HPP & microbiome impact

HPP doesn’t target only “bad bacteria.” Here’s what to know about microbial viability and raw feeding goals.

A common marketing message is that HPP reduces “harmful bacteria” while leaving the food otherwise essentially the same. The technical reality: HPP is designed to inactivate pressure-sensitive vegetative cells—it is not selective for “bad” microbes only.^[1]^[3]

Why this matters in raw feeding

Many raw feeders believe the microbial ecology of raw food (and how it supports the broader gut environment) is part of the point. Even if microbial counts are “small,” a raw diet is often chosen for its biological character.

What studies show about viability

Effects depend on organism type and processing conditions. In some contexts, high pressure can reduce viability; in others, it can push organisms into states like VBNC (viable but non-culturable), where they may be alive but hard to detect by standard culture methods.^[5]

Reviews of HPP’s impact on probiotics emphasize that outcomes vary by pressure range, duration, storage, and strain—there is no universal “HPP preserves beneficial microbes” guarantee.^[4]

Plain-language takeaway: if “keeping raw, living character” is one of your reasons for raw feeding, a broad-spectrum pressure intervention conflicts with that goal—even if it also reduces risk.