There are few certainties in life. You will pay taxes. You will die. You will fart. In fact, you’ll most likely fart when you die—but that’s a whole other story. Of all three mortal assurances, the only one we truly take for granted is making little trumpet sounds from our buttholes. It’s a collective social assumption that we all fart, but the nuances of our collective flatulence are often completely overlooked. Which is a damn shame, because there’s a lot we can learn from our farts.

For instance, did you know farting in front of your romantic partner can lead to a deeper connection? “Farting in front of your significant other means you feel free to move beyond your roles," Dr. Robert Huizenga writes on his marriage blog. "You may even find yourselves discussing family roles and expectations that you bring to each other." Farts are a pathway to empathy.

And if you think farts too crude or juvenile a subject to take seriously, you need to study up on the career of Joseph Pujol. He was a professional farter. He would go on stage at the Moulin Rouge, fart the tune of the French national anthem, and extinguish candles with his butt-blowhole from yards away to the delight of Parisian socialites. Pujol—a hilarious name for a professional farter—even performed for Prince Edward of Wales, King Leopold II, and Sigmund Freud. Farts can be high art.

Deeply examining our farts is important both for personal and societal development—we can now all agree on that—but to truly understand farts, you must understand their root cause. You know that beans are the magical fruit, and the more you eat, the more you toot, but do you know what polymer of fructose molecules in garbanzos are doing the damage? (SPOILER ALERT: It’s frictans!) Do you know the scientific reasons why Taco Bell causes such explosive anus applause? If you do, that’s awesome, and I’m super proud of you. But there are many of us out there still confounded by the many mysteries expelled from the sphincter. So we enlisted the help of gastroenterologist Dr. Jitesh Patel to preach the air biscuit gospel.

Spices: nature’s anus perfume!

According to Dr. Patel, who often designs diets for patients suffering from gastrointestinal disorders, the most fart-inducing foods are covered under the acronym FODMAP (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols). The scientific umbrella term refers to the types of sugars and fibers that produce excess gas when broken down by bacteria during the metabolic process. Not only do high FODMAP foods induce flatulence, but they also can lead to burping and excess gas bloating. For all you out there without a medical degree, you may know the condition better as “bubble gut.” Everyone knows about beans and broccoli, but your brown thunder can also be spurred on by lesser known high FODMAP foods like apples, pears, and even garlic salt.

Sadly, for all you aspiring fart sommeliers, there’s not a pure one-to-one relationship between what you eat and how your fart smells. Even with a Joel Robuchon-level nose and palate, it would be impossible to distinguish between a Brussels sprout fart and a cauliflower fart. But, there are foods that are associated with particularly potent fog slicers.

“Sometimes we have patients that complain about really bad smelling flatus (a fun Latinate term for farts), and that’s often associated with methane producing bacteria,” Dr. Patel says. “It’s specific to everyone, but I’ve noticed most of my patients complain about really bad gas when they’re eating predominantly meats as opposed to vegetables.” He did go on to add that certain spices you’re eating may contribute to your particular fart smell. You won’t exactly blow cumin clouds out of your b-hole, but it could contribute a certain piquancy, which is kind of hilarious to think about. Spices: nature’s anus perfume!

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The reason fart smells are so unpredictable is because of the sprawling Wild West that is your gut’s microbiome. There are hundreds of species of bacteria that help break down food in your GI tract, and having a variety of species—which comes from eating a healthy and diverse diet—can reduce gas bloating, which can reduce methane production, which can reduce those silent but deadly, assassin-type farts. Not only is this affected by diet, but also by extraneous factors. If you’re on antibiotics, or even if you’ve traveled to a different country, your gut bacteria can shift and change, leading to wonky anus aromas.

Despite the mysteries hidden in your gut, there is one constant: Taco Bell will always guarantee some gnarly farts. There’s no secret ingredient that causes such voracious butt burps—it’s just the perfect storm of farty ingredients. “There is grease, there is red meat—and processed meat consumption does also tend to cause problems, especially when combined with the oil; and then there’s the pinto beans if you have their refried beans,” says Dr. Patel. “So it’s definitely a recipe for flatulence." Combine all that with the heavily spiced beef ragu they pack into tacos, and you have a beautiful symphony of butt odors.

The body is just one giant meat sack of mystery, and the gases pouring out of that meat sack are just as mysterious. That means being a professional fart sommelier, plucking fermented leek and overripe plum notes from thin air, is not likely in your immediate future. Still, there’s something beautiful and humbling knowing that science—which is responsible for putting a man on the moon, curing polio, and inventing the Doritos Locos Taco—still hasn’t fully decoded the trombone notes playing from our collective assholes.