SUMMARY: This study compared the fecal samples of children with autism to children without autism (control). The autism group was also divided into two groups in a later section, one taking probiotics and one not taking probiotics, and their fecal samples were then compared. Results showed that children with autism had lower amounts of Bifidobacteria and higher levels of Lactobacillus (both are beneficial bacteria) compared to typical children. The autism group also showed a lower level of lysozyme (used in this experiment to indicate inflammation) and short chain fatty acids (SCFA). The autism group that took probiotics showed a lower level of SCFA. The study cannot explain the difference in SCFA levels and gives several reasons in the results section. What the study concludes is that there is definitely a strong correlation between gut microbiota and autistic symptoms.
LESSON COMMENTS: The methodology is quite easy to read, and due to the inconclusive nature of some of the results, I would use this paper to teach students how to analyze methodology in a science paper. What are some issues with the way the study was conducted? What are some strong points in the methodology? Did the results and explanations in the discussion section match up?
Adams, J. B., Johansen, L. J., Powell, L. D., Quig, D., & Rubin, R. A. (2011). Gastrointestinal flora and gastrointestinal status in children with autism–comparisons to typical children and correlation with autism severity. BMC gastroenterology, 11, 22. doi:10.1186/1471-230X-11-22