You may have recently read the article What’s The Deal With Gut Microbiota and have been introduced to the wonderful world of the gut microbiome/microbiota ( essentially just gut bacteria), or perhaps this is a topic you were already familiar with. Either way, I am very excited to fill you in on some major findings in this rapidly advancing area of research! Today, w’re discussing why diet matters for a healthy gut microbiome.
It appears scientists are one step closer to understanding the mechanisms behind how diet influences gut bacteria. This includes discovering which particular nutrients have different effects. It seems that our relationship with our own microbiome is similar to the relationships we have with humans. If we act in a way that encourages cooperation with each other, we are likely to achieve a healthy relationship. Similarly, if we eat in a way which promotes cooperation between ourselves and our gut bacteria, we are likely to achieve a good microbiome.
Scientists have also discovered that microbiota act like peacekeepers on the genetic level. This is by helping to regulate which of our genes become activated. These findings are helping us uncover how and why the gut microbiome matter.
Plant-based diets VS Westernised diets
Findings from research carried out at the University of Wisconsin-Madison in the US reveal that the type of food we eat influences how the gut bacteria communicate with cells to control our gene activity and health. A plant-based diet rich in carbohydrates (similar to fruit and vegetables), was compared to a typical western diet (high in simple sugars and fat) in this study.
The results of this study indicate a plant-based diet produces a healthier microbiome. This diet also favours better communication between us and our gut bacteria. This is likely due to the metabolism of plant fibre by the gut bacteria. This is due to gut bacteria producing short-chain fatty acids that act as messengers to better communicate with our cells. On the flip side, the mimicked westernised diet (rich in sugar and fat) led to poor cell communication. This led to a less healthy microbiome. Foods high in fat and sugar are easier for us to digest. However, they are not necessarily a good fuel source for gut bacteria. This is particularly true for processed kinds which are abundant in the typical western diet.
This research also showed that our communication with gut bacteria is not exclusive to the gut/colon. It seems communication also occurs with cells in the liver and some fatty tissue. The liver is responsible for many key functions such as metabolism. This emphasises the important role gut bacteria play in health and well-being.
Influence of protein and carbohydrate
Research carried out at the University of Sydney has shown a relationship between the amount of gut microbe species and dietary protein/carbohydrate intake. The main nutrient sources for gut bacteria are carbon and nitrogen, found in various foods. The availability of nitrogen in the intestine for gut bacteria is important for achieving good communication with the host (us).
Whilst protein contains nitrogen, carbohydrates do not. Therefore, the way in which gut bacteria respond to our food intake is greatly affected by the ratio of protein to carbohydrate in our diet.
This tells us that diets rich in carbohydrates were more likely to support better communication between ourselves and our gut bacteria. However, those benefits were relative to protein intake. This suggests the makeup of our microbiome is shaped by a need for bacteria to access nitrogen in the intestine.
What this means for the western diet
The rise in chronic health conditions and gut disorders such as IBS may be partly due to advancements in research. It is likely this increase may also be linked to a shift from the plant-based diets of our ancestors. This shift has been towards to typical western diets (high in saturated fats, sugar, red meat, and highly processed foods). This suggests the template of a healthy gut microbiome may have been set in the past, when diets were higher in plant foods, and lower in sugar and fat.
Now this definitely does not mean you need to revert back to a hunter-gather lifestyle, nor does it mean you need to cut out meat or never have your favourite dessert again! But it does mean the following:
- Try and ensure a large portion of your diet is made up of plant-based foods including fruits, vegetables and legumes.
- Opt for Low GI wholegrain varieties when choosing carbohydrate-rich foods such as bread, cereals, pasta, and grains
- For optimal health benefits choose more unsaturated fat food sources such as olive oil, nuts/nut butters, seeds, avocado, and fatty fish.
- Meat is an excellent source of essential nutrients like protein and iron – but try not to go over-board. The recommendations for meat vary, but on average are 2.5-3 serves per day. Try stick to eating red meat 2-3 times per week. Go for lean meat varieties as they are lower in saturated fat.
- You can still enjoy less-healthy food choices, but keep these as an occasional food choice.
By Amanda Gaukroger