Laxative-probiotic sequential usage for irritable bowel syndrome: A novel method inspired by mathematical simulation of the microbiota

Probiotic is a major intervention to the microbiota and key therapeutic method for multiple diseases, including the irritable bowel syndrome (IBS). But current probiotic usage is limited by two factors: 1) its dynamic effect on the intestinal microbiota remains unclear, 2) probiotic strain generally can not colonize intestine lastingly. We used the generalized Lotka-Volterra equations to model the intestinal microbiota. By mathematical simulation, we identified a best administration opportunity when the colonization resistance was breakdown by laxative bowel purge, a routine preparation before colonoscopy. We then conducted a clinical trial comparing three opportunity to prescribe the Clostridium butyricum for IBS patients: starting probiotic usage immediately after colonoscopy (LP), starting probiotic usage 2 weeks after colonoscopy (L2P), and using probiotic without laxative preparation and colonoscopy (P). During the 2 weeks' probiotic treatment, the LP group demonstrated the most significant relieve in IBS summed symptom score, abdominal pain, abdominal discomfort, bowel distention or fluctuation, and defecation urgency (all p<0.05 among three groups). Our study demonstrated that the mathematical model could provide new insight into the dynamics of gut microbiota. Laxative-Clostridium butyricum usage could enhance the therapeutic benefits for IBS patients.