To Investigate the Effects of Bifidobacterium Animalis Subsp. Lactis XLTG11 on Growth and Development, Incidence of Allergy and Immune Function in Infants

Inclusion Criteria: * Term infants are 37≤ gestational age \< 42 weeks, and the birth weight is between 2500g and 4000g (only applicable to 0\~12 months old) * Breastfed or mixed-fed healthy infants and young children, aged 0\~3 (inclusive) years old, gender is not limited * The allergy risk score calculated by the Infant Allergy Risk Assessment Table is ≥6(Refer to the National Center for Women and Children's Health, Chinese Center for Disease Control and Prevention: Investigation and Research on Allergy Symptoms and Risk Factors in Infants and Young Children) * Family primary guardians agree to collect fecal samples of infants and young children during this study * Have not used antibiotics in the past month * Have not used probiotics in the past three months * Family primary guardians committed not to add additional Bifidobacterium dietary supplements to infants and young children during the intervention period * The guardians of the enrolled subjects agree to participate in this interventional study and sign a written informed consent form, and are able to understand and fill in forms such as infant diaries as required * Signed informed consent and willing to follow up at the time specified in the trial Exclusion Criteria: * The mother of the infant has a history of diabetes, hepatitis B, HIV and other infectious diseases * Clinicians diagnosed with allergic diseases (including but not limited to eczema, asthma, allergic proctocolitis, allergic rhinitis, hay fever, etc.) at the time of enrollment of infants and young children * Infants and young children who are known to be allergic to the ingredients of probiotic products * In the opinion of the investigator, the subject has other reasons that make it unsuitable to participate in this clinical study