A Preliminary Study Of Lactobacillus Plantarum N-1 On Autism-like Behavior

OBJECTIVEUsing the maternal immune activation(MIA)model to study the behavior of autism spectrum disorder(ASD),we investigated whether Lactiplantibacillus plantarum N-1(LPN1)can improve autism-like behaviors to provide a perspective for the intervention of ASD.METHODSC57BL/6 female mice were randomly divided into control and MIA groups on day 12.5 of gestation,with the MIA group receiving a single intraperitoneal injection of Poly(I:C)20 mg/kg and the control females receiving a single intraperitoneal injection of the same amount of saline.Male offspring in the MIA group were randomly divided into ASD and ASD+LPN1 groups,and male offspring in the control group were in the PBS group.The male offspring of the MIA group were divided into ASD and ASD+LPN-1 groups,while the control male offspring were in the PBS group.The PBS and ASD groups were fed with normal chow at 8 weeks after birth,and the ASD+LPN-1 group was fed with LPN-1 powder(2×10^9 CFU/g)for 4 weeks.body weight was measured weekly.Sociability,anxiety-like behavior,depressive behavior and gut microbiota were assessed.RESULTSThe results of the three-chamber social test showed that there was a significant difference in the time spent with stranger 1 in the PBS group(P<0.0001),while there was no significant difference in the time spent between objects and stranger 1 in the ASD group(P=0.0921),indicating some degree of social deficit.There was a significant difference(P<0.0001)in the time spent with stranger 1 in the ASD+LPN-1 group after LPN-1 supplementation,indicating some recovery of social behavior in the ASD+LPN-1 group mice.The results of the open field test showed a significant difference in the time spent in the central area by mice in the ASD group compared with mice in the PBS group(P=0.0454),indicating a significant anxiety behavior in the ASD group.The mice in the ASD+LPN-1 group spent more time in the central area after supplementation with LPN-1,with no significant difference compared with the PBS group(P=0.1987),indicating that the mice had reduced anxiety behavior.The results of the tail suspension test showed an increase in the immobility time of mice in the ASD group compared with those in the PBS group,with a significant difference(P=0.0363),indicating a significant depressive behavior in the ASD group.The mice in the ASD+LPN-1 group showed a decrease in immobility time after LPN-1 supplementation,with no significant difference compared with the mice in the PBS group(P=0.9973),indicating that the mice in the ASD+LPN-1 group had reduced depressive behavior.The results of the novel-object recognition test showed no significant difference in the discrimination index(DI)of mice in the PBS,ASD and ASD+LPN-1 groups,indicating that there was no significant difference in the cognitive abilities of the three groups of mice.16S rRNA sequencing showed that LPN-1 supplementation significantly elevated the abundance of beneficial bacteria including Allobaculum and Oscillospira(P<0.01)in the intestinal flora of ASD mice,as well as Ruminococcus,Bifidobacterium and Akkermansia.Further calculations showed that Allobaculum was elevated from 14.33%to 62.04%after LPN-1 supplementation compared with the ASD group.In addition to increasing the variety of probiotic bacteria,we observed that LPN-1 supplementation also significantly suppressed the abundance of the harmful bacterium Sutterella(P<0.05).Specially,Desulfovibrio showed a decreasing trend in the ASD+LPN-1 group.CONCLUSIONOur study found that LPN-1 supplementation may improve social,anxious,and depressive behaviors in mice with ASD by increasing the abundance of beneficial bacteria including Allobaculum and Oscillospira and suppressed the abundance of the harmful bacterium Sutterella and Desulfovibrio,providing new ideas and insights for the future use of LPN-1 probiotics as an adjunctive treatment option for ASD.