Millions of Americans take probiotics – living bacteria are considered useful – assuming there are only positive effects. The truth is that you really do not know how any probiotic will affect you. To cite the American Gastroenterology Association's Center for Research and Intestinal Microbiology Education, "it is not yet clear which strains of bacteria at which dose and by which route of administration are safe and effective for which patients."
Things can go awry in patients: Among patients with severe acute pancreatitis, one study found that a dose of probiotics increased the chance of death. Even randomized controlled trials of probiotics rarely report damage adequately and the long-term effect has not been studied.
In June, [gastroenterologist Satish] Rao created an uproar when he and his co-authors reported that a cluster of their patients with "brain fog" [improved] dramatically when they were removed from their probiotics and given antibiotics as well.
His idea was that lactobacilli and other bacteria colonize their small intestines, rather than reaching the colon as intended – a condition known as "overgrowth of small intestine bacteria" (SIB0) that some gastroenterologists treat with antibiotics. In this group, he argues, the small intestine produced the symptoms of brain fog as a consequence of D-lactic acidosis, a phenomenon usually associated with damaged intestines. "If you have cerebral nebulosity along with gas and bloating, please do not take probiotics," Rao says.
Read the full and original post: Could your probiotic be making you sick?