Changes in Protein Expression Levels (IMAGE) Kumamoto University Caption When the intestinal flora changes, as happens when antibiotic drugs are administered, drug-metabolizing enzymes and drug-transporting proteins are greatly reduced leading to a decreased ability to detoxify and eliminate the drugs from the system and can lead to an increase of side effects. Credit Dr. Sumio Ohtsuki Usage Restrictions This image may only be used in conjunction with the accompanying release, or stories written about the work described in the release with reference to the original work. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.