Children with acute and persistent diarrhea exhibited distinct gut microbiota alterations, with more pronounced microbial dysbiosis observed in persistent diarrhea, including expansion of Proteobacteria, depletion of Bacteroidota-associated commensals, and a significantly reduced Bacteroidota-to-Firmicutes ratio.
Key Findings
Results
Alpha diversity declined progressively from healthy children to acute diarrhea and was lowest in persistent diarrhea, with significant reductions in Shannon index and Faith PD metrics.
97 children under 5 years of age were divided into three groups: healthy children (HC; n=48), acute diarrhea (AD; n=32), and persistent diarrhea (PD; n=17)
Alpha diversity showed a trend of declining from HC to AD and reaching its lowest point in PD
Significant reductions were specifically observed for the Shannon index and Faith's phylogenetic diversity (Faith PD)
16S rRNA gene sequencing targeting the V3 to V4 region was used to analyze stool samples
Results
Children with acute diarrhea showed enrichment of Actinobacteriota and potentially pathogenic genera, along with depletion of beneficial commensal taxa compared to healthy children.
Acute diarrhea was associated with enrichment of Actinobacteriota at the phylum level
Potentially pathogenic genera enriched in AD included Streptococcus and Escherichia-Shigella
Beneficial commensal taxa were depleted in the AD group relative to HC
LEfSe analysis was used to identify differentially abundant bacterial taxa across groups
Results
Persistent diarrhea exhibited more pronounced dysbiosis than acute diarrhea, characterized by expansion of Proteobacteria, depletion of Bacteroidota-associated commensals, and a significantly reduced Bacteroidota-to-Firmicutes ratio.
PD showed expansion of Proteobacteria compared to HC and AD groups
Bacteroidota-associated commensal bacteria were depleted in the PD group
The Bacteroidota-to-Firmicutes ratio was significantly reduced in PD
PD dysbiosis was described as more pronounced than that observed in AD
Taxonomic classification was performed following 16S rRNA gene sequencing of the V3-V4 region
Results
Beta diversity analysis revealed significant differences in gut microbiota composition among healthy children, children with acute diarrhea, and children with persistent diarrhea.
Beta diversity metrics were estimated as part of the analytical approach
Gut microbiota composition differed significantly among all three groups (HC, AD, and PD)
Both alpha and beta diversity metrics were used to characterize microbiota differences across diarrhea duration groups
The cross-sectional study design enrolled 97 Vietnamese children under 5 years of age
Results
Gut microbiota composition and diversity profiles were distinct between acute and persistent diarrhea groups, indicating that diarrhea duration is associated with different patterns of microbial dysbiosis.
AD and PD exhibited distinct gut microbiota alterations from each other as well as from HC
The study was cross-sectional in design, recruiting children under 5 years old from Vietnam
Authors noted the findings support future longitudinal studies to clarify temporal relationships between microbiota alterations and diarrhea duration
Authors highlighted the potential for microbiome-based biomarkers and microbiota-targeted interventions based on these distinct profiles
What This Means
This research suggests that children under 5 years old with diarrhea have measurably different gut bacterial communities compared to healthy children, and that these differences become more pronounced the longer the diarrhea lasts. The study examined 97 Vietnamese children divided into three groups—healthy, those with acute diarrhea (short-term), and those with persistent diarrhea (longer-lasting)—and analyzed the bacteria in their stool samples using genetic sequencing. Children with acute diarrhea had more potentially harmful bacteria like Streptococcus and Escherichia-Shigella and fewer beneficial bacteria, while children with persistent diarrhea had even greater disruption of their normal gut bacterial balance, including an overgrowth of a bacterial group called Proteobacteria and a significant loss of other normally protective bacteria.
This research suggests that the longer diarrhea continues in young children, the greater the disruption to the gut's normal bacterial ecosystem—a condition called dysbiosis. The diversity of bacteria in the gut, measured by multiple methods, was lowest in children with persistent diarrhea, which may reflect a more severely compromised gut environment. These findings are important because they show that acute and persistent diarrhea are not simply the same condition at different time points, but may involve distinct microbial processes.
Practically, this research suggests that understanding the specific bacterial changes associated with different types of childhood diarrhea could eventually help in developing new diagnostic tools or treatments that target the gut microbiome. The authors note that future studies following children over time—rather than just taking a snapshot as this study did—would help clarify whether microbial changes cause prolonged diarrhea or result from it, and could help identify whether restoring beneficial bacteria might be a useful therapeutic strategy.
Chung N, Nguyen T, Pham V, Nguyen L, Phan N, Vo C, et al.. (2026). Characterization of gut microbiota in Vietnamese children under 5 years of age with acute and persistent diarrhea: A cross-sectional study.. Medicine. https://doi.org/10.1097/MD.0000000000050433