Ask An Expert·3 min read

How Do Antibiotics *Really* Impact Your Immune System?

A woman looking at a bottle of pills
Design: theSkimm | Photo: iStock
January 23, 2024

Without antibiotics, getting an infection would generally be a much scarier threat. But there is such a thing as taking too many. We asked Arik Alper, MD, a pediatric gastroenterologist at Yale Medicine, if antibiotics weaken your immune system — and how to make sure your body doesn’t become resistant to certain bacteria. 

Does taking antibiotics impact my future immunity?

Not necessarily. “The purpose of antibiotics is to kill bacteria. That means that if I have a strep throat, the antibiotics would kill my strep throat,” Alper says. “Antibiotics can help facilitate the function of the immune system and prevent complications.” 

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Arik Alper, MD

Arik Alper, MD - A pediatric gastroenterologist at Yale Medicine

That said, if you take them too often, “the [bad] bacteria can outsmart it,” Alper says. That can lead to antibiotic-resistant bacteria, “and you're at risk of an infection you cannot fight,” he says. 

So how do I avoid becoming antibiotic-resistant? 

Only take antibiotics as needed, says Alper. It might seem obvious, but overuse is a common thing he sees: Sometimes doctors may overprescribe them. Other times, “people do not discontinue the antibiotics [when they are told to], because they think ‘Oh my god if I started antibiotics, I need to [finish] it.’” While that may be the case sometimes, it’s important to listen to your doctor’s instructions carefully. 

That said, he stresses the importance and safety of antibiotics for their prescribed use. “If you need antibiotics, you need to take antibiotics,” he says. 

Other ways to prevent developing antibiotic-resistant bacteria is to practice good hygiene and avoid getting sick (easier said than done). So wash your hands often and get vaccinated as your doc recommends. It can be tricky to treat resistant bacteria, but your doctor may try a combination of medicines or other antibiotics to treat your infection. 


When it comes to antibiotics — as with most things in life — more isn’t always more. So if you end up needing them for an infection, be sure to listen closely to your doctor’s directions. Your future self will thank you. 

Ask an Expert is for informational purposes only, does not constitute medical advice, and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician, mental-health professional, or other qualified health provider with any questions you may have regarding a medical condition. By submitting a question, you are agreeing to let theSkimm use it—in part or in full—and we may edit its answer for length and/or clarity.

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