B. Infantis Supplementation to Improve Immunity in Infants Exposed to HIV

This study is testing whether giving infants a probiotic supplement containing Bifidobacterium infantis (a beneficial gut bacteria) can improve immune development and reduce the risk of HIV infection in babies who are born to HIV-positive mothers and are breastfed. Even when a mother is on HIV medication, breastfeeding carries a small risk of transmitting HIV, and a healthy gut microbiome may help protect the baby's immune system. **You may be eligible if (mother):** - You are 18 years or older and HIV-positive - You started antiretroviral therapy (HIV medication) before the third trimester of pregnancy - You plan to exclusively breastfeed your baby for the first 6 months **You may be eligible if (baby):** - Your baby tested HIV-negative at birth - Your baby was born at full term (at least 37 weeks) with a birth weight above 2.4 kg **You may NOT be eligible if:** - Your baby has a severe illness such as sepsis at birth - Your family has known or active tuberculosis exposure - Your baby has a condition, pregnancy complication, or congenital abnormality that affects immunity - Your baby is already taking other probiotics or prebiotics Talk to your doctor to see if this trial is right for you.