Background: Early childhood development forms the foundation of health, learning, and behavior throughout life. Sleep plays a crucial role in brain maturation, synaptic reorganization, and cellular homeostasis. Sleep disturbances affect approximately 33% of children and are associated with cognitive deficits, behavioral problems, and metabolic dysfunction. Nutrition, particularly the composition of infant feeding, may significantly influence sleep architecture and neurophysiological development.

Objective: To evaluate the role of natural (breastfeeding) and artificial feeding (with and without probiotics) on brain bioelectrical activity and sleep–wake cycle formation in early childhood.

Methods: A one-year prospective study was conducted involving 122 children (62 boys, 60 girls) divided into three groups: Group 1 (n=22) – exclusively breastfed; Group 2 (n=50) – fed with infant milk formulas without probiotics; Group 3 (n=50) – fed with infant milk formulas containing probiotics. Psychosomatic status and sleep–wake rhythms were assessed using electroencephalography (EEG), sleep duration measurements, and analysis of daytime/nighttime awakenings. Bacteriological stool examination was also performed.

Results: At 1 month of age, all groups showed normal EEG indicators. From 3 to 12 months, Group 2 demonstrated significantly lower alpha-wave index values (p < 0.01) and delayed maturation of bioelectrical brain activity compared to Groups 1 and 3. The delta index showed the strongest age-related reduction in Group 3 (p < 0.01). At 12 months, REM sleep duration was highest in Group 3 (70%), while deep sleep predominated in Group 1 (60–65%). Children in Groups 1 and 3 had fewer nighttime awakenings (1–2 vs. 2–3 in Group 2; p ≤ 0.05) and more organized sleep cycles. Bacteriological analysis revealed that 90.1% of children in Group 2 had reduced bifidobacteria counts compared to Group 1 (p ≤ 0.001).

Conclusion: Breastfeeding and probiotic-supplemented infant formulas are associated with more favorable EEG parameters, accelerated maturation of bioelectrical brain activity, improved sleep architecture, and healthier gut microbiota compared to standard formula without probiotics. These findings support the importance of optimal nutrition for early neurodevelopment.

Early childhood development, brain maturation, sleep–wake cycle

Gilchrist, A., Aylward, B. S., Laine, C. M., & Karp, H. (2025). Maturation of infant sleep during the first 6 months of life: A mini-scoping review. Frontiers in Neuroscience, 19, 1581325.

Schoch, S. F., Kurth, S., & Huber, R. (2021). Developmental changes in sleep and their relation to neurodevelopment in infants and children. Current Opinion in Psychiatry, 34(6), 493–499.

Colombo, M., Lokhandwala, S., & Spencer, R. M. C. (2021). Sleep neurophysiology and cognitive development in infancy. Developmental Psychobiology, 63(7), 1010–1022.

Mindell, J. A., & Lee, C. (2015). Sleep disturbances in infants and toddlers: Prevalence, impact, and management. Sleep Medicine Reviews, 19, 50–58.

Tikotzky, L., Sadeh, A., & Glickman, I. (2023). Infant sleep and parental well-being: Longitudinal perspectives. Journal of Sleep Research, 32(1), e13789.

Ednick, M., Cohen, A. P., McPhail, G. L., Beebe, D., Simakajornboon, N., & Amin, R. S. (2009). A review of the effects of sleep on growth hormone secretion and neurodevelopment in infants. Pediatric Pulmonology, 44(4), 356–364.

Santi, D., Debbi, V., Costantino, F., Spaggiari, G., Simoni, M., Greco, C., & Casarini, L. (2023). Microbiota composition and probiotics supplementation on sleep quality: A systematic review and meta-analysis. Clocks & Sleep, 5(4), 770–792.

Zimmermann, P., Kurth, S., Giannoukos, S., Stocker, M., & Bokulich, N. A. (2024). NapBiome trial: Targeting gut microbiota to improve sleep rhythm and developmental outcomes in early childhood. BMJ Open, 15(3), e092938.

Matin, M., Brockway, M., Badejo, A., Kouroupis, A., Janke, R., & Keys, E. (2024). Effect of biotic supplementation on infant sleep and settling behaviours: A systematic review and meta-analysis. Beneficial Microbes, 15(6), 609–641.

Sharkey, K. M., Iglowstein, I., & Owais, S. (2016). Sleep patterns and sleep problems in infants and toddlers: Clinical implications. Sleep Medicine Clinics, 11(4), 533–544.

Anders, T. F., & Keener, M. A. (1985). Developmental course of nighttime sleep–wake patterns in full-term and premature infants during the first year of life. Sleep, 8(3), 173–192.

Jenni, O. G., & Carskadon, M. A. (2004). Spectral analysis of the sleep electroencephalogram during adolescence. Sleep, 27(4), 774–783.

Grigg-Damberger, M. M. (2016). The visual scoring of sleep in infants 0–2 months of age. Journal of Clinical Sleep Medicine, 12(3), 429–445.

Bathory, E., & Tomopoulos, S. (2017). Sleep regulation, circadian rhythms, and early childhood development. Pediatric Clinics of North America, 64(3), 563–579.

Halal, C. S. E., & Nunes, M. L. (2019). Sleep and early brain development: The role of nutrition and environment. Sleep Medicine, 60, 1–7.

Taveras, E. M., Rifas-Shiman, S. L., Oken, E., Gunderson, E. P., & Gillman, M. W. (2008). Short sleep duration in infancy and risk of childhood obesity. Archives of Pediatrics & Adolescent Medicine, 162(4), 305–311.

Lozoff, B., Beard, J., Connor, J., Barbara, F., Georgieff, M., & Schallert, T. (2006). Long-lasting neural and behavioral effects of iron deficiency in infancy. Nutrition Reviews, 64(5), S34–S43.

Walker, M. P., & Stickgold, R. (2006). Sleep, memory, and plasticity. Annual Review of Psychology, 57, 139–166.

Horne, R. S. C., & Ferens, D. (2018). Infant sleep and sudden infant death syndrome (SIDS): Neurophysiological perspectives. Sleep Medicine Reviews, 42, 84–96.

Montgomery-Downs, H. E., Crabtree, V. M., & Gozal, D. (2005). Infant sleep and sleep disorders: Implications for cognitive and behavioral development. Sleep Medicine Reviews, 9(2), 119–135.

Franco, P., Scaillet, S., Wermenbol, V., Valente, F., Groswasser, J., & Kahn, A. (2000). Sleep architecture and sleep-related breathing disorders in infants. Sleep Medicine, 1(2), 121–132.

Feldman, R. (2007). Parent–infant synchrony and the development of sleep regulation. Journal of Child Psychology and Psychiatry, 48(6), 593–611.

Tarullo, A. R., & Gunnar, M. R. (2006). Infant sleep and stress regulation: Cortisol rhythms and caregiving. Developmental Psychobiology, 48(5), 460–474.

Peirano, P., Algarín, C., & Uauy, R. (2003). Sleep and neurofunctions throughout childhood: Nutritional bases. Nutrition Reviews, 61(6), 193–204.

Jenni, O. G., & Dahl, R. E. (2008). Sleep, cognition, and emotion: A developmental view. Child Development, 79(1), 35–48.