When Morgan Spurlock famously spent a month eating large portions of McDonalds for the purposes of his documentary Supersize Me, he gained weight, damaged his liver and claimed to have suffered addictive withdrawal symptoms. This was popularly attributed to the toxic mix of carbs and fat plus the added chemicals and preservatives in junk foods. But could there be another explanation?
We may have forgotten others who really don’t enjoy fast food. These are the poor creatures that live in the dark in our guts. These are the hundred trillion microbes that outnumber our total human cells ten to one and digest our food, provide many vitamins and nutrients and keep us healthy. Until recently we have viewed them as harmful – but those (like salmonella) are a tiny minority and most are essential for us.
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 poo samples before, during and after his diet and send them to three different labs to check consistency.
Tom started in high spirits and many of his fellow students were jealous of his unlimited junk food budget. As he put it:
I felt good for three days, then slowly went downhill, I became more lethargic, and by a week my friends thought I had gone a strange grey colour. The last few days were a real struggle. I felt really unwell, but definitely had no addictive withdrawal symptoms and when I finally finished, I rushed (uncharacteristically) to the shops to get some salad and fruit.
Tom’s gut had seen massive shifts in his common microbe groups for reasons that are still unclear. Firmicutes were replaced with Bacteroidetes as the dominant type, while friendly bifidobacteria that suppress inflammation halved. However the clearest marker of an unhealthy gut is losing species diversity and after just a few days Tom had lost an estimated 1,400 species – nearly 40% of his total. The changes persisted and even two weeks after the diet his microbes had not recovered. Loss of diversity is a universal signal of ill health in the guts of obese and diabetic people and triggers a range of immunity problems in lab mice.
We are unlikely to stop people eating fast food, but the devastating effects on our microbes and our long term health could possibly be mitigated if we also eat foods which our microbes love like probiotics (yogurts), root vegetables, nuts, olives and high-fibre foods. What they seem to crave, above all else, is food diversity and a slice of gherkin in the burger just isn’t enough.
http://www.iflscience.com/health-and-medicine/your-gut-bacteria-don-t-junk-food-even-if-you-do
2024.11.22 - 16:35:03
