Should You Eat Fermented Foods on an Empty Stomach? 2023 | Well+Good (2024)

Fermented foods have been having a *major* moment in the wellness world as of late, and it’s easy to see why. After all, they’re proven to diversify the gut microbiome, promote digestion, and lower inflammation—and, if you ask me, they’re incredibly delicious to boot. TL; DR? The likes of kimchi, kombucha, and kefir definitely deserve a spot in your diet.

Yet given the acidic nature (and oftentimes, probiotic powers) of these gut-friendly heroes, you may be wondering if it’s all good, gut health-wise, to eat fermented foods on an empty stomach. In search of clarity, we consulted Sarah Greenfield, RD, CSSD, a functional medicine dietitian who specializes in all-things gut health.

Is it safe to eat fermented foods on an empty stomach?

In short: it depends. Generally speaking, if your gut is in good shape and your body typically responds well to fermented foods, eating them on an empty stomach should be completely fine. “Fermented foods are typically fine to eat on an empty stomach since they help to support digestion,” Greenfield says. “Bitter foods stimulate bile and HCL production, which help the body digest foods more efficiently. They also contain acetate, which helps to feed and fuel good bacteria in the gut.”

However, there are exceptions to this general rule, particularly if you have certain food sensitivities, health conditions, and/or imbalances.

Who shouldn’t eat fermented foods on an empty stomach?

To start, Greenfield always takes care to note that while certain foods can be beneficial in and of themselves—with fermented bites and beverages among them—all bodies are different and can react either poorly or positively to specific items. For instance, if you’re sensitive or reactive to cabbage, loading up on kimchi or sauerkraut could end up exacerbating digestive distress instead of helping to fix it… especially if you consume them on an empty stomach.

Moreover, if you’re struggling with indigestion or stomach pain, Greenfield warns against eating fermented foods on an empty stomach—and potentially even within your diet at large. “If your gut microbiome is out of balance, fermented foods can actually create a lot of digestive discomfort in the form of bloating, and even diarrhea and constipation in some cases,” she says. Greenfield also mentions that those suffering with IBS may also struggle to tolerate fermented foods on account of gut imbalances. The same goes for people who have yeast overgrowth. “I do a lot of food sensitivity testing, and if I find a high level of reactivity to candida albicans, it's usually an indication that fermented foods will not be tolerated and are upregulating the immune system,” she says.

All said, fermented foods do have the potential to plenty of good for your gut, but if you deal with digestive issues or sensitivities, it may be best to consume them in moderation and not on an empty stomach.

How to tell if fermented foods may help or hurt your digestion

All too often, people who feel like they may be reactive to certain foods—or that something simply doesn’t feel right in terms of their greater health—can’t quite pinpoint their dietary triggers or the root causes of their wellness woes. If you’re in this gray area and haven’t successfully discovered these insights just yet, it helps to know what should and shouldn’t happen after you eat fermented foods.

“If you have daily bowel movements that are well-formed, good energy levels, few skin flare-ups, and no major gut distension after eating, you’re likely in the clear to eat fermented foods on an empty stomach or otherwise,” Greenfield says. “But if you eat them and get gassy shortly thereafter—or notice fatigue, sluggishness, skin flare-ups like redness and eczema, dandruff, and/or vagin*l itching—it could signal that your body is reacting poorly to them.” At that point, it’s worth getting a food sensitivity test under the guidance of a functional medicine practitioner to discover, with certainty, if fermented foods are contributing to these symptoms.

In addition, it can help to know what additional telltale signs of microbiome imbalance and candida overgrowth look like if they’ve neither been confirmed nor ruled out. “Pay attention to brain fog, a white coating on the tongue, intense sugar cravings, sudden skin irritations, loose or hard-to-pass stools, and blood sugar irregularities,” Greenfield advises. If and when these symptoms crop up, it’d be wise to halt your intake of fermented foods and consult an expert.

The bottom line

If you eat Greek yogurt upon waking up each morning, sip on a glass of kombucha for a midday pick-me-up, and munch on sauerkraut in between meals, there’s no need to slow your roll if your body reacts as well to these foods as your taste buds do. Yet if you think that your intake of fermented foods on an empty stomach could potentially be working against you, you may want to enjoy eating them paired with other foods to see if positive changes arise.

“I like to use sauerkraut on a salad or on gluten-free toast with eggs and avocado, and love adding pickles to sandwiches for crunch and flavor.” Greenfield says. “You can also add kefir or fermented coconut yogurt to a smoothie—but make sure to add it after it's blended so you don't kill any probiotics.”