According to a study presented at the European Congress of Clinical Microbiology and Infectious Diseases (ECCMID) in Copenhagen, Denmark, researchers have identified several protective drugs that can reduce the collateral damage caused by antibiotics without compromising their effectiveness against harmful bacteria. The use of antibiotics can be beneficial in treating bacterial infections, but they can also destroy the beneficial microorganisms that are found in the gut, which can have long-term health effects.

Some of the promising drugs identified by the researchers include the anticoagulant dicumarol, the gout medication benzbromarone, and two anti-inflammatory drugs, tolfenamic acid, and diflunisal. In the study, researchers from the European Molecular Biology Laboratory in Heidelberg, Germany, analyzed the growth and survival of 27 different bacterial species commonly found in the gut following treatment with 144 different antibiotics.

They also determined the minimal inhibitory concentration (MIC), i.e., the amount of antibiotic required to prevent bacteria from multiplying in over 800 of these antibiotic-bacteria combinations. The results showed that many gut bacteria had slightly higher MICs than disease-causing bacteria, implying that most of the examined gut bacteria will not be affected by widely used antibiotic doses.

However, the findings of the study also showed that tetracyclines and macrolides not only stopped the growth of healthy bacteria at much lower concentrations than those required to stop the growth of disease-causing bacteria, but they also killed more than half of the gut bacterial species tested, potentially altering the gut microbiome composition for a long time. 

(Source: https://health.economictimes.indiatimes.com/news/industry/researchers-discover-compounds-that-reduce-side-effects-of-antibiotics-on-gut-bacteria/99537633 )