How Seriously Should We Take the Promising News on Long COVID?
One of the biggest challenges of the COVID-19 pandemic is the way in which it has forced us to question our hopes. In normal times, hope is a tonic we take in small doses to keep us moving forward through the slog of daily life. The pandemic, however, has made it a much scarcer commodity, spurring us not only to seek it more desperately but to scrutinize it more closely.
Every bit of reassurance seems to come with caveats: Masks can shield us from the coronavirus, but they may need to be doubled in some situations to provide adequate protection. Vaccines work, but they may not be as effective against some viral variants—and they can cause extremely rare but serious side effects. Every few weeks, another potential miracle cure makes headlines (Hydroxychloroquine! Convalescent plasma!), only to prove disappointing on closer inspection. It's hard to know which alleged breakthroughs are worth pinning our hopes on, and which are the products of wishful thinking or hucksterism.
In January 2021, a study published in the journal Gut offered evidence that bacteria in the intestines might influence a whole spectrum of symptoms in long-haul patients.
Lately, two possible sources of hope have emerged concerning so-called "long COVID"—the debilitating syndrome, estimated to affect up to one-third of patients, in which physical, neurological, and cognitive symptoms persist for months. The first encouraging item has gotten plenty of media attention: reports that some long-haulers feel better after being vaccinated. The second item, while less widely covered, has caused a stir among scientists: a study suggesting that rebalancing the gut microbiome—the community of microorganisms in our intestines—could decrease both the severity and duration of the illness.
How optimistic should we allow ourselves to be about either of these developments? Experts warn that it's too soon to tell. Yet research into how vaccines and gut bacteria affect long-haulers—and how both factors might work together—could eventually help solve key pieces of the pandemic puzzle.
Investigating the Role of the Gut Microbiome
The idea that there may be a link between COVID-19 and gut health comes as no surprise to Jessica Lovett. Her case began in June 2020 with gastrointestinal distress—a symptom that was just beginning to be recognized as commonplace in what had initially been considered a respiratory illness. "I had diarrhea three to five times a day for two months," Lovett recalls. "I lost a lot of weight." By July, she was also suffering shortness of breath, chest pain, racing heartbeat, severe fatigue, brain fog, migraines, memory lapses, and more. As with many other COVID long-haulers, these troubles waxed and waned in an endless parade.
Lovett was the marketing manager for a music school in Austin, Texas, and the mother of a two-year-old boy. Just before she got sick, she ran a 5K race for her 40th birthday. Afterward, she had to give up her job, stop driving, and delegate childcare to her husband (who fell ill shortly before she did but recovered in 12 days). Tests showed no visible damage to her lungs, heart, or other organs. But she felt intuitively that taming her GI troubles would be key to getting well. On the advice of fellow patients in a long-COVID Facebook group—and, later, with the guidance of a doctor—she tried avoiding foods thought to trigger histamine reactions or inflammation. That seemed to help some, as did nutritional supplements, antihistamines, and angina medications. Still, she relapsed frequently, and was often bedridden.
In January 2021, a study published in the journal Gut offered evidence that bacteria in the intestines might influence a whole spectrum of symptoms in patients like Lovett. Researchers at the Chinese University of Hong Kong examined blood and stool samples and medical records from 100 hospital patients with lab-confirmed COVID-19 infections, and from 78 people without the disease who were taking part in a microbiome study before the pandemic.
The team, led by professor Siew Chien Ng, found that the makeup of the gut microbiome differed sharply between the two groups. Patients with COVID had higher levels of three bacterial species than those without the infection, but lower levels of several species known to enhance immune system response. Reductions in two of those species—Faecalibacterium prausnitzii and Bifidobacterium bifidum—were associated with more severe symptoms. And the numbers of such helpful bacteria remained low in stool samples collected up to 30 days after infected patients had seemingly cleared the coronavirus from their bodies.
Analysis of blood samples, moreover, showed that these bacterial imbalances correlated with higher levels of inflammatory cytokines (immune system chemicals that are elevated in many patients with severe COVID-19) and markers of tissue damage, such as C-reactive protein.
These findings led the researchers to suggest that rebalancing the microbiome might lessen not only the intensity of COVID symptoms, but also their persistence. "Bolstering of beneficial gut species depleted in COVID-19," they wrote, "could serve as a novel avenue to mitigate severe disease, underscoring the importance of managing patients' gut biota during and after COVID-19."
Soon afterward, Ng revealed that she was working on a solution. Her team, she told Medscape, had developed "a microbiome immunity product that is targeted to what is missing in COVID-19 patients." Early research showed that hospitalized patients who received the treatment developed more antibodies, had fewer symptoms, and were discharged sooner. "So it is quite a bright and promising future," she enthused, "in alleviating some of these detrimental effects of the virus."
