B ackgroun Previous study gut microbiota might modulate brain development in early stages of life H. pylori can cause inflammation Need to be researched which activates the immune system the interplay between H pylori and normal gut 02 microbiota whether H. pylori affect growth in early lifePrevious study： • gut microbiota might modulate brain development in early stages of life • H. pylori can cause inflammation which activates the immune system 01 02 Need to be researched： • the interplay between H. pylori and normal gut microbiota • whether H. pylori affect growth in early life Background