Learn About Your Gut Microbiome

Learn about your gut microbiome

The gut microbiome is a collection of trillions of bacterial, and other microscopic, cells that live in your large intestine. You may have heard of the term gut bacteria or ‘friendly’ bacteria which also refer to these incredible microbes. 

Bacteria are everywhere and live all around you, on your skin and inside you. We have been taught that bacteria are harmful, and while some are, most are actually really helpful. Scientists have been able to find out a lot about our gut bacteria in recent years due to advances in genetic testing technology that can identify DNA from dead bacterial cells in your stool.

Your gut microbiome is unique to you and reflects your journey through life, it starts to develop while you are inside your mother’s womb and is influenced by many factors including your birth, early life, what you do, where you’ve been and what you eat. 

This complex ecosystem feeds off foods we eat but it doesn’t just take from us, it provides us with a huge array of health benefits. So, let’s look at what these microbes do for us and how we can keep them happy.

Bacteria are everywhere and live all around you, on your skin and inside you. We have been taught that bacteria are harmful, and while some are, most are actually really helpful. Scientists have been able to find out a lot about our gut bacteria in recent years due to advances in genetic testing technology that can identify DNA from dead bacterial cells in your stool.

Your gut microbiome is unique to you and reflects your journey through life, it starts to develop while you are inside your mother’s womb and is influenced by many factors including your birth, early life, what you do, where you’ve been and what you eat. 

This complex ecosystem feeds off foods we eat but it doesn’t just take from us, it provides us with a huge array of health benefits. So, let’s look at what these microbes do for us and how we can keep them happy.

A diverse and healthy gut microbiome:

  • Supports a balanced immune system
  • Encourages normal gut motility – that’s the passage of food and waste through the bowel
  • Helps prevent colonisation by unfavourable microbes
  • Helps us digest plant fibres that we can’t break down
  • Improves nutritional status (making B vitamins, vitamin K, encourages mineral absorption and metabolises various compounds from our diets for our benefit)
  • Produces fuel for our gut lining and helps keep it healthy
  • Influences mood management
  • Reduces inflammation
  • Regulates our metabolism and weight
Our gut microbiome should be made up of lots of different bacterial species,

all with different roles and functions.

They interact with each other and also perform overlapping roles. Sometimes, certain species can overgrow, and if conditions are right some less friendly or less helpful bacteria can dominate and contribute to a range of health problems. Research now indicates an imbalanced, or dysbiotic, gut microbiome has a role in the following chronic health conditions:

  • Inflammatory Bowel Disease
  • Irritable Bowel Syndrome
  • Metabolic Syndrome
  • Cardiovascular disease
  • Auto-immune conditions
  • Mental health conditions such as stress, depression, autism, Parkinson’s disease, and Alzheimer’s disease

Dysbiosis indicates negative alterations in the communities of bacteria that make up a microbiome.

Inflammation as driver for chronic disease

Chronic low-grade inflammation is considered to be a key underlying factor in many modern chronic diseases such as diabetes, cardiovascular diseases, cancer, neurodegenerative diseases and ageing 

How our bodies react to the bacteria is really key in driving this inflammation. The cell walls of some ‘unfriendly’ bacteria are particularly problematic if present in high numbers. Portions of the cell walls from these bacteria cause an immune or inflammatory response and can compromise the integrity of the intestinal lining resulting in ‘leaky gut’.

The intestinal lining should work as a selective barrier, allowing digested food and nutrients from our guts into the blood stream, but preventing anything unwanted from passing through. If this barrier becomes ‘leaky’ because of irritation from these bacteria then our immune system has to work overtime. 24

There are several ways that these ‘unfriendly’ bacteria and ‘leaky gut’ can increase and cause problems:

  • If we eat diet with lots processed foods (typical western diets low in fibre, rich in fat and refined carbohydrate vs whole plant foods)
  • Due to long term use of medications such as pain killers and frequent or prolonged courses of antibiotics
  • Alcohol binge drinking
  • Frequent consumption of soft drinks, fruit juice and other sugar drinks
  • If we eat too often. Every time we eat the gut lining needs to become more permeable, and this lasts about 4 hours. If we are continually snacking the gut lining never gets to close up and the gut’s immune system will be constantly stimulated resulting in low grade inflammation.
  • Stress and lack of sleep
How to keep your gut bacteria happy, healthy and diverse so they can help you:

To encourage more ‘friendly’ bacteria, the ones that produce substances that are helpful, we need to eat plenty of fibrous plant foods. We also need to encourage a wide diversity of microbes in our gut ecosystem and eating a varied diet really helps.  

