Oral Semaglutide's Absorption Enhancer SNAC Disrupts Gut Bacteria and Triggers Inflammation | Research

The takeaway

The absorption enhancer SNAC used in oral semaglutide significantly altered gut microbiota and triggered systemic inflammation in rats, potentially contributing to GI side effects.

SNAC drives gut disruption
Absorption enhancer, not semaglutide, is a major contributor to microbiota perturbation and inflammation

What the researchers found

SNAC absorption enhancer in oral semaglutide significantly disrupts gut microbiota and triggers systemic inflammation in rats, independent of semaglutide's effects.

Why it matters

If SNAC contributes to oral semaglutide's GI side effects, developing better absorption technologies could improve tolerability and reduce treatment discontinuation.

How the study worked

Preclinical study in Sprague Dawley rats over 21 days; three treatment groups (SEM, SNAC, SEM-SNAC) with microbiota analysis, metabolic profiling, and inflammatory marker assessment.

What this study cannot tell us

Animal model — rat gut microbiome differs from human; 21-day duration may not capture long-term adaptation; SEM dose may not perfectly model human exposure.

How to read the evidence

Preclinical animal study — important mechanistic finding but requires human validation.

When this study was published

Published 2026 in Journal of Controlled Release.

The bigger picture

Understanding excipient contributions to drug side effects is crucial for next-generation oral peptide formulations — the problem may be the delivery technology, not the drug itself.

Questions still open

Would alternative oral peptide delivery technologies avoid SNAC-related gut disruption?
Do these findings translate to human oral semaglutide users?

Common questions

Why does oral semaglutide cause stomach problems?

This study suggests that SNAC, the absorption enhancer needed for the pill to work, disrupts gut bacteria and triggers inflammation — meaning the delivery technology, not just the drug, may contribute to GI side effects.

What is SNAC?

Salcaprozate sodium (SNAC) is a compound added to oral semaglutide (Rybelsus) that helps the drug get absorbed through the stomach lining. Without it, almost none of the semaglutide would reach the bloodstream.

Read the original research

Gut microbiota perturbation and systemic inflammation are associated with salcaprozate sodium (SNAC)-enabled oral semaglutide delivery.

Journal of controlled release : official journal of the Controlled Release Society, 392, 114711

View on PubMed ↗Publisher’s paper ↗

Citation

Ariaee, Amin; Noueihad, Karim; Hunter, Alex; Wignall, Anthony; Wardill, Hannah R; Davies, Maya; Prestidge, Clive A; Joyce, Paul. (2026). Gut microbiota perturbation and systemic inflammation are associated with salcaprozate sodium (SNAC)-enabled oral semaglutide delivery.. Journal of controlled release : official journal of the Controlled Release Society, 392, 114711. https://doi.org/10.1016/j.jconrel.2026.114711