The Chicken-and-Egg Problem
Ng's study isn't the only one to suggest a connection between the gut and long COVID. Researchers led by gastroenterologist Saurabh Mehandru at New York's Mount Sinai Hospital recently determined that SARS-CoV-2, the virus that causes COVID-19, can linger in the intestines for months after a patient tests negative. Some studies have also found that gastrointestinal symptoms in the acute phase of the illness correlate with poorer outcomes—though that's far from settled. (In another study, Mehandru's team found lower mortality among patients presenting with GI symptoms.) But the Hong Kong group's paper was the first to posit that resident microbes may play a decisive role in the disease.
That view reflects growing evidence that these bugs can influence a range of ailments, from diabetes to schizophrenia. Over the past decade, the gut microbiome has emerged as a central regulator of the immune system. Some intestinal bacteria emit chemicals that signal immune cells to reduce production of inflammatory proteins, or help those cells effectively target invading pathogens. They also help maintain the integrity of the intestinal lining—preventing the syndrome known as "leaky gut," in which harmful microbes or toxins penetrate to the underlying tissue, potentially wreaking havoc throughout the body and brain.
Nonetheless, many experts have responded to Ng's findings with distinct caution. One problem, they point out, is the chicken-and-egg question: Do reduced levels of beneficial gut bacteria trigger the inflammation seen in COVID-19, or does inflammation triggered by COVID-19 kill off beneficial gut bacteria? "It's an issue of causality versus just association," explains Somsouk Ma, a professor of gastroenterology at the University of California, San Francisco. "I tend to think that the shift in microbes is more likely a consequence of the infection. But, of course, that's just speculation."
A related issue is whether a pill that replenishes "good" bacteria can really combat the effects of COVID-19—whether acute or chronic. Although scientists are studying fecal transplants and other probiotic therapies for many disorders, none has yet been approved by the U.S Food and Drug Administration. "The only situation where bacterial transplantation is known to work is in a form of colitis called Clostridium difficile," notes Mehandru. "I think it's a bit premature to lay too much emphasis on this in the context of COVID."
Placebo-controlled clinical trials will be needed to determine the efficacy of Ng's approach. (Consumer warning: The bacteria she's employing are not found in commercially available probiotics.) Whatever the results, such research—along with studies that track patients' gut microbiomes before, during, and after COVID-19 infection—could help scientists understand why some people have such trouble kicking the disease.
An Unexpected Benefit of Vaccines
The question of what causes long COVID is also central to understanding the effects of vaccines on the condition. In March, as inoculation campaigns took off across the nation, many long-haulers were delighted to see their symptoms disappear within days of getting the shot. "I woke up and it was like, 'Oh what a beautiful morning,'" one patient told The New York Times.
Yet the effects have been far from uniform. Although scientific surveys have not yet been conducted, an April poll by a Facebook group called Survivor Corps found numbers close to experts' estimates: 39 percent said they experienced partial to full recovery post-vaccination; 46 percent saw no difference; and 14 percent felt worse.
How could vaccines—which are designed to prevent COVID-19, not cure it—help some chronic patients get well? In a blog post, Yale immunologist Akiko Iwasaki suggested that the answer depends on what is driving a particular patient's symptoms. Iwasaki identified three possible mechanisms behind long COVID: 1) a persistent viral reservoir; 2) a "viral ghost," composed of fragments of the virus (RNA or proteins) that linger after the infection has been cleared but can still stimulate inflammation; and 3) an autoimmune response triggered by the infection, inducing a patient's immune cells to attack her own tissues.
These mechanisms "are not mutually exclusive," Iwasaki wrote, "and all three might benefit from the vaccines." If a patient has a viral reservoir, vaccine-induced immune cells and antibodies might be able to eliminate it. If the patient has a viral ghost, those vaccine-primed immune responses might knock it out as well. And if the patient is suffering from a COVID-triggered autoimmune syndrome, the vaccine might act as a decoy, shifting the immune system's attention to antigens contained in the shot (and perhaps reprogramming autoimmune cells in the process). The varying role of these underlying factors, and possibly others—such as the gut microbiome—might also help explain why vaccines don't benefit all long-haulers equally. Iwasaki and her team recently launched a clinical study to investigate this theory.