Here are some foods to focus on, in particular:

  • Eat lots and lots of vegetables (aim for 6 + portions per day) and up to 2 portions of fruit. Have a wide variety and eat a rainbow of colour each day! 33
  • ✔ Include prebiotic-rich foods – these are fibre-rich foods that the beneficial microbes in our gut feed on: onions, garlic, leeks, artichoke, chicory root, dandelion greens, asparagus, bananas, legumes, beetroot, sunflower and pumpkin seeds 34
  • Alcohol binge drinking
  • Frequent consumption of soft drinks, fruit juice and other sugar drinks
  • If we eat too often. Every time we eat the gut lining needs to become more permeable, and this lasts about 4 hours. If we are continually snacking the gut lining never gets to close up and the gut’s immune system will be constantly stimulated resulting in low grade inflammation.
  • Stress and lack of sleep

Eat lots and lots of vegetables (aim for 6 + portions per day) and up to 2 portions of fruit. Have a wide variety and eat a rainbow of colour each day! 33

  Include prebiotic-rich foods – these are fibre-rich foods that the beneficial microbes in our gut feed on: onions, garlic, leeks, artichoke, chicory root, dandelion greens, asparagus, bananas, legumes, beetroot, sunflower and pumpkin seeds 34

Include prebiotic-like foods – such as brown rice, carrots, black currants, dark cocoa, almonds, green tea, barley, oats, flaxseeds and apples are also good sources of fibre that the friendly microbes like.

Eat resistant starch-rich foods – found in unripe bananas, green peas, legumes, oats that have been soaked overnight rather than cooked but also from potatoes, root vegetables, pasta and rice that has been cooked and cooled – eg eating leftovers the next day. You can reheat the leftovers and please be careful to cool rice asap after cooking and not to keep cooked rice for more than a day).

Eat a variety of polyphenol–rich foods. Polyphenols are a special type of phytonutrient that the beneficial microbes in our gut love . Found in black olives and olive oil, veg like broccoli, spinach, red onions, asparagus, red lettuce, purple and orange carrots; dark chocolate (85% or higher cocoa content); tea; coffee (decaff is fine if you don’t do well on caffeine); red wine (just a glass!!), red grapes skins; nuts & seeds; herbs; cranberries; pomegranate; red dragon fruit; cherries, black currants; blueberries; red and black rice  quinoa and wholegrain rye sourdough  

Include probiotic / fermented foods  these contain live bacteria or yeasts that have a positive impact on the microbial balance in your intestine: yoghurt (look for plain, bio-live versions or make your own), unpasteurised cheese eg Gouda, mozzarella, cottage cheese, blue cheese, feta, aged parmesan; kefir (fermented milk or you can get water kefir); sauerkraut (fermented cabbage); kimchi (fermented vegetables typical in Korean cuisine). Do buy unpasteurised versions (ask in your health food shop) or make your own. Apple cider vinegar can be drunk diluted in water (take up to 2 tbsp in a glass of water) or made into a salad dressing

If you are not used to eating many of these foods it is sensible to introduce them gradually!

 

More on probiotics:  Microbial cultures have been used to produce beer, wine, green olives, cheese and other fermented foods, such as live yoghurts, kombucha (a type of fermented tea), sauerkraut (fermented cabbage), kimchi (a spicy mix of fermented vegetables usually with garlic and chilli) and kefir (a fermented milk drink) for many thousands of years. Infact consumption of fermented dairy products is believed to date back to as far back as 5000 BC. Ancient physicians like Hippocrates and Galen advocated fermented milks for the treatment of gastrointestinal ills. The Bulgarian scientist Metchnikoff researched the bacteria in fermented milk and identified two key species (now known as Lactobacillus delbrueckii ssp. Bulgaricus and Streptococcus thermophilus) which are responsible for the taste, consistency and smell we associate with yoghurt.

Increase omega 3 fats from oily fish, linseeds, walnuts and reduce saturated fats or processed fats from foods like pastries, sausages and ready meals. 

It also helps to snack less and leave a longer gap overnight without eating – or fasting – as this allows bacteria that like to clean up the digestive tract to flourish. Try to leave 12 hours between finishing your evening meal before you have breakfast the next day 

Artificial Sweeteners – Not so Sweet?

Due to pressure from the government to reduce the amount of added sugar in foods, food manufacturers are increasingly using artificial sweeteners. At the moment it is believed they are safe to consume in small amounts, however

  • Growing evidence suggests that sweeteners may induce glucose intolerance due to alterations in the gut microbiota
  • They may change the way we taste food / overstimulate sugar receptors
  • May result in increased sweet cravings
  • Because we might think we are reducing sugar intake by switching to a low-sugar, artificially sweetened food or soda we might then think it is ok to consume sugar elsewhere - ‘I’m drinking diet soda, so it’s ok to have cake’
  • Some animal studies have shown saccharine is more addictive than cocaine
  • There are also some studies show people who drank diet soda became more obese than those who drank less, we are not sure why at this point and it maybe because of other unhealthy food and lifestyle choices but until we know more it is sensible to limit the amount of artificially sweetened foods.

Easy swaps

Normal version Healthy alternative
Soft drinks and sodaSparkling water with lemon, lime or orange slices
Fruit juiceWhole fruit or a homemade smoothie (where you whizz up whole fruit)
ConfectionaryA couple of squares of dark chocolate and a small handful of fresh nuts.
Ready saucesPesto. Passata or tinned tomatoes. A drizzle of olive oil and a little grated parmesan. Cook from scratch using herbs like parsley, basil, rosemary and thyme.* Spices like ginger, cumin, coriander. Lemon zest and juice is great for adding flavour.
White bread, pasta, riceWholegrain or brown bread, pasta or rice or root vegetables like carrots, beetroot, parsnips, sweet potato, turnip, swede.