Understanding digestive disease

Shanthi SrinivasanPhysician scientist Shanthi Srinivasan heads a research lab at the VAMC to find better treatments for irritable bowel syndrome.


Atlanta Veterans Affairs Medical Center

VA

Emory and the Atlanta VA Medical Center have been affiliated since 1946. They share a back yard and connecting footbridge, and shuttles run between campus and the hospital every 20 minutes. Emory provides physician care at the facility and has made it one of the nation's most successful VA centers for research to improve care for veterans. Emory investigators attracted more than $15 million in VA funding and $10.2 million in non-VA funding for such research last year.

 

Corporal Jenny Straton performed admirably during her tour of duty in Afghanistan, even after a roadside explosion killed her best friend.

But shortly after she returned home, she experienced frequent diarrhea and abdominal pain so severe she headed to the Atlanta VA Medical Center. Because of the prevalence of digestive problems among veterans, the gastrointestinal clinic headed by Shanthi Srinivasan includes five full-time and five part-time GI specialists, who every week see some 200 outpatients and perform roughly 100 endoscopies.

A complete workup of Straton ruled out cancer, intestinal blockages, and ulcers. Based on her symptoms, she was diagnosed with irritable bowel syndrome (IBS), a condition she shares with one in five American adults and even more fellow veterans, especially women.

Srinivasan advised the young woman to make some dietary changes, including eliminating certain foods. She also started her on antidiarrheal medications, which help some patients. When that didn't work for Straton, the doctor added probiotics to stimulate growth of helpful bacteria and other microorganisms in the gut. Straton's symptoms slowly faded. She told the medical team she was getting her life back.

Good for Straton, but not good enough for Srinivasan. She wants to know why IBS develops and how it can be treated with greater precision. Based on her clinical observations and detailed studies involving mice, she believes changes in the intestinal microbiota damage the enteric nervous system, which governs the function of the GI tract.

Factors that can lead to worsening IBS symptoms include stress and diet. Different diets can lead to changes in microbiota and worsening of symptoms. This can explain why probiotics are effective in some IBS patients. With a more precise understanding of how the microbiota affects the enteric nervous system, Srinivasan's research team is now closing in on a new target for drugs that could restore the damaged brain-gut communication pathway and help alleviate IBS symptoms.