Goran Lab: Impact of Sugars and Human Milk Oligosaccharides on Infant Microbiome and Obesity

Magnified image of bacteria

Latino children face a high risk of obesity compared to non-Latino populations, a disparity that exists by age 2. Our previous work found that high dietary sugars in early life contribute to this increased risk. However, childhood exposure to extended (not exclusive) breastfeeding for more than 12 months obliterated this adverse effect.

Sugars and extended breastfeeding exert opposing effects on early obesity risk, but the mechanisms are unclear. Sugars and breast milk may affect gut microbiome development, which rapidly evolves during the first 24 months of life. The gut microbiome plays a role in the development of obesity. Gut microbial changes have also been documented in response to dietary sugars and factors in breast milk.

Exposure to high dietary sugars in infancy could also impact obesity risk by disrupting cognitive function and appetite regulation. Evidence suggests that the gut microbiome might mediate this disruption, and that HMOs protect against these impairments. However, we lack human studies in this area.

Outcome measures and study aims

In this study, we examine these concepts in a cohort of 209 Latino women and their newborn infants that we have been following since birth. We frequently sample and assess breast milk for HMO composition, maternal and infant microbiota, maternal and infant diet, and infant eating behaviors.

The primary outcome is infant body fat and secondary outcomes are infant cognition and appetite regulation. In the current funding period, we are bringing children back for more testing at 6-years of age for follow-up testing of diet, gut microbiome, obesity and cognitive function as well as detailed measures of brain development using brain imaging. The testing will allow us to examine the impact of early nutrition and breastmilk HMOs on these outcomes.

This study has four aims, to determine:

  1. The effects of dietary sugars and HMOs on infant gut microbiome development.
  2. Whether gut microbiome changes mediate the effects of dietary sugars and HMOs on body fat changes over the first 24 months of life and by 6 years of age.
  3. The effects of dietary sugars and HMOs on cognitive outcomes, eating behavior, appetite regulation and whether gut microbiome changes mediate these effects.
  4. Whether extended breastfeeding offsets the negative effects of dietary sugars via delivery of specific HMOs that contribute to a beneficial microbiome and improved cognition and appetite regulation.

Study impact

This study will move the field forward by identifying how early-life dietary exposures (focusing on dietary sugars, breastfeeding and HMOs) affect the growth of gut microbiota. We will investigate how the gut microbiome then impacts obesity, brain development and appetite regulation.

Identification of specific HMOs in breastmilk that may be protective for obesity and brain development can be used to inform the design of more effective supplements that could be used to boost availability for breastfed infants or added to infant formula. Identified HMOs could also be explored for potential utility in the broader population beyond infants. Findings from this cohort will also be important in terms of the design of healthier formulas to optimize growth and development.

ClinicalTrials.gov Identifier: NCT04434027