In the first of a two-part series on digestive health in ASD, Mia Kotikovski summarizes scientific information about what the complicated microbiome is, how it influences physical and psychiatric health, if it is altered in autism, and what causes it to be different in ASD.

On this week’s podcast, we answer your question: “what’s the evidence of a gut-brain connection”? We can’t answer that question without starting off with a description of the microbiome. The microbiome is the colony of organisms in your gastrointestinal system that is showing increasing evidence of influencing brain function. We asked three experts: Calliope Holingue from JHSPH, Helen Vuong from UCLA and Stewart Campbell of Axial Therapeutics what is happening in research around the microbiome in autism, and what therapeutics are being developed to help those with GI issues and ASD.

This week’s podcast includes a summary of the new study, this time in an animal model, looking at microbiome transplantation.  Because this was more of an experimental model, the researchers could be more rigorous in their design and look at things like behavior, brain activity, and specific biological pathways.  While a mouse does not have autism, transplantation of the autism microbiome resulted in autistic-like behaviors.   Second, a hopeful message of the value of participating in research on outcomes – those infants that were tracked prospectively showed improved outcomes later on, suggesting that all of the extra attention they get leads to a reduction in symptoms and an improvement in adaptive behavior.  Even if you do not have a family history of autism – participate in research.  It’s good for your child, and it’s good for other people’s children.

https://www.cell.com/cell/fulltext/S0092-8674(19)30502-1 

https://www.ncbi.nlm.nih.gov/pubmed/31032937

You may have heard on the internet that a new “radical” treatment leads to a “50% reduction” in autism symptoms.  This radical treatment is fecal transplants, which is taking the bacteria from the feces from one person and putting them in another person.  This is a still experimental treatment, and while the microbiome should be researched more in regards to its relationship to autism, there might be a less invasive way to alter the microbiome which could stand up to the rigor of a well designed trial.  Also this week, new prevalence data on 4 year olds across multiple years.  Did it change across time, and is it different from 8 year olds, and why is this difference important?

https://www.ncbi.nlm.nih.gov/pubmed/30967657

https://www.ncbi.nlm.nih.gov/pubmed/30973853

People with autism have higher levels of GI problems then people without a diagnosis, and the microbiome is associated with GI function, so is the microbiome linked to autism?  Some studies say yes, but this week studies in China look at non-caucasian people eating different diet.  Do the differences still hold?  Also, while GI  symptoms have been studied in relation to core autism features, they have not yet been linked to psychiatric issues like anxiety, ADHD, and aggression.  Until now.  This week’s podcast features three new studies looking GI issues and the causes of those issues, in kids with autism.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6204460/

https://www.ncbi.nlm.nih.gov/pubmed/30394313

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6143520/

This podcast was going to be dedicated to new early detection research which shows what the USPSTF has been looking for – the link between early detection, early intervention, and improved outcomes in a community setting.  Those findings are still included this week, but there is a slight diversion in theme.  The podcast will also include  an explanation of the immune/microbiome study published in Nature and misrepresented  by Korea Daily.  The study is important, however, the media sensationalized the findings and did the research no favors by labeling it a “major cause”.   Learn what the study did and what it actually discovered in this week’s podcast.

Here are the references of the studies mentioned in the podcast:

https://www.ncbi.nlm.nih.gov/pubmed/28902840

https://www.ncbi.nlm.nih.gov/pubmed/28905160

https://www.ncbi.nlm.nih.gov/pubmed/27474118

This week’s ASF Podcast is a special interview with Dr. Gil Sharon from CalTech, who studies the microbiome in animal models and potential link to ASD.  The microbiome is the full community of bacteria that live in our bodies and outnumber cells 10-1. They can affect the genome directly and they can respond to environmental factors which means they may be a site for important gene x environment interactions in autism.  Some people with ASD, especially those with gastrointestinal problems, show alterations in the microbiome and more and more scientists are starting to incorporate studying this complex system into their research.  Most importantly, new research is suggesting potential for probiotic therapies to not only treat GI symptoms, but also core autism symptoms.  If you like the podcast, Dr. Sharon has provided a list of resources which can provide more detail:

Interventions in mice –

Hsiao, E.Y., McBride, S.W., Hsien, S., Sharon, G., Hyde, E.R., McCue, T., Codelli, J.A., Chow, J., Reisman, S.E., Petrosino, J.F., et al. (2013). Microbiota modulate behavioral and physiological abnormalities associated with neurodevelopmental disorders. Cell 155, 1451–1463.

Buffington, S.A., Di Prisco, G.V., Auchtung, T.A., Ajami, N.J., Petrosino, J.F., and Costa-Mattioli, M. (2016). Microbial Reconstitution Reverses Maternal Diet-Induced Social and Synaptic Deficits in Offspring. Cell 165, 1762–1775.

Intervention in humans –

Kang, D.-W., Adams, J.B., Gregory, A.C., Borody, T., Chittick, L., Fasano, A., Khoruts, A., Geis, E., Maldonado, J., McDonough-Means, S., et al. (2017). Microbiota Transfer Therapy alters gut ecosystem and improves gastrointestinal and autism symptoms: an open-label study. Microbiome 5, 10.

Microbiome profiling –

Gondalia, S.V., Palombo, E.A., Knowles, S.R., Cox, S.B., Meyer, D., and Austin, D.W. (2012). Molecular characterisation of gastrointestinal microbiota of children with autism (with and without gastrointestinal dysfunction) and their neurotypical siblings. Autism Res. 5, 419–427.

De Angelis, M., Piccolo, M., Vannini, L., Siragusa, S., De Giacomo, A., Serrazzanetti, D.I., Cristofori, F., Guerzoni, M.E., Gobbetti, M., and Francavilla, R. (2013). Fecal microbiota and metabolome of children with autism and pervasive developmental disorder not otherwise specified. PLoS One 8, e76993.

Son, J.S., Zheng, L.J., Rowehl, L.M., Tian, X., Zhang, Y., Zhu, W., Litcher-Kelly, L., Gadow, K.D., Gathungu, G., Robertson, C.E., et al. (2015). Comparison of Fecal Microbiota in Children with Autism Spectrum Disorders and Neurotypical Siblings in the Simons Simplex Collection. PLoS One 10, e0137725.