Week IX

I thoroughly enjoyed this week’s topic. One aspect I particularly enjoyed about this week’s topic is how an imbalance in the gut microbiome can cause a variety of disorders depending on how the microbiota is disrupted. I preferred Buffinton et al. over Reber et al. because it Buffington et al. only focused on Autism Spectrum Disorder (ASD) while Reber et al. seemed to split its focus on anxiety/depression and colitis. It felt like the Reber paper focused more on inflammation and colitis than on any psychiatric disorder.

Reber et al. stated reasons why the Western world gut microbiota is disrupted including a diet composed of low-microbial accessible food, and lack of contact with a diverse range of microbes. Buffington et al also explored the idea that diet is a major contributing factor of gut dysbiosis. I do not recall if the paper directly stated why L. reuteri populations were drastically reduced in MHFD offspring. I think it would be interesting to learn the source of these bacteria since it seems its live presence in the gut is directly responsible for normal social behavior. The researchers hypothesized that the mechanism by which L. reuteri promote oxytocin levels is via the vagus nerve. The next logical study would be one designed to test this hypothesis. In addition I would be interested to know if a deficiency in this particular species of bacteria is necessary for normal social behavior or if there a way to circumvent issues that arise when there is an imbalance in the gut.

I thought the proposed treatments of dysbiosis were of particular interest because they seem relatively straightforward. Patients could either take a probiotic or receive an inoculation to combat the microbial imbalance. However, I thought the comment made in Reber et al. regarding exposure to increased environmental organisms was curious. One would think exposure to “old pathogens” may do more harm than good if our modern immune systems would be unable to combat the pathogens, even if they were attenuated. Overall I deeply enjoyed the alternative perspective regarding the pathogenesis of psychiatric illness that these two papers provided. I look forward to reading about future research regarding the gut-brain axis and how it relates to psychiatric/neurological disorders/diseases.