Hatayama K., Kono K., Okuma K., Masuyama H. Effect of a specific food intervention with Tamogitake mushroom, Moringa leaves, or rice bran on intestinal microbiota and cognitive function in elderly Japanese. Front Nutr. 2025;12:1585111.
Rationale
Tamogitake is Japan's richest ergothioneine mushroom; the researchers asked a subtler question than "does it work" — does the cognitive response depend on the gut microbiota each person brings?
Methods
A multicenter dietary intervention without a placebo arm: 231 enrolled, 170 analyzed (ages 60–79) — 8 weeks of tamogitake, moringa or rice bran, with 16S gut-microbiota sequencing and Cognitrax cognitive testing.
Results
"Responders" (those whose cognitive scores improved) showed characteristic bacterial shifts — Faecalibacterium, Blautia, Parabacteroides among them — and the pattern of shift depended on which food was eaten and on the participant's sex.
Conclusions
The cautious conclusion: not "this mushroom works for everyone," but the match between a food and a baseline microbiota determines the response — personalized nutrition in action.
Worth noting
No placebo arm — a deliberate design choice, traded for the three-food comparison. The responder/non-responder microbiota split is the scientifically valuable part: it reframes null results elsewhere (maybe the wrong microbiota, not the wrong mushroom). n=170 analyzed is decent; food × sex interaction is the finding to watch being replicated.