This post was inspired by the book Gut: The Inside Story of Our Body’s Most Under-Rated Organ by Giulia Enders.

The gut is a diverse world of many species and strains of bacteria. Many haven’t been identified yet due to our limitations with their cultivation. That’s one of the best things about science – it’s never over, there’s always so much to discover.

If we had a transparent body, we could see the beauty of how it works – like clockwork. Everything is timed and perfectly connected when healthy. So if you ever feel unhappy for some not too important reason, think of how many processes our bodies are managing every moment just to keep us alive. Why waste all the energy and time on feeling bad when we could be doing so much to make us feel good!

The digestive tract starts with the mouth

Our saliva contains a painkiller much stronger than morphium. It was only discovered in 2006 and named opiorphin. It is produced in minimal quantities as its purpose isn’t to get us constantly high – a very small volume is perfectly efficient for its function. This molecule has to always be present as the mouth is very sensitive, with many nerve endings. For example, if we wound our elbow so much that it actually hurts , the wound has to be relatively large and/or deep, whereas in the mouth, the smallest wound hurts and bothers us a lot. It would be unimaginably painful without the opiorphin.

Food as we see it only exists before the first bite. When the chewed material enters the digestive tract it is not, say, an apple, anymore, it is a nutrient solution of billions of energy rich molecules. In order for the intestine to take all in, or at least the majority of it, the intestine has to have a very large surface. In fact, it is about 7 km long and has about 30-40 square meters of surface.

Appendix

While the walls of the colon are mostly covered with stocks of immune cells, the appendix even consists of immune tissue. Meaning that every pathogen that comes near this area, gets surrounded by immune cells immediately. Which is, of course, good, but also bad, because so many potential inflammatory cells are concentrated in one area. This way the tissue can potentially get inflamated quickly. The appendix is also something as an archive. In case of a severe flow through the intestine, when all the good bacteria get washed out, making room for pathogenes and potential pathogenes, the appendix provides all the necessary microbial cells to cover the intestinal mucosa again. This being the first and basic protection from pathogenes. What the microbiota provides is coverage – when all the »good« cells cover an area, there’s no more room for »bad« ones.

Parts of the tract

While digestion takes place mostly in the small intestine, resorption takes place in the colon. Minerals like calcium find their way back to metabolism (Ca atoms are needed at digestion and this way the body reabsorbs them). Because the gut and the microbiota cooperate well, the body with their help also reabsorbs energy-rich fatty acids, vitamin K, B12, B1 and B2 and water.

The most important phase of digestion happens in the small intestine, where food scatters – the smallest pieces are broken up over the largest possible surface. This is the place for enzyme activity.

There are hardly any bacteria in the small intestine. So the third part of digestion, which happens here (first – mouth, second – stomach) is carried out only with the enzymes which are released from pancreas and gallbladder. Digestion with the help of bacteria takes place later – towards the end of small intestine and in the gut.

Fatty acids – animal vs. plant

Animal fatty acids in meat, milk and eggs contain much larger amounts of arachidonic acid than vegetable fats. Arachidonic acid is omega 6 fatty acid that the body needs to produce hormones which enhance the sensation (feeling) of pain. So we do need them, just not in as large quantities as most people manage to take in.

Rapeseed, linseed, hemp seeds and some vegetables (salad variety called gentile, for example) contain more alpha linolenic acid (also known as omega 3), which has anti-inflammatory effects.

Quick conclusion: it is better to replace the animal fatty acids with those from the named seeds and several vegetables.

Aminoacids

There are 20 aminoacids in existence. DNA is in every live functioning cell and it is built of aminoacids, among others. Meaning it is also in every plant cell on this planet. So every plant we can eat, contains proteins. Just this fact makes it the time and place to stop asking vegans where they get their proteins.

Bacteria, microbiota

How are the calories in processed food different from those in unprocessed organic raw food? The answer is bacteria. From indigestible carbohydrates of processed food they produce a variety of fatty acids, while from plant food they produce fatty acids mainly targeted for intestine and the liver and secondly targeted for other parts of the body. That’s one of the main reasons to why it’s harder to become overweight from bananas than from bread or chocolate. Even if we get the same amount of calories from those different molecules. They’re not the same. Vegetable carbohydrates are used more efficiently and work more locally.

For the relationship between inflammatory and other diseases and the composition of the gut microbiota, science has proposed that a positive-feedback loop exists between the host for a particular dietary regimen, the composition of the gut microbiota that depends on this regimen, and the preferences of the host as influenced by the gut microbiota. So the microbiota can directly affect our brain and our decision making when it comes to our diet!

Intersting fact: alcohol can increase the gas excreting bacteria up to a thousand times. Some in fact need alcohol as food (fermentation). When intestine is full of these gas producers, the evening party can become a morning noise. Who wants that? Seriously.

Serotonine

95 % of all serotonine in human body is produced in gut cells. There it helps the nerves to regulate muscle movements and is thus one of the most important mediators. So the reason for not feeling best or even feeling depressed at times is not at all just in our brains. We should direct the focus to our intestine and digestion.

The gut and the brain are closely connected, this interaction is an important part in gastrointestinal function and also in certain feeling states and intuitive decision making. Recent neurobiological insights into gut-brain crosstalk have revealed a complex, bidirectional communication system that ensures the proper maintenance of gastrointestinal homeostasis and digestion and is also likely to have multiple effects on motivation and higher cognitive functions, including intuitive decision making. Disturbances of this system have been implicated in a wide range of disorders, including functional and inflammatory gastrointestinal disorders, obesity and eating disorders.

Quick conclusion: when the intestine and digestion works as it should (based on good nutrients), one has hormonally and phisically no reason to be unhappy, it’s quite impossible.

Conclusion – things to do to be healthy and happy:

• listen to your body, pay very close attention, it always knows what it needs
• eat nutrient rich, organic, non-processed food
• rest your body and your gut – after every meal there should be at least a 2-hour gap in order for the digestive tract to clean itself and get ready for a possible next meal
• move, be active

Other sources:

– Mayer: Gut feelings: the emerging biology of gut-brain communications. 2011

– Norris: Bacteria control host appetites. 2013

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