Everyone is obsessed with gut health. To many people, gut health is a means to decrease bloating or to help with weight loss, but the gut is arguably the most powerful system in the body that literally affects everything from the way we age to the glow of our skin to the strength of our immune systems. I always tell clients that if you’re looking for the biggest bang for your buck, look to gut health. Because we don’t talk about it enough and there’s so much confusion over the trendy topic, here are the eight most surprising facts I’ve learned about gut health that you probably haven’t heard before.

The gut is where food is digested, metabolized, and absorbed to be delivered into the cells

This process of breaking down foods creates bioactive compounds that either help health or lead to inflammation. In other words: what you’re digesting and how you’re digesting is two of the most important factors of health.

2. Your gut health is established the minute you are born

Of course everything you’re doing in the present can either help or hurt the gut, but the microbiome is a complex system that starts to take shape from the second we’re born. A baby receives its gut bacteria from the mother’s birth canal. After that, everything from diet during infancy and childhood to antibiotic usage as children has played a part in the gut bacteria we have today.

3. The life in foods is what gives us life

You already know that probiotic-rich foods (like kefir, sauerkraut, kimchi, etc.) is good for the gut, but anything that is “living” contains rich, healthy bacteria that helps the gut thrive. Think: unpasteurized cheeses and yogurts, sourdough bread, freshly picked plants, etc.

4. Gut “housekeeping” happens between meals

When the body is not digesting food, it is able to repair and restore the gut and digestive tract. While you should always eat when you’re hungry as it’s your body’s way of telling you it needs nutrients, try to give the body a few hours between meals and at least 12 hours between dinner and breakfast the next day to repair the gut.

5. Stress is the #1 cause of an unhealthy gut (no, really)

While low-fiber foods and processed ingredients get the bad rap, chronic stress is actually worse for the gut than anything you could eat. Let me explain: There are more nerve endings in the gut than in the central nervous system. Stress impacts digestion, absorption, microbiota, and barrier function (or what causes a “leaky gut”).

6. The gut works as a second brain

Now you know that stress affects the gut, but the gut also affects stress, as well as anxiety, depression, and general mood. The brain-gut connection shows not only the amount of nerve endings in the gut, but how the gut and the brain are in constant contact. For example, this is why you get butterflies in the stomach (or nauseous) when you’re nervous, and why even just thinking about eating can release digestive juices in the stomach before you even take a bite. Some research has even found probiotics can be effective in treating anxiety and depression, and nutritional psychiatry is an entire field dedicated to the connection of the gut as the second brain.

7. The most overlooked part of the digestive tract is the mouth

When we talk about gut health, we’re typically talking about what’s going on in the large intestine and stomach. However, the digestion in the large intestine and stomach heavily relies on what’s going on in the mouth (which we often forget about). Saliva is crucial because it breaks down everything, so it’s important to enjoy our food because when we salivate, we digest better. Also, chewing is meant to break down the food into an almost liquid consistency so that rest of the digestive tract does the heavy lifting of extracting nutrients and getting rid of waste–not breaking down solids into liquids. Chew more thoroughly and I promise most symptoms (like heart burn, bloat, stomach aches, etc.) might go away.

8. Sugar is also sabotaging your gut health

So it’s not super surprising that sugar isn’t good for you (doesn’t everyone know that sugar is as addictive as cocaine?), but when it comes to the gut, sugar is the most common cause for an overpopulation of candida (or yeast) because this bacteria eats sugars, allowing bad bacteria to survive and populate in the gut. Having birthday cake or a bowl of ice cream here and there won’t make a difference, but sneaky sugars in salad dressings, pasta sauces, and cereals that you eat every day (and every meal every day) is probably damaging your gut bacteria.