Microbiome Markers Linked to Quality of Life for Women with IBS

A 28-day patient log of gastrointestinal symptoms, stool consistency, psychological distress, and extraintestinal pain ratings informs investigators on the significance of markers.

Emily B. Hollister, PhD

Stool microbial diversity and composition are directly linked to daily extraintestinal symptoms, stool consistency, and quality of life for women with irritable bowel syndrome (IBS).

A team led by Emily B. Hollister, PhD, Department of Pathology and Immunology, Texas Children’s Microbiome Center, evaluated the relationship of fecal microbiota to gastrointestinal symptoms, stool consistency, psychological distress, extraintestinal pain, and quality of life in patients meeting the Rome III criteria for IBS.

Altered microbial diversity has been associated with gastrointestinal symptoms in patients with irritable bowel syndrome. However, there is not much known about the link between microbiome with extraintestinal pain and psychological distress symptoms and quality of life in patients with IBS.

The study included 76 women who completed a 28-day diary that included gastrointestinal symptoms, stool consistency, psychological distress, and extraintestinal pain ratings.

Participants also completed the IBS-specific Quality of Life questionnaire.

The investigators collected and analyzed stool samples by 16S rRNA gene sequencing and performed principal component analysis, using the first 2 components—PC1 and PC2—to test the relationships among bacterial families and clinical measures.

The team categorized patients as either IBS Constipation (n = 22), IBS diarrhea (n = 39), IBS mixed (n = 13), or IBS unsubtyped (n = 2).

“There was a significant group effect for the Firmicutes to Bacteroidetes ratio and PC1,” the authors wrote. “Lower microbial diversity and richness were associated with increased urgency and extraintestinal pain, worse [quality of life], and looser stools.”

Lower extraintestinal pain was also linked with increased abundancies of Rikenellaceae, Christensenellaceae, Dehalobabacteriaceae, Oscillospiraceae, Mogibacteriacea, Ruminococcaceae, Sutterellaceae, Desulfovibrionaceae, and Erysipelotrichaceae.

Quality of life was positively associated with many of the same bacterial families. Higher Firmicutes to Bacteroidetes ratio was positively linked with loose stools, but there were no statistically significant relationships between daily psychological distress or abdominal pain and bacterial families.

Research has shown that the gut microbiota of patients with IBS lack a healthy abundance of bifidobacteria. Human milk oligosaccharides (HMOs) may help boost bifidobacteria and may also have a beneficial impact on gut motility and visceral pain, according to a new multi-center, open-label trial in patients with IBS.

In results presented at the American College of Gastroenterology’s Annual Scientific Meeting (ACG 2019) in San Antonio, TX, investigators report the ability of HMOs to support normal bowel habits and improve other symptoms of IBS.

The research team recruited 317 subjects from 17 sites across the US (70.7% females; mean age 44.0 years, range 18-93 years). Participants had received a physician diagnosis of IBS plus displayed Rome IV criteria. The study product comprised 5 grams of the HMOs 2’fucosyllactose (2’FL) and lacto-N-neotetraose (LNnT), which were administered in a 4:1 mix daily by mouth for 12 weeks. Investigators logged bowel habits, IBS symptoms, and quality of life at baseline and every 4 weeks during the study period.

A total of 245 subjects were included in the intent-to-treat analyses. From baseline to 12 weeks, all participants demonstrated a significant reduction in total percentage of abnormal bowel movements (Bristol Stool Form Scale types 1, 2, 6, or 7), overall IBS Symptom Severity Score, abdominal pain and bloating severity, and an improvement in health-related quality of life.

The study, “Relationships of Microbiome Markers With Extraintestinal, Psychological Distress and Gastrointestinal Symptoms, and Quality of Life in Women With Irritable Bowel Syndrome,” was published online in the Journal of Clinical Gastroenterology.