Well the intestines has a ''mind'' of its own.
The Enteric Nervous System: The Brain in the Gut has a good description of the system.
''The gut's brain or the "enteric nervous system" is located in the sheaths of tissue lining the esophagus, stomach, small intestine and colon. Considered a single entity, it is a network of neurons, neurotransmitters and proteins that zap messages between neurons, support cells like those found in the brain proper and a complex circuitry that enables it to act independently, learn, remember and, as the saying goes, produce gut feelings.''
Usually, when we smoke dmt and or maoi we are mainly only affecting the energy center inside the head (brain). When we take oral dmt/maoi it targets the brain and enteric nervous system. So when only smoking, we are not activating a separate very important subsystem that is integral to our psycho/phsycial/spiritual functioning. I can't think of a good analogy for it, but it's not usually beneficial to only activate one system inside of a highly complex, extremely interconnected bio spiritual computer.
Now i'm not saying that it is always better to take pharma. It depends on the person, because sometimes it is necessary to only activate one energy center. (the brain) (by smoking).
But by activating multiple energy centers, it allows for energy to flow between them smoother and make stronger connections, allowing for a more integrated whole.....which really is what we are after, even if we don't realize it. Unifying all the systems in the psycho-spiritual biocomputer...aka humans. And by unifying, it implies purifying....removing the blockages and obstacles that keep the human from being ''whole''