serves as precursors of eicosa-noids,act as ligands for membrane receptors and transcription factors that regulate gene expression and are pivotal for normal chick growth and development.Considering the role of egg lipids as the sole source of essential fatty acids to the hatchling,dietary deficiencies or inadequate in ovo supply may have repercussions in tissue PUFA incorpora-tion,lipid metabolism,chick growth and development during pre and early post-hatch period.This review focus on studies showing how maternal dietary n-3 or n-6 fatty acids can lead to remodeling of long chain n-3 and n-6 PUFA in the hatching egg and progeny chick tissue phospholipid molecular species and its impact on chick growth and PUFA metabolism during early life.

Comparison of the effects of 3 kinds of oils rich in omega-3 polyunsaturated fatty acids on glycolipid metabolism and lipoprotein subfractions

Dietary omega-3 polyunsaturated fatty acids(ω-3 PUFAs)can be classifi ed into animal-and plant-derivedω-3 PUFAs.Patients with type 2 diabetes(T2DM)are frequently accompanied by dyslipidemia,which is closely related to the high-density lipoprotein(HDL-C)subfractions change.This study aimed to determine the effects of different sourcesω-3 PUFAs on glucolipid metabolism and lipoprotein subfractions in T2DM with dyslipidemia.Ninety T2DM patients with dyslipidemia were randomly assigned to take 3 g/day fi sh oil(FO,containing eicosapentaenoic acid(EPA)and docosahexaenoic acid(DHA)),3 g/day perilla oil(PO,containingα-linolenic acid(ALA)),or 3 g/day blend oil(BO,containing EPA,DHA and ALA)for 3 months.90 patients completed the intervention.There was a significant reduction of glycated hemoglobin(HbA1c)in all the groups.The triglycerides(TG)in the FO group were signifi cantly different with a group×time interaction(P=0.043),which was higher compared with the other two groups.The serum small HDL-C subfractions in the PO group was higher and the serum large HDL-C subfractions in the PO group was lower than those in the BO and FO groups.Plant-derivedω-3 PUFAs are more effective at controlling blood glucose than animal-derivedω-3 PUFAs.However,animal-derivedω-3 PUFAs have a signifi cant lowering effect on TG compared with plant-derivedω-3 PUFAs.Particularly,large HDL-C subfractions after animal-derivedω-3 PUFAs intake were higher than plant-derivedω-3 PUFAs intake;while small HDL-C subfractions were lower.Both the animal-and plant-derivedω-3 PUFAs have practical value in improving glucose and lipids metabolism in T2DM patients with dyslipidemia.

The role of gut microbiota and its metabolites short-chain fatty acids in food allergy

Emerging evidence indicated that the increase in food allergy(FA)over the past few decades was associated with the abnormal compositional and metabolic changes of gut microbiota.Gut microbiota played a vital role in maintaining the homeostasis of the immune system and the dysbiosis of gut microbiota promoted the occurrence of FA.Recent research suggested that short-chain fatty acids(SCFAs),the main metabolites derived from gut microbiota,contributed to FA protection.Herein,we provided a comprehensive review on the relationship between gut microbiota and FA.The multifaceted mechanisms underlymg beneficial effects of gut microbiota composition/metabolites on the regulation of diverse cellular pathways in intestinal epithelial cells,dendritic cells,innate lymphoid cells,T cells,B cells and mast cells in the immune system were discussed systematically.These findings emphasized the positive function of gut microbiota in FA and provided novel ideas for the treatment or prevention of FA in the future.

