[Article Review] The Gut-Brain Connection: Bacteroidetes-Dominant Microbiome Linked to Enhanced Neurodevelopment in Infancy

Reference

Tamana, S. K., Tun, H. M., Konya, T., Chari, R. S., Field, C. J., Guttman, D. S., Becker, A. B., Moraes, T. J., Turvey, S. E., Subbarao, P., Sears, M. R., Pei, J., Scott, J. A., Mandhane, P. J., & Kozyrskyj, A. L. (2021). Bacteroides-dominant gut microbiome of late infancy is associated with enhanced neurodevelopment. Gut Microbes, 13(1), 1930875. https://doi.org/10.1080/19490976.2021.1930875

Review

The article by Tamana et al. (2021) investigates the association between gut microbiota and early neurodevelopment in infants. The authors analyzed data from 405 infants from the Canadian Healthy Infant Longitudinal Development (CHILD) Cohort Study, using the Bayley Scale of Infant Development (BSID-III) to assess neurodevelopmental outcomes at 1 and 2 years of age. Fecal samples were collected at a mean age of 4 and 12 months for microbiota profiling using 16S rRNA gene sequencing.

The study identified three infant groups based on the relative abundance of gut microbiota at 12 months: Proteobacteria-dominant, Firmicutes-dominant, and Bacteroidetes-dominant clusters. The Bacteroidetes-dominant cluster demonstrated a significant positive association with cognitive, language, and motor development scores at age 2, particularly among male infants. The genus Bacteroides abundance in gut microbiota was positively correlated with cognitive and language scores at age 2. The study found no associations between 4-month microbiota clusters and BSID-II scores.

Tamana et al. (2021) suggest that Bacteroidetes-dominant gut microbiota in late infancy is associated with better neurodevelopment, particularly in males. Enhanced sphingolipid synthesis and metabolism, as well as antagonism or competition between Bacteroides and Streptococcus, were characteristic of Bacteroidetes-dominant gut microbiota. This study contributes valuable insights into the gut-brain connection and the potential impact of gut microbiota on early neurodevelopment.

[Article Review] Uncovering the Impact of Cannabis on Youth IQ: A Comprehensive Review

Reference

Power, E., Sabherwal, S., Healy, C., O'Neill, A., Cotter, D., & Cannon, M. (2021). Intelligence quotient decline following frequent or dependent cannabis use in youth: a systematic review and meta-analysis of longitudinal studies. Psychological Medicine, 51(2), 194-200. https://doi.org/10.1017/S0033291720005036

Review

In their recent study, Power et al. (2021) aimed to investigate the relationship between frequent and dependent cannabis use among youth and subsequent decline in Intelligence Quotient (IQ). The authors conducted a systematic review and meta-analysis of cohort studies that included pre- and post-exposure measures of IQ in non-treatment-seeking samples.

The authors searched Embase, PubMed, and PsychInfo databases from their inception until 24 January 2020, and pre-registered their review on PROSPERO (ID no. CRD42019125624). A total of seven cohort studies were identified, including 808 cases and 5308 controls. The studies were of moderate to high quality, and there was a low level of statistical heterogeneity (I2 = 0.2%) among them.

The results indicated a significant effect of frequent or dependent cannabis use in youth on IQ change, with a Cohen's d of -0.132 (95% CI -0.198 to -0.066) and p < 0.001. This translates to an average decline of approximately 2 IQ points following exposure to cannabis in youth. The authors suggest that future studies should include longer follow-up periods to assess the magnitude of developmental impact.

This study is an important addition to the literature on the effects of cannabis use on cognitive functioning and intelligence, particularly in young people. By providing a rigorous, systematic review and meta-analysis, Power et al. (2021) offer valuable insights into the potential negative consequences of frequent or dependent cannabis use on IQ and overall cognitive development.

[Article Review] Shining a Light on the Link between Vitamin D during Pregnancy and Children's Cognitive Development

Reference

Melough, M. M., Murphy, L. E., Graff, J. C., Derefinko, K. J., LeWinn, K. Z., Bush, N. R., Enquobahrie, D. A., Loftus, C. T., Kocak, M., Sathyanarayana, S., & Tylavsky, F. A. (2021). Maternal Plasma 25-Hydroxyvitamin D during Gestation Is Positively Associated with Neurocognitive Development in Offspring at Age 4–6 Years. The Journal of Nutrition, 151(1), 132-139. https://doi.org/10.1093/jn/nxaa309

Review

Melough et al.'s (2021) study explored the relationship between gestational 25-hydroxyvitamin D [25(OH)D] levels and IQ scores among children aged 4-6 years. The researchers used data from the CANDLE (Conditions Affecting Neurocognitive Development and Learning in Early Childhood) cohort, which included 1,503 women in their second trimester of healthy singleton pregnancies. The study found that higher maternal 25(OH)D levels during the second trimester were associated with higher Full Scale IQ, Verbal IQ, and Nonverbal IQ scores in offspring at 4-6 years old. The authors observed no evidence of effect modification by race.

The results of this study suggest that gestational vitamin D status may be an essential predictor of neurocognitive development. These findings have implications for prenatal nutrition recommendations and are particularly relevant for Black and other dark-skinned women who are at a higher risk of vitamin D deficiency. By emphasizing the importance of maintaining adequate vitamin D levels during pregnancy, healthcare providers can better support optimal neurocognitive development in children.

[Article Review] Nourishing the Mind: How Early Nutrition Shapes Cognitive Outcomes in Children

Reference

Anjos, T., Altmäe, S., Emmett, P., Tiemeier, H., Closa-Monasterolo, R., Luque, V., ... & Campoy, C., & The NUTRIMENTHE Research Group. (2013). Nutrition and neurodevelopment in children: focus on NUTRIMENTHE project. European Journal of Nutrition, 52(8), 1825-1842. https://doi.org/10.1007/s00394-013-0560-4

Review

Anjos et al. (2013) delve into the potential links between early nutrition and subsequent cognitive performance in children. Recognizing the profound implications this relationship holds for health policy, human biology, economic development, and beyond, the article gives weight to the role of maternal diet during gestation and its potential to mold future cognitive and behavioral outcomes of the offspring.

Central to the review is the acknowledgment of certain micronutrients—specifically folate, n-3 fatty acids, and iron—as playing pivotal roles in brain development. While the advocacy for nutrient-rich diets for pregnant women isn't novel, the article brings to light the notion that simplistic, single-nutrient supplementation may not be as effective as more comprehensive formulas. This perspective offers a more nuanced view of nutritional recommendations, suggesting that a holistic approach might be more effective. Additionally, the review appropriately underscores the importance of considering genetic variability in future research endeavors. A notable element of this work is its presentation of the European Project NUTRIMENTHE, which aims to further unravel the complexities of nutrition’s impact on cognition and behavior in children.

Anjos et al. (2013) offer a balanced overview of the existing evidence connecting nutrition to cognitive and behavioral outcomes in children. By emphasizing the need for further research, especially in the realm of holistic supplementation and genetic factors, the review aptly points towards future research directions and provides foundational knowledge for those interested in the nexus of nutrition and neurodevelopment.