What does baby poo have to do with well-behaved toddlers?
Updated: Jan 10, 2022
Update: February 2020
This week, the journal article that the presentation I describe below was finally published!
It was the longest time to publication that I've ever experienced. I began the project in late 2016, with previously collected data, an analysis plan, and tons of enthusiasm. It was supposed to be a quick 3-4 month project.
As my first human microbiome data analysis project, there was a steep learning curve in scripting the analysis. I had used R to do my PhD, but microbiome data is another thing altogether. I spent, hours, days and weekends nutting out the coding and learning new skills. It was work, but I loved it.
And so in May 2017, as per the original post below, I presented the initial findings at a conference. I won a travel grant for my submission and spoke in the main conference hall. As I had only recently made the transition from my epilepsy PhD topic to microbiome research, this was a huge thrill. My PhD thesis hadn't even been officially passed yet!
The two and half years that followed since then have entailed refining the analyses, discussing the approach and interpretation of results amongst a group of senior and thoroughly talented colleagues with highly divergent views. We have also sought the ideal journal for publication, and dealt with flat rejections, and requests for animal studies to back up our findings.
So it is with relief and pride that I share the final product of this long journey.
Access the full-text of the article for free here.
Original post (May 2017)
Recently I presented at the Falk Foundation’s 207th symposium, ‘Gut Microbiome and Mucosal or Systemic Dysfunction: Mechanisms, Clinical Manifestations and Interventions’. It was in Brisbane, and was a stimulating start to a warm weekend getaway (from Melbourne’s impending wintery weather).
The research I was presenting in a talk and the poster on this page was about the relationship between gut bacteria in the poo of infants at 12 months and their behavioural or emotional problems at 2 years of age. It’s a really interesting question, because we know that there is a gut-brain axis - a link from gut to brain that goes in both directions. And the gut bacteria is an important part of what allows these communications to happen.
What we found in this study was that there are differences in the microbial composition of poo of infants at 12 months that relates to their future risk of behaviour problems (measured 1 year later). The lower the diversity, or variety of different types of bacteria, the lower the likelihood of having behavioural or emotional problems. Most of the evidence in humans suggests that diversity in gut bacteria is a good thing, but we know that the gut microbiome changes over the lifespan. These results suggest that for the bubs who might still be breastfed, less diversity is best. Breastfeeding is associated with lower diversity of gut bugs - mostly just Bifidobacterium. Breastmilk has nutrients such as human milk oligosaccharides that are actually food for the developing community of gut bugs - not the baby!
We also found two particular kinds of bacteria were particularly associated with future behaviour problems - one was protective and one increased the risk. Because my team and I are still working on understanding this in more detail, and getting these findings published, I’m not allowed to say the names of the bacteria just yet. They are bugs that have cropped up as being important for a few different kinds of physical, as well as mental health outcomes in childhood. To me this is more important than what exact bacteria they might be. Why? Because the fact that certain bacteria contribute to health problems of various kinds supports the idea that the body is an integrated whole - what’s good for your heart health (for example), is also good for your brain health. For the most part, you don’t need to do anything special to look after one organ separately from another. They are all connected and benefit from the same health behaviours, and perhaps, gut bacteria. Mind is connected to body, and microbiome certainly has a part to play in the health of both.
While reading this, you might be wondering if and how to lather your infants in good bacteria. The short answer is, maybe, but you probably don’t need to go out of your way to do it. Many early life experiences can help set up a child’s healthy gut bacteria community - things like mode of birth (vaginal), breastfeeding, antibiotics (not too many - though they can save lives so obviously sometimes necessary), exposure to pets and bits of dirt here and there. And when it comes to weaning, the food that’s good for their bodies is good for their brains (and minds) - so real, fresh food and minimal processed nasties. By the way, there’s also good reason to steer clear of harsh antibacterial cleaning products and neurotoxins such as solvents, lead, pesticides (e.g. DDT) and plastics where possible. Bisphenol-A (BPA) has been in the limelight for being a harmful plastic that is considered toxic and ‘endocrine-disrupting’, however there are here are other kinds of plastics that have not yet been banned that are also likely to be harmful. This might need to be a topic for another dedicated post!
Falk Foundation image of Amy Loughman