My theory on what causes 'Fecal Body Odor'

At the moment the health community has not heard of 'Fecal Body Odor'.

For those interested, here are my theories on  what is known on the internet forums as 'Fecal Body Odor' and what may cause it. 

Note : Since nothing is yet proven as to what causes 'Fecal Body Odor', there are a few opinions as to what causes 'Fecal Body Odor' (e.g. 'leaky gas'). My own opinion is that it is a METABOLIC condition and this blog and post only refers to the METABOLIC theory.

When someone smells metabolically, the smell is coming through their bloodstream and/or lymph.
Examples :
When some people eat a curry, later they can smell of the volatile compounds in the curry through their skin (e.g. armpits).
When someone drinks heavily, they can smell of alcohol the next day, as the ethanol leaves unprocessed through their breath and skin.

When you smell metabolically : you smell of one or more volatiles circulating in your system.
Then the question is, what enzyme(s) is supposed to neutralize the volatile(s) ?
My current guess at a suspect enzyme : FMO3.
FMO3 oxidizes a wide range of sulfides/amines of a certain stucture.

My current views :

What is 'Fecal Body Odor' :
On body odor forums, rather than the obvious complaints such as underarm body odor, the main complaint is 'fecal body odor'. That is, the person smelling of 'feces' or 'colon gases'. It is my opinion that these malodors are probably mainly sulfides and maybe amines. Although the person may post about 'fecal body odor', it's likely they can smell of a whole range of malodorous sulfides and amines generated in humans.

It is metabolic :
My current view is that the sulfides and amines should be oxidized (i.e. neutralized), but instead are circulating in the bloodstream (and lymph ?) at levels that are detectable to the human nose. You probably don't need high levels of sulfide to 'kick up a stink'.

They are probably mainly sulfides and maybe amines too :
It is my opinion that when you look at the range of compounds known to be in humans, that malodorous ones of this description are probably sulfides such as dimethylsulfide or other variant sulfides. Usually these should be oxidized to be neutralized.

What could cause it :
There is a group of enzymes in humans known as various names that oxidize compounds in humans. My usual name for them is the 'mixed function oxidase' group of enzymes. These enzymes oxidize a wide range of compounds in humans. There are a few known 'mixed function oxidase' enzymes in humans, major players being the Cytochrome P450 enzymes (e.g. CYP3A4). FMO3 is also a mixed function oxidiase enzyme. All of these enzymes tend to 'cover' each other, but each tend to have a 'speciality' for efficiency. Currently it is my view that FMO3 may be the 'weakness' in 'fecal body odor', as it oxidizes 1,000s of compounds that tend to be small sulfides and amines of a certain structure that are common in humans. However if it was a mixed function oxidizing enzyme at fault, it could be another or a mx.

FMO3 malodor syndrome :
So I would call my own theory for 'Fecal Body Odor' as something like 'FMO3 malodor syndrome', meaning the person is prone to overload of many small sulfides and amines of a certain structure in their circulation.

Sufferers usually cannot smell themselves :
I believe this is because the brain tends to ignore compounds circulating in the bloodstream.

Related people of sufferers cannot smell sufferers :
I suspect they will be 'carriers'. Many small FMO3 'faults' are carried by populations. One small fault at codon 158 is guesstimated to be carried by around 40% of whites. For reason such as this, I think the % of  those who cannot smell the smells may be pretty high. Say about 20% population.

More to be added ......

Last update : May 2017