Pato Hebert, a professor of art and public policy at NYU, contracted COVID-19 in March 2020 while on sabbatical in Los Angeles. Hebert, then 50, started out with mild flu-like symptoms, but he was slammed with fatigue, headaches, and confusion a week after testing positive. In April, he landed in urgent care with severe shortness of breath. His brain fog worsened that summer, and a gentle swim brought on a dizzy spell so overwhelming that he feared it was a stroke. (Thankfully, tests showed it wasn't.) In September, he developed severe GI issues, which came and went over the following months. He found some relief through medications, dietary adjustments, acupuncture, herbal remedies, and careful conservation of his physical and mental energy—but a year after his diagnosis, he was still sick.
Hebert received his first dose of the Moderna vaccine on March 1, 2021; it made no difference in his symptoms. After his second dose, on the 29th, he suffered terrible headaches—"like early COVID days," he told me. A week later, his condition had improved slightly compared to pre-vaccination. "With a few exceptions, my fatigue and brain fog have been less challenging," he reported. "I'm cautiously optimistic." But in late April, he suffered another flareup of respiratory and GI issues.
For Jessica Lovett, the vaccine's effects were more dramatic. After her first dose of the Pfizer-BioNTech formula, on February 26, her cognitive symptoms improved enough that she was able to drive again; within a week, she was pushing her son uphill in a stroller, lifting light weights, and running for short distances. After the second dose, she says, "I had incredible energy. It was insane, like I drank three cups of coffee."
Lovett (who now runs a Facebook support group for Austin locals, ATX Covid Long Haulers) stresses that the vaccine hasn't cured her. She winds up back in bed whenever she pushes herself too hard. She still needs to take antihistamines and shun certain foodstuffs; any slip-up brings another relapse. Yet she's able to live more fully than at any time since she fell ill—and she has begun to feel a renewed sense of hope.
Recently, in fact, she and her husband decided to expand their family. "I guess that tells you something," she says with a laugh. "The doctors have given us the okay, and we're going to try."
Stronger psychedelics that rewire the brain, with Doug Drysdale
A promising development in science in recent years has been the use technology to optimize something natural. One-upping nature's wisdom isn't easy. In many cases, we haven't - and maybe we can't - figure it out. But today's episode features a fascinating example: using tech to optimize psychedelic mushrooms.
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These mushrooms have been used for religious, spiritual and medicinal purposes for thousands of years, but only in the past several decades have scientists brought psychedelics into the lab to enhance them and maximize their therapeutic value.
Today’s podcast guest, Doug Drysdale, is doing important work to lead this effort. Drysdale is the CEO of a company called Cybin that has figured out how to make psilocybin more potent, so it can be administered in smaller doses without side effects.
The natural form of psilocybin has been studied increasingly in the realm of mental health. Taking doses of these mushrooms appears to help people with anxiety and depression by spurring the development of connections in the brain, an example of neuroplasticity. The process basically shifts the adult brain from being fairly rigid like dried clay into a malleable substance like warm wax - the state of change that's constantly underway in the developing brains of children.
Neuroplasticity in adults seems to unlock some of our default ways of of thinking, the habitual thought patterns that’ve been associated with various mental health problems. Some promising research suggests that psilocybin causes a reset of sorts. It makes way for new, healthier thought patterns.
So what is Drysdale’s secret weapon to bring even more therapeutic value to psilocybin? It’s a process called deuteration. It focuses on the hydrogen atoms in psilocybin. These atoms are very light and don’t stick very well to carbon, which is another atom in psilocybin. As a result, our bodies can easily breaks down the bonds between the hydrogen and carbon atoms. For many people, that means psilocybin gets cleared from the body too quickly, before it can have a therapeutic benefit.
In deuteration, scientists do something simple but ingenious: they replace the hydrogen atoms with a molecule called deuterium. It’s twice as heavy as hydrogen and forms tighter bonds with the carbon. Because these pairs are so rock-steady, they slow down the rate at which psilocybin is metabolized, so it has more sustained effects on our brains.
Cybin isn’t Drysdale’s first go around at this - far from it. He has over 30 years of experience in the healthcare sector. During this time he’s raised around $4 billion of both public and private capital, and has been named Ernst and Young Entrepreneur of the Year. Before Cybin, he was the founding CEO of a pharmaceutical company called Alvogen, leading it from inception to around $500 million in revenues, across 35 countries. Drysdale has also been the head of mergers and acquisitions at Actavis Group, leading 15 corporate acquisitions across three continents.
In this episode, Drysdale walks us through the promising research of his current company, Cybin, and the different therapies he’s developing for anxiety and depression based not just on psilocybin but another psychedelic compound found in plants called DMT. He explains how they seem to have such powerful effects on the brain, as well as the potential for psychedelics to eventually support other use cases, including helping us strive toward higher levels of well-being. He goes on to discuss his views on mindfulness and lifestyle factors - such as optimal nutrition - that could help bring out hte best in psychedelics.
