Research into GI health, diet, and exercise are top priorities for UofL Health gastroenterologist
LOUISVILLE When it comes to treating gastrointestinal issues, the key to success for Kristine Krueger, MD, is helping patients understand the interconnectedness between gut health and their overall health.
Krueger, the Nancy Middleton Smith Professor at the UofL School of Medicine and the chief of academic and clinical affairs for gastroenterology, hepatology and nutrition at UofL Health – UofL Physicians, says that the calling to help others and teach about the science behind all aspects of medicine is something that she’s had since childhood.
Krueger, who earned her BS in biology and chemistry at Florida State University, received her medical degree at the University of Florida before doing her residency at the Medical University of South Carolina Medical Center.
The daughter of an Air Force engineer and pilot, Krueger says she grew up in a military family and moved frequently. When her father was stationed in Vietnam, her mother took a job as a nurse. Fascinated by the stories her mother was telling her, she fell in love with medicine.
“I wanted to do medicine because I liked biological sciences and the body,” she says. “Then Mom said, ‘Well, you don’t want to be a nurse, you want to be the one making the decisions. You want to be a doctor.’ And I decided she was right.”
Krueger says that her practice at UofL Health is separated into the administrative functions of running the division, including hiring doctors and teaching medical students, plus spending time with direct patient contact. Patients run the gamut from highly complex diagnoses that require hospitalization to patients needing endoscopy, she says
More and more, Krueger says, her patients are younger, a trend seen nationwide.
A Changing GI Patient Population
According to a report published in JAMA Network Open, gastrointestinal cancers, including colorectal, pancreatic, and bile duct cancers, are presenting in younger adults more often than they were a decade ago. The study, “Patterns in Cancer Incidence Among People Younger Than 50 Years in the US,” published in August 2023, found that between 2010 and 2019, early-onset cancers in people under the age of 50 increased by 0.74 percent. The study also found that early onset gastrointestinal cancers had the greatest increase during that time (from 6,431 cases in 2010 to 7,383 cases in 2019), and incidents of those cancers rose the fastest, at a rate of 2.16 percent annually.
As a young parent, Krueger says she recognized a link between what children are being fed and health complications later on.
“When I had my own children, I became very much interested in childhood nutrition,” she says. “I was just appalled at kid’s menus, how they were 50 percent fat, and this concept of there being ‘kid food’ versus ‘adult food.’ I knew right away that didn’t make any sense from a science standpoint… the kid learns bad habits that will correspond down the road to type 2 diabetes, obesity, and other health problems.”
Additionally, Krueger says, younger people are not as healthy as they were decades ago.
“They’re 20 years old, but they can’t jog a half a mile before getting short of breath,” she says. “They don’t go outside and play sports anymore. They’re sedentary. They eat too much fast food. They sit in front of the TV and eat, which makes them overeat, which contributes to all those diseases that we talk
about — accelerated atherosclerotic heart disease, diabetes, and cancers. And we really don’t know why. We don’t have the exact answers, but we see the trends.”
Research in Microbiota
Researchers in gastroenterology have begun to identify some causes, Krueger says, like fermented products in the digestive system and their damaging effects on the mucosa in the digestive system, among others. Research into the impact of GI health on other aspects of health is ongoing, she says.
Other developments include looking into the microbiota within the body and how it affects other aspects of health. Researchers are also studying issues like firmicutes, bacteroides, and other viruses in the GI tract and their impact on health.
“The science is now looking at how your gut bacteria influence neurodegenerative diseases,” Krueger says. “Some folks are looking at autism, Parkinson’s disease, and MS, and how the microbiota is different in these diseases.”
As a cyclist, she was particularly interested in research that has identified a particular bacterium that allowed some cyclists to extract more energy from the food they eat and have better performance or endurance. In another study, a childhood disease called PANDAS (pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections) was found to have been caused by a chronic streptococcal infection that altered behavior in children.
“When they found out that they had a chronic infection that crossed the blood-brain barrier, and that with effective antibiotic treatment it was normalized, that opened up a lot of people’s eyes to the concept that the microbiome has a lot to do with your overall body’s health, including your brain,” Krueger says. “We need more doctors to be on the side of ‘That’s interesting. I’m going to be open-minded to seeing what we can do.’”
Traditional, Complementary, Alternative, and Innovative
Some of the treatments, while FDA approved and effective, may not be completely accepted, Krueger says. “When the FDA approved fecal transplants for C. diff (Clostridioides difficile) diarrhea… it worked twice as well as vancomycin, the current treatment,” she says. “It cured people that were going to die from C. diff. That has been the single most impressive medical advancement in GI in my career. And that is just astounding, because it doesn’t follow any of Koch’s postulates. You’re giving billions of someone else’s germs, basically bacteria, fungus, viruses, and you’re sticking them in a host who’s sick… and within 48 hours, they’re off their pressors. To me, that was just an absolute astounding discovery. And still, a decade later, we have doctors who say that it’s barbaric.”
Looking at new findings, as well as at complementary and alternative medicines, she says, is an important part of treating the whole patient. Treatments from ancient medical procedures from China or Ayurvedic medicine from India give patients more decision-making authority, Krueger says, and are more cost-effective in some ways. It is also practical to address those treatments because some patients will already be using them, and not acknowledging them can disrupt a more traditional treatment.
“You have to be open-minded because if you aren’t and you don’t ask patients what they take, they’re not going to tell you what they’re doing,” Krueger says. “Then when they’ve had their liver transplant but they’re taking St. John’s wort, it will interfere with their immune-suppressants and they reject their liver. People are going to seek alternative therapies that are less expensive, less of a hassle and don’t require a copay. You need to be aware of those factors in your particular specialty.”
By creating a direct bond with her patients and understanding them as human beings, Krueger says she can help guide them to better healthcare choices that are personalized for them and their needs.
Working with them for positive outcomes, she says, is what drives her.
“I think the ancient art of healing patients is a calling that you are driven to,” Krueger says. “Maybe it’s selfish, but when you come home at night, even after a busy day… the smile on a patient’s face when they say, ‘Thank you, doctor’ will melt your heart and you want to do it again and again and again.”