The development of gut microbiota in infants after age 9 months is largely determined by the types of food a baby begins to eat and not by maternal obesity, according to a study, “Infant Gut Microbiota Development Is Driven by Transition to Family Foods Independent of Maternal Obesity,” published in mSphere, an American Society for Microbiology (ASM) online open-access journal.
“Our results reveal that the transition from early infant feeding to family foods is a major determinant for gut microbiota development,” said Dr. Tine Rask Licht, the study’s senior author and a professor at Technical University of Denmark (TUD), Soborg, where she is also head of Research Group for Microbiology and Immunology at the National Food Institute, in a press release. “Maternal obesity did not influence microbial diversity or specific taxon abundances during the complementary feeding period.”
Children are born without practically any microbes in their gut, which is colonized beginning at birth and increasingly established during the first years of life. The gut microbiome is a continuously growing, complex community of microorganisms that settles in the digestive tract, and is unique to individuals. In adults, gut microbiota can undergo slight variations according to diet, but is largely fixed. “When you look at an adult’s gut microbiota, it is more or less like a fingerprint,” Professor Licht said.
Due to its strong connection to diet, gut microbiota has been associated with obesity. Children with obese parents are at higher risk of developing the disease, but this is only in some measure due to genetics. While many studies have analyzed the impact of an infant’s earliest diet, especially breastfeeding, few have analyzed the influence of maternal obesity on the infant gut microbiota, which could be passed through microbes transmitted during birth or through the family’s dietary habits.
Martin Laursen, a PhD student at TUD and study’s first author, and his teammates compared two cohorts of infants’ gut microbiotas: those born to a random sample of healthy mothers (n=114), and those born to obese mothers (n=113). The research team assessed stool samples from the children at nine and 18 months, and found that, at nine months, the majority of the children had already transitioned, or partially transitioned, to a complementary diet.
Microbiota data were compared to breastfeeding patterns and personal dietary recordings. The researchers found that the major factors in the development of the gut microbiota were the duration of breastfeeding and composition of the baby’s complementary diet. Importantly, they also found that, in both cohorts, gut microbial composition was much more heavily affected by the introduction of a normal family diet, with high protein and fiber levels, than by the mother’s obesity status.
“We found that introduction of family foods is the main driver of development of the complex microbial ecosystem in the gut at age 9 months. The food determines the diversity and the composition of the microbiota, and this is very important,” concluded Professor Licht. “It is well known that breast feeding has a great impact on gut microbiota, but nobody has addressed the effect of diet at this age before.”