Don’t be ashamed of passing gas! It’s a sign your gut microbiota rocks

It was one of those family meals you have once a year. Grandparents, aunts, uncles, cousins, brothers and sisters-in-law, siblings, all together gathered around a splendid table, chatting, eating the delicacies cooked by grandma, when all of a sudden, a familiar but surprising sound followed by that… smell made everyone silenced. Pooh! Then, ‘It’s just a little fart!’ said my 2-year-old toddler, smiling funny, after being ‘betrayed’ by her still-in-progress gut microbiota. ‘Maybe too many hummus last night?’ I thought, really embarrassed.

All of us pass gas. Nevertheless, healthy people do not realize because the majority of times it is at night, when they are sleeping and do not really control.  “There is a lot of stigma attached to passing gas and, obviously, passing it in front of a bunch of people is not the best thing”, claimed gastroenterologist Purna Kashyap, leading the Gut Microbiome Lab at the Mayo Clinic at the Gut Microbiota World Summit held spring 2019 in Miami (USA).

“The gas is just bacteria fermenting what you cannot eat, that is fiber, to produce by-products. So, if you are producing gas, that means bacteria have something to ferment and they are eating, so that’s a good thing for you!”, he added.

As we have already explained in this blog, fiber is essential for having a healthy gut microbiota and thus for our general health. It is known that richness, abundance and diversity are three key factors for gut microbiota. There are a lot of dietary fibers and it is advisable to eat a diversity of them, as different type of fibers feed different types of microbes.

“We haven’t yet identified which specific fibers would be the best for each of our gut microbiota, and that’s the goal of a lot of research going on now. What we already know is that if you decrease the fiber, then your gut microbes become more reliant on your mucus layer, this protective substance that lines the interior of the intestine, and start devouring it. That’s when health problems start”, highlighted Kashyap.

But increasing suddenly your amount of fiber intake can cause health problems and inconvenience too. For instance, bloating, due to gas formation, that can cause belly pain. “Better make changes little by little”. If you were only eating white bread all your life, you could start with half a toast in your breakfast. Whole grain breads have at least 2 grams of fiber per slice. According to the American Heart Association, for instance, the daily value for fiber is 25 grams per day on a 2,000 calorie diet for adults (women under 50, from 21 to 25 grams per day, and men under 50, from 30 to 38 grams per day). “It is not a good idea to go from eating 10g of fiber to 40 g of fiber in a day”, considered Kashyap.

Also, if you detect there are certain foods giving you more gas, you can switch them for other less gassy. For instance, maybe spinach gives you too much flatulence, but lettuce is not. Besides that, dose is also important: maybe eating a whole plate of hummus makes your belly a balloon, so you’d rather try one third of that.

For Doctor Kashyap, our mind is also a factor to take into account. “A lot of us work with anticipation: if I put my hand on the stove and I burn it, the next time I am going to be looking again to make sure it is hot. Our body is very good at learning these responses and so they perpetuate themselves. That’s where the whole gut-brain axis comes in. It functions as one unit, so there are a lot of factors that drive how you respond to different diets”.

At the end, according to Doctor Kashyap, eating healthily is about including everything in a good quantity. It’s all about balance.

Cristina Sáez
Cristina Sáez
Cristina Saez is a freelance science journalist. She works for several media, for instance the Spanish newspaper La Vanguardia, where she coordinates the science section, Big Vang; as well as research centres and scientific societies. She has been awarded for her journalistic work, among others, with the Boehringer Ingelheim Award in Medical Journalism 2015. Follow Cristina on Twitter @saez_cristina