Can Dehydration Affect Your Gut?
Health ConditionsDigestive Health

Can Dehydration Affect Your Gut?

Can Dehydration Affect Your Gut?
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Updated on July 10, 2026
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Water is essential for your health. Proper hydration helps deliver essential nutrients to cells to help organs function.

 Conversely, mild dehydration can cause problems with your body temperature, heart rate, and blood pressure.

How well you’re hydrated also affects your gut.

“Hydration plays a key role in intestinal secretions, nutrient digestion and absorption, gut motility, waste removal, and gut microbiome support,” says Candace Pumper, RD, a staff dietitian at the Ohio State University Wexner Medical Center in Columbus.

How Dehydration Affects the Gut Microbiome

The gut microbiome is made up of bacteria, viruses, parasites, and fungi — called microbes — mostly in the small and large intestines. The balance of microbes in your gut impacts your digestion, immunity, nervous system, hormones, and metabolism.

Adequate hydration is part of the ideal environment for a healthy gut microbiome, and the amount of water we drink may also influence its composition and variation.

“Dehydration fosters constipation, resulting in hard stools that can be difficult to evacuate,” says Adrienne Lenhart, MD, a gastroenterologist at the Goodman-Luskin Microbiome Center at UCLA in Los Angeles. Research suggests that constipation may contribute to gut dysbiosis — or an imbalance of beneficial and harmful bacteria that can have negative health effects. In fact, the two conditions have a bidirectional relationship, with each contributing to the other, according to one international study.

Dehydration also increases the risk of digestive issues such as bloating.

 “This suggests that insufficient fluid replacement affects gut function and may impact the gut microbiome,” Pumper adds.
People with chronic abdominal bloating tend to have significant gut dysbiosis, according to a small study of Turkish adults. Although bloating itself isn’t thought to contribute to gut issues, it can often be a symptom of problems such as difficulty digesting certain foods, including FODMAPs (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols), or of conditions like irritable bowel syndrome or depression.

Factors That Raise the Risk of Dehydration

The most common cause of dehydration is, perhaps unsurprisingly, not drinking enough water. But some people may dehydrate more easily than others. “Anyone is susceptible to dehydration, especially older adults, children, and infants,” says Megan Porter, RD, CDCES, clinical educator at Randall Children’s Hospital and founder of the Healthy Family in Portland, Oregon.

Athletes or other physically active people who don’t replace fluid (lost through sweat) at regular intervals during training or competition increase their dehydration risk too.

Some common causes of dehydration include:

How Much Water Should I Drink?

How much water you need depends on factors including your age, sex, activity level, overall health, and environment. Pregnant and nursing women, for example, may need more water, while those with advanced kidney disease may need to restrict their intake.

However, most healthy men need to consume about 15.5 cups per day, and most healthy women need about 11.5 cups per day. While that may sound like a lot, remember that it includes everything you eat and drink in a day, not just plain water.

Unless you’re exposed to extremely hot temperatures or are in a sports competition, you probably don’t need to chug water all day long to stay adequately hydrated. Instead, you can incorporate a steady intake of fluids into your routine. “I recommend having a beverage — mostly water, fat-free milk, or a milk alternative — with each meal, and to drink water in between meals,” Porter says. “My goal is to fill a water bottle in the morning and to drink it by lunch, then to refill it and drink it down again by dinner. Then, be sure to add in high-water-content foods to each meal or snack you have,” she suggests.

You can tell you’re drinking enough water if you’re not often thirsty and your urine is very pale yellow or clear.

5 Healthy Ways to Support Your Gut

Your daily fluid intake is mostly made up of what that you eat and drink. “Water and other beverages contribute about 70 percent of the body’s total water intake,” Pumper says. Foods generally make up about 20 percent of the body’s total water intake.

 The process of metabolizing foods also produces some water as a by-product, which makes up about 10 percent of the water available to the body.

The following tips can help you get enough fluids each day.

1. Eat Lots of Fruits and Vegetables

“Besides drinking water, you can enjoy a variety of fruits and vegetables that are high in water content to stay hydrated,” says Vandana Sheth, RDN, a registered dietitian in private practice in Los Angeles and the author of My Indian Table: Quick & Tasty Vegetarian Recipes.

