Often referred to as the “second brain,” our microbiome—which constitutes the bacteria, fungi, and viruses that live on or within our body—is becoming an important focus of disease research. We are beginning to interrogate how these microbes interact with one another within their environment and how they play a critical role in maintaining a healthy body and indeed mind. The concept of bi-directional communication along the gut—brain axis is not a new one but is undoubtedly a complex one given the estimated 100 trillion microbes that inhabit our intestines. Making sense of their function and relationship to one another is no trivial task but what is becoming clear is that the cross talk between the metabolic, neuro-endocrine, and immune systems will need deep explorative work across a range of disciplines to elucidate the intricate interplay of these bioiogical systems and how it dictates our vulnerability to disease.

The well worn phrase —“you are what you eat” resonates now more than ever in the current research into how the gut responds to the nutrients we feed it. Generally speaking, we know that diets rich in fruit, fiber, vegetables, and proteins contribute to a diverse mix of microbiota which offers a foundational baseline for a healthy microbiome. Conversely, we know the opposite to be true with diets rich in fats and sugars. How we translate this knowledge to help mitigate diseases like Alzheimer’s and Parkinson’s is ongoing, with a “gut first” hypothesis gaining traction, along with research into microbiome dysbiosis, and we might be able to address the imbalance that leads to digestive disorders, autoimmune diseases, metabolic disorders, and mental health conditions. With more longitudinal research on the diet and the microbiome, enabling a more comprehensive understanding of which foods contain beneficial microbes, we can, as we look to the future, tailor preventative treatments through dietary modifications much earlier for those individuals who we feel may be at risk or are demonstrating early symptomology.

Autoimmune diseases are increasing, our environment and modern lifestyles are contributing to this rise and of course improved diagnostic methods have made it easier to diagnose such conditions. Research into autoimmunity and the interaction with the microbiome is providing correlative insights. These are still experimental findings from animal studies and we know that certainly in the case of the mouse, its microbiome varies significantly from that of the human microbiome. So we will need to focus our efforts on human clinical trials, coupled with deep phenotyping layering in a multi-omic approach to realize how we develop successful therapeutic interventions. So there is much still to unravel in how the microbiome withstands and reacts to biological, physical, and environmental stresses. My feeling is that some of the answers to these questions will not result in biological reasoning alone, but moreover, with more research on the impact of societal stress and how that affects health outcomes. A slower pace of life might just be what the doctor should order.