The study is a parallel, randomized, double-blind, placebo controlled clinical trial will evaluate the effect of Lactobacillus plantarum DSM 33464 on reduction of Blood lead levels and general well-being of children.

Inclusion Criteria:

The subjects who meet all of the following selection criteria can participate in this study:

1. Children age 3-12 years
2. BLL 35-249 µg/L
3. Subjects, their parents or legal guardians are able and willing to comply with research guidance
4. Subject's parents or legal guardians sign written informed consent.

Exclusion Criteria:

Subjects who meet any of the following exclusion criteria may not participate in this study:

1. Diagnosed with nervous system diseases, genetic and metabolic diseases, endocrine diseases, lung diseases, severe or unstable cardiovascular diseases, clinically significant kidney or liver diseases, blood system diseases, any other clinically significant diseases and Other investigators judge that the participation of subjects in the study will increase the risk of the subjects' diseases;
2. History of infection or organ transplantation of human immunodeficiency virus or other acquired congenital immunodeficiency diseases;
3. Take probiotic products in the last two weeks
4. Known or suspected sensitivity or allergy to food or any constituents tested in the trial
5. Participation in another clinical trial or food study 4 weeks prior and during the trial