What Happens to Your Gut When You Drink Seltzer

With zero sodium, calories, cholesterol, saturated fat or sugar, seltzer seems like the beverage that can do no wrong. Whether we like it plain, infused with flavors or sparkling with festive fizz, it’s become a favorite for many. But those bubbles come with one lingering question: Is seltzer actually good for your gut, or could it be causing more trouble than you expect?

To answer that, it helps to understand what happens inside your digestive tract when you sip something carbonated. The bubbles we love are simply carbon dioxide (CO2) dissolved in water. Once that CO2 hits the warmer environment of your stomach, it turns into gas that needs somewhere to go, and there are two routes it can take. For some people, beyond the noise, that’s no big deal. For others, especially those with sensitive gastrointestinal tracts, those bubbles can bring bloating, pain or discomfort that’s hard to ignore.

Here’s what the latest science says about how seltzer affects your gut, along with insights from nutrition experts and simple strategies for enjoying the fizz without the unwanted side effects.

The Benefits for Gut Health

It Can Support Better Hydration

Most of us don’t drink enough water, and seltzer can help bridge that gap. If bubbles make plain water more appealing, that can translate to better overall hydration, and better hydration helps promote optimal digestion. Seltzer comes in a variety of flavors, so this sparkling beverage pairs perfectly with a meal instead of a high-added-sugar beverage. Plus, it can take center stage in a tasty mocktail.

Dawn Jackson Blatner, RDN, CSSD, points out, “Seltzer hydrates just like regular water, and staying well-hydrated is one of the best things you can do for smooth digestion and regularity.” Blatner highlights, “If the fizz or flavor makes water feel exciting, seltzer can be a fun add-in to your plain water rotation to help you drink more overall. However, if someone notices digestive symptoms from drinking seltzer, they should ditch the bubbles and switch to the still stuff.”

“Beyond hydration,” Keri Gans, RDN, says, “carbonation itself doesn’t offer specific gut perks—the real benefit is simply meeting your fluid needs.”

Buyer beware, however, since some seltzers also come with added sugar, caffeine or other additives you may not have counted for in this clear beverage. Moreover, not all seltzers are calorie-free, so be sure to read labels carefully to understand what you’re buying.

It May Help You Feel Fuller

“Carbonation can create a gentle stretching in the stomach, which may help you feel full a little sooner,” says Gans. “It’s not a magic trick for weight control, but for some people it can take the edge off hunger between meals,” Gans points out. Studies have suggested that carbonation might slightly enhance satiety, which could be helpful if you’re trying to lose weight.

It’s a Smart Swap for High-Sugar Drinks

If your choice is between soda and seltzer, your gut wins with selecting seltzer. You’ll avoid added sugars, no- or low-calorie sweeteners, sugar alcohols and acids that can irritate digestion for some people. Even though seltzer is carbonated, some people notice improvements in bloating or general GI discomfort transitioning from high-sugar or high-acid beverages to sparkling water.

The Downsides for Gut Health

It Can Cause or Worsen Bloating

When carbon dioxide reaches the stomach, it creates gas, and for people with irritable bowel syndrome (IBS), gastroesophageal reflux (GERD) or sensitive digestion, that can feel uncomfortable. Seltzer doesn’t cause these issues, but it can amplify symptoms if you’re prone to them. One study found drinking carbonated beverages was associated with almost three times more reported IBS symptoms compared to people not drinking carbonated beverages.

Tara Collingwood, M.S., RDN, CSSD, LD/N, ACSM-CPT, says, “Once seltzer (water infused with carbon dioxide gas) reaches the stomach, some of that gas is released, which can create a feeling of fullness or the urge to burp.” Collingwood assures us, “It doesn’t harm the digestive tract. It’s really just some extra gas your body has to manage.  The water part is absorbed the same way regular water is.”

It Might Trigger Reflux

Those bubbles can increase pressure in the stomach, and that extra pressure may relax the lower esophageal sphincter, making reflux more likely. Not everyone reacts this way, but if you’ve noticed heartburn after drinking seltzer, the carbonation might not bring the benefits you’re looking for.

Although sugar-sweetened and citrusy beverages have been found to exacerbate symptoms of gastrointestinal distress, Blatner says, “Because carbonation can also be the culprit, it’s likely that any variation of sparkling water will impact the gut similarly for those who are sensitive.”

It Might Impact Tooth Enamel

Carbonation makes water slightly acidic, and if you’re reaching for seltzer often, particularly the flavored versions, your enamel may become more sensitive over time. A recent review found that frequent exposure to carbonated drinks increases the risk of enamel erosion—even when there’s no sugar involved. Blatner suggests drinking seltzer with food or simply rinsing your mouth with regular water afterward.

Cold Seltzer Can Slow Digestion Slightly

Some studies suggest that very cold drinks may delay gastric emptying, which can contribute to fullness. These findings demonstrate that consuming cold beverages may reduce energy intake, but if your stomach is feeling sensitive, carbonation can still create discomfort.

Flavored Seltzers May Be More Irritating

Mineral waters that naturally contain magnesium or calcium can be mildly helpful for staying regular. Collingwood states, “Flavored seltzers without added sugar or sweeteners are generally fine, but those containing artificial sweeteners or sugar alcohols can trigger bloating or diarrhea in some sensitive people.” Collingwood went on to say, “More acidic or citrusy seltzers can potentially make reflux worse for people with GERD.” Acidic water won’t hurt your gut microbiome, but it can irritate stomach lining or contribute to discomfort for some people.

How to Drink Seltzer in a Gut-Friendly Way

• Pair it with food so gas isn’t hitting an empty stomach.
• Sip slowly instead of chugging, which traps more air.
• Don’t drink seltzer through a straw, since that might exacerbate discomfort.
• Choose plain or “no-acid-added” varieties if you’re sensitive.
• Let it sit for a few minutes to allow some bubbles to dissipate.
• Stick to room-temperature seltzer if cold beverages bother your gut.
• Rotate with still water if you’re prone to bloating.
• Test your tolerance—everyone’s gut responds differently.
• Avoid drinking it right before exercise if it makes you feel overly full.
• Be sure to read beverage labels to see what you’re getting besides water.

Our Expert Take

Overall, seltzer is perfectly fine for most people and, for many, it may even support healthier hydration habits. The key is knowing how your body reacts. If you find yourself feeling bloated or have reflux symptoms after drinking it, consider limiting carbonated beverages or trying different temperatures or flavors. But if your gut feels great and you enjoy the bubbles, keep sipping. Blatner sums it up by saying, “Seltzer may aggravate gastrointestinal symptoms, but it’s not necessarily true for everyone, so you have to listen to your body.”