(OR18-01-26) Associations Between the Gut Microbiome and Neurodevelopment Scores in a Breastfed Infant Complementary Feeding Trial

Objectives: The complementary feeding period (~6-24 months) is critical for brain and gut microbiome development with potential to impact long-term functional outcomes. Although emerging research has linked early-life gut microbiome to neurodevelopment, few studies have examined this relationship within complementary diet interventions. Our primary aim is to characterize associations between the gut microbiome and neurodevelopment scores within a complementary feeding trial.

Methods: In a randomized, controlled trial with semi-controlled complementary feeding, healthy, term, exclusively breastfed infants were assigned to a meat-enriched (ME) or ad-libitum (REF) diet. A baseline visit (5-6 months) was followed by bi-monthly home visits, with study food delivery (ME only) and diet record collection, and a 12-month visit with a Bayley Scales of Infant and Toddler Neurodevelopment Third Edition (BSID-III) assessment and stool-derived bacterial 16S rRNA gene profiling. Diet group differences in macronutrient intake, microbiome composition, and BSID-III scores were tested with t-tests. Linear models assessed associations between genus-level relative abundance and BSID-III composite subset scores, with sequencing run and diet group included in models as covariates.

Results: No differences were observed between diet groups in total macronutrient intake, microbial composition, or BSID-III scores (n=76; all p>0.05). Of 96 annotated genera, 38 were significantly associated (p < 0.05) with >1 BSID-III subset score. 24 genera were negatively (β < 0) and 16 were positively (β>0) correlated with >1 score. 13 positively associated genera (e.g. Roseburia, Lachnospira) are known short-chain fatty acid (SCFA) producers, while 18 negatively associated genera (e.g. Haemophilus, Neisseria) are potentially pro-inflammatory or opportunistic pathogens.

Conclusions: Although the complementary diet intervention did not alter outcomes, taxa associated with SCFA production were linked to better neurodevelopmental outcomes, and pro-inflammatory taxa were associated with lower scores. Additional investigations of potential interactions among complementary diet, microbiome maturation and neurodevelopment are warranted.

Funding Sources: University of Colorado NIDDK Nutrition T32 and CCTSI, National Pork Board, Meat Foundation