IBS Patients with Low Alistipes Less Responsive to FMT Interventions

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Investigators were uncertain as to whether low fecal Alistipes could be used as a marker for predicting the outcome of FMT.

A new investigation into the efficacy of fecal microbiota transplantation (FMT) interventions found that both male and female patients with irritable bowel syndrome (IBS) and low fecal Alistipes levels were most likely not to respond to treatment.

However, investigators were uncertain as to whether low fecal Alistipes could be used as a marker for predicting the outcome of FMT.

Despite the prevalence of FMT interventions, recent research has suggested that the treatment is not successful for every IBS patient, since the outcome of FMT varies with the IBS subset.

As such, investigators led by Magdy El-Salhy, MD, PhD, Department of Clinical Medicine at the University of Bergen, Norway, investigated the factors that could potentially affect FMT response using a patient cohort from the team’s previous study.

The Methods

Patients included in the study completed 5 questionnaires that assessed their symptoms and quality of life at baseline and at 2 weeks, 1 month, and 3 months following FMT.

The questionnaires included the IBS-SSS, Birmingham IBS Symptom, Fatigue Assessment Scale (FAS), IBS Quality of Life Scale (IBS-QoL), and the Short-Form Nepean Dyspepsia Index (SF-NDI).

Inclusion criteria consisted of being between 18-75 years and having moderate-to-severe IBS symptoms.

Patients were tasked with providing fecal samples at baseline and 1 month after the intervention, and were subsequently randomized at a 1:1:1 ratio into placebo, 30-g, and 60-g groups.

From there, the transplant was mixed manually and administered to the distal duodenum via a gastroscope.

The Findings

The study included a total of 109 patients who received allogenic FMT.

Investigators observed that the response rates in males were significantly lower than in females (p=0.006). Regarding responders, the proportion of females was significantly higher than males, while in nonresponders the proportion of males was significantly higher than females.

No differences between responders and non-responders in IBS subtypes, age, or IBS duration was observed.

Additionally, the total IBS-SSS and Birmingham IBS Symptom scores did not differ between responders and non-responders at baseline, but decreased among responders 3 months after FMT.

However, the fluorescence signals of 6 bacteria including AlistipesActinobacteriaBacteroides fragilisBacteroides pectinophilusStreptococcus salivarius ssp. thermophilusand sanguinis, and Akkermansia muciniphila differed considerably between responders and non-responders.

The fluorescence signals of AlistipesBacteroides fragilisStreptococcus salivarius ssp. thermophilus, and Streptococcus sanguinis were higher in responders than in non-responders, while the fluorescence signals of ActinobacteriaBacteroides pectinophilus, and Akkermansia muciniphila were lower in responders than in non-responders.

With the exception of Alistipes following FMT, no differences in the fluorescence signals of the bacteria were seen.

Additionally, though the fluorescence signals of Alistipes increased significantly after FMT in non-responders, it was not comparable to the levels observed in responders.

Regarding these changes in the fluorescence signals of Alistipes, the team noted that they have yet to determine the extent of these changes in regards to IBS improvement.

“Further studies are needed to establish whether Alistipes levels can be used as indicator to the FMT outcome,” the team wrote.

The study, "Irritable bowel syndrome patients who are not likely to respond to fecal microbiota transplantation," was published online in Neorogastroenterology and Motility.