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Engineered Bacillus subtilis for Preventing Antibiotic-Associated Diarrhea in Children
CradleShield
Engineered Bacillus subtilis for Preventing Antibiotic-Associated Diarrhea in Children
Project Abstract
Antibiotic-associated diarrhea (AAD) affects 27–83% of children on antibiotics, yet current probiotics are antibiotic-sensitive, require cold chain, and act too slowly. We engineer Bacillus subtilis spores to produce butyrate on-site, strengthening the gut barrier within 48 hours. Our strain is naturally antibiotic-resistant, storable at room temperature, and self-limiting via dal auxotrophy — a safe, effective solution for pediatric AAD.
The Problem
27-83% of children suffer from AAD (PLoS One 2025).
Recommended probiotics (L. rhamnosus GG, S. boulardii) face three bottlenecks:
Antibiotic-sensitive
Cold-chain dependent
Slow onset
Our Solution
- 🛡️ Spore-based B. subtilis — naturally antibiotic-resistant.
- ❄️ No cold chain — stable at room temperature.
- 🧪 On-site butyrate — strengthens gut barrier in 48h.
- 🔒 Self-limiting safety — dal auxotrophy.
📊 Key Achievements
≥1.5 g/L
Butyrate yield (HPLC)
↑30% TEER
Barrier repair (Caco‑2)
↓50% HDAC8
Molecular mechanism
↓50% diarrhea
Mouse AAD model
⚙️ Engineering Design
Δdal Host
D‑alanine auxotrophy, no antibiotic markers.
Step 1Butyrate Cluster
6 genes assembled via Golden Gate.
Step 2Chromosomal Integration
amyE locus → stable & safe.
Step 3Human Practices
Parents and doctors confirmed the need: real comments, interviews, and a survey (N=46) show over half are willing to try a new solution that requires no refrigeration and can be taken with antibiotics.
We are not making a “better” probiotic.
We are dismantling the barriers.
CradleShield is built for the millions of families facing this daily struggle.