A new study, led by the National Food Institute at the Technical University of Denmark (DTU-Food), suggests that longer breastfeeding encourages lactic bacteria to develop in the gut for longer.
Researchers in the past have explored the benefits of longer breastfeeding and found that breastfed babies tend to be a little slimmer and grow more gradually than formula-fed infants. Breastfeeding has also been linked to a decreased risk of obesity, diabetes, inflammatory bowel disease, and allergies later in life.
Published in the journal Applied and Environmental Microbiology, the researchers used a new culture-independent technique to extract DNA "signature sequences" of the gut bacteria of 330 children in their first 3 years of life and analyzed stool samples collected at age 9, 18 and 36 months.
The results showed substantial variances in bacteria composition between infants either breastfed or no longer breastfed at 9 months. They also showed that the gut bacteria changed significantly between the ages of 9 months and 18 months as breastfeeding ceased and infants were weaned with other foods.
Senior author Tine Rask Licht, professor and research manager at DTU-Food, says, “We have become increasingly aware of how crucially important a healthy gut microbial population is for a well-functioning immune system. Babies are born without bacteria in the gut, and so it is interesting to identify the influence dietary factors have on gut microbiota development in children's first three years of life.”
The researchers also found clear links between the body mass index and increase in bacteria that dominated when breastfeeding stopped. Up to the age of three, the gut bacteria become more complex and stable over time.
“The results help to support the assumption that the gut microbiota is not – as previously thought – stable from the moment a child is a year old. According to our study important changes continue to occur right up to the age of three,” Licht said. “This probably means that there is a ‘window’ during those early years, in which intestinal bacteria are more susceptible to external factors than what is seen in adults.”
This study can encourage mothers to breastfeed their children more often to promote more beneficial gut bacteria.