Good question and a popular one, denoting a bit of impatience.
We damage our health over years, but expect results from our remedies in days if not hours. The good news is that probiotics seem to get to work fast: feeding on a tangle of food fibers, fighting the natives for space and basically invading and setting up shop faster than Amazon did on the internet.
Of course, there can be resistance. It may take a bit longer to find traction in some people, those with weak immune systems or long entrenched disturbances like colitis or in the case on e-retail, people who prefer shopping malls. And sometimes the new healthy probiotics find they are driven out completely, unable to find a place at the table.
Think of bread making. Add yeast to warm water with a bit of sugar and within minutes bubbles erupt as the microbes feast and grow. Fast action. But throw the whole mixture with flour into a loaf in the oven and it takes more time. And still the bread may be lumpy and rock hard or light and moist.
Same with probiotics: they work fast but results will vary, depending on all sorts of reasons ranging from what your mother ate or smoked when she was pregnant with you to whether you ate a sugary donut or steel-cut oats that morning for breakfast.
Probiotics are not drugs. Often doctors will know fairly well when a pill will begin its work whether to stop a fever or pain or even to bring down cholesterol. Experience and billions of dollars in research provide this information.
But probiotics are not so precise–yet.
In his excellent book, The Probiotics Revolution immunologist Gary Huffnagle writes that much depends on the specific issues you’re hoping to address. “Minor bowel problems tend to be alleviated pretty quickly,” he writes. “For example, if you use probiotics to counter antibiotic-associated diarrhea, you might see a difference in a day or two.” And with serious digestive disorders, Huffnagle continues, “you should see improvements within two weeks.” While his mold allergies took several weeks to subside, allergies to food improved more subtly.
Probiotics may also prevent health problems. But without clinical trials and all the double-blind controls required for certainty, educated guesses are what we work with. Here’s the conundrum:
Say you take a probiotic supplement and load your diet with fermented foods. Still, you won’t know if it was the new regimen or something else that protected you from flu or food poisoning, because you won’t have it. But you will notice the trend over time: months or years down the road, you’ll find yourself thinking: “my allergies don’t seem so annoying this spring” or “seems I haven’t had a cold in three years.”
So, eat plenty of prebiotic and probiotic-rich foods and maybe take a supplement. But be patient: While some colonies are built in a day, many aren’t.