A few of the most hydrating fruits and vegetables include:

  • Cucumbers
  • Celery
  • Watermelon
  • Oranges
  • Grapes
  • Cabbage
  • Baby carrots
  • Asparagus
  • Spinach
  • Lettuce
  • Pineapple
  • Cooked corn
Research shows that in addition to keeping you hydrated, a diet rich in fruits and vegetables supports gut health, because the fiber in these plant-based foods feeds helpful bacteria. Additionally, micronutrients and compounds such as antioxidants help reduce inflammation, preserve the gut barrier, and support cellular health. In fact, one review concluded that adopting a plant-based diet has “profound” benefits for gut health.

2. Try Sparkling or Mineral Waters

As for beverages, healthy alternatives to plain water include mineral and sparkling waters. You can also add flavor with fresh lime or lemon juice, or by infusing your water with fresh mint, basil, strawberries, or cucumber slices.

Sparkling water and seltzer are just as hydrating as regular H2O, but they can contribute to bloating in some people.

3. Drink a Few Cups of Tea or Coffee

Plain tea and coffee are also good, flavorful options that provide fluids, caffeine, and other compounds — such as antioxidants — that support gut health.

Besides hydration, tea can support gut health by promoting the growth of beneficial bacteria while keeping harmful ones in check, according to an international review of research. Additionally, it may help strengthen the gut lining and suppress inflammation in the colon.

Coffee similarly supports gut health by feeding beneficial bacteria and lowering inflammation. People who regularly drink four or five cups of coffee per day also have more of certain gut microbes that help ward off infections and harmful bacteria, according to one international study.

Just be sure not to consume too much caffeine, since it’s a diuretic. Usually, caffeinated beverages have a net-hydrating effect, due to their water content. But adults who exceed 400 milligrams of caffeine per day and don’t consume enough other, non-caffeinated liquids may be at higher risk of dehydration.

4. Consume Probiotic-Rich Kefir or Yogurt

Consuming any liquid or water-rich foods can help with hydration, but fermented products like kefir and yogurt are particularly beneficial for gut health. That’s because these foods contain probiotics (live, beneficial bacteria). Regularly consuming fermented foods helps support microbiome health and diversity, reduce inflammation, and enhance the gut barrier, according to a review.

 If you can’t or choose not to eat dairy, plant-based alternatives like soy and almond yogurt are also good options.

5. Steer Clear of Sodas, Sports Drinks, and Most Juices

It’s best to steer clear of regular and diet sodas, as well as most fruit juices, due to their high added sugar and artificial sweetener content.

Pumper also advises against relying on electrolyte (sports) drinks for daily hydration, since these tend to contain more sodium and added sugar than most people should have in a day.

“Electrolyte beverages, including drink mixes and powders, are generally intended for rehydration after fluid losses from exposure to heat for an extended period. For example, bouts of diarrhea or vomiting, and during strenuous exercise,” Pumper explains.

EDITORIAL SOURCES
Everyday Health follows strict sourcing guidelines to ensure the accuracy of its content, outlined in our editorial policy. We use only trustworthy sources, including peer-reviewed studies, board-certified medical experts, patients with lived experience, and information from top institutions.
Resources
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  12. Zhao Z et al. Effects of Differently Processed Tea on the Gut Microbiota. Molecules. August 25, 2024.
  13. Boscaini S et al. Habitual Coffee Intake Shapes the Gut Microbiome and Modifies Host Physiology and Cognition. Nature Communications. April 21, 2026.
  14. Grounded in Reality: Does Coffee Really Dehydrate You? Cleveland Clinic. May 21, 2024.
  15. Park I et al. Fermented Foods as Functional Systems: Microbial Communities and Metabolites Influencing Gut Health and Systemic Outcomes. Foods. June 28, 2025.
  16. What to Look for in Yogurt. Academy of Nutrition and Dietetics. January 30, 2026.
  17. Sad but True: Diet Sodas Are Bad for Your Health. Cleveland Clinic. May 19, 2023.
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