Infant gut microbes altered by their mother's obesity can cause inflammation and other major changes within the baby, increasing the risk of obesity and non-alcoholic fatty liver disease later in life, according to researchers at the University of Colorado Anschutz Medical Campus.
The study was published Oct. 26 in the journal Nature Communications.
"Alteration of the gut microbiome early in life may precede development of obesity instead of being caused by established obesity," said the study's lead author Taylor Soderborg, an MD/PhD candidate in the Integrative Physiology Program at the University of Colorado School of Medicine. "This is the first study to show a causative role of these microbes in priming development of obesity."
Childhood obesity is a world-wide epidemic with recent predictions saying that 57 percent of today's children will be obese by age 35. That parallels the rate of maternal obesity which is nearly 40 percent. Obesity increases the risk of non-alcoholic fatty liver disease (NAFLD) which impacts at least 30 percent of obese children. NAFLD can lead to liver failure, requiring a transplant.
In this study, researchers looked at two-week old infants born to normal weight mothers and obese mothers. They took stool samples from infants from both groups and colonized them inside germ-free mice.
They discovered that the gut microbes from babies born to obese mothers caused metabolic and inflammatory changes to the liver and bone marrow cells of the mice. Then, when fed a Western-style high fat diet, these mice were predisposed to more rapid weight gain and development of fattier livers.
"This is the first experimental evidence in support of the hypothesis that changes in the gut microbiome in infants born to obese mothers directly initiate these disease pathways," Soderborg said.
For the study's senior author, Jed Friedman, PhD, MS, professor of pediatrics and neonatology at the CU School of Medicine, the findings offer potential hope for understanding how early microbes might go awry in children born to obese mothers.
"About 35 percent of these kids have NAFLD and there is no known therapy for it," he said. "But if we can alter the microbiome we can change the course of NAFLD."
Friedman said the study shows that the microbiome can cause the disease rather than simply be associated with it. Newborns of obese mothers, he said, could be screened for potential changes in their gut that put them at risk for NAFLD.
"If we could modify the first two weeks of the infant microbiome, we could reduce the risk of this disease," said Friedman.
That could be done through giving the infant probiotics or other supplements.
Soderborg said future studies on pre and probiotics are needed to better understand how they could help modify the risk of childhood obesity and the risk of liver disease in infants born to obese mothers.
Obesity-related heart disease deaths rise sharply in the U.S. between 1999 and 2020