As the national conversation about ultra processed foods continues, some companies are taking a curious approach. What if your new favorite soda was good for your gut health?

That's the overarching claim of prebiotic sodas — that is, soft drinks that contain prebiotics, which are dietary fibers that our bodies can't digest but can feed the microbes in our gut.

Are prebiotic sodas better for you than other types of soda or carbonated beverages? Or is it all hype? And if you're not drinking prebiotic sodas, should you be?

Prebiotics: Food for probiotics

"A prebiotic is a substance that promotes the growth of beneficial bacteria," says Dr. Eamonn Quigley, a gastroenterologist at Houston Methodist. "It's usually some form of complex carbohydrate. Some of these are fibers; other examples are inulin and oligosaccharides."

These fibers and compounds are non-digestible, so they pass through the upper gastrointestinal tract to travel to the colon, where they are fermented by the microbiota in your gut to stimulate the activity of probiotics, or healthy bacteria, in your gut.

The main benefit of prebiotics is to help boost or support the diversity of your microbiome, according to Dr. Quigley. Prebiotics are known to help with constipation, bloating, and aiding in symptoms for irritable bowel syndrome and inflammatory bowel disease.

So where can we find prebiotics? Fruit, vegetables and whole grains are a good place to start. Prebiotics are produced by many plants — you can find them in bananas, leeks, onions, garlic, asparagus, artichokes and in whole grains like wheat and barley. Additionally, there are prebiotic supplements.

Why is prebiotic soda having a moment?

Traditional sodas, considered sugar-sweetened beverages, are one of the leading sources of added sugars in the average American diet, according to the CDC. Drinking sugar-sweetened beverages is associated with a host of chronic conditions, including weight gain, heart disease, kidney disease, non-alcoholic liver disease, cavities, tooth decay and gout. And while diet or sugar-free soda options are available, many choose to forego them due to their use of artificial sweeteners.

Many consumers seek a classic soda taste but would prefer a healthier alternative. Enter prebiotic sodas, which have lower amounts of sugar and calories compared to full-sugar soda, and are fortified with prebiotic dietary fibers, usually isolated from plant-based sources such as inulin, chicory root, sunchokes or guar gum.

These sodas come in popular flavors, such as cola, orange, lemon-lime, root beer, cherry, as well as a flavor associated with a fictitious doctor. Depending on the brand, these sodas can have anywhere from two to nine grams of dietary fiber.

So is prebiotic soda good for you?

The makers say that the fiber-infused sodas help feed the probiotics in your gut and therefore can make your microbiome healthier. But the truth is much murkier.

"We currently don't have enough evidence about these prebiotic sodas to evaluate the claims made by the manufacturers," says Dr. Quigley says. "To be able to evaluate these claims, there would need to be legitimate studies evaluating the prebiotics used in the product, and whether the prebiotics exist in enough quantities to be impactful to the microbiome, and the outcomes."

With prebiotics and probiotics alike, Dr. Quigley says that consumers should take manufacturer claims with a grain of salt.

"Many probiotic products on the market do not have adequate quality control, meaning they have not tested the viability of the product either at the time of sale or during the shelf life," Dr. Quigley says.

That's an enormous problem. For prebiotics, the issue is evidence — or lack thereof — that they actually stimulate the growth of "good" bacteria," Dr. Quigley says.

"In contrast, there are some prebiotics and probiotics out there which have been subjected to rigorous quality control," says Dr. Quigley. "Some prebiotics actually have been tested to find out what dose is needed to be effective. But the biggest problem of all, is that most of them have not made even an attempt to prove that they actually confer the health benefit that they claim."

Related: PODCAST: What Are Probiotics & Who Should Take Them?

So while there is no definitive evidence that prebiotic sodas are considered healthy, they may have a marketing health-halo due to their fiber and lower sugar content. However, there is no nutritional benefit to soda, whether it's regular, diet or otherwise. Like regular soda, prebiotic soda contains added sugar and calories, which can add up if you're having several in a day.

If you're interested in prebiotic sodas solely for the potential benefits for your gut health, you would be better off modifying your diet. Adding a variety of fruits, vegetables and whole grains to your meals could boost your prebiotic intake — aim for five veggies or fruits a day, and a serving of whole grains with each meal. Getting prebiotics through your diet also means you're getting other crucial vitamins and minerals as well. You could also consider an evidence-based supplement or functional foods to help with gut health, if that's your aim.

Dr. Quigley says the allure of products like prebiotic sodas will likely continue to grow for consumers, since people tend to prefer food or drinks over supplements. But where manufacturers make claims, Dr. Quigley says there should be evidence to back those claims.

"Your prebiotic must be produced with high quality control, and it must be shown to have the effects that a prebiotic should have," Dr. Quigley says. "And it should be shown to be effective in whatever condition you're treating."