Unlocking a novel determinant of athletic performance:The role of the gut microbiota,short-chain fatty acids,and“biotics”in exercise

The gut microbiota refers to the collection of trillions of intestinal microorganisms that modulate central aspects of health and disease through influential effects on host physiology.Recently,a connection has been made between the gut microbiota and exercise.Initial investigations demonstrated the beneficial effects of exercise on the gut microbiota,with cross-sectional studies revealing positive correlations between exerciseassociated states,and healthy gut microbiota and exercise interventions showed post-intervention increases in the abundance of beneficial bacterial taxa.More recent investigations have focused on exploring the reverse relationship:the influence of the gut microbiota on exercise performance.Murine investigations have revealed that certain bacterial taxa may enhance endurance exercise performance by augmenting various aspects of lactate metabolism.Further,short-chain fatty acids—which modulate metabolism at various organ sites,including within skeletal muscle—have been shown to enhance endurance exercise capacity in mice.This review highlights what is currently known about the connection between the gut microbiota and exercise,with a particular focus on the ergogenic potential of the gut microbiota and how it may be leveraged to enhance endurance exercise performance.

Supplementing the early diet of broilers with soy protein concentrate can improve intestinal development and enhance short-chain fatty acid-producing microbes and short-chain fatty acids,especially butyric acid

Background:Research on nutrition in early-life commonly focuses on the maturation of the intestine because the intestinal system is crucial for ensuring continued growth.To explore the importance of early nutrition regulation in animals,soy protein concentrate(SPC)was added to the early diet of broilers to investigate its effects on amino acid digestibility,intestinal development,especially intestinal microorganisms,and broiler metabolites.A total of 192 oneday-old Arbor Acres(AA)male broilers were randomly assigned to two experimental treatments with 8 replicates of 12 birds.The control group was fed a basal diet(control),and the treatment group was fed a basal diet supplemented with 12%SPC(SPC12)during the first 10 d(starter phase).From d 11 to 21(grower phase)and d 22 to 42(finisher phase),a basal diet was fed to both treatment groups.Results:SPC reduced the pH value and acid-binding capacity of the starter diet(P<0.05,d 10);SPC in the early diet enhanced the gizzard weight(P<0.05,d 10 and d 42)and the ileum weight(P<0.05,d 10)and decreased the weight and length of the jejunum(P<0.05,d 10)and the relative length of the duodenum and jejunum(P<0.05,d 10).At the same time,SPC enhanced villus height(P<0.05,d 10)and muscle thickness in the jejunum and ileum(P<0.05,d 10)and increased the number of goblet cells in the duodenum(P<0.05,d 10).Meanwhile,SPC increased the Chao1 index and the ACE index(P<0.05,d 10)and altered the composition of caecal microflora at d 10.SPC also increased the relative abundance of Alistipes,Anaerotruncus,Erysipelatoclostridium,Intestinimonas and Flavonifractor bacteria(P<0.05,d 10).At the same time,the concentrations of caecal butyric acid and total short-chain fatty acids(SCFAs)were also increased in the SPC12 group(P<0.05,d 10).Conclusions:In summary,the results showed that supplementing the starter diet of broilers with SPC has a significant effect on the early development of the intestine and the microflora.

Cinnamic acid regulates the intestinal microbiome and short-chain fatty acids to treat slow transit constipation

BACKGROUND Slow transit constipation(STC)is a disorder with delayed colonic transit.Cinnamic acid(CA)is an organic acid in natural plants,such as Radix Scrophulariae(Xuan Shen),with low toxicity and biological activities to modulate the intestinal microbiome.AIM To explore the potential effects of CA on the intestinal microbiome and the primary endogenous metabolites-short-chain fatty acids(SCFAs)and evaluate the therapeutic effects of CA in STC.METHODS Loperamide was applied to induce STC in mice.The treatment effects of CA on STC mice were assessed from the 24 h defecations,fecal moisture and intestinal transit rate.The enteric neurotransmitters:5-hydroxytryptamine(5-HT)and vasoactive intestinal peptide(VIP)were determined by the enzyme-linked immunosorbent assay.Hematoxylin-eosin and Alcian blue and Periodic acid Schiff staining were used to evaluate intestinal mucosa's histopathological performance and secretory function.16S rDNA was employed to analyze the composition and abundance of the intestinal microbiome.The SCFAs in stool samples were quantitatively detected by gas chromatography-mass spectrometry.RESULTS CA ameliorated the symptoms of STC and treated STC effectively.CA ameliorated the infiltration of neutrophils and lymphocytes,increased the number of goblet cells and acidic mucus secretion of the mucosa.In addition,CA significantly increased the concentration of 5-HT and reduced VIP.CA significantly improved the diversity and abundance of the beneficial microbiome.Furthermore,the production of SCFAs[including acetic acid(AA),butyric acid(BA),propionic acid(PA)and valeric acid(VA)]was significantly promoted by CA.The changed abundance of Firmicutes,Akkermansia,Lachnoclostridium,Monoglobus,UCG.005,Paenalcaligenes,Psychrobacter and Acinetobacter were involved in the production of AA,BA,PA and VA.CONCLUSION CA could treat STC effectively by ameliorating the composition and abundance of the intestinal microbiome to regulate the production of SCFAs.

