If you have heard about gut microbiome testing and are trying to figure out whether it is worth doing, whether the version marketed in Japan is different from Biome or ZOE, or whether the results actually change anything a doctor would recommend, this article is the one to read first.<\/p>\n
We use Mykinso<\/strong>, Japan’s largest and most peer-reviewed consumer gut microbiome test, in the BIOTOPE Clinic workflow \u2014 and we are careful about what it can and cannot tell us. This guide walks through the test honestly for Japanese patients living abroad and English-speaking readers in Tokyo.<\/p>\n Two framings up front. First, Mykinso is an assessment, not a diagnosis<\/strong>. It is not classified as a medical device in Japan, and no consumer gut microbiome test anywhere in the world is currently approved to diagnose a disease.<\/p>\n Second, the strongest reason to consider Mykinso specifically \u2014 rather than one of the American or British options \u2014 is that it is built on a Japanese reference cohort of roughly 250,000 samples<\/strong>. If you are a Japanese person tested against a Western reference population, the reading will systematically look “unusual” in ways that reflect ethnicity, diet, and geography rather than anything about your health.<\/p>\n Mykinso is developed by Cykinso, Inc.<\/strong> (\u682a\u5f0f\u4f1a\u793e\u30b5\u30a4\u30ad\u30f3\u30bd\u30fc), a Tokyo microbiome company founded in November 2014 as an Osaka University Research Institute for Microbial Diseases spinout. The consumer product launched in November 2015 as Japan’s first at-home direct-to-consumer gut microbiome test. The current consumer version, Mykinso Gut V2<\/strong>, was released on 23 January 2024 and doubled the number of report items from 10 to 20.<\/p>\n There are two lines you should know about:<\/p>\n The underlying method is 16S rRNA gene sequencing<\/strong>. Specifically, Mykinso amplifies the V1\u2013V2 region of the 16S rRNA gene, sequences it on the Illumina MiSeq platform, and classifies organisms at the genus level against the Cykinso reference cohort.<\/p>\n That method has technical trade-offs \u2014 it does not read species or strain level, and it does not tell you whether a bacterium is active or dormant \u2014 but for population-scale comparison it is the industry standard.<\/p>\n This is the single most important thing to understand before ordering any gut microbiome test.<\/p>\n Every microbiome test compares your sample to a reference population. The reference decides what “average,” “high,” and “low” mean for every genus reported. Japanese guts differ meaningfully from Western guts on several key genera.<\/p>\n The Cykinso team, in their 2021 peer-reviewed cohort paper (Watanabe et al., Bioscience of Microbiota, Food and Health<\/em>, PMID 33996369), found that Japanese individuals have higher baseline levels of Bacteroides<\/em>, Faecalibacterium<\/em>, and Bifidobacterium<\/em> than Western reference populations \u2014 with sex differences in Akkermansia<\/em> (higher in women) and Prevotella<\/em> (higher in men), and an age-related decline in Actinobacteria<\/em>.<\/p>\n The practical consequence is that a Japanese person tested against a Western cohort will consistently register as an outlier on genera that are entirely normal for their population. Reports get flagged in ways that do not reflect a real anomaly, and downstream recommendations skew toward correcting things that are not actually off. Testing against a Japan-specific reference removes that source of noise, which is why we prefer Mykinso for our Japanese-abroad patients.<\/p>\n The current 20-item report is structured around the following categories:<\/p>\n Because this is a topic where marketing and science do not always overlap, we think it is important to lay out where the microbiome literature is firm and where it is still exploratory.<\/p>\nWhat Mykinso is<\/h2>\n
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Why the reference cohort matters<\/h2>\n
What the Gut V2 report measures<\/h2>\n
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What the evidence supports \u2014 and what it does not<\/h2>\n