Children often prefer fries and candy over healthier foods, despite their parents’ best efforts. However, nutrition is just one aspect contributing to childhood obesity, a complex issue influenced by multiple factors that affect a growing number of children worldwide.
“Obesity is a complex disease attributable to one’s genes and environment, ranging from diet, physical activity, sleep habits, and more,” said Germaine Yong, a Scientist at A*STAR’s Singapore Institute of Food and Biotechnology Innovation (SIFBI).
Scientists have found that changes in gut bacteria are common in people with obesity and that similar changes in babies can lead to weight gain later in life. However, until now, no one had shown exactly how the gut bacteria in babies might influence their chances of becoming obese later, or pinpointed specific bacterial features that increase this risk.
Yong, along with collaborators from the University of California–San Francisco, Augusta University, Columbia University and the Henry Ford Health System in the US, investigated potential links between early-life gut microbiome composition and childhood obesity. They studied a cohort of nearly 350 one-month-old infants, analysing the microbiome composition of their fecal samples. The team conducted metagenomic and metabolomic analyses to identify gut microbiota and metabolic features related to obesity outcomes.
The researchers found that infants with a higher obesity risk had a more mature gut microbiome, enriched with specific bacterial families, such as Lachnospiraceae and Ruminococcaceae, and with fungi typically found in older infants. Higher-risk microbiomes also exhibited distinct metabolic profiles, including changes in lipid and amino acid metabolism.
“Accounting for the many factors that affect obesity during statistical modelling was complex,” commented Yong. “For example, it’s challenging to accurately measure physical activity in infants,” she acknowledged, noting some limitations of their dataset.
The team’s findings showed that infants with a high-risk microbiome had a 2.52 times higher risk of obesity by age two. The microbiome in this high-risk group produced metabolites that reduced intestinal barrier integrity, a known pathological feature of obesity. These metabolites also promoted the expression of genes that increase insulin resistance and inflammation and alter neuroendocrine signalling.
Yong said their findings highlight the importance of early interventions such as screening and early-life nutrition advice to lower the risk of obesity in childhood and later in life. In an ideal scenario, Yong said infants would undergo gut health screenings during their routine wellness checks to monitor how their microbiome is developing in relation to their age.
As a study follow-up, the researchers plan to follow the children in this study into adolescence. Meanwhile, they are exploring how maternal transmission and early-life factors shape the infant gut microbiome and how this might affect other diseases.
The A*STAR-affiliated researchers contributing to this research are from the Singapore Institute of Food and Biotechnology Innovation (SIFBI).
