Gut: The Inside Story of Our Body’s Most Underrated Organ

Gut takes an entertaining yet scientific look at an organ that is just as interesting and important as the brain – the gut. By tracking a piece of cake as it works its way through the digestive system, you'll come to appreciate the gut for the sophisticated and impressive ecosystem that it is. This underrated human organ is increasingly linked to killer diseases – and optimum health.

The book also suggests that microbes are an important part of a healthy mind and body, and we can help them do their job by using probiotics, changing our diet and introducing more prebiotics. To make sure we maintain a healthy community of microbes in our gut, we must also be wary of antibiotics and be conscious of the effects they have on our microbiome and the food we eat.

Written by Giulia Enders (a German writer scientist) the book has sold more than two million copies in Germany and that was published in English, French (more than one million copies sold), Italian and other translations in 2015.

My highlights:
The gut is a unique and impressive organ – nothing to be ashamed of!

Our digestive system has a nervous system of its very own, allowing our digestive system to independently perform all of its functions. The work it does takes place without the involvement of our conscious mind, which makes the gut a very unique human organ. Another incredible fact about our gut is the mind-boggling amount of bacteria living inside of it. Our entire digestive system contains up to 100 billion bacteria. This accounts for 99 percent of all microorganisms in our entire body!

From the esophagus, our food enters the gut and the small intestine. As new food continues to be swallowed during a meal, your stomach expands to accommodate. It's so flexible that it's nearly impossible to eat more than it can handle.Interestingly, emotions can have the opposite effect on the stomach. Stress and anxiety can cause your stomach to contract and you'll find yourself losing your appetite.
The real digestion takes place in the small intestine.

Contrary to popular belief, when you hear your gut growling, it isn't telling you it's hungry; it's actually your small intestine cleaning up.

The ileocecal junction allows the body to absorb any remaining fluids, including B12 vitamins and gastric acid.Like the stomach, this area can also be affected by stress and anxiety. This can result in the unpleasant experience of diarrhea.

At a minimum, the entire digestive process takes ten hours. But it's possible for digestion to take up to 100 hours, from the first bite until the end of the process.
The origin of allergies and lactose intolerance are assumed to reside in the gut.

There's an interesting theory about the role your gut plays in the allergies you experience. Lactose intolerance falls into a similar category. Anyone with lactose intolerance knows what happens next: flatulence, gas pains and diarrhea. Unfortunately, as we get older, 75 percent of the population will experience a genetic change that will shut off the production of the enzyme responsible for breaking down lactose.

Surprise, surprise: the gut can influence our brain!

As we follow the paths of communication between the brain and gut through the central nervous system, the question arises: Does our gut also influence our emotions?Science has been looking into that very question. And experiments conducted on mice indicate that the probable answer is yes.

Depressed mice that were given bacteria to support digestion quickly became active, showed fewer signs of stress and performed better in learning and memory tests.

It all supports the theory that a healthy gut leads to a healthy mind.

The gut contains a rich and vital world of microbes.

As well as having its own nervous system, the gut also accounts for 80 percent of our immune system. It seems that microbes in the gut can influence our consciousness.

There are as many as 100 trillion microorganisms in our digestive tract, a community called the gut flora. And they may have an intimate relationship with our brain.

Is it possible that microbes in our gut tell our brain what kind of food we're craving?It might sound a little out there. How exactly do microbes in the gut send messages all the way to the brain – a place that is protected from all but the tiniest of particles?The answer? Amino acids. Bacteria produce amino acids like tyrosine and tryptophan, which can pass through the brain's protective layers. Once inside, these substances get transformed into biochemicals like dopamine and serotonin, which make us happy and drowsy. You can think of it as a reward system for giving your body certain nutrients.

Instead of feeling disgusted by microbes, we should learn to integrate them into our lives

We now know that probiotic bacteria can produce fatty acids that protect your stomach and help the immune system.These benefits have been found to extend to what we call prebiotics as well. These are fibrous foods that manage to go undigested through the small intestine and produce healthy bacteria in the large intestine. It is recommended to eat 30 grams of prebiotics a day, though people on average often consume only half that much.

There are more microbial cells than human cells in your body and they're essential to your health.

About 85 percent of the microbes on your hand are different to anyone else's, giving you what is known as a “microbial fingerprint. The influence of microbes extends to determining how much you weigh and how anxious you are.

Microbiome-gut-brain axis. Bacteroides fragilis, it not only reversed some symptoms but also repaired cognitive and gut problems.

Gamma-Aminobutyric acid, which is a neurotransmitter used in sleep supplements that can calm the brain, but can also lead to depression.

A truly important factor in how much you weigh are the microbes in your gut.In fact, scientists have proven that microbes can determine the weight of a mouse.

The microbes in your gut can even influence your anxiety levels and how your brain functions.

Probiotics and prebiotics are two ways to improve your microbiome.

Take probiotics (a type of live bacteria) and prebiotics (non-digestible carbohydrates, mainly fibre) to feed the good bacteria in our guts.

Probiotics are supplements that encourage the repopulation of a healthy microbiome. Think of it like putting high-quality grass seed on a distressed lawn.

Most prebiotics consist of dietary fibers such as inulin, or nutrients such as lactulose or galacto-oligosaccharides, all of which are beneficial to bacteria.

Prebiotics, which are basically foods that microbes love to eat.

Probiotics contain strains of bacteria or live microorganisms that are often described as “good bacteria” or “helpful bacteria.”

The overuse of antibiotics can be harmful to our health and result in dangerous antibiotic resistance. Antibiotics are indiscriminate. When we use them to kill disease-causing bacteria, they also kill a lot of beneficial bacteria and severely damage our microbiota.

Administering loads of antibiotics to livestock has dire consequences for us. Harmful antibiotic residues get carried into our food and water, and the microbes inhabiting farm animals develop antibiotic-resistant microbes.

The majority of antibiotics in the United States aren't produced for humans, but for farm animals.

Conclusion
The key message in this book is that our gut is an incredibly fascinating organ, comparable to the brain in terms of complexity and importance. Our large intestine harbors a rich world of microorganisms that serve our well-being. When we make conscious food choices, we can influence these microorganisms. It is a fun, informative read; recommended for anyone who wants to optimise their health.