Peptide field guide
Phosphorylated lantibiotics (pLANs)
Phosphorylated lantibiotics (pLANs) are a recently described class of RiPP (ribosomally synthesized and post-translationally modified peptide) antimicrobials. A 2026 NPJ Biofilms & Microbiomes paper linked pLAN-producing oral commensals (Streptococcus salivarius) to pathogen suppression in dysbiotic biofilms and reported an early human feasibility signal after short-term dosing.
What it is
Phosphorylated lantibiotics (pLANs) are described in the literature as a class of ribosomally synthesized and post-translationally modified peptides (RiPPs).
They sit in the broader family of lantibiotic-like antimicrobial peptides, but with additional biochemical features (including phosphorylation) that may contribute to activity and immune interactions.
Why people care about it
Two reasons:
- Antimicrobial activity against clinically relevant pathogens.
- A potential path toward “precision” microbiome interventions, where a commensal organism produces peptides locally (for example in the oral cavity), rather than relying on systemic dosing of a purified antimicrobial.
What we know vs what we don’t know
What we know:
- pLANs are reported as a RiPP class with antimicrobial activity.
- A 2026 paper reported that a pLAN-producing oral commensal (Streptococcus salivarius; strain SALI-10) can engraft in dysbiotic biofilm models and suppress pathogen signals.
What we don’t know:
- Which specific pLAN sequences/structures will be most relevant for translation (pLANs is a class, not a single molecule).
- How durable, clinically meaningful effects are in humans.
- How frequently resistance emerges, and what the off-target microbiome consequences look like across longer periods.
Latest updates
- 2026-04-03: NPJ Biofilms & Microbiomes reports pLAN-producing S. salivarius (SALI-10) associated with pathogen suppression in dysbiotic biofilms and an early first-in-human feasibility signal after 1 week daily oral administration. https://pubmed.ncbi.nlm.nih.gov/41932913/ (doi:10.1038/s41522-026-00976-y)
Safety reality
pLANs are not an approved therapeutic category. “Live” commensal administration and antimicrobial peptide production both raise safety questions (microbiome perturbation, unintended selection pressure, immunologic effects) that require controlled clinical data.