Probiotic ‘backpacks’ show promise for treating IBD

A new pre-clinical study by researchers at the University of Wisconsin, US, demonstrated just how much promise some well-equipped gut-friendly bacteria hold for improving treatments of inflammatory bowel disease (IBD), including Crohn’s disease and ulcerative colitis.

The research, published in Science Advances, builds on technology the team had previously designed. That prior technology encases beneficial bacteria within a very thin protective shell to help them survive an onslaught of stomach acids and competing microbes long enough to establish and multiply in the guts of mice.

While the technology makes orally administered probiotics more effective, IBD is a complex disease that usually involves more than gut microbial communities that are not working.

The team devised specialised nanoparticles to neutralise molecules implicated in IBD. They have also figured out a way of attaching these nanoparticle “backpacks” to beneficial bacteria after encasing them in the protective coating. Combined with the probiotics themselves, these nanoparticle backpacks could significantly improve and simplify IBD treatments.

The causes of IBD are complex and still being studied, but one culprit involves the overproduction of molecules known as reactive oxygen species. These molecules are crucial for certain human body functions, however too many of them in the gut can fuel damaging inflammation along the lining of intestines.

The role of the nanoparticle backpacks is to use tiny particles that are part sulphide and part hyaluronic acid. The acid is powerfully anti-inflammatory, and the sulphide directly targets the reactive oxygen species.

Conducted in mice, the latest research shows that probiotic bacteria Escherichia coli encased in a protective shell and outfitted with the nanoparticle backpacks are significantly better at relieving IBD symptoms than their counterparts without the additional gear.

The researchers estimated the effects of the treatments in two ways: by measuring changes in weight and changes in the colon length of mice with IBD that did and did not receive the treatment.

Like humans, mice with IBD commonly experienced weight loss and colon shortening as the disease progresses. The researchers found that mice that received the full treatment experienced the least amount of weight loss and much less colon shortening than their counterparts, who received partial or no treatments.

“That is the most exciting part of this research for me,” said Professor Quanyin Hu, a biomedical engineer in the UW–Madison School of Pharmacy. “We did not want to target a specific IBD stage. We wanted to select the most important factors that contribute to curing or treating the disease at whatever stage.”

Additionally, the treatment is administered orally, which could make it a palatable alternative to other, more invasive forms of IBD treatment such as partial or complete removal of the colon.

While the results are promising, it will be some time before the treatments are tested in humans.

Next in the teams’ sight is testing whether the nanoparticle backpacks work well with other probiotic bacteria species and documenting whether the treatment has any unwelcome side effects. Simplifying the process of creating and attaching the nano-backpacks will also be crucial for making the treatments clinically feasible.