Postbiotic Clinical Evidence for Dogs — Sordillo 2025 RCT

What the trial measured

Halitosis — chronic bad breath — affects a large share of adult dogs and is often the most visible owner-facing symptom of underlying oral microbial imbalance. Rather than masking odor, the Sordillo et al. trial tested whether feeding a defined postbiotic preparation could shift the upstream biology that produces the odor: the oral odor compounds generated by oral bacteria.

Design

• Prospective, parallel-arm, randomized. Dogs were assigned to either the postbiotic group or a matched-appearance placebo.
• Double-blind. Investigators and owners were blinded to group assignment.
• 14-day intervention with oral-odor measurement at baseline, Day 7, and Day 14.
• Sample size: 24 dogs total, evenly split (12 per arm).

What was given

The active preparation was a heat-treated, inactivated postbiotic combining fermentation products of Pediococcus pentosaceus and Bacillus subtilis on a tapioca maltodextrin carrier. Because the microbes were heat-treated, this is a true postbiotic — not a live probiotic — meaning the benefit derives from the bacterial metabolites and cell-wall components rather than colonization.

Headline results

The Day-7 result is notable because it suggests onset of effect within a relatively short window. Owners often expect to wait weeks or months before any change is visible in functional dog-health products; a measurable effect by Day 7 is unusual.

Why this matters for Plentum

Plentum is built on the broader thesis that targeted, evidence-backed postbiotic and synbiotic strategies may support several dimensions of canine wellness. Studies like this one — small but rigorous, peer-reviewed, placebo-controlled — are the type of evidence we look for when evaluating ingredient partners and informing formulation choices.

The Sordillo et al. trial focuses specifically on oral microbial outcomes (halitosis) rather than systemic gut health, and we present it as that — a halitosis trial. We do not extrapolate its findings beyond oral health. Broader claims about gut, skin, or immune outcomes would require separate evidence, which is why we publish the studies that apply to each topic on the relevant article.

Limitations

• Small sample (n = 24). Replication in larger cohorts is needed to refine effect estimates.
• Short duration (14 days). Long-term durability of the effect is not addressed.
• Single outcome domain (oral odor). The study did not measure broader microbiome or systemic gut/skin markers.
• Funded by the ingredient developer. This is disclosed in the published paper and is common for early-stage ingredient validation; readers and clinicians should weigh that context.

Citation

Disclosure

Plentum evaluates published ingredient research from multiple external groups as part of its evidence review process. Plentum did not fund this study; the funding source is disclosed in the published paper. We highlight this trial because it is the most rigorous independent clinical evidence currently available on the specific postbiotic family we work with.