Show links:
Doug Drysdale full bio
Doug Drysdale twitter
Cybin website
Cybin development pipeline
Cybin's promising phase 2 research on depression
Johns Hopkins psychedelics research and psilocybin research
Mets owner Steve Cohen invests in psychedelic therapies
Doug Drysdale, CEO of Cybin
How the body's immune resilience affects our health and lifespan
Story by Big Think
It is a mystery why humans manifest vast differences in lifespan, health, and susceptibility to infectious diseases. However, a team of international scientists has revealed that the capacity to resist or recover from infections and inflammation (a trait they call “immune resilience”) is one of the major contributors to these differences.
Immune resilience involves controlling inflammation and preserving or rapidly restoring immune activity at any age, explained Weijing He, a study co-author. He and his colleagues discovered that people with the highest level of immune resilience were more likely to live longer, resist infection and recurrence of skin cancer, and survive COVID and sepsis.
Measuring immune resilience
The researchers measured immune resilience in two ways. The first is based on the relative quantities of two types of immune cells, CD4+ T cells and CD8+ T cells. CD4+ T cells coordinate the immune system’s response to pathogens and are often used to measure immune health (with higher levels typically suggesting a stronger immune system). However, in 2021, the researchers found that a low level of CD8+ T cells (which are responsible for killing damaged or infected cells) is also an important indicator of immune health. In fact, patients with high levels of CD4+ T cells and low levels of CD8+ T cells during SARS-CoV-2 and HIV infection were the least likely to develop severe COVID and AIDS.
Individuals with optimal levels of immune resilience were more likely to live longer.
In the same 2021 study, the researchers identified a second measure of immune resilience that involves two gene expression signatures correlated with an infected person’s risk of death. One of the signatures was linked to a higher risk of death; it includes genes related to inflammation — an essential process for jumpstarting the immune system but one that can cause considerable damage if left unbridled. The other signature was linked to a greater chance of survival; it includes genes related to keeping inflammation in check. These genes help the immune system mount a balanced immune response during infection and taper down the response after the threat is gone. The researchers found that participants who expressed the optimal combination of genes lived longer.
Immune resilience and longevity
The researchers assessed levels of immune resilience in nearly 50,000 participants of different ages and with various types of challenges to their immune systems, including acute infections, chronic diseases, and cancers. Their evaluation demonstrated that individuals with optimal levels of immune resilience were more likely to live longer, resist HIV and influenza infections, resist recurrence of skin cancer after kidney transplant, survive COVID infection, and survive sepsis.
However, a person’s immune resilience fluctuates all the time. Study participants who had optimal immune resilience before common symptomatic viral infections like a cold or the flu experienced a shift in their gene expression to poor immune resilience within 48 hours of symptom onset. As these people recovered from their infection, many gradually returned to the more favorable gene expression levels they had before. However, nearly 30% who once had optimal immune resilience did not fully regain that survival-associated profile by the end of the cold and flu season, even though they had recovered from their illness.
Intriguingly, some people who are 90+ years old still have optimal immune resilience, suggesting that these individuals’ immune systems have an exceptional capacity to control inflammation and rapidly restore proper immune balance.
This could suggest that the recovery phase varies among people and diseases. For example, young female sex workers who had many clients and did not use condoms — and thus were repeatedly exposed to sexually transmitted pathogens — had very low immune resilience. However, most of the sex workers who began reducing their exposure to sexually transmitted pathogens by using condoms and decreasing their number of sex partners experienced an improvement in immune resilience over the next 10 years.
Immune resilience and aging
The researchers found that the proportion of people with optimal immune resilience tended to be highest among the young and lowest among the elderly. The researchers suggest that, as people age, they are exposed to increasingly more health conditions (acute infections, chronic diseases, cancers, etc.) which challenge their immune systems to undergo a “respond-and-recover” cycle. During the response phase, CD8+ T cells and inflammatory gene expression increase, and during the recovery phase, they go back down.
However, over a lifetime of repeated challenges, the immune system is slower to recover, altering a person’s immune resilience. Intriguingly, some people who are 90+ years old still have optimal immune resilience, suggesting that these individuals’ immune systems have an exceptional capacity to control inflammation and rapidly restore proper immune balance despite the many respond-and-recover cycles that their immune systems have faced.
Public health ramifications could be significant. Immune cell and gene expression profile assessments are relatively simple to conduct, and being able to determine a person’s immune resilience can help identify whether someone is at greater risk for developing diseases, how they will respond to treatment, and whether, as well as to what extent, they will recover.