Granted. Nothing changes.
You actually have taste receptors all throughout your digestive system. They aid in the absorption of sugar and carbohydrates.
Granted. Nothing changes even a little bit. Only shitbags are elected and they stay so full of shit they taste it constantly, sometimes even spitting it out in your face.
Granted, now you are the world’s most famous politician, you have a compulsion to lie you cannot ignore, and you have raging diarrhea on a daily basis
Why just politicians though?
The effect initially works. Political discourse is generally honest, but the job is now unbelievably gruelling. The asshole gene mutation is initially kept secret and turnover of politicians is very high as more and more people cannot cope with the overwhelming taste of feces. The political landscape has forever been shifted to be more honest regardless of potential consequence – but the consequence of even the smallest of white lies at home have a notable effect on quality of life and suicide rates among anyone who enters the profession.
The high turnover in the political field causes a relative abundance of this new mutation and the gene causing it becomes more and more prominent amongst humans as it is passed to offspring. Within time, this gene is rife amongst the population. The amount of lies someone has told naturally accrues through their life and makes life more and more unbearable as it goes on. People tend to give up or generally be unable to cope.
In your old age, as a grandparent, you take in some of your last breaths. Your grandson sits by you quietly holding your hand to give you just a little comfort in your moment of passing. You think of what you’ve inflicted on him and the world – the neverending torment and disgust that will plague his and every man, woman and child’s existence. Your last breath draws, heavy with the onset of guilt, and your conciousness fades – the sound of your flesh and blood softly suppressing a gag beside you dwindles to nothing.