Gut health is all the rage at the moment.
As we are learning more about the gut and its role in human health, nourishing our gut microbiome has become big business.
From gut health powders and bone broth to gut-friendly cookbooks, there is definitely money to be made from those looking to boost the health of their gut.
The most confusing part of all of this is actually differentiating between things that may assist with improving gut health and the things that really move the needle.
In this blog post, we will be going over the top nutrition tips for gut health with a focus on things you can do from a diet perspective that will make the most difference.
What Is The Microbiome?
The collection of microbes that live in and on the human body is known as the microbiota. The microbiome, therefore, refers to the complete set of genes within these microbes. A vast majority of them reside in the gastrointestinal tract (often referred to as the ‘gut’).
The gut microbiome mainly comprises bacteria, viruses, fungi and other microbes and is critical to proper bodily functions.
The microbiota of the gut have an integral role in digestion, immune function, brain health, and metabolism. There have also been more recent links to mood and mental health.
The research of the gut microbiome is still relatively new and there is no current consensus on what is a healthy or ideal gut microbiome.
At this stage, it is understood that everyone is different and therefore what is ideal can vary. However, the diversity of bacteria is important. Such diversity may mean that your gut is in a better position to fight off and resist pathogens.
Preliminary research has shown us that one of the most important things microbes do for us is to help with digestion. Recent studies have also demonstrated that the roles of these microbes extend far beyond this. Other roles of good microbes include:
- Regulating the immune system and reducing the risk of immune-related diseases
- Contributing to brain functioning and optimal brain health
- Contributing to a healthy circulatory system and heart health
- Controlling blood sugar and reducing the risk of obesity and diabetes
- Controlling sleep and the sleep-wake cycle
Dysbiosis of the gut microbiome is the alteration or imbalance of the microbiota that can result from numerous things including poor diet, antibiotics, stress, a lack of physical activity, and bowel infections.
Non-Diet Factors That Can Affect Gut Health
Antibiotics & Gut Health
Aside from making changes to your diet, the best way to improve your gut health is to ensure you only take antibiotics when absolutely necessary. This is because if you take antibiotics often, you can upset the balance of microbes in your gut – remember, if we target bad bacteria, we automatically target good bacteria as well.
Stress & Gut Health
Our gut affects how our brain functions. But what many people do not know is that this highway is multidirectional; our brain can affect our gut health as well! Although stress is unavoidable, there are many things we can do to reduce our stress levels, such as managing our time better, getting enough sleep, connecting with others, and taking time out for yourself.
Exercise & Gut Health
A balanced training regime that consists of low-moderate intensity activities, occasional high-intensity activities, and regular strength training could help you build a better microbiome.
How Can Diet Help To Improve Gut Health?
Ultimately, diet plays one of the largest roles in improving and maintaining good gut health. You can take all of the gut health tonics, powders and pills that you want but nothing quite moves the needle like having a fibre rich diet with a variety of plant foods.
Eat a fibre-rich diet
Fibre is a type of non-digestible carbohydrate that is found exclusively in plant-based foods.
Unlike other nutrients, fibre moves through the gastrointestinal system undigested and unabsorbed until it reaches the large intestine. Here, gut bacteria ferment fibre into by-products that are healthful and absorbed.
High fibre intake has most consistently shown increases in lactic acid bacteria, such as Ruminococcus, E. rectale, and Roseburia, and a reduction Clostridium and Enterococcus species.
However, it is interesting to note that vegetarians and vegans who typically have a fibre intake of >40g per day tend to have better gut health. Although this may also be due to being more likely to consume different types of fibres and a reduced intake of processed foods amongst other things.
Nonetheless, if your fibre intake is below the 25-30g per day recommendation, your gut would definitely benefit from including more fibre rich foods in your diet.
You can simply do this via a fibre supplement such as psyllium but increasing the volume and variety of plant-based foods in your diet will likely move the needle even more.
