UMIN-CTR Clinical Trial
| Unique ID issued by UMIN | UMIN000062228 |
|---|---|
| Receipt number | R000071205 |
| Scientific Title | Effects of Rice Koji Intake on Changes in Gut Microbiota and Cognitive Function, and Their Association with a Japanese-style Diet |
| Date of disclosure of the study information | 2026/07/14 |
| Last modified on | 2026/07/14 08:00:03 |
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Basic information
Public title
Effects of Rice Koji consumption on gut microbiota and brain health (cognitive function), and its association with a Japanese diet
Acronym
KOME-COG
Scientific Title
Effects of Rice Koji Intake on Changes in Gut Microbiota and Cognitive Function, and Their Association with a Japanese-style Diet
Scientific Title:Acronym
KOME-COG
Region
| Japan |
Condition
Condition
dementia
Classification by specialty
| Neurology | Adult |
Classification by malignancy
Others
Genomic information
NO
Objectives
Narrative objectives1
While the Japanese-style diet is recognized for its excellent nutritional balance and its contribution to longevity and the prevention of lifestyle-related diseases, its preservation has become challenging in recent years due to factors such as the Westernization of diets and a shift away from traditional Japanese cuisine.
Amidst this context, research focusing on the relationship between the Japanese diet, gut microbiota, and cognitive function is underway; studies have reported that frequent consumption of a Japanese diet leads to an increase in butyrate-producing bacteria in the gut. Butyrate is a type of short-chain fatty acid known for its antidepressant and cognitive-enhancing properties. Research conducted by the National Center for Geriatrics and Gerontology has also reported that individuals without dementia tend to have higher "Japanese diet scores" than those with dementia. Fermented foods -- an essential component of the Japanese diet -- have also been the subject of recent research into their various health benefits; for instance, ergothioneine, found in rice koji, has demonstrated antioxidant properties in mouse experiments and has been linked to antidepressant effects and improvements in cognitive function.
This study aims to clarify the relationship between adherence to a Japanese-style diet and gut microbiota composition, the effects of rice koji consumption on gut microbiota and cognitive function, and how the baseline level of adherence to a Japanese-style diet influences these outcomes
Basic objectives2
Efficacy
Basic objectives -Others
Trial characteristics_1
Exploratory
Trial characteristics_2
Explanatory
Developmental phase
Not applicable
Assessment
Primary outcomes
Cognitive function assessment test (Trail Making Test-B) 12 weeks after the intervention
Key secondary outcomes
Cognitive function assessment (Stroop Test), gut microbiota, and blood tests [BDNF, metabolome analysis, general hematology, liver function, renal function, blood lipids, blood glucose, etc.] and Japanese Diet Score at 6 and 12 weeks post-intervention.
Base
Study type
Interventional
Study design
Basic design
Parallel
Randomization
Randomized
Randomization unit
Individual
Blinding
Double blind -all involved are blinded
Control
Placebo
Stratification
YES
Dynamic allocation
NO
Institution consideration
Blocking
YES
Concealment
No need to know
Intervention
No. of arms
2
Purpose of intervention
Prevention
Type of intervention
| Food |
Interventions/Control_1
Consuming one bottle (118 g) of rice-koji amazake daily for 12 weeks.
Interventions/Control_2
Consuming one bottle (118 g) of a placebo beverage daily for 12 weeks.
Interventions/Control_3
Interventions/Control_4
Interventions/Control_5
Interventions/Control_6
Interventions/Control_7
Interventions/Control_8
Interventions/Control_9
Interventions/Control_10
Eligibility
Age-lower limit
| 40 | years-old | <= |
Age-upper limit
| Not applicable |
Gender
Male and Female
Key inclusion criteria
Healthy adult men and women aged 40 or older
Key exclusion criteria
-Individuals currently receiving treatment or medication for gastrointestinal, inflammatory, or metabolic diseases diagnosed by a physician (e.g., gastrointestinal diseases such as inflammatory bowel disease, irritable bowel syndrome, or celiac disease; diabetes; dyslipidemia; chronic liver disease; chronic kidney disease)
-Individuals with a history of surgery for gastrointestinal diseases, such as gastrectomy or intestinal resection
-Individuals currently receiving treatment or medication for dementia, Alzheimer's disease, psychiatric disorders, or cerebrovascular disease
-Individuals who have used or are currently using the following medications within the past 3 months: Antibiotics, steroids, immunosuppressants, or antacids (e.g., proton pump inhibitors, H2 blockers)
-Individuals who habitually and frequently consume probiotics, prebiotics, or supplements that may affect the gut microbiota
-Individuals who are pregnant or breastfeeding
-Individuals planning significant changes to their dietary or lifestyle habits (e.g., extreme dietary restrictions, weight loss programs) during the study period
-Individuals currently participating in another clinical trial or who have participated in one within the past 4 weeks
-Individuals otherwise deemed unsuitable for participation in this study by the principal investigator
Target sample size
60
Research contact person
Name of lead principal investigator
| 1st name | Koro |
| Middle name | |
| Last name | Gotoh |
Organization
Oita University
Division name
Research Center for GLOBAL and LOCAL Infectious Diseases
Zip code
879-5593
Address
1-1 Idaigaoka, Hasama-machi, Yufu City,Oita
TEL
097-586-5409
gotokoro@oita-u.ac.jp
Public contact
Name of contact person
| 1st name | Koro |
| Middle name | |
| Last name | Gotoh |
Organization
Oita University
Division name
Research Center for GLOBAL and LOCAL Infectious Diseases
Zip code
879-5593
Address
1-1 Idaigaoka, Hasama-machi, Yufu City,Oita
TEL
097-586-5409
Homepage URL
gotokoro@oita-u.ac.jp
Sponsor or person
Institute
Oita University
Institute
Department
Personal name
Funding Source
Organization
Oita University
Organization
Division
Category of Funding Organization
Japanese Governmental office
Nationality of Funding Organization
Other related organizations
Co-sponsor
HAKKAISAN BREWERY CO., LTD.
Name of secondary funder(s)
IRB Contact (For public release)
Organization
Clinical Research Center for Medical Development, Oita University Hospital
Address
1-1 Idaigaoka, Hasama-machi, Yufu City,Oita
Tel
097-586-6163
gcrcjimu@oita-u.ac.jp
Secondary IDs
Secondary IDs
NO
Study ID_1
Org. issuing International ID_1
Study ID_2
Org. issuing International ID_2
IND to MHLW
Institutions
Institutions
大分大学医学部附属病院（大分県）
Other administrative information
Date of disclosure of the study information
| 2026 | Year | 07 | Month | 14 | Day |
Related information
URL releasing protocol
Publication of results
Unpublished
Result
URL related to results and publications
Number of participants that the trial has enrolled
Results
Results date posted
Results Delayed
Results Delay Reason
Date of the first journal publication of results
Baseline Characteristics
Participant flow
Adverse events
Outcome measures
Plan to share IPD
IPD sharing Plan description
Progress
Recruitment status
Preinitiation
Date of protocol fixation
| 2026 | Year | 07 | Month | 14 | Day |
Date of IRB
| 2026 | Year | 06 | Month | 10 | Day |
Anticipated trial start date
| 2026 | Year | 07 | Month | 21 | Day |
Last follow-up date
| 2027 | Year | 11 | Month | 30 | Day |
Date of closure to data entry
Date trial data considered complete
Date analysis concluded
Other
Other related information
Management information
Registered date
| 2026 | Year | 07 | Month | 14 | Day |
Last modified on
| 2026 | Year | 07 | Month | 14 | Day |
Link to view the page
Value
https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000071205
