Does Day-to-Day Variability in Stool Consistency Link to the Fecal Microbiota Composition?

Area of Science:

• Gastroenterology
• Microbiology
• Human Gut Microbiome Research

Background:

• Fecal microbial composition is linked to stool consistency.
• Variability in stool consistency over time is common in individuals with and without gastrointestinal disorders.
• The impact of day-to-day stool consistency fluctuations on fecal microbiota requires investigation.

Purpose of the Study:

• To evaluate the within-subject day-to-day variability in stool consistency.
• To assess the association between stool consistency and fecal microbiota composition.
• To investigate these associations in individuals with irritable bowel syndrome (IBS) and healthy controls.

Main Methods:

• 12 IBS patients and 12 healthy subjects provided daily fecal samples over seven days.
• Stool consistency was assessed using the Bristol Stool Scale (BSS) and fecal dry weight.
• Fecal microbiota was analyzed using 16S rRNA gene sequencing to determine microbial richness and community structure.

Main Results:

• Significant associations were found between stool consistency and microbial richness (alpha diversity).
• Significant associations were observed between stool consistency and microbial community structure (beta diversity).
• No significant time effect was detected for within-subject day-to-day variations in stool consistency or its impact on microbiota.

Conclusions:

• Stool consistency is associated with fecal microbiota, but short-term (seven-day) fluctuations do not affect it.
• This study underscores the importance of considering stool consistency in gut microbiota research.
• Single fecal sample collection remains valid for representing an individual's microbiota at a specific time point.