What are the gut microbiome differences between diarrheal and non-diarrheal samples?
Diarrhea changes the balance of bacteria in the gut. Research shows that people with diarrhea have fewer different types of bacteria and more of the kinds that cause infection. Healthy guts usually have a richer mix of microbes that help the body function properly.
What the research says
Studies comparing stool samples found that children with diarrhea had lower overall bacterial diversity compared to those without diarrhea 5. This loss of variety is often worse in cases of long-lasting diarrhea 5.
Specific bacteria change in predictable ways. Diarrheal samples are often enriched with harmful species like Escherichia and Campylobacter 5. At the same time, beneficial bacteria such as Prevotella copri and Faecalibacterium prausnitzii are depleted or missing in these samples 5.
Chemotherapy-induced diarrhea also shows a clear pattern. In patients taking certain cancer drugs, those who developed diarrhea had a significant drop in microbial diversity, while those without diarrhea did not 4.
Another study using DNA sequencing confirmed that the ratio of certain bacteria groups was consistently lower in diarrheal samples. The group of bacteria known as Firmicutes was the most common in healthy samples, but the balance shifted significantly in those with diarrhea 26.
What to ask your doctor
- How does my current diet affect the balance of bacteria in my gut?
This question is drawn from common patient questions about Gastroenterology and answered using cited medical research. We do not provide individualized advice.