How often do you fart? This smart flatulence underwear can tell you that and more

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Everyone farts. But not everyone tracks their farts.

Now, smart underwear is making a case for paying closer attention to what comes out of your body. Its creators said they hope that tracking flatulence could eventually give researchers new insight into digestive health — and how a person’s farts offer clues about what’s happening in the gut.

Brantley Hall, the brains behind the smart underwear and an associate professor at the University of Maryland’s department of cell biology and molecular genetics, said the team’s “ultimate mission is to help people eat high-fiber diets comfortably with low intestinal gas.”

In the United States, it is estimated that 95% of Americans don’t eat enough fiber. The nutrient plays a critical role in digestive health, blood sugar and cholesterol regulation, and maintaining a healthy gut microbiome . (That’s the community of helpful bacteria and other microorganisms that live in your digestive system.)

But for some people, eating more fiber also means more gas, especially at first. When you eat fiber, the gut microbes ferment it , resulting in production of gases such as hydrogen — and those gases eventually become farts.

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By studying who farts more, who farts less and how flatulence changes with diet, researchers aim to understand how microbes respond to different foods and why some people can tolerate high-fiber diets comfortably while others struggle with gas.

The smart underwear is the first wearable designed to measure human flatulence. The measuring device is a small disc that snaps into the back of a person’s underwear. It then uses tiny electrochemical sensors to detect hydrogen, providing insight on the wearer’s flatulence. The results contribute to the Human Flatus Atlas , a research project that has recruited people around the world to wear the smart device while also documenting every meal they eat.

While it is not a medical device, researchers said the technology could eventually have applications in medicine, including helping scientists identify early signs of gastrointestinal problems.

Hall said the team hopes to help people “who show up at their doctor and say, ‘I feel bloated, or ‘I feel gassy,’ or ‘I feel abdominal pain.’“

By not just relying on people’s perceptions, but instead objectively measuring the production of farts, Hall said he and other researchers can do a better job understanding their digestive issues.

There is not a universal baseline of how many farts a day is normal, partly because it varies with each person. But that’s also because, before the smart underwear, there hasn’t been an efficient way to track farts. Doctors would either have to rely on a person to track their own farts or use a pretty invasive procedure to monitor them, Hall said.

“There’s this guy; he’s named the King of Farts,” Hall said, referring to gastroenterologist Michael Levitt and his research. “He’s kind of like where all the fart studies came from, and he used a very embarrassing technique to measure farts. It was rectal tubes. It was like tube in the ass and counting farts as they came out.”

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The smart underwear, on the other hand, allows people to go about their days while simultaneously tracking their farts. It also can detect sleep flatulence, which is “a completely understudied or unstudied scientific topic. No one really knows how people are farting in their sleep,” Hall said.

The Human Flatus Atlas has recently finished its second study of smart underwear users. In the first study, users were asked to wear the device for about 12 hours a day for seven days. In that paper , published in December in the scientific journal Biosensors and Bioelectronics, the researchers found that the average amount of farts was around 32 during that time period.

For the new paper, which gathered data from more than 500 volunteers, subjects were asked to wear the device for at least 22 hours for anywhere between three to 30 days, only to take it off for activities such as showering and going to the bathroom. Hall said the team plans to release the new study soon.

His hope is that, with the help of the smart underwear, doctors can one day better understand what’s happening in the gut and eventually identify patterns that could diagnose or monitor certain digestive conditions.

Hall pointed to a 2023 study that looked at the digestion issues of nearly 89,000 Americans included in the National GI Survey II. The researchers found that about 1 in 4 had problems related to gas, whether that meant bloating, excessive gas or abdominal pain.

Dr. Jordan Axelrad agreed that the smart underwear could one day “provide a continuous, noninvasive, real-world measure of microbial metabolic activity,” and could maybe even help researchers identify gastrointestinal problems before they fully develop. Axelrad, an associate professor at the New York University Grossman School of Medicine and codirector of the Inflammatory Bowel Disease Center at NYU Langone Health, was not involved with the Human Flatus Atlas project.

For the most part, people don’t need to worry about the amount of gas they’re passing unless it is accompanied by other issues such as bloating, abdominal pain, diarrhea, constipation, weight loss, blood in the stool or a change in bowel habits, Axelrad said.

“Passing gas is a normal and important part of digestive health,” Axelrad said in an email. “Most intestinal gas comes from bacteria in the colon fermenting carbohydrates that our bodies don’t completely digest, so the amount of gas we produce can vary considerably depending on what we eat, our gut microbiome, and even how much air we swallow with huge individual variation.”

