We're pooping wrong, and more lessons from the book Gut

1. Fructose is not your friend.

Food manufacturers add fructose (fruit sugar) to everything from ketchup to yogurt, so we’re now ingesting twice the amount that generations before us did — and way more than our bodies are designed to handle. Forty percent of people in the Western Hemisphere suffer from fructose malabsorption, which causes diarrhea, stomach aches, flatulence and, over longer periods, depressive disorders. Too much fructose means other nutrients (like tryptophan, which the body needs to produce serotonin, the happiness hormone) have trouble making it into our bloodstream.

2. We’re pooping wrong.

Turns out, the invention of the toilet is a royal pain in the butt for the digestive system. According to Enders, squatting keeps our exit pathways clear, whereas sitting throws a kink into the digestive tract. North American sitters exert more energy during bowel movements and are prone to hemorrhoids and constipation, unlike squatters in parts of Asia, Africa and Europe, who enjoy relaxed muscles, straight intestinal tracts and fewer digestive complaints.

3. Stones in your tonsils can cause bad breath.

If you’ve brushed your teeth, chewed through a pack of gum and still have bad breath, it may be time to check your tonsils. To perform their immune system duties, tonsils form deep grooves used to assess the substances we ingest, and they train the immune system to either welcome or attack. Clusters of calcified materials in the form of white stones can also find their way into these crevices — and they smell horrible. The stones eventually come out on their own, but a doctor can also remove them.

4. Your gut has a big influence on your brain.

The gut sends signals to parts of the brain that are responsible for self-awareness, emotion, morality, fear, memory and motivation. “This does not mean that our guts control our moral thinking,” says Enders, “but it allows for the possibility that the gut might have a certain influence on it.” In one 2013 study, the areas of people’s brains that process emotion and pain were altered after a month of taking a bacteria cocktail. Enders concludes that without the gut, the brain wouldn’t be quite so impressive.