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Published on: November 30, 2016
Fecal Microbial Composition and Predicted Functional Profile in Irritable Bowel Syndrome Differ between Subtypes and
Jose F Garcia-Mazcorro1, Mercedes Amieva-Balmori2, Arturo Triana-Romero2
1Research and Development, MNA de Mexico, San Nicolas de los Garza 66477, Mexico.
Abstract:
Increasing evidence suggests a microbial pathogenesis in irritable bowel syndrome (IBS) but the relationship remains elusive. Fecal DNA samples from 120 patients with IBS, 82 Mexican (IBS-C: n = 33, IBS-D: n = 24, IBS-M: n = 25) and 38 British (IBS-C: n = 6, IBS-D: n = 27, IBS-M: n = 5), were available for analysis using 16S rRNA gene sequencing. Firmicutes (mean: 82.1%), Actinobacteria (10.2%), and Bacteroidetes (4.4%) were the most abundant taxa. The analysis of all samples (n = 120), and females (n = 94) only, showed no significant differences in bacterial microbiota, but the analysis of Mexican patients (n = 82) showed several differences in key taxa (e.g., Faecalibacterium) among the different IBS subtypes. In IBS-D there were significantly higher Bacteroidetes in British patients (n = 27) than in Mexican patients (n = 24), suggesting unique fecal microbiota signatures within the same IBS subtype. These differences in IBS-D were also observed at lower phylogenetic levels (e.g., higher Enterobacteriaceae and Streptococcus in Mexican patients) and were accompanied by differences in several alpha diversity metrics. Beta diversity was not different among IBS subtypes when using all samples, but the analysis of IBS-D patients revealed consistent differences between Mexican and British patients. This study suggests that fecal microbiota is different between IBS subtypes and also within each subtype depending on geographical location.
Insights
Irritable bowel syndrome (IBS) gut bacteria vary by subtype and location. Mexican IBS patients showed distinct microbial differences compared to British patients, highlighting geographical impacts on the gut microbiome in IBS.
Area of Science:
- Gastroenterology
- Microbiome Research
- Human Health
Background:
- Irritable bowel syndrome (IBS) is increasingly linked to gut microbial imbalances, though the exact relationship remains unclear.
- Understanding these microbial differences is crucial for developing targeted IBS therapies.
Purpose of the Study:
- To investigate the fecal microbiota composition across different IBS subtypes (IBS-C, IBS-D, IBS-M).
- To explore potential geographical variations in the gut microbiome within the same IBS subtype, comparing Mexican and British patient cohorts.
Main Methods:
- 16S rRNA gene sequencing was performed on fecal DNA samples from 120 IBS patients (82 Mexican, 38 British).
- Microbiota composition, alpha diversity, and beta diversity were analyzed across IBS subtypes and geographical groups.
Main Results:
- While overall microbiota showed no significant differences between genders or all IBS subtypes combined, Mexican patients exhibited distinct key taxa differences among subtypes.
- Significant differences in Bacteroidetes abundance were found in IBS-D patients between British and Mexican cohorts.
- Geographical location influenced microbial signatures within the IBS-D subtype, with differences observed at lower phylogenetic levels and in alpha diversity metrics.
Conclusions:
- Fecal microbiota composition differs not only between IBS subtypes but also within subtypes based on geographical origin.
- These findings suggest that geographical factors play a role in shaping the gut microbiome in IBS patients, potentially impacting disease presentation and requiring location-specific considerations.
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