Our gut microbiome has 109 microorganisms, so it would be quite difficult to ingest enough probiotic supplements to overpower these. However, it is possible that taking too many can trigger uncomfortable symptoms such as gas, bloating, abdominal cramping, and diarrhea. There are some people who would be harmed by taking even the recommended dose, namely those with compromised immune systems and those that are severely ill. Supplementing may lead to sepsis, bacterial or fungal blood infection, and in rare cases, anaphylaxis.