Biology of Humans 6th Edition by Judith Goodenough,Betty McGuire

Exercise 1

We have a greater number of microbes in our gut than we have cells in our whole body, and they do a great deal more for us than produce vitamins and, perhaps, some foul-smelling gas. Changes in the composition and diversity of the community of microbes can have health ramifications. For example, the results of several studies suggest that microbial populations of gut bacteria (microflora) help regulate weight control. Professor Timothy Spector from Kings College London has published a book titled The Diet Myth: The Real Science behind What We Eat.1 You can read the entire blog article-D. R. Costa, Fast food kills gut bacteria that can keep you slim, book claims, PBS News Hour blog The Rundown, May 10, 2015-at: http:// www.pbs.org In his book, Spector describes a study he undertook on his 23-year-old son, Tom. He required that Tom eat nothing but fast food from McDonald's (burgers, chicken nuggets, fries, and Coca- Cola) for 10 days. Before he began this diet, Tom had 3500 species of bacteria inhabiting his gut. At the end of the 10-day period, Tom had lost 1300 species of bacteria and the dominant type of bacteria had changed. A PBS NewsHour blog called The Rundown titled its article about Spector's book as follows: "Fast food kills gut bacteria that can keep you slim, book claims."
This study has one subject. Is one subject sufficient Why or why not