A new study is challenging long-held assumptions about coffee’s effects on digestive health, suggesting the popular beverage could offer benefits for both the gut and the brain.

The research, published in Nature Communications, examined 62 participants, half of whom were regular coffee drinkers, to explore how coffee consumption influences the gut microbiome and mental well-being. Using psychological assessments alongside dietary tracking and biological samples, researchers found that individuals who drank coffee, whether caffeinated or decaffeinated, reported lower levels of stress, depression and impulsivity.

The findings point to a growing scientific consensus: coffee is more than just a caffeine delivery system. According to the study’s authors, it acts as a complex dietary component that interacts with gut bacteria, metabolism and even emotional health.

Researchers also observed higher levels of beneficial bacteria among coffee drinkers, including strains linked to protection against harmful microbes and inflammation. Caffeinated coffee, in particular, was associated with reduced anxiety, improved attention and lower markers of inflammation.

Still, OSF HealthCare gastroenterologist Omar Khokhar, MD, cautions against drawing sweeping conclusions.

Kinds of coffee could make a difference

Dr. Khokhar points out it’s a small study that supports a hypothesis, but it’s not definitive proof that coffee will improve gut health or mood.

“There are so many different kinds of coffee. There’s Turkish coffee, there’s South American coffee, there’s Dunkin Donuts coffee, there’s Folger’s and Sanka for some of the people watching this on Facebook.” He points out, “It just comes down to each person and their own individual microbiome and how it responds to whatever particular type of coffee they’re ingesting.” 

Instead, Dr. Khokhar believes the study contributes to a broader shift in how scientists understand nutrition. Rather than labeling foods as strictly “good” or “bad,” researchers are increasingly focusing on individual responses, particularly how a person’s unique gut microbiome influences their reaction to what they consume.

Coffee itself is chemically complex, containing compounds such as polyphenols, which Dr. Khokhar says might act to feed beneficial gut bacteria.

“Now let’s suppose you’re at baseline and you have overall good gut hygiene and function; coffee could potentially be a good thing. It could be a prebiotic of sorts, that could potentially support your microbiome in that case.” 

This could help explain the observed microbiome changes in coffee drinkers.

However, those same compounds can have downsides. Coffee is known to relax the lower esophageal sphincter, potentially triggering heartburn, and Dr. Khokhar stresses coffee exacerbates symptoms in people with conditions such as irritable bowel syndrome.

The study did not differentiate between types of coffee, such as espresso versus brewed coffee, highlighting another limitation and an area for future research.

More research is needed

Dr. Khokhar says the study shows a link but not a direct cause and he thinks more controlled studies are needed to determine how specific varieties and preparation methods influence health outcomes.

“What I would like to see personally is if you controlled for what specific coffee a group of volunteers ingested and then either through blood or stool, looking at their exact gut microbiome diversification or pattern to see if that improved or how that changed from a robustness and a diversity point of view,” he says. “That would be more objective.” 

The research also raises intriguing questions about the gut-brain connection. Scientists now understand that the gut microbiome plays a role in producing neurotransmitters like serotonin, which can influence mood, sleep and behavior.

Whether coffee can enhance mood indirectly by improving gut health remains a hypothesis but an appealing one for millions of daily coffee drinkers.

For now, the takeaway is about embracing moderation and self-awareness. As Dr. Khokhar puts it bluntly, “If it makes you feel bad, don’t do it.” But he says if people can tolerate coffee well, in moderation, it might not be as harmful as once thought and could even be helpful, but more research is needed to prove that.

If you have questions about what's best for their health, talk to your primary care provider. 

Video clips with Dr. Omar Khokhar

B-roll-Coffee and gut microbiome

Whether you’re dealing with a job loss, financial woes or embroiled in relationship issues, we all suffer from stressful situations from time to time.

No matter what the situation, stress is not good for our health in so many ways. It can impact our cardiovascular health, mental health, sleep and even our skin and hair. One of the biggest problems is how stress affects our gut health. Stress can cause diarrhea, constipation, bloating or make conditions such as irritable bowled syndrome or bowel diseases like Crohn’s even worse.

