You’re carrying a population of gut bacteria that took years to establish. It settled in early, shifted about according to how you’ve eaten and lived, and by now it’s reasonably stable. Most of the time it looks after itself, and you never think about it.
Then something knocks it back.
Antibiotics don’t aim. They deal with the infection you’re treating, and they clear out a good deal of everything else while they’re at it. That’s the trade you make, and usually it’s worth making.
What follows is a period where the resident population is depleted and rebuilding. It does recover. It just takes time, and those weeks afterwards are when people most often notice their digestion isn’t quite behaving.
This is when most people reach for a probiotic, and it’s the most sensible moment to. There’s an actual gap, and something is going in while the population rebuilds.
Illness does something similar, particularly if you’ve had a stomach bug. So does a long stretch of eating badly, or a period where everything else in life has taken priority and food has been whatever was quickest.
Assuming you do reach for a probiotic, there’s a problem to solve first. The bacteria have to get past your stomach, which is acidic enough to kill most things.
That’s why the strains used in a good supplement are chosen for being acid-resistant and for whether they can survive the trip. That’s the first hurdle, and plenty of organisms don’t clear it.
The dose works the same way. The number on the bottle is high because a proportion won’t make it, and what counts is how many are still alive at the far end.
Probiotic strains in a capsule don’t take up permanent residence. They pass through, and once you stop taking them they’re gone within a few days.
So they have to go in daily. There’s no reserve building up, nothing banked for later, and yesterday’s dose isn’t doing anything for you today. During a recovery period, the daily part is most of what makes it work.
The other route is fermented food. Live yoghurt, kefir, sauerkraut, kimchi, unpasteurised cheese.
Same principle, same transience, just arriving as part of a meal rather than out of a bottle. It’s cheap, it goes in daily, and for general purposes it’s a perfectly good habit.
Two things it doesn’t do. You’ve no idea of the dose. A jar of sauerkraut might be teeming or mostly spent depending on how it was made and how long it’s been open, and nothing on the label will tell you. Plus, a fair number of people simply don’t like any of it, which rules the whole approach out before it starts.
So when you’re covering a specific gap, after antibiotics or a bad stomach bug, a supplement is the more reliable option. You know what’s going in and how much, and you don’t have to learn to enjoy kefir first.
This is the bit that carries across.
A depleted gut population comes back on its own eventually. Putting something in while it does means the system isn’t managing the whole rebuild on its own.
The same holds for the work we do here. The period after something has been disrupted is when steady input counts for most, and it’s also when people are most inclined to leave it a while and see. The body will usually get there either way. How well it gets there, and how long it takes, has a great deal to do with what it’s given while the rebuilding is going on.
All the best,
Tom
