Effect And Mechanism Of Lactobacillus Plantarum CCFM8610 On Alleviating Foodborne Cadmium Toxicity

Cadmium pollution still exists in China,especially around mining areas.In the process of mineral production and smelting,cadmium in slag will be washed into soil and lakes with rainwater,which can cause environmental cadmium pollution.Cadmium in soil can be absorbed by plants and auumulated in animals through food chain.Due to the high accumulation of cadmium in animals,it will eventually threaten human life and health.In recent years,it is found that there are many binding forms of cadmium in food,including cadmium-citrate,cadmium-malate,cadmium-cysteine,cadmium-glutathione and so on.However,the toxicity of different foodborne forms of cadmium has not been systematically compared.Studies have shown that some Lactobacillus have the potential to alleviate cadmium toxicity,and our laboratory has screened a Lactobacillus plantarum strain named CCFM8610 that can alleviate the toxicity of cadmium chlorid.However,its mitigation effect on foodborne cadmium toxicity is still unknown.At the same time,there is no literature clearly indicating that probiotics can reduce the blood cadmium content of people with foodborne cadmium intake.Based on the above background conditions,this study explored the toxicological differences of three common foodborne cadmium: cadmium-citrate,cadmium-glutathione and cadmiummetallothionein,and the mitigation effect of Lactobacillus plantarum CCFM8610 on its toxicity.The effect of L.plantarum CCFM8610 on blood cadmium was explored,and the protective mechanism of L.plantarum CCFM8610 on foodborne cadmium intake was further explored from the perspective of intestinal flora macrogenomics,plasma metabolomics and cadmium excretion kinetics.Firstly,three common foodborne cadmium reported in the literature: cadmium-citrate,cadmium-glutathione and cadmium-metallothionein were selected to evaluate acute and chronic oral toxicological differences in mice.The results showed that the toxic effects of different foodborne cadmium on mice were different.Among them,cadmium chloride and cadmium-citrate can increase cadmium accumulation in mice and aggravate oxidative stress.Dietary cadmium exposure can change the abundance of serum metabolites in mice,mainly including amino acids and fatty acids.The effects of different dietary cadmium exposure on serum metabolites in mice were different.The above results indicate that the toxicological characteristics of different foodborne cadmium are different.The binding forms of cadmium in food should be considered when exploring methods for the mitigation of foodborne cadmium toxicity.Secondly,a strain of L.plantarum CCFM8610 with the ability to alleviate the toxicity of cadmium chloride screened in our laboratory was used to explore its ability of relieving the toxicity of different foodborne cadmium.L.plantarum CCFM8610 could alleviate the acute and chronic toxicity of different food derived cadmium.It is mainly manifested in decreasing blood,hepatic,and renal cadmium concentration,and alleviating the oxidative stress caused by acute and chronic exposure to foodborne cadmium.The correlation analysis and KEGG pathway analysis showed that Lactobacillus plantarum CCFM8610 may affect serum citrulline,ketoglutarate,and ?-D-glucopyranose content by regulating the abundance of intestinal Bifidobacterium,Butyricimonas,Candidatus Arthromitus,Desulfovibrio,Mucispirillum,p-75-a5,Parabacteroides,Pseudomonas Ruminococcus,and Sutterella,which will then regulate the body's arginine biosynthesis,D-glutamine and D-glutamate metabolism,and fructose and mannose metabolism activities,thereby alleviating the acute toxicity of food-borne cadmium.It can also adjust the abundance of Bacteroides,Prevotella and Corynebacterium and then affect the content of serum L-phenylalanine and hippuric acid and regulate the metabolic activity of phenylalanine in the body,thereby alleviating the chronic toxicity of food-borne cadmium.The results showed that L.plantarum CCFM8610 also has a good toxic mitigation effect on foodborne cadmium.Based on the above results,the protective effect of L.plantarum CCFM8610 on foodborne cadmium intake population was further evaluated.By testing the content of cadmium in hair,blood and living environment of the population in the test area,it is determined that the population is in the state of foodborne cadmium exposure.3 months of intervention with L.plantarum CCFM8610 decreased the content of blood cadmium significantly.The result proved that L.plantarum CCFM8610 can effectively reduce the blood cadmium content of people with foodborne cadmium intake.At the same time,L.plantarum CCFM8610 has no other significant impact on the tested population.It can be considered as a safe product suitable for human consumption and can be used commercially.The study further evaluated the mechanism of alleviating the toxicity of foodborne cadmium by L.plantarum CCFM8610.It was found that L.plantarum CCFM8610 could rise the fecal cadmium content of people with foodborne cadmium intake,and reduce the accumulation of cadmium in the body.Meanwhile,the intervention of L.plantarum CCFM8610 can regulate intestinal Prevotella,Eubacterium and Roseburia faecis,Blautia obeum,Oscillibacter Er4 and Ruminococcus,which resulted in the regulation of the fructose and mannose metabolism and nitrogen metabolism of intestinal flora,and then affect the metabolic pathways such as pyrimidine metabolism,tyrosine metabolism,phenylalanine,tyrosine and tryptophan biosynthesis,arachidonic acid metabolism,so as to protect the people with foodborne cadmium intake.