Benefits
Immune cell signaling in a laboratory dish
In one laboratory study, heat-killed Phorum strains were added to human CD14+ monocytes (a type of white blood cell) in culture, and the cells raised their production of cytokines, the signaling proteins immune cells use to communicate. That is activity in a dish, not a health benefit. The cells were blood monocytes, not gut tissue, so nothing in this work touched the gut. Higher cytokine output is inflammatory signaling, and whether it helps a person, does nothing, or is unwanted has not been tested, because no one has taken Phorum in a published study.
Non-living cells, with no human testing
Because postbiotics are inactivated, they deliver immune-signaling cell fragments without needing living organisms to survive digestion. No study has tested whether people who tolerate live probiotics poorly do better on Phorum, and no study has measured it engaging the gut immune system in a person.
Shelf-stable and consistent
Postbiotics stay active without refrigeration and hold up across a wide range of formats and formulations, so a consistent daily dose is easier to deliver and store than with many live probiotic products.
Built on well-characterized strains
Phorum uses the same Lactobacillus and Saccharomyces strains studied in BIOHM's probiotic work, applied here in a heat-killed form. Those earlier studies tested the live organisms in a different blend that also contained Bifidobacterium breve 19bx and alpha-amylase, so their results do not carry over to this product.
Mechanism of action
Postbiotic immune signaling
Fragments of the heat-killed microbes, such as cell-wall peptidoglycans and polysaccharides, are recognized by pattern-recognition receptors on immune cells, which is the proposed route by which a non-living postbiotic could act without needing to colonize the gut. This has not been shown in anyone taking Phorum.
Cytokine induction in monocytes
In isolated human CD14+ monocytes, the heat-killed strains raised cytokine gene and protein expression. The two bacteria were similarly stimulatory, and heat-killed S. boulardii alone was less stimulatory than the bacteria at the same concentration, although adding the yeast to the two bacteria increased stimulation further. This is cell-culture activity only, and raised cytokine output is inflammatory signaling whose value in a living person has not been measured.
Tyndallized (heat-killed) cells
Controlled heat treatment inactivates the organisms while preserving their bioactive cell structures, giving the stability and safety of a postbiotic while retaining the immune-signaling surface molecules.
Clinical trials
Laboratory study of the Phorum postbiotic strains (heat-killed L. acidophilus 16axg, L. rhamnosus 18fx and S. cerevisiae var. boulardii 16mxg) on cytokine production by human CD14+ monocytes in culture (Roberts et al., Life, 2024). No people took the product. The work was sponsored in part by a grant from BIOHM Health, LLC and the senior author is a founding partner of the company. The manufacturer says a human study in active adults is underway; it is unpublished and no ClinicalTrials.gov registration for it could be located.
Not people: human CD14+ monocytes in cell culture.
Heat-killed L. acidophilus and L. rhamnosus both stimulated naive monocytes to produce cytokines, with no significant difference between them. Heat-killed S. boulardii produced less cytokine stimulation than the bacteria at the same concentration, but adding the yeast to the two bacteria increased stimulation further. All of this happened in cell culture, so no clinical outcome was measured. Human efficacy outcomes have not yet been published.