Personalized IBS Treatment Associated With Symptom-Based Alterations to Gut Microbiota

gut microbiome
Treatments guided by metagenomics may result in symptom improvement for patients with irritable bowel syndrome.

Metagenomic-guided interventional treatment for irritable bowel syndrome (IBS) reduced symptoms and altered gut microbiome profiles, according to study findings published in Precision Clinical Medicine.

Individuals with IBS (n=83) and healthy controls (n=5) had stool samples sequenced to assess their microbiome before and after treatment. All patients received personalized interventions for 30 days which included dietary supplementation, prebiotics or probiotics, and recommendations for lifestyle changes. Participants responded to a questionnaire about the severity of their IBS symptoms, for each category (cramps, pain, bloating, constipation, diarrhea, gas, heartburn, nausea, and vomiting), a score of 1 indicated few symptoms and 10 indicated the most severe. The final score was a normalized sum of all scores.

Participants in the control group reported an average symptom score of 20.8. The average symptom score among participants with IBS at baseline was 160. The symptom score in the IBS cohort decreased to 100.9 at the study conclusion (P =.005). Patients with constipation symptoms reported the highest symptom score reduction (-25.7 points; P =.0003).

Prebiotic and probiotic supplements had varying success according to each patient’s symptoms. Arabinex and Bacillus coagulans had larger decreases to constipation symptoms (P =.0001 and P =.0009, respectively) and Enteromend better improved diarrhea symptoms (P =.00484) compared with other supplements.

Gut microbiome profiles differed according to reported symptoms. Patients with constipation had significantly higher levels of Pseudomonas and Bacteroides thetaiotamicron and were depleted of Paraprevotella. At the study conclusion, all participants demonstrated reductions of inflammatory-associated organisms, including Streptococcus, Erysipelotrichaceae, and Campylobacter jejuni.

At baseline, a biochemical analysis indicated that among patients with diarrhea symptoms, the top pathways were biosynthesis pathways of nucleotides and fatty acids. This differed from patients with constipation symptoms; top pathways for these patients involved sugar and amino acid metabolism. At the study conclusion, patients with diarrhea had more anaerobic metabolism and the citric acid cycle pathways, but fewer nucleotide biosynthesis pathways; patients with constipation had fewer sugar and amino acid biosynthesis pathways.

The limitations of this study included the small sample sizes, especially among control individuals, and the lack of diversity among study participants.

The study authors concluded that after a personalized therapy, patients with IBS observed reductions of their symptoms and shifts to their gut microbiomes. “Given the complex nature of IBS, further studies with larger sample sizes, more targeted analyses, and a broader population cohort are needed to explore these results further,” they wrote.

Disclosure: Multiple authors declared affiliations with industry. Please refer to the original article for a full list of disclosures.

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Meydan C, Afshinnekoo E, Rickard N, et al. Improved gastrointestinal health for irritable bowel syndrome with metagenome-guided interventions. Precis Clin Med. 2020;3(2):136-146.