Junk Foods are cause of obesity. But do you know that junk foods do more than increasing your weight? A new British research says that junk foods can wipe out your gut bacterial flora by more than a third leading to increased risk to cancer, obesity and heart disease.

The new discovery was carried out by a professor in London who used his 23-year-old son, Tom by consuming only McDonald's foods for straight 10 days. Tom ate junk foods including McDonald's hamburgers, chicken nuggets, fries and coke, the Next Shark reports.

Tom stated that before he started the junk food study by his father Professor Tim Spector of Genetic Epidemiology at King's College London, he has 3,500 bacterial species, firmicutes in his gut, but after consuming junk foods, he lost about 1,300 of gut species and his gut was dominated by bacteriodetes.

"What is emerging is that changes in our gut microbe community, or microbiome, are likely to be responsible for much of our obesity epidemic, and consequences like diabetes, cancer and heart disease," Professor stated.

The normal gut has approximately 3,500 difference microbial species that constitutes about three pounds of one's weight. However, junk foods can kill these bacteria that protect against diseases including obesity, cancer, heart disease, diabetes, autism and inflammatory bowel conditions the Telegraph reports.

This is the reason by Spector and his team concluded that junk foods can wipe out gut bacteria by more than a third.  He also said that stomach flora is very critical in getting rid of potentially harmful microbes, regulating the metabolism.

Spector added that possessing different microbes in the gut is what keeps the body thin and healthy.  The professor advised that the key to remain healthy and slim for the coming years is to consume a diet that would increase the number of bacteria in the stomach.

Spector also emphasized that by increased bacterial flora in the gut, people will prevent diseases that were mentioned above.

The British junk food study of Spector challenges the findings that obesity is caused by simply overeating.