Susceptibility of dairy cows to subacute ruminal acidosis is reflected in both prepartum and postpartum bacteria as well as odd-and branched-chain fatty acids in feces

Background:The transition period is a challenging period for high-producing dairy cattle.Cows in early lactation are considered as a group at risk of subacute ruminal acidosis(SARA).Variability in SARA susceptibility in early lactation is hypothesized to be reflected in fecal characteristics such as fecal pH,dry matter content,volatile and odd-and branched-chain fatty acids(VFA and OBCFA,respectively),as well as fecal microbiota.This was investigated with 38 periparturient dairy cows,which were classified into four groups differing in median and mean time of reticular pH below 6 as well as area under the curve of pH below 6.Furthermore,we investigated whether fecal differences were already obvious during a period prior to the SARA risk(prepartum).Results:Variation in reticular pH during a 3-week postpartum period was not associated with differences in fecal pH and VFA concentration.In the postpartum period,the copy number of fecal bacteria and methanogens of unsusceptible(UN)cows was higher than moderately susceptible(MS)or susceptible(SU)cows,while the genera Ruminococcus and Prevotellacea_UCG-001 were proportionally less abundant in UN compared with SU cows.Nevertheless,only a minor reduction was observed in iso-BCFA proportions in fecal fatty acids of SU cows,particularly iso-C15:0and iso-C16:0,compared with UN cows.Consistent with the bacterial changes postpartum,the lower abundance of Ruminococcus was already observed in the prepartum fecal bacterial communities of UN cows,whereas Lachnospiraceae_UCG-001 was increased.Nevertheless,no differences were observed in the prepartum fecal VFA or OBCFA profiles among the groups.Prepartum fecal bacterial communities of cows were clustered into two distinct clusters with 70%of the SU cows belonging to cluster 1,in which they represented 60%of the animals.Conclusions:Inter-animal variation in postpartum SARA susceptibility was reflected in post-and prepartum fecal bacterial communities.Differences in prepartum fecal bacterial communities could alert for susceptibility to develop SARA postpartum.Our results generated knowledge on the association between fecal bacteria and SARA development which could be further explored in a prevention strategy.

Effects of dietary ratio of n-6 to n-3 polyunsaturated fatty acids on immunoglobulins, cytokines, fatty acid composition, and performance of lactating sows and suckling piglets

