How do you know if SIBO is caused by bacteria from the oropharynx (mouth and throat)?

Regarding children, we presently do not have evidence that bacteria from the oropharynx can lead to bacterial overgrowth in the small intestine (SIBO). There is only evidence that this can occur in adults.nnDetermining what type of bacteria is overgrowing within the small intestine can be determined only through a very specialized form of upper endoscopy (EGD) available only in the research environment. Tests examining blood or stool can not provide this type of information.