Note: The microbiological information in this post comes from ChatGPT 5.2. Because AIs can be wrong (though they’re very good at science), I’ve asked another AI — Claude — to fact-check ChatGPT’s facts. As always, I don’t allow ChatGPT to write for me. I use it only for research.
For a long time, I’ve been working on improving my microbiome. Only in the past decade or two have we really learned how important this is for health. But articles in the media rarely provide information or advice other than to eat a varied, balanced diet with fiber and to eat fermented foods such as yogurt, kefir, and sauerkraut. But I wanted to get technical and go beyond that.
What one learns, I think, is that we all eat for two — ourselves, and our microbiome. The typical American diet is aimed at feeding oneself (though poorly) while the microbiome is left to starve. The trick is to feed both ourselves and our microbiome with the same foods.
Here is a list of the nutrients that our microbiome needs:
1. Resistant starch. Sources: Some legumes (especially lentils), not-quite-ripe bananas, cooked and subsequently chilled starches such as potatoes and pasta.
2. β-glucans (a viscous fermentable fiber). Sources: Barley and oats.
3. Inulin and fructo-oligosaccharides. Sources: Leeks, onions, garlic, chicory root.
4. Pectins. Sources: Apples, pears, plums, carrots.
5. Hemicelluloses (partially fermentable structural fibers). Sources: Whole grains, beans, lentils, cabbage, root vegetables.
6. Legume carbohydrates (galacto-oligosaccharides + resistant starch). Sources: All beans, lentils, chickpeas.
7. Polyphenols. Sources: Berries, cocoa, coffee, tea, olive oil, red cabbage.
Note what is missing from the list above: Meat. Meat, we now know, has very little or no food value for the microbiome. In fact, meat-eating shifts the microbiome toward inferior types of microorganisms.
Also note that the foods listed above are the foods that are almost certainly missing in a diet of fast foods and processed foods.
It’s quite a wonderful thing, really, that all of these foods are abundant and cheap. Historically, the people with the best diets would have been people living in the country with farms and gardens. In times of plenty, at least, country people would have had an excellent diet.
Many of the most common health problems closely correlate with diets that leave the microbiome underfed. These health problems become chronic, and they cause us to age more quickly.
As I’ve said here many times before, I’m a barley evangelist. Bread is one of my favorite foods, but white wheat bread has very little to offer the microbiome. In fact most of it is absorbed upstream (as empty calories) and never reaches the microbiome.
It may take some determination to wean oneself off of wheat and switch to barley, because wheat and everything made from it are such appealing foods. But barley is more versatile than we might think. Pearl barley is much better than no barley, but the best barley is hulled barley, which is a whole grain. It’s possible to buy barley flour, but I greatly prefer to buy organic hulled barley and grind it myself. Below is a photo of my vintage Champion juicer with the mill attachment. I use it every day.
We all would benefit from detailed discussion with an AI about our diets, our health issues if any, and how we might better feed not only ourselves, but also our microbiome. It’s entirely possible that both of ourselves will want the same supper.
