The Weekly Biome
A clearer view of microbiome science. Expert-developed articles connect mechanisms, evidence, and limitations—so you can understand what a finding means and how much confidence it deserves.
One expert-developed article each Tuesday. Free access on Substack, delivered to your inbox.
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a scientific standard.
A defined question
Each article begins with a focused question and a documented search across relevant peer-reviewed research.
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Our scientists connect the findings across papers, weigh the evidence, and explain mechanisms alongside uncertainty.
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Claims and references are verified. A member of the team other than the writer reviews the article before publication.
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Read published articles below, or visit Substack for the current editions and subscription options.
Why Resistant Starch Does Not Work the Same Way in Every Gut
Resistant starch is often described as a fiber that reaches the colon, feeds beneficial bacteria, and increases butyrate. That description is broadly correct, but it leaves out two important variables: resistant starch is not a
From Fiber to Butyrate: The Microbial Partnerships That Make It Possible
Fiber does not enter the colon and automatically become butyrate. In many cases, no single bacterial species can complete that conversion alone. Butyrate production depends on a series of metabolic exchanges among organisms with different
When Fiber Runs Low, Protein Fermentation Gains Ground
The colon is not a uniform fermentation chamber. It is a metabolic gradient. In its first region, known as the proximal colon, gut bacteria generally have greater access to resistant starch and other fermentable carbohydrates.
Most Probiotics Don’t Stay in the Gut. That Doesn’t Mean They Failed.
Probiotics are often presented with an appealing idea: beneficial bacteria enter the intestine, establish themselves, and become permanent members of the gut microbiome. Most conventional probiotic strains do not behave that way. They may appear