“I know for a lot of people, the first thing that happens when they have something big and stressful coming up, they are running to the bathroom, or they don't go to the bathroom at all,” says Nicole O’Neill, a dietitian with OSF HealthCare. “So, there's a definitive connection between stress and gut.”

O’Neill says the reason for this is because the brain and gut are connected through nerves and gut bacteria. And the nervous system, which controls digestive functions, communicates with the brain through the vagus nerve.

“The vagus nerve is connected, literally from your brain to your gut, and it's one of our longest nerves,” O’Neill says. “And if your brain is in distress, it directly connects to your gut and causes your gut distress. The opposite is true too. If your gut is in distress, your brain is in distress. It's all tied together.”

Diet plays a major role in the relationship between stress and gut issues. O’Neill says when most people are stressed, they tend to reach for something unhealthy instead of fruits or vegetables, for example.

“When you're stressed out, do you eat the same as when you're not stressed out? Most of us don’t. We trend towards wanting sweet things or salty things,” O’Neill says. “They alter the chemical composition in your gut, which also alters the bacteria that can live in your gut.”

O’Neill adds that bacteria is resourceful. For example, say you’re a person who craves sugar when you’re stressed. But more sugar in the gut leads to the growth of bad bacteria, which dysregulates the gut lining. The gut lining becomes more porous or leaky causing a disruption in the gut.

So, what’s the solution? O’Neill says it starts with reducing the stress in your life. That can be achieved in several ways such as more physical activity or taking more time for yourself by reading, listening to music or spending time with friends. It also means learning to say no to things that stress you out, becoming a better manager of your time and working to stay positive during stressful times. And consider talking to a mental health professional.

As a dietitian, O’Neill says getting control of your diet should be a priority.

“If you eat an excellent diet, plenty of fruits and vegetables, lean meats, proteins, whole grains, then you're creating a safe environment for the good bacteria to grow, and that good bacteria allow your brain rest and relaxation.”

If you experience stress and gut issues, you’re not alone. O’Neill says it’s a common problem among her patients.

“We see a lot of people that stress is driving their gut. And we see a lot of people that their gut is driving their stress,” she says.

“It can flip flop either direction, but there are solutions. So, if you're struggling with your gut, if you're struggling with stress, getting the proper help that you need from any provider is going to help the other one.”

For more information, visit the OSF HealthCare website.

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Due to overall health benefits and the increased concern of gastrointestinal cancers in younger people, #fibermaxxing is one of the latest health trends to hit social media. 

“Protein has a competitor right now, and I’m not mad about it,” says Jeanna Brouwer, oncology registered dietitian with OSF Cancer Support Services. “Fibermaxxing is when people are going above and beyond past the recommended daily amount you need, which is about 25 grams for women and 30-38 for men. Fibermaxxing is usually when people are tracking their fiber and trying to get between 40 and 70 grams of fiber in a day.”

Brouwer says that fiber is a powerhouse to help prevent all kinds of cancer. Yet most Americans aren't getting the right amounts. 

The American Society for Nutrition (ASN) reports only 5% of men and 9% of women are getting the recommended daily amount of dietary fiber. 

The ASN reports that eating more fiber can reduce your risk of heart disease and diabetes as well.

When #fibermaxxing goes too far

“Fibermaxxing can be a wonderful and beautiful thing that helps you get adequate nutrition for long-term health; however, you need to be methodical about it. Some people overdo it very quickly,” Brouwer says. “You can jump from only getting 15 grams a day all the way to 50, and you’ll notice some impact in your system. That can show up as gas, bloating, changing in your bowel habits and being uncomfortable.”

For certain cancer and gastrointestinal patients, fiber intake needs to be limited.

“There are some in the population, like my patients who receive radiation to the GI area, where we want to restrict fiber for a little bit,” Brouwer says. “Some people with severe cases of irritable bowel syndrome (IBS) need to be very methodical and work with a health care provider. Other people who are having GI surgeries or recovering from surgery, you don’t want to go extreme with fiber.”