This experiment was conducted to investigate the effects of dietary ratios of n-6：n-3 polyunsaturated fatty acids （PUFA） on the performance of lactating sows and their piglets. Thirty pregnant Landrace sows were assigned to one of three treatments from d 108 of gestation until weaning （26-29 d） and were fed diets containing different ratios of n-6：n-3 PUFA including 3：1,9：1 and 13：1. The effects on sow and litter production traits were examined together with an assessment of sow body condition. No differences were detected among the treatments for the daily feed intake of sows or changes in sow weight and back-fat levels during lactation （P 〉 0.05）. Litter size at d 14 and d 21 were tended to increase in 3：1 treatment compared with 9：1 and 13：1 treatments （P 〈 0.10）. Litter weight gain （1.77 kg/d） from d 0 to d 14 was tended to increase in 9：1 groups compared with the other two treatments （P 〈 0.10）. A significant difference was observed for the content of a -linolenic acid, total n-3 PUFA, and the ratio of n-6：n-3 PUFA in the colostrum, milk, and piglets plasma （P 〈 0.01）. The effects of different ratios of n-6：n-3 PUFA in sow diets on colostrum, milk and piglet plasma immunoglobulin concentrations are studied. No difference was observed among treatments in the concentrations of IgM, and IgA in colostrum （P 〉 0.05）. A great significant difference for IgG concentration was observed among 3 group in colostrum. A great significant difference for IgA, and IgM （P〈 0.01） concentrations in piglet plasma at d14 and a significant difference for IgG（P 〈 0.05） was observed at d14. Furthermore, at d 21 of lactation, piglet plasma IgG and IgA concentration were greater in 3：1 compared with 13：1 group （P 〈 0.01）. In summary, the current study demonstrated that altering the ratio of n-6：n-3 PUFA in lactating sow diet had an effect on the immune component including immunoglobulin and cytokines, and it tended to increase the litter average daily gain and improve the immune status of piglets when dietary ratio of n-6：n-3 PUFA was 9：1.

Effects of the Ratio of n-6∶n-3 Polyunsaturated Fatty Acids in the Maternal Diet on Immunoglobulins,Fatty Acid Composition,and Performance of Lactating Sows and Suckling Piglets under Conditions of Low Maternal Energy Intake

This experiment was conducted to investigate the effects of different ratios of n-6 ∶ n-3 polyunsaturated fatty acids （PUFA） in sow diets on the performance of lactating sows and their piglets at low digestible energy intakes. Twenty-one pregnant Landrace sows were assigned to one of three diets from day 108 of gestation until weaning （26 to 29 d） ,containing n-6∶n-3 PUFA ratios of 3 ∶1,8 ∶1 and 11 ∶1. The effects on sow and litter production traits and on sow body condition were examined. There were no differences among treatments in daily feed intakes or in changes in sow weight and back-fat levels during lactation. Litter size,litter weight at birth and weaning and litter average daily weight gain were also unaffected by treatment. As expected, large differences were observed in n-6 and n-3 fatty acids in the colostrum and plasma of sows and piglets （P 〈 0. 01） . The ratio of n6 ∶ n-3 PUFA the diet was positively correlated with those in colostrum,sow plasma and piglet plasma （R 2= 0. 55,0. 80 and 0. 80,respectively） . Sow plasma insulin and IGF-I levels at weaning were unaffected by the treatments. Plasma leptin （P 〈 0. 05） concentrations were increased in sows fed the diet with a n-6∶n-3 ratio of 8 ∶ 1. Immunoglobulin concentrations in colostrum were not altered by dietary treatment. Plasma IgG concentrations at d 14 were highest in piglets from sows fed the 8 ∶ 1 ratio of n-6∶n-3. Furthermore,this group had the highest IgA concentrations at day 21 of lactation compared with the other two groups （P 〈 0. 05） . In summary,our study demonstrated that at low digestible energy levels,altering the ratio of n-6 ∶ n-3 PUFA in the diets for lactating sows affected immune components and the fatty acid composition of lactating sows and their piglets. Further studies are needed to examine whether higher levels of fat supplementation than those used in the present study （1. 5%） can successfully enhance performance.

Role of functional fatty acids in modulation of reproductive potential in livestock

Fatty acids are not only widely known as energy sources,but also play important roles in many metabolic pathways.The significance of fatty acids in modulating the reproductive potential of livestock has received greater recognition in recent years.Functional fatty acids and their metabolites improve follicular development,oocyte maturation and embryo development,as well as endometrial receptivity and placental vascular development,through enhancing energy supply and precursors for the synthesis of their productive hormones,such as steroid hormones and prosta-glandins.However,many studies are focused on the impacts of individual functional fatty acids in the reproductive cycle,lacking studies involved in deeper mechanisms and optimal fatty acid requirements for specific physiological stages.Therefore,an overall consideration of the combination and synergy of functional fatty acids and the establish-ment of optimal fatty acid requirement for specific stages is needed to improve reproductive potential in livestock.