GREAT News for Coffee Lovers! New Research Links Coffee to Gut Health

New data published in Nature Microbiology reveals a striking connection between coffee and gut health. Discover the connection and how many drinks contributes to the greatest effects.

Coffee isn’t just a morning pick-me-up—it might be a microbiome wake-up call too.

And this may be one way coffee exerts its many health benefits—or at least, that’s the claim circulating around a new paper published in Nature Microbiology. I know we all want this to be true, but is it?

Well, I do have great news for you! —But you’re going to need to delay gratification, just like waiting for that delectable cup of brew at your favorite coffee shop.

This letter will reveal what they discovered, tell you how much coffee to drink to get the health benefits, compare caffeinated vs. decaf, and more. I hope you’ve had a cup or two because you’ll need focus for this.

Background: The Many Health Benefits of Coffee

First, coffee intake has already been associated with lower mortality, reduced cardiovascular disease-related death, and a lower risk of type 2 diabetes. But nutritional epidemiology—the study of diet and health outcomes in large populations—has its limitations because it can only look for correlations.

To solidify coffee’s health halo, what we want is a complementary biological mechanism, a physiological story that helps it all make sense.

Coffee Changes the Microbiome: Lawsonibacter asaccharolyticus

So, let’s introduce the protagonist of this story, a gut bacterium named Lawsonibacter asaccharolyticus. I know, it sounds kind of like a Harry Potter spell. And while it might not be magical, I think the microbiome’s governance of our health is just as mysterious.

Anyway, what the researchers did to discover the Lawsonibacter asaccharolyticus–coffee link was take information they’d gathered from highly detailed food questionnaires—including data on over 150 foods—and microbiome samples, then look for connections between specific foods and microbiome signatures.

Among the >150 foods analyzed; coffee stood out for having the clearest microbiome signature.

For further analyses, they broke participants into three groups:

• “Never” drinkers: Consumed less than three cups per month

• “Moderate” drinkers: Consumed more than this but fewer than three cups per day

• “High” drinkers: Consumed more than three cups per day

The strongest correlation between coffee consumption and the microbiome was Lawsonibacter asaccharolyticus. And—because I know you’re wondering, as I was when reading the paper—this association was independent of caffeine.

So yes, decaf counts!

The researchers also showed that Lawsonibacter asaccharolyticus is rare in newborns and children and in samples from ancient populations, two groups where coffee intake is rare.

And, across nations, coffee consumption is also linked with Lawsonibacter, reinforcing that the connection exists at both the individual and population levels.

To hammer home the point, they finally showed that Lawsonibacter grows better outside the body (in vitro) when fed coffee.

All these lines of evidence point to a model whereby coffee intake stimulates Lawsonibacter in the human microbiome.

Microbiome Metabolite “Quinic Acid” - The Next Piece of the Puzzle

Now, the next question—does Lawsonibacter asaccharolyticus do anything? This is quite a difficult question to answer. But one way to begin unraveling the mystery is to look for metabolites associated with coffee intake and Lawsonibacter abundance that are known to exert positive health effects.

One such compound the researchers discovered was quinic acid.

Quinic acid is a natural compound found both directly in coffee and also appears to be influenced be Lawsonibacter. It is thought to contributes to coffee’s perceived acidity and slightly sour, sharp quality. And though its metabolism is quite complex – it undergoes many ‘biotransformation’ by the gut – literature shows quinic acid and its metabolites have antioxidant and anti-inflammatory properties, which could provide a mechanistic basis for some of coffee’s associated health benefits, including in the brain and cardiovascular system.

Coffee & Disease - Umbrella Review

On these benefits, a landmark umbrella review of 201 observational studies found that coffee intake was associated with:

• 17% reduced risk of all-cause mortality

• 19% reduced risk of cardiovascular disease-related death

• 15% reduced risk of cardiovascular disease

• 18% lower risk of developing cancer

• 30% reduced risk of type 2 diabetes

• 36% reduced risk of Parkinson’s disease

This umbrella review alone can’t claim causation, but the consistency of results and impressive effect sizes are encouraging.

Oh, and the biggest effects were seen at 3-4 cups per day.

Since we will never have a 20-year randomized controlled trial on coffee – and before you say “I volunteer,” bear in mind ‘randomized’ means you could be placed in the coffee-restricted group for 20 years – what we need to do is piece the puzzle together by investigating how coffee might be exerting its beneficial effects.

The connection between coffee, Lawsonibacter, quinic acid, and other microbe-derived metabolites could be part of that picture.

For example, one can imagine a scenario where quinic acid and its derivatives scavenge harmful free radicals, reduce levels of inflammatory molecules, prevent LDL particle oxidation, improve blood vessel function and circulation.

I’m not claiming this is all proven in humans beyond a shadow of a doubt. What I am saying is that the literature—epidemiological and mechanistic—collectively and rather consistently points to the health benefits of coffee, with the greatest benefits seen at ~4 cups per day. The research is still steaming hot, but it’s already showing some strong results.

Finally, let me express-o myself and thank you for reading this far! I hope you found the paper digest interesting and useful. But we don’t have to be done: Starting today, I’m introducing new exclusive content for premium subscribers. To gain access to the coffee Q&A — What’s healthier, light or dark roast? What’s the healthiest coffee bean? etc. — and fun fast facts below, and more exclusive content in future (data digests, guides, and early data access) in future please consider supporting me and our Metabolic Health Mission by becoming a paid subscriber.

Coffee Q&A and Fun Fast Facts! …