The human microbiome (all of our microbes’ genes) can be considered a counterpart to the human genome (all of our genes). The genes in our microbiome outnumber the genes in our genome by about 100 to 1. Meet the Microbiome. Microbes are everywhere: in the soil, in the water, and even in our bodies.
So it’s pretty complicated and can time to adjust.
This advice usually works - 5-7 days at 1 meal per day, then 5-7 meals at 2 meals, then 5-7 days at 3 meals, then go 100% if you are aiming for 100%. But of course everyone is different.
The good news is that is usually passes in the end.
The worst your diet was before Huel the longer it will take to adjust, for example if you consumed a lot of sugar, the microorganisms that lived of sugar will “kick off” due to the lack of sugar in Huel.