Dr. Trisha Pasricha, a physician-scientist at Beth Israel Deaconess Medical Center in Boston and assistant professor of medicine at Harvard Medical School, added that she often sees people in her clinic who suspect they have extra flatulence when actually they are within the normal range.

“People often worry they fart more than average because we’re all so embarrassed about it — nobody’s counting how often they fart and sharing that number with their best friend,” said Pasricha, author of “ You’ve Been Pooping All Wrong : How to Make Your Bowel Movements a Joy,” in an email. She also was not involved with the Human Flatus Atlas project.

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On the flip side, if someone notices that they haven’t passed gas at all and are having abdominal pain and no bowel movements, that’s a medical emergency that could represent a bowel obstruction, and they should seek care immediately, she said.

“Right now, we have a lot of work left to do in understanding how changes in the gut microbiome truly connect to disease, and how changes we make to our diet can influence conditions that don’t even seem gut-related — things like cardiovascular disease or dementia, which can ultimately be shaped by our gut bacteria,” Pasricha said.

With more research and data from studies such as the Human Flatus Atlas, she said we may get to the point of individualized microbiome-targeting therapies, such as personalized diets or probiotics. But there’s more work to be done before the connections can be made between specific microbes and disease. While researchers know that certain microbial species are more common in particular diseases, they don’t yet know whether those microbes are causing the problem or simply responding to an environment created by something else.

“There isn’t good data showing that the number of farts alone signals something is wrong or points to a particular disease,” Pasricha said.

“It can be a symptom of certain conditions — celiac disease or lactose intolerance, for example — but there’s no clear-cut correlation between disease and fart count, if you will. In fact, people often become gassier as they increase their fiber intake, especially at first, and that’s usually a good thing, not a warning sign.”

Taylor Nicioli is a freelance journalist based in New York.

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每个人都会放屁。但并非每个人都会记录自己放屁的情况。

如今，智能内衣正促使人们更加关注自己的排泄物。其研发者表示，他们希望通过追踪放屁情况，最终能让研究人员更深入地了解消化系统健康——以及一个人的屁如何反映肠道状况。

智能内衣背后的策划者、马里兰大学细胞生物学和分子遗传学系副教授布兰特利·霍尔表示，该团队的“最终目标是帮助人们舒适地食用高纤维饮食，同时减少肠道胀气”。

据估计，美国有95%的人膳食纤维摄入不足。这种营养素在消化健康、血糖和胆固醇调节以及维持健康的肠道菌群方面发挥着至关重要的作用。（肠道菌群是指生活在消化系统中的有益细菌和其他微生物群落。）

但对某些人来说，摄入更多膳食纤维也意味着会产生更多气体，尤其是在初期。当你摄入膳食纤维时，肠道微生物会对其进行发酵，从而产生氢气等气体——而这些气体最终会变成屁。

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多久排便一次才合适？答案可能出乎你的意料。

通过研究谁放屁多，谁放屁少，以及放屁如何随饮食变化，研究人员旨在了解微生物如何对不同的食物做出反应，以及为什么有些人可以舒适地耐受高纤维饮食，而另一些人则饱受胀气困扰。

这款智能内裤是首款专为测量人体放屁而设计的可穿戴设备。测量装置是一个小型圆盘，可以卡入内裤后部。它利用微型电化学传感器检测氢气，从而提供穿着者放屁情况的信息。这些结果将用于“人类放屁图谱”研究项目。该项目已招募世界各地的人们佩戴这款智能设备，并记录他们的每一餐。

虽然它不是一种医疗器械，但研究人员表示，这项技术最终可能会在医学领域得到应用，包括帮助科学家识别胃肠道问题的早期迹象。

霍尔表示，该团队希望帮助那些“去看医生时说，‘我感觉腹胀’、‘我感觉胀气’或‘我感觉腹痛’的人”。

霍尔表示，通过不仅仅依赖人们的感知，而是客观地测量放屁的产生量，他和他的研究团队可以更好地了解人们的消化问题。

目前尚无普遍适用的每日放屁次数标准，部分原因是每个人的情况都不相同。但更重要的是，在智能内裤出现之前，一直缺乏有效的放屁追踪方法。霍尔表示，医生要么只能依靠患者自行记录放屁次数，要么需要采用侵入性较强的检查方法来监测。

“有这么一个人，人称‘放屁之王’，”霍尔说道，他指的是肠胃病学家迈克尔·莱维特和他的研究。“所有关于放屁的研究都源于他，他用了一种非常尴尬的方法来测量屁。那就是直肠管。就像把管子插进屁股里，然后数着放出来的屁。”

