Which Foods are Good and Bad for Your Gut Health?

5 minutes read.

Wonderful Facts about your Guts

It’s our second brain and doesn’t need our first brain’s input. It has more than 100 million brain cells and has its own nervous system.

There is a nerve, known as the ‘vagus nerve’ and 90% of its fibres carry information from the guts to the brain.

The gut influences emotions, the immune system and long term health.

Starting with your emotions; 95% of serotonin (neurotransmitter which affects your moods and other complex functions) is found in your gut. When your digestion is compromised, your body can underproduce it which could contribute to causing low mood and anxiety.

Serotonin also helps to stimulate contractions that push food through the gut. If you eat something that is either harmful or an allergen, it releases extra serotonin which increases the contractions to expel the harmful food; causing vomiting or diarrhoea. A low amount is associated with constipation.

A study has shown that different foods when introduced to the gut via feeding tubes, have been shown to change people’s moods. For example, fat increased feelings of happiness and pleasure because it appeared to trigger the release of dopamine.

emotional woman with sprinkles on tongue
Photo by Cleyton Ewerton on Pexels.com

Guts have 70% of your immune cells in the form of Gut Associated Lymphoid Tissue (GALT). GALT and gut microbiome kill and expel pathogens.

Your gut bacteria can influence your brain health. There was a study carried out at the Washington University School of Medicine on mice, genetically predisposed to develop symptoms like Alzheimer’s, which showed gut bacteria produce compounds that influence behaviour of immune cells. As well as the ones on the brain that can cause neurodegeneration.

10 facts about your guts you can easily digest.

  1. There are opiate receptors in your guts! Your gut is susceptible to addictions like your brain.
  2. Digestion starts in your mouth. Therefore, you should chew your food thoroughly.
  3. Your guts are about 9m long with 800-900 folds. When laid out flat, they would cover an entire tennis court!
  4. They contain 1.5kg to 2kg of bacteria; heavier than your brain.
  5. They self clean. An hour after eating, the clean up starts with a powerful wave of peristalsis moving through the tubes. This moves along any undigested food.
  6. Your have detergents in your guts! Made by the liver, these are known as ‘bile ducts’. Fats wouldn’t be digested or absorbed without them. They make fat mix well with water, then digestive enzymes break down the fat for absorption into your bloodstream.
  7. Your produce about 2 pints of saliva every day.
  8. A study published in 2019 has found that people with dementia showed differences in their gut microbiome, (Microorganisms that help to digest food), from people of similar ages without dementia. They had lower levels of a type of bacteria called ‘enterotype 1’ and a higher level of ‘enterotype 111’, than other people with healthier brains.
  9. Stomach growling, known as ‘borborygmic’, happens all the time but is louder when your stomach is empty because there is no food to muffle it.
  10. You have hydrochloric acid in your stomach, yes, the same stuff that can be used to remove rust, clean metals and bricks! This acid is secreted by cells along the inner wall of your stomach and approximately 2 litres is produced each day. Despite the corrosiveness of this acid, your stomach has a thick coating of mucus which is replaced every two weeks.

Which foods are good for your gut health?

Eating the following can help:-

  • More fibre like whole grains, leafy greens like spinach or kale. When gut bacteria ferment fibre, they produce short-chain fatty acids which encourage proper function in the cells lining the colon. Spinach and kale contain a sugar that helps healthy gut bacteria to grow.
  • Nuts and avocados. These are a good source of potassium which help to promote healthy digestive function.
  • A wide range of plant-based foods. A healthy gut has a diverse community of microbes and each of them prefer different foods. A word of caution. Those of you who are prone to gas and bloating may need to be careful of eating too many fruits that are high in fructose like apples, pears and mangos.

On the other hand, berries, citrus fruits, and bananas are easier to tolerate because of their lower fructose content and are less likely to cause gas. Even better, bananas contain a substance called ‘inulin’ which stimulates good bacteria in your guts.

  • Eat fermented foods that contain live microbes like unsweetened yoghurt, kefir (sour milk drink) sauerkraut, soybean based products and kimchi. Kimchi is a Korean dish made from garlic, cabbage and chilli.
  • Excellent news! Alcohol has been shown to increase microbe diversity.
photo of a woman holding an ipad
Photo by Andrea Piacquadio on Pexels.com

Bad news! Only drink alcohol in small amounts otherwise large amounts are harmful to your gut microbes.

Which foods are bad for your gut health?

  • Highly processed foods. These foods can cause inflammation in the lining of your GI tract. Your guts may not recognise junk food as digestible food and they may think they are invaders. Therefore, an inflammatory response in your body fight these foods as though they are infections. Also, these foods can often contain ingredients that either suppress ‘good’ bacteria or increase ‘bad’ bacteria.
  • Red meat because it has been found to promote colon bacteria that produces chemicals associated with an increased risk of clogging your arteries.
  • Artificial sweeteners like aspartame because they disrupt the microbes’ metabolism.

You can also look after your guts by:-

  • Eating slowly and chewing food thoroughly. This action can help you to promote full digestion and absorption of nutrients.
  • Drinking plenty of water which has been shown to have a beneficial effect on the mucosal lining of the intestines, as well as on the balance of good bacteria in your guts.
  • Exercising regularly. Research shows that it changes the composition of microbiota in your guts, decreases inflammation and increases beneficial bacteria, which have links with a better metabolism.
  • Reducing your stress because it can either slow down digestion causing bloating, pain and constipation or speed it up causing diarrhoea.
  • Spending more time in the countryside. Gardening and other outdoor activities are good for microbiome.
  • Stroke animals. Studies have shown that people who own dogs have more microbe diversity. (Eh? What about cats?)
  • Trying not to take antibiotics because they destroy good and bad microbes.

Have I missed anything? Feel free to let me know in the comments below.

Thank you for reading.

Rachel x


healthline.com, bbc.co.uk, nhs.co.uk, medicalnewstoday.com, hopkinsmedicine.org, health.harvard.edu, sciencefocus.com, mentalfloss.com, wildelicious.com, benenden.co.uk, healthclevelandclinic.org, theconsciouslife.com, bustle.com, livescience.com, sciencedaily.com

6 thoughts on “Which Foods are Good and Bad for Your Gut Health?

  1. We have the same interests, Rachel! There is a lot of talk in the scientific world about the gut microbiome. I’m sure that in the future there will be scientific breakthroughs related to the gut. This will surely help us improve our health.
    You made me laugh when you explained that the bacteria in our gut are heavier than our brain!

  2. I had no idea we had opiate receptors in our guts, nor did I know we had a self cleaning system for our guts which helps move along any undigested food. The human body is fascinating. That wasn’t the only thing I learn from you post, but the two that really surprised me. You’re post has been quite an eye-opening education on the body. I look forward to the next one

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