The invisible garden in your gut.

Your gut is home to trillions of bacteria that do a lot more than help you digest lunch. They produce compounds your body uses every day, regulate parts of your immune system, and influence everything from inflammation to mood to metabolic health. These bacteria are known collectively as the microbiome, one of the most powerful systems in your body, and one of the most overlooked.

I like to think of a healthy microbiome as a garden in your gut. Like any garden, it needs the right conditions to thrive.

Prebiotics are the fertilizer. They're the fibers and plant compounds your body doesn't fully digest, but your bacteria do. Oats, bananas, apples (with the peel), carrots, onions, garlic, beans, asparagus are all prebiotic-rich. So if you're eating a fiber-rich diet, you're already feeding your bacteria well.

Probiotics are the plants themselves. They're the live bacteria, what you add to the system through food (yogurt, kimchi, sauerkraut, kefir) or supplements. Like any garden, yours needs diversity. Different strains do different things, which is why it's worth paying attention to what's actually in your probiotic supplement.

Postbiotics are the "fruit" those plants produce. When your bacteria are well-fed and functioning, they make compounds your body actually uses: things like short-chain fatty acids, which help maintain the gut lining and regulate inflammation. You can think of these as the fruits and vegetables the garden grows.

From there, supplementation is a question of what your specific garden needs. For most people, feeding the bacteria through a fiber-rich diet is enough; you don't need a prebiotic supplement on top of it. A probiotic can be useful when the system has been disrupted or needs reinforcement, and postbiotic supplements are worth considering in more specific cases. The point is to add what's actually missing, not to stack all three by default.

The other thing worth being thoughtful about is antibiotics. They're miraculous when you genuinely need them, but they aren't selective. Antibiotics can't tell the difference between the bacteria making you sick and the beneficial bacteria living in your gut. They kill both. It's the difference between weeding your garden by hand and spraying herbicide across the whole thing. Even one course can disrupt the microbiome significantly, and repeated courses can make it harder for the ecosystem to rebuild on its own. This is why I'm careful about antibiotic use, especially in children, whose microbiomes are still being built. And after a course of antibiotics, I almost always recommend a probiotic to help the garden rebuild.

When you tend it properly, your microbiome quietly does an extraordinary amount of work on your behalf. I consider it one of the most important things to take care of in your daily regimen.