When my kids were little, I used to joke that bacteria are our friends, so I didn’t worry much when their pacifiers fell on the ground. As an infectious diseases specialist I had also seen the harmful effects of using too many antibiotics – emergence of bad bacteria like MRSA (methicillin resistant Staphylococcus aureus) and development of diseases due to killing off of good bacteria (like Clostridium difficile colitis, a serious inflammation of the gut caused by antibiotics). So I also tried to avoid giving them antibiotics. New research suggests that bacteria may be more helpful than we ever knew.
In a recent interview on NPR, Dr. Martin Blaser suggests that the overuse of antibiotics may be contributing to the rise in allergies, asthma, diabetes, obesity, inflammatory bowel disease and other chronic medical problems. His research suggests that by killing some good bacteria in the gut, antibiotics are making us sicker, especially when they are given during the first 3 years of life. There are trillions of bacteria (called the microbiome) in each of our bodies. Most of them are in the gut and they protect us and help us make necessary vitamins and other substances that keep our bodies healthy. Dr. Blaser reports than other modern medical practices may be contributing to problems with the balance of bacteria in the microbiome. For example, babies born by cesarean section do not get exposed to the bacteria in the mother’s birth canal and their microbiomes look different from babies born by vaginal delivery.
Michael Pollan wrote a great article about the microbiome in the NY Times magazine in May 2013 entitled “Some of my best friends are germs” in which he tested the bacteria in his gut and found that a single course of antibiotics changed the types of bacteria in his gut to a much less healthy collection of bacteria. He also reported on studies showing that what you eat influences the types of bacteria that are able to survive in your gut – and eating lots of junk food and processed foods causes some good bacteria to die off.
Two recent stories in the news add more support to the importance of bacteria in keeping us healthy. The first was a story in the NY Times entitled “The Fat Drug” reporting on research suggesting that antibiotics given to children may be a cause of obesity by killing off certain good bacteria in the gut (antibiotics have been fed to farm animals for decades to make them fatter). A second story on NPR reported on research suggesting that people with Crohn’s disease (a type of inflammatory bowel disease) had an unhealthy mix of bacteria in their guts – too many bacteria that cause inflammation. So you not only need bacteria in your gut to stay healthy, but you also need the right bacteria.
I’ve written before about the association between food and inflammation and the effect that food can have on the bacteria in the gut.
Perhaps eating the right foods, avoiding antibiotics when possible and accepting a little more dirt in our lives will keep our bacteria happier and help us avoid chronic medical problems.