Breastfed Babies Have Fewer Antibiotic-Resistant Bacteria in Their Guts
Infants who are breastfed for at least 6 months have fewer antibiotic-resistant bacteria in their guts, likely because the sugars in breast milk feed “good bacteria,” which prevents the proliferation of harmful microbes, a new study shows.
It’s an important benefit of breastfeeding, as antibiotic-resistant superbugs are increasing worldwide, fueling fears that modern medicine could be wiped out if new treatments aren’t soon developed.
Researchers from Helsinki University analyzed the genes of 16 mothers and their babies over 8 months. The team sequenced the DNA of a total of 96 samples, including breast milk and feces, from the mothers and their infants.
Some Interesting Findings
Babies that were breastfed for at least 6 months had less antibiotic-resistant bacteria in their guts, compared with babies who were not breastfeed.
Lead study author Katariina Pärnäne said:
“The results suggest that early termination of breastfeeding might have negative health effects for infants … due to an increased resistance potential of the gut microbiota against certain antibiotics.”
The study also showed that mothers who received antibiotics during delivery had babies with a greater number of antibiotic-resistant bacteria in their guts. The effect was still noticeable 6 months after birth. 
Additionally, researchers found that breast milk contains antibiotic-resistant bacteria that gets passed on to infants via breastfeeding. Yet, breastfeeding still reduced the number of resistant bugs in the bellies of infants, suggesting that breastfeeding helps cancel out any “bad” microbes a mom might pass along. In fact, only some of the resistant bacteria the team found in infants originated from their mothers. The majority came from the environment and other people.
“As a general rule, it could be said that all breastfeeding is for the better.
The positive effect of breastfeeding was identifiable also in infants who were given formula in addition to breast milk. Partial breastfeeding already seemed to reduce the quantity of bacteria resistant to antibiotics. Another finding was that nursing should be continued for at least the first six months of a child’s life or even longer.
We have already known that breastfeeding is all in all healthy and good for the baby, but we now discovered that it also reduces the number of bacteria resistant to antibiotics.”