Surprisingly, no one has specifically investigated the effect of junk food on westerners from the perspective of the microbiome.
For the sake of science and research for my book The Diet Myth, I have been experimenting with several unusual diets and recorded their effects on my gut microbes. These include fasting, a colonoscopy diet, and an intensive unpasteurised French cheese diet. My son Tom, a final year student of genetics at the University of Aberystwyth suggested an additional crucial experiment: to track the microbes as they changed from an average western diet to an intensive fast food diet for over a week.
I wasn’t the ideal subject since I was no longer on an average diet, but Tom, who like most students enjoyed his fast food, was. So he agreed to be the guinea pig on the basis that I paid for all his meals and he could analyse and write up his results for his dissertation. The plan was to eat all his meals at the local McDonalds for ten days. He was able to eat either a Big Mac or Chicken nuggets, plus fries and Coke. For extra vitamins he was allowed beer and crisps in the evening. He would collect stool samples before, during and after his diet and send them to three different labs to check consistency.