I recently had the opportunity to interview Professor Margaret Morris
, Head of Pharmacology at the University of New South Wales. She and her colleagues are involved in some extremely relevant and fascinating research into the role of the gut bacteria in regulating weight, mood, overall health and how this research might apply to treating obesity and major illness and disease. While there is still much to be discovered and investigated, there is also much to be excited about.
Essentially, if you are eating a balanced, healthy diet rich in complex carbohydrates, unprocessed foods including plenty of veggies and fruit (organic is ideal!) and meats, fish, tofu, soy and legumes then you're setting up your guts and your body for optimum fitness, stable energy and mood and an overall more happy, healthy life.
The good news is - though it takes time for change to show definite, measurable results in regards to weight, mood and wellbeing, it doesn't matter how old you are, how active you currently are or how often you dine on Krispy Kremes at this point. You can make small changes from today and see results over time and you can change your guts, you can change your whole life for the better.
My interview with Margaret is a podcast on iTunes
or free stream on Soundcloud
Cat: For those new to the term, what is the gut microbiota?
The term refers to the suite of organisms that reside inside our gastrointestinal tract (gut). There are many bacteria in our intestine and colon, that number in the trillions. In fact the number of bacteria outnumber the number of cells in our body!
Bacteria is usually a word associated with germs and dirtiness. Can you explain the role of bacteria in the gut and why the term “bacteria” is not referring only to the “bad” bacteria?
The bacteria in our gut perform a wide range of functions, and in fact, they are required for a healthy gut. Some of the functions include- They are harvesting nutrients from food; vitamin production; maintaining a healthy lining of the inside gut wall; healthy immune function.
How long have you been working in the field of gut microbiota and its role in health?
I have been working on obesity for 20 years, focusing on how the brain regulates appetite (and what goes wrong in the face of unlimited palatable food) and more recently began to examine the changes in gut microbiota profile across a range of interesting experimental models that we have – so about 4 years.
What are the most exciting studies you’ve been involved with lately and what do they show us about lifestyle choices affecting gut microbiota and overall health?
We are very excited by our research in animals into the link between cafeteria diet induced changes in memory, and the effect on the gut microbiota. Consumption of an unhealthy diet (e.g. high in saturated fat, high sucrose, low in fibre) is associated with less diversity in the bacteria in the gut - so-called ‘dysbiosis’ - and we found that the reduction in cognitive function was linked to changes in certain types of bacteria. This means that in the future, we may be able to introduce the missing bacteria to improve cognition.
What role does the gut bacteria play in regulating mood and could studies lead to better treatment of depression, psychiatric illness and sleep problems such as insomnia and apnoea? Could these studies also mean that there will be preventative approaches & holistic non-pharmacological interventions provided by the educational, government and healthcare industries in future?
Evidence suggest that the composition of the gut microbiota is altered in people with mood disorders (although the issue of causality arises here). In terms of using knowledge about the gut microbiota to more effectively treat certain disorders, there is a precedent for this with some serious infections of the gut. I can refer your listeners to our piece in The Conversation
Other work of Pedersen et al, Nature 2016 has shown that the microbiota may be very relevant to insulin sensitivity, leading to the conclusion that ‘Our findings suggest that microbial targets may have the potential to diminish insulin resistance and reduce the incidence of common metabolic and cardiovascular disorders', so I think there will be future developments in this space.
How is the medical and health industry (private and public) as well as government responding to your studies and conclusions around dietary, behavioural and lifestyle choices in overall health of children and adults?
No formal responses from government - but interest from the scientific community. And we have funding to continue some of this work.
Can you explain the link between the intestinal function and cognition and memory? What does this say about memory, learning and how it is related to diet?
There are a range of studies demonstrating a link between a healthy diet and memory and learning. Many of these are observational - they study a large number of people and look for associations between diet and brain function. Some studies have shown that various food patterns are linked to poorer cognition, or greater cognitive decline over time. Clearly it is time-consuming and difficult to conduct this type of work - and showing a cause-effect relationship is challenging. However on balance, there does appear to be evidence for poor diet linking with poorer function, and possibly brain changes (e.g. smaller hippocampus).
How does a high fibre diet affect the gut microbiota and what sort of foods are ideal to add or increase in the diet?
Diets that are rich in plant fibre are generally good for the gut microbiota.
Have studies into omega 3 (and healthy fats found in nuts, fish, avocado and seeds) shown to have a positive effect on hormones and the gut microbiota?
Yes, omega 3 in the diet can influence the makeup of the gut microbiota, so this may explain some of the benefits of eating foods that are rich in omega 3. In humans there is evidence that low omega 3 is linked to increased risk of depression.
See ‘Role of Omega-3 fatty acids in the etiology, treatment, and prevention of depression: Current status and future directions
’ Robert K. McNamara; Journal of Nutrition & Intermediary Metabolism 5 (2016) 96e10.
While highly processed carbohydrates such as those in white bread, donuts, chips and takeaway burgers are well known to be “unhealthy” choices, it is also unhealthy to cut whole food groups. As an active person, what carbohydrates are healthy choices for balancing the gut microbiota?
Generally complex carbohydrates that are unprocessed are best – these include whole grains, oats and the like. Refined sugars are less helpful. In fact, we observed changes in gut biota and impaired memory in animals that are eating a healthy diet, but supplementing that with high sugar intake.
Of course, small amounts of refined sugar are probably ok and it is important to enjoy food and eating with friends…
Agreed that the importance of sharing meals and enjoying food is vital so the occasional donut or Tim Tams with the workmates should not be declined or denied!
What role does the timing of meals have in regulating gut microbiota and how can people use this to their advantage? For example, many people skip breakfast or eat smaller lunches to excuse late night snacking.
Not much know (I believe) regarding impact of meal timing on the microbiota – it is an interesting question.
What current studies are under way and what do you hope to see as far as investment in this area from public and private government and health investors?
We have a range of studies underway - for instance, we are interested in the effect of exercise on the gut microbiota (even in the face of an unhealthy diet) as well as the impact of probiotics on gut microbiota and memory.