5 Weeks of Postbiotics Significantly Improved Skin Elasticity and Hydration
Can what you swallow actually reach your skin? Research on the gut-skin axis, the biological pathway connecting intestinal health to skin condition, has been expanding rapidly. A randomized, double-blind, placebo-controlled trial (RCT) jointly conducted by Japan’s Kaneka and Spain’s AB-Biotics offers the latest evidence.
Heat-Treated Bacteria, Measurable Skin Changes in 5 Weeks
The trial enrolled 50 women aged 30~50. The treatment group received Lactobacillus sakei KABP-065 (brand name proBio65) at a dose of 10 billion cells per day for 5 weeks. The critical detail: this strain was not a live probiotic but a heat-treated postbiotic. The premise is that even after the bacteria are inactivated, cell wall components and metabolic byproducts can still transmit immune signals.
Results were measured with clinical-grade instruments. Cutometer readings showed that skin firmness improved significantly compared to placebo. Transepidermal water loss (TEWL) also decreased, indicating better moisture retention.
More Pronounced Improvement in Women Over 40
Subgroup analysis by age revealed a notable pattern. Participants in their 40s showed greater firmness gains than those in their 30s. Collagen synthesis naturally slows and skin barrier function begins to weaken during the fourth decade. When the baseline is lower, the impact of supplementation tends to become more visible, a pattern consistently observed in collagen supplement trials as well.
How the Gut-Skin Axis Works
There are three primary pathways through which gut microbiota influence the skin. First, a compromised gut barrier allows inflammatory molecules to enter the bloodstream and trigger skin inflammation. Second, short-chain fatty acids (SCFAs) produced by gut bacteria modulate systemic immune responses. Third, gut-derived serotonin synthesis participates in the skin cell renewal cycle. Postbiotics are thought to act primarily through the first and second pathways.
What to Check Before You Start
This trial was relatively small (50 participants) and short (5 weeks). Whether the benefits persist with long-term use, or remain after discontinuation, has not been established. When selecting a postbiotic product, verify the strain name (L.sakei KABP-065 in this study) and cell count on the label. Monthly costs for commercially available postbiotic products typically range from $15 to $40.
Frequently Asked Questions
How are postbiotics different from probiotics? Probiotics are live beneficial bacteria. Postbiotics are metabolic byproducts obtained after heat-treating or fermenting those bacteria. Even without living organisms, postbiotics can support immune regulation and barrier protection, with the added benefit of easier storage and greater stability.
What dosage was used in this trial? Participants took 10 billion (10^10) cells of heat-treated L.sakei KABP-065 (proBio65) daily for 5 weeks. Since postbiotic products vary in strains and cell counts, checking the label for strain name and cell count is essential.
If the effect was stronger in women over 40, is there any point for younger women? Improved moisture retention was observed in younger participants as well. Women over 40 saw more pronounced results likely because natural collagen decline and barrier weakening begin around that age, making external supplementation more impactful by comparison.