You might want to consider trying Prescript Assist first. It's a "soil-based organisms" pre/probiotic. Not as cheap as dirt, but likely safer.

I'm guessing Hendrikus Schraven of Hendrikus Organics is who you should talk to about this. He is the guy when it comes to dirt and soil. You might even call him obsessed. I've seen footage of him tasting soil to see if it was mixed right for whatever he was planting.

The green powder supplement I take sometimes (called Vitamineral Green) claims to be chock full of Natural Soil Organisms.

I have taken straight up NSO supplements before, but I don't remember the brand off the top of my head.

We are in an area that was part of a smelter plume until about 10 years ago, and we're supposed to hose down the kiddos after going to the park, so I'd be pretty wary of chowing down on dirt from the back yard. One thing I have started doing with high quality potting soil is eating unwashed herbs from our container garden.

First, watch this: http://www.youtube.com/watch?v=X29lF43mUlo, then come hang out with me at the ranch for half a day. Everything you own, including your food, will be covered in a fine (or not so fine) layer of dirt and poo. After a few weeks you can't even smell it any longer (but your friends still can). I know when you let chickens poke around in the poo of ruminants, they're healthier because of the lacto-bacillus they ingest. Can people, who eat pretty much the same diet as chickens be very different? Good bacteria compete with pathogens, so wallowing in lots of good bacteria can only be a good thing, just so long as you only hang out with other ranchers ;)

Unless I could go somewhere I could be reasonably sure man has never been or does not frequent, I don't know that I'd trust eating dirt due to concerns about fertilizers and the like. It seems like you can get a good quality probiotic with much more than "only a few species."

For the record I would agree HGs ate dirt and it was beneficial for them, but the dirt they ate was much different than the dirt most of us have access to, unless you live in the mountains in BFE.

If you're dead set on eating dirt, you could go to the farmers market and talk to the vendors and find someone that could give you some decent assurances their soil is as clean as possible. Then you could buy some of their products and eat them unwashed.

I would grow plants and eat the plants. Eating dirt is pretty much unavoidable if you take a carrot out of the ground and wipe it off on your shirt. You can't strip a plant of it's soil bacteria by just running it under the tap for a few minutes, which is what most of us do for washing veg. Every time I've straight up eaten dirt (can you tell I grew up in the country, haha, this was the basis of most childhood dares) it is kind of rocky and unpleasant. Rubs on your teeth and is hard to rinse out. Most of the clay that is sold have real woo-woo descriptions of all the magical things they are supposed to do, but that could potentially be a source of easier to eat dirt, although you'll never know if it's truly contaminated.

I usually recommend against buying probiotics because you can usually get a much greater impact by having the real thing, but in your case it might be worth a shot. My microbio prof used to say "eat old stuff and fresh stuff" meaning eat fermented foods and salads (plenty of soil bacteria still hanging around, a rinse doesn't get rid of them). Have you tried water kefir? That is my main source of bacteria.

80-90% of surface water in the US is contaminated and must be filtered/treated before drinking.

Dirt is dirtier, if you will, than water.

Caveman dirt did not have pollution.

Your backyard dirt does.

garden of life probiotics are soil based and work very well for me. i eat a lot of dirt when i am out working on farms, never wash my veggies :)! also you might want to look into teraganix effective microorganisms. they are soil probiotics basically that are used agriculturally as well as for health, the ag kind are safe for humans to consume, although should be diluted a bit, and my prefference, but yes eat dirt....find a local established farm that has proper practices and ask them if they have any dirt that hasnt been recently amended with manure(hehe) or any thing else and then ask them if you can have some, and then feast.

Eating dirt could be part of the reason paleos had short lifetimes. Longevity has improved with sanitation and dental care. Eating abrasive media works for chicken digestion but is hard on human teeth. Amoeba, amanita fungal hyphae and fecal coliform don't go down well either.

Maybe if the dirt were baked and sifted and used as a seasoning. As recipes instruct, a light dusting. I'd start on something easy first - like kaolin clay or diatomaceous earth - before advancing to sandy loam or rich humus.

Biting my fingernails is something I still do and I'm about as healthy as a 50 year old could ever hope to be. I'm sure I pick up loads of bacteria that way. I wonder if that's why babies put everything in their mouth, and my dog eats poop?

I often wonder what the chlorine in water kills off.

We're not supposed to use hand sanitiser, you're supposed to not be socially isolated, or use antibiotics of course.