Article from NIH. Your digestive system is busy. When you eat something, your food takes a twisty trip that starts with being chewed up and ends with you going to the bathroom. A lot happens in between. The health of your gut plays a key role in your overall health and well-being. You can make choices to help your body stay on tract.

Your digestive, or gastrointestinal (GI), tract is a long, muscular tube that runs from your mouth to your anus. It’s about 30 feet long and works with other parts of your digestive system to break food and drink down into smaller molecules of nutrients. The blood absorbs these and carries them throughout the body for cells to use for energy, growth, and repair.

With such a long GI highway, it’s common to run into bumps in the road. About 60 to 70 million Americans are affected by digestive diseases, like gastroesophageal reflux disease (GERD) or irritable bowel syndrome (IBS). GERD happens when your stomach acid and/or contents come back up into your esophagus (swallowing tube) or throat. This causes uncomfortable symptoms like heartburn and indigestion. IBS is a group of symptoms that includes pain in the abdomen and changes in bowel habits. People with IBS may have constipation, diarrhea, or both. Many more people have other digestive problems, like bloating and stomach pain.

“There are many factors that can impact gut health,” says Dr. Lin Chang, a GI expert at the University of California, Los Angeles. How your body’s built, your family and genetic history, how you manage stress, and what you eat can all affect your gut.

“I see a lot of lifestyle-related GI issues, and there are often no quick fixes for that,” she says. “In general, people do well when they create a more routine schedule, eat a healthy diet and smaller more frequent meals, add in some exercise, and get a good amount of sleep.”

Chang studies the connection between stress and IBS. Her research group has found that people who have early life stress are more likely to develop IBS. “However, this increased risk for IBS went down when people confided in someone they trust about the stress they experienced,” she explains. “Finding healthy ways to manage stress is important for GI health, and your health overall.”

What you eat can help or hurt your digestive system, and influence how you feel. “Increasing fiber is really important for constipation,” says Chang. “Most Americans do not eat a lot of fiber so you have to gradually increase the fiber in your diet. Otherwise you might get gas and more bloating, and won’t stick with [the changes].”

Chang says you should eat at least 20–30 grams of fiber a day for constipation. You can spread out your fiber in small amounts throughout the day. Start with small servings and gradually increase them to avoid gas, bloating, and discomfort.

Try to eat fruits and vegetables at every meal. A variety of fruits, vegetables, whole grains, and nuts can provide a healthy mix of different fibers and nutrients to your diet. An added benefit is that the more fiber and whole foods you eat, the less room you’ll have for less healthy options.

But some fiber-rich foods, called high FODMAP foods, can be hard to digest. Examples include certain fruits and vegetables, dairy products, and wheat and rye products. If you have IBS, your doctor may recommend a diet low in FODMAPS. Learn more about the Fodmap diet here: Low-FODMAP and Vegan: What to Eat When You Can't Eat Anything.

Researchers are coming to understand the complex community of bacteria and other microbes that live in the human GI tract. Called gut flora or microbiota, these microbes help with our digestion. But evidence has been growing that gut microbes may influence our health in other ways too. Studies suggest that they may play roles in obesity, type 2 diabetes, IBS, and colon cancer. They might also affect how the immune system functions. This can affect how your body fights illness and disease. Recent studies have found that microbes’ effects on the immune system may impact the development of conditions such as allergy, asthma, and rheumatoid arthritis.

You might have heard that probiotics—live microbes that are similar to those found in the human gut—can improve your gut health. These are also called “friendly bacteria” or “good bacteria.” Probiotics are available in dietary supplements and in certain foods, such as yogurt.

There is some evidence that probiotics may be helpful in preventing diarrhea associated with antibiotics and improving symptoms of IBS, but more needs to be learned. Researchers still don’t know which probiotics are helpful and which aren’t. They also don’t know how much of the probiotics people would have to take or who would most likely benefit from them.

Certain food additives called emulsifiers are something else that may affect your gut health. Emulsifiers are added to many processed foods to improve texture and extend shelf life. But studies show they can affect our gut flora.

“Our work and other research indicate that emulsifiers and other food additives can negatively impact the microbiota and promote inflammatory diseases,” says Georgia State University’s Dr. Andrew Gewirtz. His group has been studying the relationships between food additives, gut bacteria, and disease in mice. The team also plans to examine how different food additives may affect people.

Based on what his team and others have found, Gewirtz advises, “The take home message: Eat a balanced diet and less processed foods.”

“The GI system is complicated and such an important part of our health,” Chang says. “It takes a real partnership between patient and doctor to get to the root of issues. Everyone has to find a healthy routine that works for them.”

She encourages you to take an active role in finding a doctor who makes you feel comfortable. The right doctor will listen carefully to your health history and symptoms. You can help keep your gut in check by talking with your doctor and—together—making the right choices for you. 

References
Adverse childhood experiences are associated with irritable bowel syndrome and gastrointestinal symptom severity. Park SH, Videlock EJ, Shih W, Presson AP, Mayer EA, Chang L. Neurogastroenterology & Motility. 2016 Aug;28(8):1252-60. doi: 10.1111/nmo.12826. Epub 2016 Apr 8. PMID: 27061107.

Dietary emulsifiers impact the mouse gut microbiota promoting colitis and metabolic syndrome. Chassaing B, Koren O, Goodrich JK, Poole AC, Srinivasan S, Ley RE, Gewirtz AT. Nature. 2015 Mar 5;519(7541):92-6. doi: 10.1038/nature14232. Epub 2015 Feb 25. PMID: 25731162.

Is eating behavior manipulated by the gastrointestinal microbiota? Evolutionary pressures and potential mechanisms. Alcock J, Maley CC, Aktipis CA. Bioessays. 2014 Oct;36(10):940-9. doi: 10.1002/bies.201400071. Epub 2014 Aug 8. PMID: 25103109.

NIH News in Health, May 2017

Learn more about keeping your digestive system healthy here: Dr. McDougall's Digestive Tune-Up.

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