Changes Of Fecal Intestinal Flora And Short Chain Fatty Acids In Preterm Rats With Cognitive Impairment

ObjectiveTo compare the differences of fecal intestinal flora and short chain fatty acids between preterm rats with cognitive impairment and preterm rats without cognitive impairment,and to explore the relationship between the changes of intestinal flora metabolites short chain fatty acids and preterm cognitive impairment.MethodsThe experimental group was given intraperitoneal injection of lipopolysaccharide,and the control group was given intraperitoneal injection of PBS.The preterm rats(22～23 days of term)were obtained by cesarean section on the 21 st day of pregnancy.The cognitive ability of preterm rats was evaluated 30 days after birth.The rats were divided into normal control group and cognitive impairment group.High throughput sequencing was used to detect the structure and distribution of intestinal flora in feces,and gas chromatography was used to quantitatively detect the content of short chain fatty acids in feces.The levels of 5-HT,GABA,CRH,GR,IL-6,TNF-α and BDNF in rat serum were determined by ELISA.ResultsThe average time to find the platform in premature cognitive impairment rats was significantly longer than that in normal control group(P<0.05).The relative abundance of Lactobacillus and bacteroides in cognitive impairment group was significantly decreased(P<0.05).The contents of total short chain fatty acids and acetic acid in cognitive impairment group were significantly lower than those in control group(P<0.05).Acetic acid was positively correlated with Lactobacillus and Bacteroides(P<0.05).Total short chain fatty acids and acetic acid were negatively correlated with navigation time(P<0.05).Compared with the normal control group,the levels of 5-HT,GABA and BDNF in the serum of premature cognitive impairment rats were decreased(P < 0.05),and the levels of GR,CRH,IL-6 and TNF-α were increased(P<0.05).Total short chain fatty acids and acetic acid were positively correlated with 5-HT(P<0.05).Acetic acid was negatively correlated with tryptophan metabolism;total short chain fatty acids was negatively correlated with glyceride metabolism,tyrosine metabolism and tryptophan metabolism(P<0.05).ConclusionThe decrease of total short chain fatty acids and acetic acid in the intestine of premature rats with cognitive impairment may be the possible cause of premature rats with cognitive impairment.