Combination Probiotic: BB-12 With LGG (Different Doses) in Treating Children With Autism Spectrum Disorder

This study tests whether a combination probiotic — containing Bifidobacterium BB-12 and Lactobacillus GG (LGG) — can reduce gastrointestinal (GI) symptoms in children with autism spectrum disorder (ASD). Many children with autism experience significant gut problems including constipation, diarrhea, bloating, and abdominal pain, which can worsen behavioral symptoms and overall wellbeing. Researchers believe the gut-brain connection may be especially relevant in ASD, and that restoring a healthy gut microbiome could help. The study is open to healthy children aged 4 to 16 who have been diagnosed with ASD and who have current GI symptoms. Two different doses of the probiotic combination are being tested, and the study will track both GI symptom changes and any side effects. You may be eligible if: - Your child is between 4 and 16 years old - Your child has a diagnosis of autism spectrum disorder - Your child has current gastrointestinal symptoms - Your child is otherwise healthy (no recognized co-morbid illness) You may NOT be eligible if: - Your child is pregnant or breastfeeding - Your child takes immunosuppressive medications or oral corticosteroids - Your child has tested positive for HIV, Hepatitis B, or Hepatitis C - Your child has inflammatory bowel disease or celiac disease - Your child has had diarrhea within the past 30 days or taken antibiotics within 2 weeks - Your child has taken probiotic supplements in the past 30 days - Your child has a prosthetic heart valve or other implanted prosthetic device Talk to your doctor to see if this trial is right for you.