Effects Of Selenohomolanthionine Supplementation During Pregnancy On The Intestinal Immune Barrier Of Postpartum Rats

As an essential trace element for animals,selenium participates in a variety of physio logical processes such as growth,immunity,and reproduction.The deficiency of selenium is considered to be one of the factors leading to the occurrence of chronic diseases related to oxidative stress or inflammation.At present,there are no researches on the effects of Selenohomolanthionine(SeHLan)on the intestinal immune barrier.Therefore,in this experiment,18 pregnant Wistar rats were selected and randomly divided into SeHLan-deficient group,Control group,and SeHLan-enriched group.They were fed with selenium-free basal diet and the water respectively supplemented with different doses(0.03 mg/kg,0.15 mg/kg,or 1.5 mg/kg)of SeHLan.The purpose of this study was to explore the effects of SeHLan on the intestinal mechanical barrier,immune function,anti-oxidation function,and intestinal flora of postpartum rats,also including the antioxidant capacity of duodenum and jejunum in neonatal rats,which would provide theoretical basis for the application of SeHLan in livestock and pet breeding.1.Effects of SeHLan supplementation during pregnancy on the intestinal mechanical barrier of postpartum ratsThe rats were euthanized on the fourth day after delivery,and samples were taken aseptically to detect the contents of selenium,diamine oxidase(DAO),and D-lactic acid(D-LA)in serum,the genes related to tight junction(ZO-1,Occludin and Claudin-1)in intestinal,and the morphology of intestinal tissue.The results showed that compared with the control group,the content of DAO and D-LA in serum rapidly increased(P<0.01),the content of selenium in serum and the relative expression of mRNA transcripts for ZO-1,Occludin,and Claudin-1 in intestinal decreased significantly(P<0.05 or P<0.01),the intestinal mucosa were damaged,and the villi of small intestine were injured and arranged disorderly in SeHLan-deficient group.In SeHLan-enriched group,the content of selenium in serum strongly increased(P<0.01),the intestinal mucosa was intact,and the villi of small intestine were neatly arranged.In general,the supplementation of SeHLan during pregnancy could protect the intestinal tight junction and maintain the integrity of intestinal morphology,which strengthened the function of intestinal mechanical barrier.2.Effects of SeHLan supplementation during pregnancy on the intestinal immune barrier of postpartum ratsThe rats were euthanized on the fourth day after delivery,and samples were taken aseptically to detect the indexes related to antioxidation(CAT,GPX,T-SOD,T-AOC,and MDA),the genes related to antioxidant(GPX-1,GPX-2,and CAT),Nrf2-Keap1 signal pathway,the content of secretory immunoglobulin A(SIgA),and the number of goblet cells in the intestine.The results displayed that compared with control group,T-AOC,the activities of CAT and GPX,the relative expression of mRNA transcripts for GPX-1,GPX-2,and CAT,the content of SIgA,the number of goblet cells,and the protein expression of Keapl markedly decreased(P<0.05 or P<0.01)in SeHLan-deficient group,which rapidly increased(P<0.05 or P<0.01)in SeHLan-enriched group.Meanwhile,the content of MDA,and the protein expression of Nrf2,HO-1,and NQO-1 significantly increased(P<0.05 or P<0.01)in SeHLan-deficient group,which markedly reduced(P<0.05 or.P<0.01)in SeHLan-enriched group.In summary,with the supplementation of SeHLan during pregnancy,the capacity of antioxidant and the immune function in the intestinal of postpartum rats were improved,and the oxidative damage was alleviated,whcih enhanced the function of intestinal immune barrier.3.Effects of SeHLan supplementation during pregnancy on the intestinal microflora of postpartum ratsThe rats were euthanized on the fourth day after delivery,and samples of microflora in ileum,cecum,and colon were taken aseptically for 16s rRNA amplicon sequencing.The results showed that there were no significant differences in a diversity,but there were differences in β diversity and community structure of microflora in ileum,cecum and colon.In SeHLan-deficient group,the abundance of pernicious bacteria such as Hepatic Helicobacter in cecum,Campylobacter,Helicobacter,Helicobacter rodentium,Helicobacter sp MIT 016451,and Desulfovibrionaceae in colon increased.In SeHLan-enriched group,the abundance of beneficial bacteria such as Peptostreptococcaceae and Romboutsia in ileum,Bacteroidales in cecum,Lactobacillaceae,Erysipelotrichaceae,Turicibacter,Faecalibacterium,and Lactobacillus reuteri in colon raised.At the same time,in SeHLan-enriched group,the predicted abundance of chemoheterotrophy and fermentation of microflora in ileum and colon of postpartum rats increased.So,with the supplementation of SeHLan during pregnancy,the structure of intestinal microbial community in postpartum rats was improved because the abundance of various beneficial bacteria increased.4.Effects of SeHLan supplementation during pregnancy on antioxidant capacity of duodenum and jejunum in neonatal ratsThe neonatal rats were weighed on the 4th day after delivery.The viscera index of thymus and spleen were evaluated,and the indexes related to antioxidation(CAT,GPX,T-SOD,T-AOC,and MDA)in duodenum and jejunum were detected after euthanasia.The results revealed that compared with the control group,the indexes of thymus gland and spleen,T-AOC,and the activities of CAT and GPX in duodenum and jejunum were separately decreased significantly(P<0.05)in SeHLan-deficient group,which markedly increased(P<0.05)in SeHLan-enriched group.Meanwhile,the concentration of MDA in duodenum and jejunum sharply boosted(P<0.01)in the SeHLan-deficient group,while in the SeHLan-enriched group,which reduced significantly(P<0.05)in duodenum.The study suggested that SeHLan supplementation to pregnant rats could enhance the antioxidant activity in the duodenum and jejunum of neonatal rats.In conclusion,the supplementation of SeHLan during pregnancy significantly strengthened the the function of mechanical barrier and immune barrier of postpartum rats’ intestines,ameliorated the intestinal microflora,and enhanced the antioxidant function of neonatal rats’intestinesl.