Gut Brain Connection - John Lambert

            The gut-brain axis is a relatively new discovery, but it has been definitively determined that there is a symbiotic relationship between the trillions of microbes that live in our gut and our own systems. Specifically, there is evidence that large changes in the microbe populations or behavior in our gut can cause changes in the central nervous system and immune system. Symbiotically, changes in the CNS and immune system can also have impacts in our gut. There have been connections determined in a variety of diseases, antibiotic use, and mental illness related to the gut-brain axis. These two papers, by Reber et al.and Buffingtonet al., use mice to examine the relationship between gut microbes and stress response or behavioral changes. 
I first read Buffingtonet al. which seemed to be the more easily understood of the two papers. The authors examined if high fat maternal diets (and that effect on gut mictobiomes) cause behavioral or neurological changes in offspring and if those can be treated by reintroducing a ‘normal’ gut microbe balance. The effects that they found were really interesting, they basically determined that there is a difference in the social behavior and in the VTA of the offspring with altered microbiomes. I thought that the authors got ahead of themselves by comparing this result in mice directly to ASD and suggesting it as a cause and probiotics as a cure. Though the experiment and data is really interesting, a lot more research is needed. I was particularly interested in their finding that reintroduction at 4 weeks, but not 8 weeks, had rescuing effects.
            The second paper we read was definitely a bit more complex, but I personally liked their approach and results better. Reber et al. examined the role that immunization of M. vaccae had on coping responses to stress, stressed induced colitis, and immune responses, and found that it resulted in mainly positive effects (that were eliminated by immuno-deficits). The immunization did not have effects on several measures that were examined, showing that this is no silver bullet. The variety of methods used to examine the effects and their cause, both behavioral and immunohistological were fantastic. I think that the authors were spot on with their discussion of results, the implications of their findings, and how they may relate to humans.  

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