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专家指出，某些颜色的粪便可能预示着危险信号。

另一方面，智能内衣可以让人们在日常生活中同时追踪放屁情况。它还能检测睡眠中的胀气，霍尔说：“睡眠胀气是一个完全未经研究或完全没有研究过的科学课题。没有人真正了解人们在睡眠中是如何放屁的。”

人类放屁图谱（Human Flatus Atlas）近期完成了对智能内裤用户的第二项研究。在第一项研究中，研究人员要求用户连续七天每天佩戴该设备约12小时。该研究论文于去年12月发表在科学期刊《生物传感器与生物电子学》（Biosensors and Bioelectronics）上，研究人员发现，在此期间，用户的平均放屁次数约为32次。

这项新研究收集了500多名志愿者的数据，受试者被要求佩戴该设备至少22小时，持续3到30天不等，仅在淋浴和上厕所等活动时取下。霍尔表示，研究团队计划很快发表这项新研究。

他希望，借助智能内衣，医生有朝一日能够更好地了解肠道内发生的事情，并最终识别出可以诊断或监测某些消化系统疾病的模式。

霍尔指出，2023年的一项研究调查了近89000名参与第二次全国胃肠道调查的美国人的消化问题。研究人员发现，大约四分之一的人存在与胀气相关的问题，包括腹胀、胀气过多或腹痛。

乔丹·阿克塞尔拉德博士也认为，这种智能内衣有朝一日或许能够“提供对微生物代谢活动的持续、无创、真实的测量”，甚至可能帮助研究人员在胃肠道疾病完全发展之前就识别出来。阿克塞尔拉德是纽约大学格罗斯曼医学院的副教授，也是纽约大学朗格尼医学中心炎症性肠病中心的联合主任，他并未参与“人类肠气图谱”项目。

阿克塞尔拉德说，大多数情况下，人们无需担心排气量，除非伴有其他问题，如腹胀、腹痛、腹泻、便秘、体重减轻、便血或排便习惯改变。

“放屁是消化系统健康正常且重要的一部分，”阿克塞尔拉德在一封电子邮件中写道。“大部分肠道气体来自结肠中的细菌发酵我们身体无法完全消化的碳水化合物，因此我们产生的气体量会因饮食、肠道微生物群，甚至吞咽空气的多少而有很大差异，个体差异也很大。”

波士顿贝斯以色列女执事医疗中心的医生科学家、哈佛医学院医学助理教授特里莎·帕斯里查博士补充说，她经常在诊所里看到一些人怀疑自己胀气过多，但实际上他们的胀气量都在正常范围内。

“人们常常担心自己放屁比一般人多，因为我们都对此感到很尴尬——没人会去数自己放屁的次数，然后把这个数字告诉最好的朋友，”《你一直都拉错了：如何让你的排便成为一种享受》一书的作者帕斯里查在一封电子邮件中写道。她也没有参与“人类放屁图谱”项目。

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哈佛大学一位医生指出，排便的三个关键要素（3P）以及如何优化它们。

另一方面，如果有人发现自己完全没有排气，并且出现腹痛和排便困难，这是一种医疗紧急情况，可能是肠梗阻，他们应该立即就医，她说。

帕斯里查说：“目前，我们还有很多工作要做，才能真正了解肠道微生物群的变化是如何与疾病联系起来的，以及我们对饮食的改变如何影响那些看似与肠道无关的疾病——例如心血管疾病或痴呆症，这些疾病最终都可能受到我们肠道细菌的影响。”

她表示，随着更多研究和来自诸如“人类肠胃胀气图谱”等研究的数据积累，我们或许能够实现针对个体化微生物组的靶向治疗，例如个性化饮食或益生菌疗法。但在建立特定微生物与疾病之间的联系之前，还有更多工作要做。虽然研究人员知道某些微生物物种在特定疾病中更为常见，但他们尚不清楚这些微生物是致病因素，还是仅仅对其他因素造成的环境做出反应。

帕斯里查说：“目前还没有可靠的数据表明，单凭放屁的次数就能判断出身体出了问题，或者指向某种特定的疾病。”

“放屁可能是某些疾病的症状——例如乳糜泻或乳糖不耐受——但疾病和放屁次数之间并没有明确的关联。事实上，人们在增加膳食纤维摄入量时，尤其是在初期，往往会更容易放屁，这通常是件好事，而不是什么警告信号。”

泰勒·尼乔利是一位居住在纽约的自由撰稿人。

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