Chronic Weight Loss And Malnutrition Join Devastating List Of Long COVID Symptoms

When Lauren Nichols caught the coronavirus in March 2020, her throat immediately suffered from severe dryness.

“It felt like I was essentially spewing fire out of my mouth,” she recalled. For five months, Nichols would continue to have this symptom, pain erupting every time she breathed or spoke. It was the first sign something was going wrong with her gastrointestinal tract (GI).

About two weeks into her infection, she began experiencing symptoms lower in that tract. “I had severe diarrhea six times a day, every single day for about four months,” she said. Nichols, who lives in Boston and works for the federal government, described herself as very physically active before catching the coronavirus. Now, she lives with an adjusted work schedule and other accommodations due to lingering fallout from her infection.

During those first few months, Nichols rapidly lost weight, sometimes struggling even to keep down a few sips of water. Over a year after she and other patients started experiencing GI symptoms, scientists are working to understand how the coronavirus persistently disrupts the digestive system -- as part of the condition known as Long COVID or Post-COVID Syndrome.

Definitions vary for Long COVID but revolve around symptoms that last for more than three months after initial infection. According to the National Institutes of Health, up to 30% of those infected with the coronavirus may develop the condition—translating to millions of Americans. Surveys of Long COVID patients have suggested that GI symptoms are common.

A large study published in June by Northwell Health, New York’s biggest private medical provider, found nearly one in five COVID-19 sufferers dealt with serious GI problems. But the study’s most striking finding was “the number of patients who were experiencing weight loss and malnutrition that persisted at three and then six months,” said Dr. Anam Rizvi, a gastroenterology fellow at Northwell Health and lead researcher on the study from The Feinstein Institutes for Medical Research.

Dr. Rizvi’s research indicates that GI symptoms are more common than the disease’s respiratory reputation may suggest. Along with other Northwell Health clinicians, she analyzed the health records of about 17,500 Northwell COVID-19 patients infected between March 2020 and January 2021. Patients hailed from Long Island, Manhattan, Queens and Staten Island.

Among those 17,500 patients, over 3,200 (or about 18.5%) had GI symptoms, the most common of which were diarrhea caused by intestinal infection, bleeding in the GI tract, and malnutrition. The researchers followed 715 of these patients after their release from the hospital, tracking their long-term symptoms.

Three months after their release from the hospital, 60% of this subset who suffered from malnutrition were still experiencing an inability to gain weight. Six months on, 56% of patients were still dealing with chronic weight loss. At this timepoint, the median malnutrition patient had lost almost 18 pounds compared to their weight at the time they entered the hospital.

“I expected a larger portion of these patients who couldn't gain weight to have had more severe hospitalizations,” Dr. Rizvi said. But in fact, only about a fifth of the patients had such severe cases. Being hospitalized with COVID-19 can often come with long-term injuries -- for example, permanent lung damage -- and consequences such as weakness and fatigue can last after a person returns home. But Long COVID happens abundantly even in people with mild cases.

While the precise biological causes of many COVID-19 symptoms are not yet known, research so far points to a protein called ACE2 as the starting point. This protein lives on the surface of cells throughout the body and acts as a doorway. The coronavirus can easily bind to ACE2 receptors, allowing it to enter cells and control their functions.

“The ACE2 receptor is lined all throughout the GI tract,” explained Dr. Rizvi. That protein’s prevalence allows the coronavirus to take over a patient’s throat, esophagus, intestines and other parts of the digestive system.

Or, as Nichols described her experience: “This virus was literally just having a party replicating in my GI tract.”

Getting Others To Trust Your Gut

The Northwell study’s findings align with Nichols’ experience of COVID-induced malnutrition, though she pointed out that her GI symptoms lasted for 18 months -- much longer than the six months the study tracked patients.

Dr. Aaron Glatt, an infectious disease epidemiologist at Mount Sinai, said that it’s difficult to generalize findings from a study like this one. “It’s easier and more publishable to collect data on hospitalized patients,” he said, but the makeup and longevity of symptoms in non-hospitalized patients may differ significantly.

The Centers for Disease Control and Prevention (CDC) now includes diarrhea, along with nausea and vomiting, on its list of potential COVID-19 symptoms. But in March 2020, health agencies had not acknowledged a strong connection between gut problems and the coronavirus, considering COVID-19 a primarily respiratory disease.

As a result, Nichols said she had to consult multiple doctors and advocate for herself in order to receive a COVID-19 test. Clinicians “wanted to assign these GI symptoms to something else,” she said. She said she went to the emergency room multiple times, where she experienced further disbelief from doctors. It wasn’t until June 2020 that she was able to receive a colonoscopy and endoscopy. The procedures confirmed that the coronavirus had multiplied in her gut.

Nichols now serves as the vice president for Body Politic, a Long COVID patient advocacy organization. She said that persistent GI symptoms are common among the more than 10,000 members of Body Politic’s COVID-19 support group. Group members widely experience diarrhea, nausea, the inability to gain weight and other digestive issues. A separate survey of Long COVID patients found that more than 80% reported at least one GI symptom.

“I am now immunocompromised as a result of COVID and Long COVID,” she said. “And my body doesn't seem to be absorbing nutrients in the same way,” Nichols said that her persistent symptoms might be tied to an autoimmune response, which scientists have hypothesized as one key trigger of Long COVID.

Dr. Paul Glynne, a doctor at the London-based Physicians Clinic who treats Long COVID patients, has seen similar trends. “In the non-hospitalized Long COVID group, we do see ongoing gastrointestinal symptoms,” Dr. Glynne explained via email. “Symptoms typically include food intolerances, altered bowel habit and nausea.”

Nichols called it a “red flag” that the Northwell study included only patients who were hospitalized for COVID-19. Many Long COVID patients, Nichols included, were never admitted to the hospital or never even had a positive test result—but they still experienced severe and persistent symptoms.

Focusing on hospitalized patients might skew GI study results in particular, Nichols said, because patients with severe diarrhea and nausea were not treated as COVID-19 patients early in the pandemic. Nichols suffered for months before doctors understood the cause of her symptoms. If she had been admitted to a hospital early on, she believes her treatment would have been more comprehensive.

Nichols also questioned the Northwell study’s finding that over 90 percent of patients with GI symptoms had recovered within six months. Dr. Glynne additionally pointed out that this study was retrospective, meaning that the researchers looked backward at patients’ hospital records rather than actively monitoring their symptoms in real-time via a clinical trial setting.

Still, Nichols said that “it’s helpful to have any study” on GI symptoms because this class of symptoms has been understudied compared to respiratory symptoms and other COVID-19 manifestations. She and Dr. Rizvi both stressed that more clinicians should be educated on COVID’s GI symptoms so that patients can receive the treatment they need.

“A lot of people may not realize that they even had an infection because they're looking only for respiratory [symptoms],” Nichols said.

Once a Long COVID patient has recognized their symptoms, Dr. Rizvi said, it’s important to seek ongoing visits with relevant specialists. For those experiencing GI symptoms, specialists could include gastroenterologists, immunologists and nutritionists educated in Long COVID or similar chronic conditions, such as ME/CFS. These chronic outcomes also serve as more motivation for ending the pandemic as soon as possible.

“[Long-term symptoms] are additional spurs to get vaccinated,” Dr. Glatt said. Younger people might think, if they get COVID-19, they’d just have flu-like symptoms, he said. But in fact, the disease can be far more dangerous.