Anna Voulgari Kokota (Wageningen University Research)

Summary of presentation:
Introduction:
Preterm birth remains a leading cause of neurodevelopmental impairment. Increasing evidence supports a critical role of the gut–brain axis in early neurodevelopment, suggesting that gut microbiome modulation through probiotics, prebiotics or their combination (synbiotics) may influence brain maturation. Bifidobacterium-dominated gut communities have been associated with favorable outcomes in preterm infants, yet the underlying microbial metabolic mechanisms are not well understood.
Methods:
We conducted a longitudinal metagenomic and metaproteomic analysis of the gut microbiome in 77 preterm infants born between 24 and 30 weeks’ gestation. Of these, 41 infants received daily enteral supplementation with a test product containing Bifidobacterium breve M-16V, short-chain galactooligosaccharides (scGOS), long-chain fructooligosaccharides (lcFOS), and L-glutamine and 36 infants received a control product. For fecal samples collected at weeks 1,3 and 6 after birth, a custom protein database was generated from sample metagenomes to enable peptide and protein identification. Differential microbial protein expression between groups was quantified using label-free metaproteomics and brain development was assessed at term-equivalent age (TEA) using the Kidokoro system, which provides subscores for cerebellar, white matter and gray matter injury based on magnetic resonance imaging (MRI). Kidokoro scores were then integrated with the revealed proteomic profiles.

Results:
Metagenomics revealed increased abundance of the genus Bifidobacterium, driven by B. breve M-16V in the test group at all time points. Particularly at week 1, Bifidobacterium-related proteins involved in stress adaptation, translation, metabolism, and energy production were significantly upregulated. Key enzymes, including glutamine synthetase, β-galactosidase, and those from the Bifidobacterium shunt and fermentation pathways for acetate and lactate production, were elevated and associated with a lower incidence of white matter myelination delay at TEA.
Conclusion:
Metaproteomic analysis demonstrated that the test product modulated microbial metabolism through enhanced carbohydrate utilization, energy production, and stress adaptation—mechanisms that may support early brain maturation in preterm infants.