Diversify your fiber

Adding more fiber into your diet isn't just switching to whole-grain breads and pastas. Brouwer says you want to "diversify your fiber," starting with fruits and vegetables. She lists some more tangible additions to our diet that can spur on nutritional benefit. 

• Barley, quinoa and oats
• Nuts (walnuts, almonds) and seeds (pumpkin and chia)
• Beans and legumes

"Pick a meal that you love and think about how you can add fiber to that," Brouwer says. "That can be throwing beans in your favorite salad, sprinkling chia seeds in your cereal or yogurt. It's slowly sprinkling these things in for the total day's count."

Fruits and vegetables aren't just fiber powerhouses; they're adding a whole list of other health benefits as well. The colors in your fruit and veggies have cancer-fighting antioxidants called polyphenols. Brouwer says polyphenols help feed the good gut bacteria and decrease inflammation. These nutrients help prevent all kinds of chronic disease. 

The type of fiber you choose also can make a difference. Natural fiber is always the best, Brouwer says, as some mainstream items can contain synthetic fibers and cause excess gas and bloating. 

Prebiotic vs. probiotic: What's the difference? 

If you've walked down the grocery aisles lately, you've probably seen the terms "prebiotic" and "probiotic" thrown out many times. 

Brouwer says probiotics are live bacteria and yeast that can benefit your gut health and fight off bad bacteria. Prebiotics are food for the good gut bacteria that already exist in your gut. Fiber-containing foods, Brouwer says, contain prebiotic fibers in them naturally. Bananas and artichokes are two great examples, she says. 

This trend comes as colorectal cancer awareness month approaches in March. Additionally, actor James Van Der Beek, who announced his colorectal cancer diagnosis in 2024, passed away from the disease in February. Recent data released in early 2026 suggests colorectal cancer is now the leading cause of cancer deaths for adults under 50. 

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B-Roll

Sydney Russell, oncology dietitian at OSF HealthCare and coordinator of the OSF HealthCare Cancer Institute Teaching Kitchen, says simple dietary additions like fiber-rich seeds, antioxidant-packed fruits and vegetables and plant-based proteins can help strengthen the body and improve your quality of life.

The power of ginger for nausea relief

Ginger has long been used as a natural remedy, and modern research supports its benefits, particularly for people undergoing chemotherapy. Ginger contains an antioxidant compound called gingerol, which helps reduce inflammation and manage nausea.

"Gingerol is one of the antioxidant compounds found in ginger. It's excellent; from reducing chronic inflammation to helping relieve joint and muscle pain," Russell says. "It also helps manage nausea. Many of my patients undergoing oncology treatment are struggling with nausea. So, ginger tea, ginger broth and ginger smoothies can be great ways to help and keep nausea at bay."

Antioxidants: “Eating the rainbow”

Antioxidants are found in a wide variety of fruits and vegetables and play a role in supporting overall health and reducing cancer risk. Russell encourages people to focus on variety.

"We refer to it as eating the rainbow," Russell says. Adding all kinds of berries, fruits (like oranges) and veggies (leafy greens) into our meals daily can help add much-needed antioxidants into our lives, she adds.

"It's important we add protein and fiber (into our diets). I would encourage emphasizing antioxidants as well. That is going to support our overall health, but specifically when we're talking about cancer and ways to reduce our cancer risk," Russell says. "Those antioxidant-rich foods can be an excellent thing to include in our diets."

Fiber: A hidden powerhouse

Many Americans do not get enough fiber in their daily diets, yet it plays a key role in digestive health, blood sugar balance and cholesterol management.

It's a "hidden powerhouse," Russell says. Pumpkin seeds are a great way to add fiber into your diet, and you can add them to things like yogurt parfaits, granola and baked goods. This feeds the bacteria in your gut to promote a healthy gut microbiome. It also keeps your blood sugars balanced and helps with cholesterol.

Russell says vitamins and minerals help our bodies function better overall. Pumpkin seeds have magnesium and zinc in them, which are great for our immune system and support both heart health and hormone health. This is impactful for those in their cancer journey, helping to keep their bodies strong.

