Childhood stunting is a significant global health issue, particularly in low- and middle-income countries (LMICs). It is associated with impaired cognitive development, increased risk of infections, morbidity, and mortality. Recent research suggests that the composition of the enteric microbiota may contribute to the pathogenesis of stunting. To explore this potential link, researchers in this study systematically reviewed studies using high-throughput genomic sequencing methods to characterize the gut microbiome in stunted versus non-stunted children under five years in LMICs.
Key Findings
Microbial Diversity
- Alpha Diversity: Most studies did not report significant differences in alpha diversity between stunted and non-stunted children.
- Beta Diversity: Four out of seven studies reported significantly higher beta diversity in stunted children, indicating differences in the overall microbial community composition.
Phylum-Level Associations
- Inconsistent Findings: Associations with stunting were inconsistent for Bacillota, Pseudomonadota, and Bacteroidota phyla across the studies.
Genus-Level Associations
- No Universal Genus: No single genus was consistently associated with stunting across all studies. Some genera showed inconsistent associations.
- Pathobionts: Stunting was often associated with an abundance of pathobionts such as Escherichia/Shigella, Campylobacter, Desulfovibrio, and Neisseria, which can drive inflammation.
- Butyrate Producers: There was a consistent reduction in butyrate producers, including Faecalibacterium, Megasphaera, Blautia, and an increase in Ruminococcus, which are important for gut health.
Oropharyngeal Taxa
- Duodenal and Fecal Samples: An abundance of taxa thought to originate from the oropharynx (e.g., Veillonella, Neisseria, Streptococcus, Haemophilus) was reported in duodenal and fecal samples of stunted children, suggesting possible microbial translocation and decompartmentalization within the gastrointestinal tract.
Metabolic Pathways
- Predictive Pathways: Metabolic pathways such as purine and pyrimidine biosynthesis, vitamin B biosynthesis, and carbohydrate and amino acid degradation pathways were identified as predictors of linear growth, linking gut microbiome function to growth outcomes.
Mechanistic Insights
- Intestinal Barrier Integrity: Disturbances in the gut microbiome may increase intestinal permeability, leading to inflammation and reduced nutrient absorption, contributing to stunting.
- Gut Microbiome Immaturity: Similar to findings in severe acute malnutrition, stunted children often have an immature gut microbiome characterized by reduced diversity and a depletion of beneficial taxa.
This systematic review underscores the potential role of the gut microbiome in childhood stunting, with stunted children showing distinct microbial patterns. While current research is limited and findings are sometimes inconsistent, future studies should focus on elucidating the mechanisms through which the microbiome influences growth. Such research could pave the way for effective microbiome-based interventions to combat childhood stunting, particularly in resource-limited settings where the burden of stunting is highest.
Link to the study : https://tinyurl.com/2asef8y4
