Gut Health as We Age

“There are a lot of myths about what happens with the gut and aging,” said Margaret Heitkemper. Heitkemper and Kendra Kamp are both researchers at the University of Washington School of Nursing who study different aspects of gut health. Their research spans a variety of digestive topics, from inflammatory bowel disease to digestion and circadian rhythms, and irritable bowel syndrome (IBS).

There’s a lot we don’t know about gut health, including as we age. Researchers used to assume that the gut naturally slows down as we get older, said Heitkemper, but that might not actually be true, especially if we exercise. Even if some intestinal muscles weaken, other muscles may be able to make up for them.

Maintaining good digestion throughout our lifespan can be confusing. Some common suggestions don’t have strong evidence behind them. For example, said Kamp, probiotics are often toted as great for digestion, but the current research isn’t clear.

“We don’t really know if they’re beneficial or not,” Kamp said. The current recommendations for anyone struggling with conditions like IBS don’t include things like probiotics, because there’s not enough evidence to back them up.

We do know that the array of bacteria that live in our stomach and intestines, also known as the gut microbiome, are important to our health. However, that research is still in its infancy, said Kamp and Heitkemper. While having many different types of gut bacteria is linked with health, research is starting to indicate the picture isn’t that simple.

“It’s not just what bugs are there, but what are those bugs doing,” Kamp said. The best gut health advice is straight-forward. Eat lots of fiber. Adding more fiber sources, like fruits, vegetables, and whole grains, is a good place to start for anyone looking to improve their gut health. When we eat fiber, it’s fermented by bacteria in our digestive tract. Those bacteria then spit out something called “short-chain fatty acids”, said Heitkemper. Those short-chain fatty acids are great for our bodies and cells, and can help protect against colon cancer.

Increasing fiber is easier said than done. “We, in this culture, do not eat enough fiber,” said Heitkemper. Just meeting the FDA’s recommendation of 28 grams daily is better than most. “I haven’t done a study yet where we’ve had an average intake that matched national recommended fiber intake, in healthy controls and in people with IBS,” Heitkemper said.

There’s still much we don’t know about the gut and aging. But sudden changes should never be written off as normal changes. The risk for some conditions, such as cancers, does increase as we age. There is also a second uptick in inflammatory bowel disease diagnoses for older adults, after the typical diagnosis period in early adulthood.

“It really is important to get evaluated if you’re noticing sudden changes in your GI symptoms,” Kamp said. Digestion or stool changes could have many different possible causes, and some might need treatment.

Research is just starting to uncover the complex links between digestion, the microbiome, and our overall wellbeing. However, like many aspects of health, improving our digestion often comes down to some commonsense recommendations: staying physically active and eating a fiber-filled diet with lots of fruits, veggies, and whole grains.