Plant-based proteins that support gut health

Plant-based proteins can be an excellent option for those looking to diversify their diet or reduce meat intake without sacrificing nutrition.

Lentils are versatile and a great way to get that needed fiber and protein and can be a substitute for meat. Not ready to fully give up meat? Russell says you can mix the lentils with meat and go half and half.

Tempeh lettuce tomato (TLT) is an alternative to a BLT. The tempeh is a plant-based protein source and is much firmer than tofu. It can have a bacon-like flavor when marinated in a mixture of low sodium soy sauce, maple syrup and liquid smoke. It can be found in the health foods section or plant-based section in the grocery store.

Tempeh is great for gut health, adding prebiotics into our diets.

Fruit that does more than taste good

Some fruits offer unique benefits beyond vitamins and antioxidants. Golden kiwis, for example, are easier to eat for some patients and provide hydration and digestive support.

Golden kiwis have great fiber found in the skin, and are sweeter than green kiwis, so they're easier to eat. They also have fantastic vitamin C levels and help keep you hydrated. They can help relieve constipation as well.

A fresh start in the new year

Russell encourages people to view the new year as an opportunity to explore new foods and expand their dietary habits.

"New Year is the perfect time to start thinking about healthy eating, it's a fresh start. The importance of trying new foods would be to expand your palette. There are so many different flavors and textures out there, as well as so many different health benefits from expanding that palette," Russell says.

By focusing on whole foods, fiber, antioxidants and nutrient-rich ingredients, Russell emphasizes that small, sustainable changes can make a meaningful difference, especially for those navigating cancer care and recovery.

It’s always important to speak with your oncology team first about dietary decisions.

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B-ROLL

TikTok is full of videos from influencers and others touting the benefits of various juice cleanses. For better or worse, the share of adults who regularly get news from TikTok has grown about fivefold since 2020 and for adults under 30, nearly 40% get their news on the social media platform.

So, there are a lot of people who could be convinced to do a juice cleanse from their exposure to those messages. Is that a bad thing? A juice cleanse involves consuming only fruit and vegetable juices for between three and seven days. OSF HealthCare gastroenterologist Omar Khokhar, MD, says the research isn't there yet for him to recommend tackling a juice cleanse to reset your gut health.

One of the biggest claims you hear on Tik Tok is that a juice cleanse can remove toxins from your body. Dr. Khokhar says there’s no data to support that.

“I don't know of any data that shows that a juice cleanse will preemptively remove toxins. That being said, if you reduce the amount of overall chemicals or ingredients that you're ingesting, you may have less toxins going in and thereby being metabolized and then excreted.”

The Food and Drug Administration (FDA) warns that some detox/cleansing products may contain illegal or potentially harmful ingredients, are marketed using false health claims, and could be harmful for people with some health conditions, such as diabetes. They also rarely lead to permanent weight loss.

Instead of a juice cleanse, Dr. Khokhar says the best approach to improving gut health is to improve what you’re ingesting every day.

“Eat on the outside of the grocery store. We talk about produce, meat, seafood, and if you can tolerate it, dairy. The other way to look at it is – and I do this very frequently in our clinic for patients who have heartburn, diarrhea, constipation – I'll tell them, ‘Give me three days. Don't eat anything out of a wrapper, box, or a can.’”

Eat more fiber

Most people need more soluble and insoluble fiber in their diet. Soluble fiber is found in apples, bananas, oats, peas, beans, avocados, and citrus fruits. Insoluble fiber is in whole wheat flour, bran, nuts, seeds, and the skins of many fruits and vegetables. Dr. Khokhar says both are critical to improving digestive health.

“The trick with the GI tract is to keep things moving. When things stagnate, that's when your GI gut microbiome can replicate in the wrong way. It's when you get constipation, and you get diverticulosis, and you get bloating. So, it's all about keeping things moving.”

