It is an interesting approach. One thing I don't understand is why they are blending the faecal matter. Most of the organisms in the gut are strict anaerobes which are killed on contact with oxygen. Blending is going to introduce an enormous amount of oxygen.

If I was doing this I would put the faecal matter in a ziploc bag containing saline, expel all the air, close the bag and gently massage it to get the nice "soup". This would stay anaerobic and save my blender too :)

Microbiologist here - the name anaerobe is a pretty broad term. Within the gut there is going to be obligate anaerobes (killed by atmospheric O2) and facultative anaerobes (can survive in both oxygen rich and oxygen deplete environments).

In a blender, the obligates will likely die but the facultative will remain.

I am also a microbiologist (my Ph.D was in molecular microbiology). I didn't work on obligate anerobes, but the lab next door did. They had to go to a lot of trouble to keep oxygen out of all their experiments by using aneroboic chambers and the like (a total pain).

The problem is that most of the organisms in the gut are obligate (strict) anerobes. Sure the faculatative anaerobes will survive, but this is going to create an imbalance in the populations being transplanted. If the aim is to restore tha balance present in a healthy individual why introduce oxygen when it is easy to avoid.

Two things, you aren't necessarily trying to achieve the identical balance. Most of the research in this area is finding the particular bacteria that are important to repopulate the ill gut. The aim is to eventually transplant only the important bugs or just grow the important ones and skip the fecal donors all together.

The other issue is that it would be very hard to get a fecal sample that hasn't been exposed to O2.

I think I remember reading that the rough-and-ready procedure being used by doctors performing the study also involved the laboratory equivalent of a blender. Not sure if I'm misremembering, or if there are laboratory blenders that don't introduce oxygen, or if the researchers don't think it matters, or what.

I am a donor at a large center performing these procedures and work with the physician and lab staff. The purpose of the blender is to make the fecal material into a slurry, after that it is filter through paper to remove food particles. The filter paper allows the bacteria to pass through. The resultant liquid is given to the patient (enema, NG tube, pill).

Can you address danieltillett's question regarding anaerobes?

For sure.... quoted below.

Microbiologist here - the name anaerobe is a pretty broad term. Within the gut there is going to be obligate anaerobes (killed by atmospheric O2) and facultative anaerobes (can survive in both oxygen rich and oxygen deplete environments).

In a blender, the obligates will likely die but the facultative will remain.

You sir, have just ruined... everything.

Reddit and having children desensitized me to that sort of stuff.

Interesting idea though. What happens if it goes wrong?

From my reading of the scientific literature in this area the worst you can expect is mild gastro - compared to a C. difficile infection this is not really a concern.

I was thinking more that the cultures in the donor poop are unknown. There are numerous horrible things that you don't want stuffed up your bum from more c.diff to worms to ulcerative bleeding carrying HIV for example.

Yes this is a risk, but in general pretty low if you know the person well. If you are taking the sample from your husband or wife you would hope you would know if they have HIV or not.

Actually the risk of getting worms is an interesting potential positive. There is a lot of data suggesting that the lack of intestinal worms in western countries is one of the reason for the rise of autoimmune diseases like Crohns. The theory is that the immune system in the gut is designed up to keep worms under control and in their absence starts attacking things like the gut tissue instead. There are a couple of stage three trial currently running that are giving people pig wipworms (they can infect but not reproduce in the human gut) to treat Crohns. The earlier trials were really encouraging so it will be interesting to see how they turn out.

This is why the doctors/scientists in the article recommended that donors be screened first.

But the more I discover about medicine and biology, the more I realize how much we still don't know. Hundreds of types of bacteria in a typical stool sample? This is amazing! Whole biomes await study... from internal gut bacteria (very small scale), to microbial colonies (regional or national scale) that we use for fermentation. Exciting!

We actually don't know how many bacteria live in the human gut, but may be as many as 100,000 different species although around 1000 dominate. One of the difficulties with estimating how many species are present is that it is hard to know if a particular species is a member of the "native" gut microflora or just passing through.

No one knows - that's the biggest issue. It is very complex. Based on studies it seems pretty low risk, as long as the donor is tested for disease.

Thanks for the warning, unfortunately I took no heed. Gonna wait it out a little longer before breakfast!

What do you mean, "taste"?