Nutrient intake, gut inflammation markers, and intestinal permeability in infants aged 6-12 months

Increased intestinal permeability and proinflammatory status have been linked with increased risk of autoimmune diseases such as type 1 diabetes. The contribution of dietary composition to gut maturation in infants consuming complementary foods remains unclear. The aim was to assess whether intake of different nutrients is associated with the level of intestinal permeability and gut inflammation markers of infants aged 6-12 months.

This was a secondary analysis using existing cohort data from a randomized controlled trial, the Early Dietary Intervention and Later Signs of Beta-Cell Autoimmunity (EDIA) Study (N = 73). Weighed 3-day food records were collected at 6, 9, and 12 months of age. At the same age points, lactulose/mannitol tests (N = 72) were performed for assessment of intestinal permeability, and stool samples (N = 72) collected for analysis of gut inflammation markers calprotectin and human β-defensin-2 (HBD-2). Generalized estimation equations (GEE) were used to assess associations between repeated measures of energy-adjusted nutrient intakes with intestinal permeability, calprotectin, and HBD-2.

Higher intake of saturated fat was associated with higher intestinal permeability, calprotectin, and HBD-2, while higher intake of dietary fibre, pyridoxine (vitamin B6), iron, magnesium, and potassium were associated with lower permeability, calprotectin, and HBD-2. The nutrients with inverse associations were intercorrelated with each other. Additionally, the intercorrelated nutrients correlated negatively with the proportion of total energy intake from breast milk, which was associated with higher permeability and inflammation markers. Adjusting models for the proportion of energy from breast milk attenuated many of the associations of nutrients, especially with permeability, but the intake of dietary fibre remained associated with lower calprotectin and HBD-2, and intake of potassium with lower calprotectin and permeability.

While breastfeeding remains a major determinant of gut maturation, consumption of complementary foods higher in intercorrelated nutrients including dietary fibre and potassium is associated with lower gut inflammation markers and, less robustly, reduced intestinal permeability in infants with genetic susceptibility to type 1 diabetes aged 6-12 months. Trial registration clinicaltrials.gov NCT01735123.