We analyzed one assertion and found that in a small group of healthy adults, antibiotics led to lasting changes in gut bacteria that matched the bacterial patterns seen in critically ill ICU patients, even though those individuals were not sick [1]. This suggests that antibiotic use may reshape the gut microbiome in ways that resemble the microbial profiles of people in intensive care, even in otherwise healthy people. The evidence we’ve reviewed so far does not include any studies that contradict this finding. However, the assertion is based on a small group of participants, and we don’t have data on how long these changes last beyond the study period, or whether they affect health outcomes. We also don’t know if the same patterns appear in larger or more diverse populations. The gut microbiome refers to the trillions of bacteria and other microbes living in the digestive tract. These microbes help with digestion, immune function, and other processes. When antibiotics are taken, they don’t just target harmful bacteria—they can also reduce or alter many beneficial ones. What we’ve seen so far is that this disruption may not fully reverse, and the new balance of microbes can look similar to what’s observed in very sick patients in the ICU. This doesn’t mean antibiotics are dangerous for healthy people, nor does it prove they cause harm. But it does suggest that even short-term use might have long-lasting effects on the gut’s microbial makeup. If you’re prescribed antibiotics, it’s still important to take them as directed when needed. But if you’re concerned about your gut health, talking with your doctor about minimizing unnecessary use and supporting recovery with diet or probiotics may be worth considering.