Effect of Lactibiane Tolerance® to Treat Leaky Gut in Irritable Bowel Syndrome With Predominant Diarrhea (IBS-D)Patients

Gut microbiota has many beneficial effects on the GI tract: barrier, immunomodulatory, metabolic, trophic among others. Microbiota unbalance or dysbiosis has been associated to digestive and extradigestive diseases.

Irritable bowel syndrome (IBS) is a common chronic disorder that affects the small and large intestine which causes cramping, abdominal pain, bloating, gas, diarrhea and/or constipation. Only a small number of people with IBS have severe signs and symptoms. Some people can control their symptoms by managing diet, lifestyle and stress. Others will need medication and counseling.

Intestinal permeability is the phenomenon of the gut wall in the gastrointestinal tract exhibiting permeability. It is a normal function of the intestine to exhibit some permeability, to allow nutrients to pass through the gut, while also maintaining a barrier function to keep potentially harmful substances (such as antigens) from leaving the intestine and migrating to the body more widely. In a healthy human intestine, small particles (\< 4 Å in radius) can migrate through tight junction claudin pore pathways and particles up to 10-15 Å (3.5 kDa) can transit through the paracellular space uptake route. One way in which intestinal permeability is modulated is via CXCR3 receptors in the gut wall, which respond to zonulin. Gliadin (a glycoprotein present in wheat) activates zonulin signaling irrespective of the genetic expression of autoimmunity, leading to increased intestinal permeability to macromolecules. Bacterial pathogens such as cholera, select enteric viruses, and parasites modulate intestinal tight junction structure and function, and these effects may contribute to the development of chronic intestinal disorders. Excessive intestinal permeability is a factor in stress, infections and in some several autoimmune conditions such as Crohn's disease, celiac disease, type 1 diabetes, rheumatoid arthritis, spondyloarthropathies, inflammatory bowel disease and irritable bowel syndrome, but it is not clear if increased intestinal permeability is a cause or a consequence of these conditions.

According to its ability to modulate gut associated immune system, to compete with other GI bacteria and to increase enterocyte regeneration, probiotic therapy could be proposed to overcome an increased intestinal permeability. In particular, preliminary data suggested that the probiotic multistrains Lactibiane Tolerance® could be effective in Leaky gut treatment.

In fact, Nébot-Vivinus et al. demonstrated that Lactibiane Tolerance® could prevent epithelial barrier disruption induced by lipopolysaccharide, stress or colonic soluble factors from IBS patients and prevent visceral hypersensitivity in experimental models of epithelial barrier function.

Furthermore, Drouault-Holowacz et al. demonstrated that Lactibiane Tolerance® has anti-inflammatory properties in vitro by stimulating IL-10 production and in vivo by conferring a significant protective effect in the 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis -induced colitis model (more than 50% decrease of colitis symptoms, P\<0.01).This pilot study has been designed to evaluate the effect of multistrains probiotic Lactibiane Tolerance® in a consecutive subset of IBS-D patients with increased Intestinal permeability.

Subject participation in this study will be for approximately 45 days which includes up to a 2-week screening period and a 30-day treatment period.

All subjects will participate to the following visits: screening, enrolment, day 15 and day 30.

30 IBS-D patients Objectives Primary objective To demonstrate the effect of the multistrain probiotic Lactibiane Tolerance® in normalizing leaky gut in IBS-D patients Secondary objectives

• To characterize the effect of Lactibiane Tolerance® in improving symptoms of IBS
• To characterize the effect of Lactibiane Tolerance® on serum levels of zonulin
• To characterize the effect of Lactibiane Tolerance® on stool consistency
• To characterize the effect of Lactibiane Tolerance® on quality of life
• To evaluate the safety and tolerability of Lactibiane Tolerance®. Primary endpoint Proportion of subjects with normal intestinal permeability assessed by 51Cr-EDTA or 99mTc-DTPA after 30 days of treatment.

Secondary endpoints

• Mean variation of scores of items evaluated by VAS-IBS questionnaire after treatment compared to baseline
• Percentage of patients answering "yes" to the self-evaluation question: "Do you feel that your IBS symptoms have been satisfactory alleviated by this treatment?"
• Mean concentration of serum zonulin before and after treatment
• Mean score on Bristol Stool Scale before and after treatment and proportions of patients with 6 and 7 on Bristol Stool scale before and after treatment
• Mean score of IBSQoL questionnaire before and after treatment
• Safety and tolerability evaluated by the frequency of AEs, SAEs and AEs leading to discontinuation of study treatment.