When increasing your fibre intake, it is best to do it slowly to allow your gut to get used to it. A sudden and drastic increase in fibre intake is not going to harm you but it may cause some uncomfortable symptoms including bloating and flatulence.
Eat >30 Different Plant Foods Each Week
The American Gut Project found that people who consumed 30 or more plant-based food per week had a more diverse gut microbiome. In comparison to those who had 10 or less per week.
Thirty may seem like a lot of different foods but when you take into account that it includes all vegetables, fruit, nuts, seeds, legumes and whole grains it becomes less daunting.
Common ways to improve the variety of plant food in your diet include:
- Having a handful of mixed nuts daily
- Make up batch of fruit salad for the week or have a different piece of fruit each day
- Use packets of mixed veggies – the more variety in a bag, the better
- Make up a mixed seeds jar to sprinkle on porridge, yogurt or salads
- Use some plant based proteins in your meals including legumes and soy foods
- Have a variety of canned legumes in your pantry and incorporate them wherever possible – a 4 bean mix is great!
- Choose a few different types of grains for the week including rice, quinoa, whole grain bread, couscous and pasta
Typically individuals or households can be pretty set in their ways. We tend to use the same 3-4 vegetables, the same couple of types of fruit and have a limited intake of nuts, seeds and legumes.
So the process of diversifying the diet can take time, but it is one of the number one things you can do to improve your overall gut health.
Have Probiotic, Prebiotic and Resistant-Starch Rich Foods Regularly
Probiotics are live microorganisms (bacteria or yeast) found in certain foods, which when consumed in adequate amounts are beneficial to our bodies.
A prebiotic on the other hand is a type of fibre found in plant-based foods, which promotes the growth and activity of good bacteria in the gut.
Basically, probiotics are the healthy bacteria that we want in our gut and prebiotics are the food for that bacteria.
Both are important to improving and maintaining good gut health.
Foods that contain probiotics include:
- Fermented milk products (kefir, buttermilk, Yakult)
- Fermented vegetables (sauerkraut, pickles, kimchi)
- Miso seasoning
Foods that contain prebiotics include:
- Vegetables – green peas, snow peas, corn, garlic, onion, leeks, spring onion, asparagus, beetroot
- Fruits – banana, watermelon, nectarines, white peaches, pomegranate, dried fruit
- Legumes – chickpeas, baked beans, red kidney beans, lentils
- Cereals – couscous, gnocchi, pasta, rye bread/crackers, barley, oats, wheat, soybeans
- Nuts – cashews, pistachio nuts
Generally having a diet that is high in a variety of plant foods with a focus on including some probiotic-rich fermented foods will do the trick.
Resistant starch can act as prebiotic fibre and also helps nourish good bacteria in the large intestine.
Because this type of fibre is more resistant to digestion, it ferments in the gut and favours the production of butyrate, a major bacterial metabolite fundamental for keeping the gut healthy and functioning normally.
Although it is hard to measure, it looks like the average Australian consumes about 3-9g of resistant starch per day. Intakes of 15-20g have been linked with positive health outcomes. Most people likely would benefit from increasing their intake.
Resistant starch is found in whole grains, legumes, nuts, starchy vegetables and some seeds but is particularly prominent in:
- Unripe bananas and green banana flour
- Cooked and cooled grains and starchy vegetables such as potato, rice & pasta
Minimise Your Intake of Processed foods, Alcohol & Meat Products
By following a more whole-food plant-based diet it is likely that you will inevitably reduce your intake of processed foods and meat products.
You don’t need to completely cut these foods out of your diet but they also shouldn’t be a large part of your daily intake.
The same thing goes for alcohol and gut health. Once again you do not need to avoid alcohol completely but you should minimise your consumption.
Why Does A Plant-Based Diet Improve Gut Health?
The link between a plant-based diet and good gut health is definitely more complicated than simply an increase in fibre intake.
