I go out of my way to make sure I get soil bits on my self-grown organic garden produce. I cured my stomach ailment/bowel problems almost immediately ( three days), after about a year of suffering with loose bowel movements. I had the idea of just eating my produce raw, and un-washed from my microbe-rich, well balanced mineral-rich soil. I found a mixture of soil supplements that were created by my local Yelm Worm Farm, in Yelm,Wasington 98597 that I added into my soil/garden. The balanced soil, along with a "soil soup (microbe-rich) watering of my garden, caused the perfect storm in my soil that caused my raw, unwashed, veggies to be the petfect medicine that cured my bowel illness.
I had tried all kinds of yogurts, homeostatic soil organism pills, vitamins, probiotics in pill-form, and none of those things worked for me. ONLY my soil from my garden on the un-washed vegetables did the trick. I did not eat a lot of the soil, just little micro bits that were left on the carrots, beans, peas, lettuce, cabbage, etc. I did not wash my own produce.
When you think about it, when was the last time you saw a horse or a cow wash it's vegetables? There is a natural balance of organisms that are needed to have a healthy body/bowel.