Leila Shinn, PhD, RDN, FAND
R&D Life Sciences Associate Principal Scientist
Feature Publication:
Bacillus coagulans Unique IS2 improves stool characteristics in healthy adults with infrequent bowel movements: a randomized, double-blind, placebo-controlled trial

What are the main takeaways from your research?
In our study, we examined if 2 billion colony forming units per day of Bacillus coagulans Unique IS2, a strain that’s been demonstrated to work as a probiotic in people with digestive disorders, like irritable bowel syndrome, could increase stool frequency in generally healthy adults with infrequent bowel movements and improve stool consistency, gastrointestinal symptoms, and their quality of life. While we saw an improvement in stool consistency after 4 weeks, no significant effects were seen on stool frequency, gastrointestinal symptoms, or quality of life. This highlights the need for further well-designed randomized controlled trials confirming the utility of the probiotics in healthy populations.
What is the current state of the science on this topic?
With the emerging popularity of biotics, the International Scientific Association for Probiotics and Prebiotics actually recently published a paper entitled “Is There Evidence to Support Probiotic Use for Healthy People?” where they concluded that currently available evidence is not sufficient to recommend that probiotics be routinely used for disease prevention by the general population. However, the research in this area continues to grow and well-designed randomized controlled trials can start to bridge this gap.
Why are you interested in studying digestive health?
I am interested in studying digestive health because it not only connects to our overall health but connects us to one another. Digestive health is something that every single human has and experiences. Further, this aspect of our lives can be modified by diet and as a Registered Dietitian, I am passionate about understanding more about how our diet impacts our digestive and overall health, while also sharing my love for food with others.
What is something surprising or exciting you found in your research?
Probiotic supplements are often studied in people with health conditions as they search for anything that can provide relief. But due to their promise in digestive conditions, biotics have entered the mainstream markets, which is exciting to see. However, it’s important to remember that many of these probiotics may have a greater benefit in people with gastrointestinal conditions than in those who are already healthy, since healthy individuals may have near optimal digestive health and have less room for noticeable improvement.
Where would you like to see the research go next?
Because the gut microbiome and digestive health field has grown so quickly over the past decade, there is A LOT of research out there. But that doesn’t necessarily mean all that research is well-designed. Specific to probiotics in healthy people, I’d like to see more well-designed randomized controlled trials examining outcomes that matter to consumers – I can try to improve every biological marker possible, but if you don’t feel the effects, do you really care?