# Not quite a cure yet: unlocking the unfulfilled promise of live biotherapeutics for disease treatment

## TL;DR

Live microbial treatments have shown mixed results in treating diseases, with inflammation and delivery challenges limiting their effectiveness.

## Contribution

The paper identifies inflammation and delivery issues as key barriers to live microbial therapies and emphasizes the need for interdisciplinary collaboration.

## Key findings

- Intestinal inflammation is negatively correlated with clinical responsiveness to probiotics.
- Escherichia coli Nissle 1917 is effective in maintaining remission but not in treating active ulcerative colitis.
- Shelf life and delivery strategies significantly impact microbial viability in the gut.

## Abstract

Few live microbial therapeutics have demonstrated conclusive or reproducible clinical efficacy. Cochrane meta-analyses of probiotic interventions across multiple clinical trials, analyzed using a rank-biserial correlation test, revealed that intestinal inflammation is negatively correlated with clinical responsiveness. This is exemplified by Escherichia coli Nissle 1917, which shows efficacy in maintaining remission comparable to frontline therapies, yet fails to demonstrate clear benefit in the treatment of active ulcerative colitis, an inflammatory bowel disease defined by chronic intestinal inflammation. Beyond inflammation as a key barrier to efficacy, inadequate shelf life and delivery strategies further compromise microbial viability and functional persistence in the gastrointestinal tract. Here, we highlight both the challenges and emerging opportunities in the field of live microbial therapeutics, emphasizing the urgent need to integrate scientific, clinical, and industrial efforts to achieve durable and clinically meaningful outcomes.