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Updated: May 18, 2026
Guided Protocol for Fecal Microbial Characterization by 16S rRNA-Amplicon Sequencing
Published on: March 19, 2018
Quantitative profiling of gut microbiota of children with diarrhea-predominant irritable bowel syndrome
Laura Rigsbee1, Richard Agans, Vijay Shankar
1Department of Biochemistry and Molecular Biology, Wright State University, Dayton, Ohio, USA.
Insights
Children with irritable bowel syndrome (IBS-D) show distinct gut microbiota profiles. Specific bacterial genera like Prevotella and Lactobacillus were increased, while Bifidobacterium was decreased in IBS-D patients compared to healthy children.
Area of Science:
- Microbiology
- Gastroenterology
- Human Health
Background:
- The human intestinal microbiota plays crucial roles in health and disease.
- Gut dysbiosis is implicated in various gastrointestinal disorders, including irritable bowel syndrome.
Purpose of the Study:
- To investigate and compare the gut microbiota composition in healthy children and those diagnosed with diarrhea-predominant irritable bowel syndrome (IBS-D).
Main Methods:
- Phylogenetic Microbiota Array (PMA) was employed for quantitative bacterial analysis in fecal samples.
- High-throughput DNA sequencing, quantitative PCR, and fluorescent in situ hybridization were used to validate PMA findings.
Main Results:
- The gut microbiota in both groups was primarily composed of Firmicutes, Bacteroidetes, and Actinobacteria (91% combined).
- A core microbiome of 55 phylotypes, dominated by Ruminococcus, was identified.
- Children with IBS-D exhibited increased levels of Veillonella, Prevotella, Lactobacillus, and Parasporobacterium, and decreased levels of Bifidobacterium and Verrucomicrobium compared to healthy controls.
Conclusions:
- While overall gut microbiota composition at higher taxonomic levels was similar, significant differences in specific bacterial genera were observed between healthy children and those with IBS-D.
- The core microbiome in children was dominated by Clostridia.
- Identified microbial genus associations offer testable hypotheses for gut microbiota cross-species interactions.
Objectives:
Human intestinal microbiota has a number of important roles in human health and is also implicated in several gastrointestinal disorders. The goal of this study was to determine the gut microbiota in two groups of pre- and adolescent children: healthy volunteers and children diagnosed with diarrhea predominant irritable bowel syndrome (IBS-D).
Methods:
Phylogenetic Microbiota Array was used to obtain quantitative measurements of bacterial presence and abundance in subjects ’ fecal samples. We utilized high-throughput DNA sequencing, quantitative PCR, and fluorescent in situ hybridization to confirm microarray findings.
Results:
Both sample groups were dominated by the phyla Firmicutes, Bacteroidetes, and Actinobacteria, which cumulatively constituted 91 % of overall sample composition on average. A core microbiome shared among analyzed samples encompassed 55 bacterial phylotypes dominated by genus Ruminococcus ; members of genera Clostridium , Faecalibacterium, Roseburia, Streptococcus , and Bacteroides were also present. Several genera were found to be differentially abundant in the gut of healthy and IBS groups: levels of Veillonella , Prevotella , Lactobacillus , and Parasporo bacterium were increased in children diagnosed with IBS, whereas members of Bifidobacterium and Verrucomicrobium were less abundant in those individuals. By calculating a nonparametric correlation matrix among abundances of different genera in all samples, we also examined potential associations among intestinal microbes. Strong positive correlations were found between abundances of Veillonella and both Haemophilus and Streptococcus , between Anaerovorax and Verrucomicrobium , and between Tannerella and Anaerophaga .
Conclusions:
Although at the higher taxonomical level gut microbiota was similar between healthy and IBS-D children, specific differences in the abundances of several bacterial genera were revealed. Core microbiome in children was dominated by Clostridia. Putative relationships identified among microbial genera provide testable hypotheses of cross-species associations among members of human gut microbiota
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