There are many factors that play a role.
Whilst a reduced bioavailability of some nutrients from plant-based foods is usually an argument against plant-based diets, it could actually be assisting gut health.
Lower bioavailability in plant foods secondary to larger food particles and intact plant cell walls means more nutrients reach the lower part of the gastrointestinal system.
Digestible And Non-digestible Carbohydrates
Non-digestible carbohydrates such as resistant starch and FODMAPs are resistant to digestion.
Therefore, they reach the large intestine undigested where they provide energy to probiotics and produce postbiotics which are incredibly beneficial to gut health.
Digestible carbohydrates from fruits (e.g. glucose, fructose and sucrose) have been shown to reduce the number of harmful bacteria in the gut.
Nonetheless, both digestible and non-digestible carbohydrates have been shown to increase levels of Bifidobacteria.
Bifidobacterium is a butyrate-producing genus known to play an important role in maintaining the integrity of the gut wall.
Proteins & Gut Health
Overall a higher protein diet can be associated with positive changes in the gut microbiome.
However, the type of protein matters.
Research shows that plant-based proteins typically increase levels of beneficial bacteria whilst diets high in animal proteins with a high-fat content result in reduced levels of beneficial bacteria in the gut.
Fats & Gut Health
The lower fat intake associated with a vegetarian or vegan diet favours beneficial bacteria in the microbiota.
Moreover, the fat that is consumed on a plant-based diet is predominantly mono and polyunsaturated which increases beneficial bacteria in the gut.
Conversely, the saturated fat found almost exclusively in animal-based foods such as meat and dairy increases bad bacteria and reduces several types of good bacteria in the gut. Some studies have linked this change in gut bacteria levels to inflammatory processes that lead to metabolic disorders.
Polyphenols are naturally occurring plant metabolites that are very beneficial to human health.
In relation to gut health, polyphenols increase bifidobacterium and lactobacillus–Enterococcus. This then leads to a greater production of short-chain fatty acids (SCFA) such as butyrate.
Polyphenols are found in fruits, vegetables, seeds, tea and cocoa.
Should You Go Vegetarian Or Vegan For Optimal Gut Health?
But you don’t have to completely eliminate animal products from your diet to optimise your gut health.
In fact, some animal products such as yoghurt and other fermented dairy products are great for gut health.
However, following a more plant-based diet is likely to have a hugely positive impact on your gut microbiome.
Aim to include a wide range of grains, nuts, seeds, legumes, fruits and vegetables in your diet and ensure you are eating more of those things over animal products.
The standard western, omnivorous diet tends to overemphasise animal products and processed foods to the detriment of our health.
So by simply switching up the ratio of plant to animal foods, you will be doing a lot to support your gut.
Start by trying some of the following tips:
- Incorporate some vegetarian or vegan meals into your week
- Play around with plant based proteins such as tofu, tempeh, edamame and beans
- Have 3-5 cups of veggies per day and focus on variety
- Have 2-3 servings of fruit per day and focus on variety
- Add nuts and seeds to meals or eat as them as snacks
- Make the plant portion of your meals ¾ of your plate for main meals
The microbiome is a complicated area of research. We are only just uncovering the importance of the gut microbiome on overall human health.
For the time being, we can be pretty positive that these things really move the needle for gut health:
- Follow a fibre rich, plant based diet that is rich in a variety of plant foods (ideally >30 different plant based foods per week)
- Incorporate foods rich in prebiotics, probiotics & resistant starch
- Reduce stress and take care of your mental health
- Exercise regularly and maintain a healthy weight
- Limit consumption of alcohol and processed foods
I am sure none of those points are a real shock to anybody, but that is what will really move the needle on gut health. Not bone broth or your naturopath’s gut concoction.
Unfortunately, there is rarely a quick and easy fix to health and gut health is just another part of your overall well being that requires a focus on eating a well-balanced, mostly plant-based diet and living an active, low-stress life.