Probiotics are generally considered safe for most people, but individuals with weakened immune systems, such as those with HIV/AIDS, those undergoing immunosuppressive therapy, or those with critical illnesses, should exercise caution as there is a risk of infections. People with short bowel syndrome might be at an increased risk of developing a bacterial infection. High doses of probiotics or using them for a prolonged period should be done under medical supervision. Pregnant and breastfeeding women should consult a healthcare professional before using probiotics. Always follow the recommended dosage and consult a healthcare provider if in doubt.