Effect Of Zinc Deficiency On Gut Microbiota And Metabolites Of School-age Children

Objective: This study aimed to investigate the zinc status,dietary intake level and health status of school-age children by anthropometric measurements,dietary survey and serum test.High-throughput sequencing and metabolome were conducted to explore the effect of zinc deficiency on the gut microbiota and metabolites to provide scientific theory and practical basis for the subsequent research on the mechanism of zinc deficiency.Methods: A total of 177 school-age children from Lujiagou Central Primary School,Lujiagou Town,Anding District,Dingxi City,Gansu Province were enrolled to conduct dietary recall,anthropometric measurements,serum zinc and serum inflammatory factors detection,and children were divided into zinc deficiency group(ZD)and control group(CK)according to the results of serum zinc.Stool samples of67 children were collected for 16 S r DNA sequencing,and PICRUSt function prediction was conducted to explore the changes of gut microbial function in school-age children with zinc deficiency.Among them,30 fecal samples were chosen to conduct metagenome and metabolome,and diversity analysis,species composition analysis,functional annotation and correlation analysis were conducted to further explore the composition and function of intestinal flora and metabolites in children with zinc deficiency.Results:(1)Among 177 school-age children,57 were zinc-deficient,and the serum zinc deficiency rate was 32%.The serum zinc level of school-age children in ZD group was lower than that in CK group(P < 0.001).In addition,the level of interleukin-6(IL-6),tumor necrosis factor-α(TNF-α)and interleukin-1β(IL-1β)were significantly increased in ZD group(P < 0.05).(2)The dietary diversity score(DDS)of ZD group and CK group were 5.71 ± 0.10 and 5.78 ± 0.07(value range: 1～9).The intake of vegetables,fruits,livestock and poultry meat,aquatic products,milk and dairy products,soybeans and nuts,and oil did not meet the recommended nutrient take.The intake of soybeans and nuts was significantly different between the two groups(P < 0.05),and there were significant differences in 13 nutrient adequacy ratios(NARs)and mean adequacy ratio(MAR)among the low,medium and high DDS groups(P < 0.05).15 NARs and MAR were positively correlated with DDS(r = 0.217～0.462,P < 0.05).(3)There was no significant difference in the composition of gut microbial communities between ZD group and CK group,but the Shannon index of ZD group was significantly higher than that of CK group(P < 0.01).Ruminococcaceae,Acetivibrio,Paraprevotella,Coprobacter,Clostridium XI,Papillibacter,Prevotella copri,Ruminococcus Calidus,Victivallaceae bacterium NML 080035,Eubacterium eligens ATCC 27750,Streptococcus anginosus were more abundant in ZD group(P <0.05).Solobacterium was more abundant in CK group(P < 0.05).The KEGG pathway,metabolism of xenobiotics by cytochrome P450,was significantly depleted in ZD group(P < 0.05).In addition,the intake of cereals and potatoes was positively associated with Bacteroides in ZD group(r = 0.399,P < 0.05),while a negative association was observed between them in CK group(r =-0.377,P < 0.05).(4)PCo A showed a significant difference in microbial composition between the two groups.134 metabolic pathways were significantly different between ZD group and CK group(P < 0.05).Several enzymes and transporters in “Taurine and hypotaurine metabolism” pathway were significantly different between two groups(P < 0.05).Besides,various glycoside hydrolases such as fucosidase,sialidase,galactosidase,Nacetylgalactosaminidase and N-acetylglucosaminidase were significantly higher in ZD group(P < 0.05).(5)PLS-DA showed that the gut metabolite composition was affected by zinc deficiency.In ZD group,the levels of 15 metabolites were higher(P < 0.05),such as Alline,Saccharin,4-Hydroxybenzenesulfonic acid,Prilocaine,and Cannabidiolic acid.In CK group,the levels of 14 metabolites were higher(P < 0.05),such as NAcetylsphingosine,Luteolin,3-hydroxy-C10-homoserine lactone,1,7-bis(4-hydroxyphenyl)heptane-3,5-diol,and 3-oxo-C12 homoserine lactone.Besides,some specific metabolites showed associations with gut microbiota.Conclusion:(1)In this study,school-age children suffered from poor dietary diversity,and insufficient food and nutrients intake,and 32% of them were zincdeficient.The inflammatory cytokines significantly increased in ZD group.(2)There were significant differences in the diversity,composition,and function of the gut microorganism in school-age children between ZD group and CK group,indicating that zinc deficiency may lead to changes in the intestinal microbiota of school-age children.(3)There was a significant difference in intestinal metabolite composition between ZD group and CK group,indicating that zinc deficiency may affect the metabolic processes,and cause the changes of metabolites.(4)Children in ZD group had higher abundance of mucin-degrading flora and metabolites such as saccharin and taurocholic acid,suggesting that the microbial composition and metabolic characteristics in children with zinc deficiency may affect health.