While some juices have antioxidants which can help protect cells from damage, reduce inflammation, and lower the risk of chronic diseases, they are also high in sugar and some, including grapefruit juice, can have a bad interaction or interfere with absorption of certain medications. So, Dr. Khokhar says it’s really important to consult your primary care provider before starting any cleanse. He also recommends limiting a juice cleanse to 72 hours.

Drink more water

Staying hydrated can also go a long way in keeping your intestinal tract healthy. Dr. Khokhar also says the body has its own system of flushing the digestive system. He explains there is something called a migrating motor complex, or MMC for short, that creates a soft tidal wave through your GI tract every two to three hours.

“That's because it's important to replenish and recycle bacteria in the gut microbiome that often, and so if you change what you're putting into your system, it will affect the composition of that system,” Dr. Khokhar stresses.

Whether that’s a good or bad influence and what that means for our health is unclear and Dr. Khokhar suggests that’s the next exciting frontier of GI research. However, Dr. Khokhar returns to his theme that focusing on putting less processed food into your body on a regular basis will go a longer way than a juice cleanse to improve your gut microbiome and reduce gastrointestinal issues.    

Dr. Omar Khokhar

B-roll for Juice cleanse

Probiotics are live bacteria and yeasts that affect your body. But, OSF HealthCare gastroenterologist Omar Khokhar, MD, says the research isn't there yet for him to recommend taking probiotic supplements. 

Instead, he suggests getting the nutrients through fermented foods and drinks.

“I suggest you take prebiotics and probiotics in their natural form – in a kefir, sauerkraut, kombucha or Greek yogurt,” Dr. Khokhar says. “Those are highly fermented foods that are in the organic state and have been shown to improve microbiome gut vitality.”

If those types of food or drinks are too challenging to include in your diet, Dr. Khokhar says to talk with your medical provider first. 

In most cases, taking prebiotic or probiotic supplements won't hurt and could possibly help.

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There have been numerous studies suggesting gut health is linked to brain health and can influence the development of diseases such as Alzheimer’s. Now, there’s research results that specifically advance the idea that a person’s gut microbiome and damage to the upper gastrointestinal tract significantly increase a person’s risk of developing Parkinson’s disease.

The study points out Parkinson’s disease is a progressive neurodegenerative disorder that affects 8.5 million people worldwide based on 2019 estimates. The number of cases has more than doubled over the past three decades. It is considered the fastest growing neurodegenerative disorder globally, even surpassing Alzheimer’s, according to the World Health Organization.

Omar Khokhar, MD, a gastroenterologist with OSF HealthCare suggests there’s a strong connection between damage to the lining of your gastrointestinal tract and the impact of damage on the rest of the body.

“There's this whole theory about absorbing things we shouldn't be absorbing, leading to systemic inflammation. And in this case with Parkinson's, is it neuroinflammation? Is it absorption of things you shouldn't be eating quickly or eventually, over time, could potentially accumulate in the brain to cause Parkinson's?”

The research involved more than 9,300 people who had a scope of their upper gastrointestinal tract, including their esophagus, stomach or upper part of the small intestine that required a biopsy. The study showed those whose mucosal lining was damaged had a 76% greater risk of developing Parkinson’s disease during the follow-up period – an average of 14.9 years for the group.

It has been a long-held belief that Parkinson’s disease has its origins in the brain, but now researchers see growing evidence it might begin in the gut. The latest study shows a strong correlation but doesn’t definitely link problems with the gut lining as a cause of Parkinson’s. However, Dr. Khokhar says it appears that gut health makes a big difference.

“If your gut lining is intact and strong, it will absorb what you should absorb for adequate nutrition, digestion and healthy living and not absorb what you shouldn’t be absorbing.”

According to the study, a protein called alpha-synuclein found in the gut can travel to the brain and form clumps called Lewy bodies, which are a hallmark of Parkinson's.

As he glances at a screen with research results, Dr. Khokhar says he looks forward to a day when a person’s microbiome health could be evaluated through a blood or breath test, and then specific prebiotics or probiotics could be ordered to address deficiencies, much like what’s done today with vitamins.

