Benefits
Skin elasticity in healthy women with dry-feeling skin
In an 8-week placebo-controlled trial in 60 Japanese women, 1 x 10^10 heat-treated cells a day raised two cheek elasticity readings, recovery and firmness, more than placebo at week 5. The recovery reading only trended higher at week 8, and the readings themselves did not differ between groups, as the supplement group started lower. Elasticity was one of three primary measures, and the maker funded and ran the trial.
Cheek skin moisture and water loss in healthy women
In the same trial, skin moisture and water loss through the skin, the other two primary measures, improved in both groups with no difference from placebo. In women in their 40s, a subgroup the registry did not plan, moisture rose more than on placebo at week 5 but not at week 8.
Self-rated facial dullness and pore appearance
On questionnaire ratings, a secondary outcome, women on the heat-treated cells rated facial dullness and visible pores lower than placebo at week 8, though the change from their own starting ratings did not differ. Ratings of dryness, itch, texture, blemishes and mood did not differ, and measured redness and pigment did not change versus placebo. Many items were compared.
Skin severity scores in children and teens
In a Korean placebo-controlled trial in children with atopic dermatitis, live cells of this strain lowered skin severity scores more than placebo after 12 weeks. In a second trial, live and heat-killed cells each lowered scores from baseline, but the abstract gives no comparison with placebo. These were small trials in a skin condition, not in healthy skin.
Live and heat-treated forms compared
The only trial that compared the two forms gave children the same daily count of live or heat-killed cells for 12 weeks and reported similar drops in severity scores and rises in skin oil. Mouse work also found both forms active. No adult trial has compared them, and the adult trial used heat-treated cells only.
Mechanism of action
Allergy-type immune signals in animals and cells
In mice with allergen-triggered skin inflammation, live or heat-inactivated cells given by mouth lowered blood IgE and the skin-homing chemokine CTACK and reduced scratching, and heat-inactivated cells lowered IL-4 and IL-6. In mast cell cultures the strain reduced degranulation and inflammatory signals. None of this was measured in the adult trial.
Skin-related chemokines in children
In the trial of live cells in children, blood levels of the chemokines CCL17 (TARC) and CCL27 (CTACK) were lower than on placebo after 12 weeks and tracked the skin severity score. These are blood markers of skin immune activity, not felt outcomes.
Proposed gut-immune-skin route for non-living cells
The trial authors propose that cell-wall parts of heat-treated cells act on immune tissue in the gut, which then influences skin barrier and inflammation. The adult trial measured skin only and did not test this route, so it remains a hypothesis.
Skin effects in dogs
In a placebo-controlled trial in dogs with allergic skin disease, two months of the strain lowered a lesion severity index. This is an animal result and has not been tested in people.
Clinical trials
Randomized, double-blind, placebo-controlled trial at a Tokyo clinical site: one capsule of 1 x 10^10 heat-treated KABP-065 cells (KCTC 10755BP, supplied by Probionic Corporation) or a starch placebo after breakfast for 8 weeks. Registered UMIN000050034 on January 13, 2023, before it started, with skin moisture, water loss and elasticity as primary outcomes. Funded by Kaneka; all six authors were employees of Kaneka Corporation or of AB-Biotics (Kaneka group), including Jordi Espadaler-Mazo of AB-Biotics (Sawashita et al. 2025, J Cosmet Dermatol)
60 Japanese women aged 30 to under 50 who felt their skin was dry; 59 completed (mean age about 42). Skin analyses used 24 women on the postbiotic and 26 on placebo after 5 were excluded for non-compliance and 4 for heavy sun exposure.
Skin moisture and water loss improved in both groups with no difference between them. The elasticity recovery reading (R2) and firmness (R7) rose more than on placebo at week 5 (P=0.022 and P=0.036); at week 8 R2 only trended (P=0.072). Net elasticity (R5) did not differ, and the elasticity readings themselves did not differ at either visit. Self-rated dullness and pores were lower than placebo at week 8 (P=0.048, P=0.045), though changes from baseline did not differ; other ratings did not differ. A subgroup in their 40s, not planned in the registry, gained more moisture at week 5 (P=0.043). Adverse events were mild or moderate, short-lived and similar between groups.
Randomized, double-blind, placebo-controlled three-arm trial in Korea: 1 x 10^10 live or dead (heat-killed) cells of L. sakei proBio65 a day, or placebo, for 12 weeks. Outcomes were SCORAD and IGA skin scores, blood inflammatory markers, and skin moisture and sebum; no registry number appears in the abstract. Three authors (Kim BC, Lee JH and the senior author Park YH) were from Probionic Corporation, the strain's developer (Rather et al. 2021, Probiotics Antimicrob Proteins)
90 children and adolescents aged 3 to 18 with atopic dermatitis were randomized; a later meta-analysis reports 58 completers (16 live, 22 heat-killed, 20 placebo).
SCORAD total score fell from baseline in the live (P=0.0015) and heat-killed (P=0.0017) groups and did not change on placebo. The abstract reports these as within-group changes and gives no between-group test; a later meta-analysis describes the scores as lower than placebo. Skin sebum rose within both active groups (P<0.0001). IGA, moisture and blood marker results are not given in the abstract.
Randomized, double-blind, placebo-controlled trial at Chungbuk National University in Korea: L. sakei KCTC 10755BP, the deposit number of proBio65 and KABP-065, or placebo daily for 12 weeks; a meta-analysis reports the dose as 5 x 10^9 CFU twice a day. The primary measure was the SCORAD score. No maker employees are listed among the authors, the abstract gives no registry number, and the paper lists non-US government support (Woo et al. 2010, Ann Allergy Asthma Immunol)
88 children aged 2 to 10 with atopic eczema-dermatitis syndrome and a SCORAD score of at least 25; 45 were given the probiotic and 75 completed (4 dropouts on probiotic, 9 on placebo).
At week 12, SCORAD total scores adjusted for baseline were lower than on placebo (P=.01): a 31% (13.1-point) improvement versus 13% (5.2-point) on placebo (P=.008), and more children reached 30% and 50% improvement. Serum CCL17 and CCL27 were lower than on placebo (P=.03 each). The cells were live, so this result does not show what the heat-treated form does.