“Once we can get to this point where we can look at ‘this is what you’re eating and what you’re eating is resulting in these different changes and levels of your specific microbiota,’ that’s where it gets really, really groundbreaking.”

But, that type of precision medicine could be five to 10 years away. So until then, what’s the best approach? Dr. Khokar says it’s important for anyone with gastrointestinal issues to improve their diet and be diligent about following up with regular check-ups. In fact, with increasing evidence that what we eat can impact gut and brain health, Dr. Khokhar says it’s time for everyone to start paying more attention to what they eat.

“I challenge everyone who eats a granola bar or who eats a bag of Doritos or whatever the case may be. If I can’t tell you and the scientists can’t tell you what ingredients six through 22 are, should you really be putting that in our mouth? Or is there a trade off or is there a cost to that?”

What about prebiotics and probiotics? Should people be taking them to keep a healthy gut? Dr. Khokhar advises a better approach is to get those nutrients through food by regularly eating things such as Greek yogurt, kefir (milk or non-dairy based milk such as soy, coconut and water), sauerkraut, kimchi, pickles, miso, tamari (soy), kombucha, sour cream, cottage cheese and aged cheese.

If those are too challenging to include in your diet, Dr. Khokhar says to talk with your medical provider. If you feel better after taking prebiotics or probiotics, then go for it.

Video with Dr. Omar Khokhar

Greasy pizza, cookies, sugary drinks – you name it – junk food has a grip on many Americans including people between 50 and 80 years old.

About 13% of adults in that age group are addicted to highly processed foods (1 in every 8), according to a study by the University of Michigan’s National Poll on Healthy Aging. 

“It doesn't surprise me: these are the ages where people are looking to retire," says Jason Crum, a dietitian with OSF HealthCare.  "And they're looking at what they're going to eat. How quickly will it take to eat these things, cooking, and processing. People don't want to do that anymore. They're tired, they're fatigued, so they look for quick, easy things.”

More than 2,100 adults between 50-80 were polled so researchers could learn more about the unhealthy relationship with processed foods including sweets, snacks, and fast food. The most common symptoms were intense cravings, the inability to cut down on intake and signs of withdrawal that caused headaches and trouble concentrating.  

“These processed foods not only have sodium, but they also have sugar of various types," says Crum. "And those paired together instigate a hormonal response that most of us don't know how to really read and respond to. So we fill ourselves with the calories instead of the actual food or the nutrients that would make our hormones work better, so it makes the addiction stronger.”

The study found that women had a greater addiction to these foods than men, especially those in their 50s and early 60s. Older adults who were overweight or suffering from mental health issues or isolation also had a greater risk of addiction to processed foods.

“We have a disconnection between how our gut really feels and how we interpret that hormonally, but also our lifestyle, how active, how busy we are," says Crum. "We see our nurses, for example, running around for 12-14 hours a day. They don't have time to eat, but it's easy in four minutes to eat a piece of pizza and a burger and fries. And that's the disconnect between our gut and our lifestyle and how we interpret that.”

According to the study, one reason that processed foods can be addictive is how they can trigger the release of dopamine in the brain’s reward system just like the effects of nicotine and alcohol.

“For most people we emotionally eat, it’s something to distract us," adds Crum. "And we tend to go for the things that will give us that reward center in our brain, sugar rewards that center, and we look for that as a temporary fix to things.”

Instead, Crum suggests people eat more “real” foods and stay away from processed ones. Real food is unprocessed, free of chemicals and full of nutrients such as fruits and vegetables, whole grains, beans, dairy, eggs and meat, fish and poultry. Real foods are low in sugar, heart healthy, high in healthy fats, and good for your gut, among other reasons.

“The first thing to do is to ask yourself if you’re hungry," he says. "And what am I looking to eat? Do I even know what it's made of? The more real the food is, the better that's going to work for us than these processed foods. There's far less added sugar, there's far less added sodium to it. So it makes it easier for our body to use the nutrients and reduce any cravings and addictions.”

For more on nutrition and general wellness, visit OSF HealthCare. 


 

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