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Feed a Virus, Starve a Bacterium?

Posted on by Dr. Francis Collins

Woman eating hot soup in bed


Yes, the season of colds and flu is coming. You’ve probably heard the old saying “feed a cold and starve a fever.” But is that sound advice? According to new evidence from mouse studies, there really may be a scientific basis for “feeding” diseases like colds and flu that are caused by viruses, as well as for “starving” certain fever-inducing conditions caused by bacteria.

In the latest work, an NIH-funded research team found that providing nutrition to mice infected with the influenza virus significantly improved their survival. In contrast, the exact opposite proved true in mice infected with Listeria, a fever-inducing bacterium. When researchers forced Listeria-infected mice to consume even a small amount of food, they all died.

Just like humans, when mice and other mammals come down with many infectious illnesses, they often lose their appetites and shun food. In the new study reported in the journal Cell, a team led by Ruslan Medzhitov, a Howard Hughes Medical Institute Investigator at Yale University School of Medicine, New Haven, CT, and former Lurie Prize winner from the Foundation for NIH, set out to explore how the presence or lack of nutrition might influence recovery from infections [1].

In one series of experiments, the researchers infected mice with the influenza virus, which caused potentially life-threatening bouts of the flu. As expected from past observations, the flu-sickened mice reduced their food intake. However, when the researchers pumped more nutrition into some of the sick mice via tube feeding, their odds of survival were significantly better than those who weren’t given the extra nutrition. Further analysis showed that the animals’ survival appeared to hinge on the availability of glucose. When mice suffering from the flu were starved of glucose, they eventually lost the vital ability to control their body temperatures, breathing, and/or heart rates.

Researchers found the situation to be dramatically different in mice that were infected with the bacterium Listeria, an occasional cause of food poisoning in humans. When mice are sickened by Listeria, they tend to stop eating for a while, before eventually resuming eating and recovering. However, in contrast to mice with the flu virus, when researchers gave the Listeria-infected mice even a small amount of nutrition, all the animals died. Again, it was all about sugar. Glucose alone, delivered via tube feeding or injection, was enough to kill Listeria-infected mice. The cause of death wasn’t an inability to clear the infection: they died from changes to their metabolism that made things worse.

PET scans of mice suffering from viral versus bacterial inflammation also revealed significant differences in the way their brains took up glucose. Taken together, these findings suggest that, by taking advantage of key metabolic differences, nutrition (or lack thereof!) may play an important role in helping mammals mount successful responses to different types of infections, just as the old “feed a cold, starve a fever” adage implies.

In light of the findings in mice, a much closer look may be needed to determine what constitutes optimal nutrition for people dealing with a wide range of infectious illnesses. Medzhitov says he and his colleagues are now in the planning stages for a human clinical trial designed to explore that very issue.

So, what to do if you or a loved one comes down with a cold, the flu, or another viral bug this season? Medzhitov wisely hesitates to provide medical advice, noting that mice are not humans and the findings need to be replicated and confirmed in people. But, in the meantime, it appears that giving the patient with a typical viral syndrome a bowl of ice cream or another glucose-rich treat probably wouldn’t hurt—and might even help. Just be sure first that it’s not a serious bacterial infection.


[1] Opposing effects of fasting metabolism on tissue tolerance in bacterial and viral inflammation. Wang A, Huen SC, Luan HH, Yu S, Zhang C, Gallezot JD, Booth CJ, Medzhitov R.Cell.2016 Sep 8;166:1-14.


Ruslan Medzhitov (Yale University School of Medicine, New Haven, CT)

NIH Support: National Institute of Allergy and Infectious Diseases; National Cancer Institute; National Institute of Arthritis and Musculoskeletal and Skin Diseases; National Institute of Diabetes and Digestive and Kidney Diseases


  • Jomy NanoSoft says:

    Can you show “feeding” more method?

  • DDA says:

    This is good news for ice cream lovers. Desserts can help a viral cold sufferer!

  • Phil Stanway says:

    The findings match those from Alberto Saco Álvarez of Vigo University, who has shown by processing millions of data that certain ailments tally with the amount of solar activity at birth and that humans also react to the amount later. He initially supposed that this was due to interference, but some ailments tally with more solar activity and some with less, so a change of amount does not improve the health but merely decreases the likelihood of some ailments and increases the likelihood of others. These ailments also tally with the season or temperature of birth, so if birth were formerly seasonal, they tallied with the climate.
    In effect, humans are like desert locusts in having two main phenotypes, adapted not only to day and night and to summer and winter but also to green age and ice age, due respectively to more or less solar activity, and each phenotype is more susceptible to certain ailments. The ice-age phenotype is more likely to have autism, diabetes and schizophrenia, and the green-age phenotype is more likely to have cancer, Alzheimer’s, birth anomalies and sclerosis.
    The green-age phenotype is also more likely to have hypoglycemia, the opposite of diabetes, as shown by the so-called electrosensitive, whose cell sensors are less able to draw a clear line between solar activity and electrosmog, overestimate the amount of solar activity and prompt the
    person as a whole to adopt an extreme version of the green age phenotype.
    During an ice age, there is less greenery at the base of the foodchain, so people are few and far between and have to be autistic (self-reliant); there is less glucose, so they have to be diabetic (process glucose less fast); and there is little to eat in winter, so they have to hibernate and may end up schizophrenic (sleep-walking) if prevented from doing so. Solar activity and temperatures are not the only cues to the climate, as the amount of food available is another.
    Apart from hypoglycemia, the ailments typifying the green-age phenotype are all autoimmune, showing that the threshold for an immune reaction is lower in the green-age phenotype than in the ice-age one, as people are more plentiful and often in contact, increasing the risk of infection, so if mice are fed, this lowers the threshold for a full-blown reaction and speeds their recovery up. But humans and mice are not alone in adapting to green ages and ice ages. When people are few and far between, microbes cannot afford to be deadly or they perish with their hosts, but when people are
    shoulder-to-shoulder, they can, so microbes too adapt.
    Fred Hoyle may have been the first to notice a correlation between a higher level of solar activity and epidemics of influenza, but viruses and bacteria may react to different cues. Viruses do not feed on sugar but bacteria may, so if a mouse with influenza is fed, this changes the mouse but not the virus, as the mouse’s immune reaction is intensified and the virulence of the virus is not. But if a mouse with Listeria is fed, this changes the bacteria too, like those which nearly wiped out the saiga antelope in Kazakhstan.
    The main advantage of lowering the threshold for an immune reaction is that it nips an infection in the bud, but the mice in the investigation were already well infected before the threshold of reaction was changed, so feeding them changed the bacteria greatly while increasing the mice’s immunity only slightly. If fed only a little glucose, men and mice begin hibernating. They do not ‘lose the vital ability to control their body temperatures, breathing and/or heart rates’, but the phenotype changes. This is adaptive regulation, not deregulation.

  • Phil Stanway says:

    A year has passed since I wrote the above, but we are now in the midst of a pandemic, most of whose characteristics it explains. The main questions being asked are:

    1. Why are there two strains of coronavirus?
    2. Why is the death rate in Italy and Spain much higher than in Germany?
    3. Why are the old affected much more than the young?
    4. Why are men affected much more than women?

    1. The two strains, one mild and one deadly, may be two genotypes or may be the ice-age phenotype and the green-age phenotype so evident in the case of the desert locust. The evidence in favor of the latter is point (2).
    2. A green age is typified by a rise in temperatures. On moving south, a genotype should be unaffected, but a virus already in a borderline state on account of global warming should switch from its mild form to its deadly form, from Dr. Jekyll to Mr. Hyde. It may be argued that Germans are just cleaner and more withdrawn than Latinos, but the same disparity in the death rate appears between Britain and Germany, though both are in northern Europe. They differ insofar as in March the average temperatures and humidity in Britain are notably higher than in Germany, whose climate is more continental.
    3. As Jakob Boehme pointed out in the early 1600s, childhood tallies with the sweet and age with the bitter. An abundance of fruit and sweetness is a sign of a green age, so a sweet diet favored by children causes them to adopt the green age phenotype. During a green age, there is more risk of infection due to the higher density of population, so a green age phenotype has a lower threshold for an immune reaction, to nip any infection in the bud. In prefering candy floss to dry wine, children are well protected.
    4. There is presently no obvious answer, though one may emerge within the above framework.

    Focusing on the coronavirus as such may be a mistake. It is only one of many microbes switching to its deadlier phenotype in the wake of global warming. It is better not to let a hydra emerge than to devise specific measures for cutting each of its heads off, but President Trump may have a point in expecting an improvement towards Easter, the season of chocolate Easter eggs and bunnies.

    • Dawn A Hatchard says:

      Static electricity. Can it kill bacterium?

      • Phil Stanway says:

        Well, if we two meet again,
        in thunder, lightning or in rain,
        and you choose a promontory
        to be safe instead of sorry,
        more than microbes may be struck
        by a thunderbolt or luck.

        To put the electrical aspect into context:

        The Yale experiments showed that the outcome for mice infected with a virus or bacterium differed with the amount they ate, essentially of sugar or glucose. It was then supposed that mammals have one way to deal with a virus and an opposite way to deal with a bacterium.

        This would be impractical, as influenza and colds are both common in winter and often occur at the same time, so the two defense forces would block each other. There would be civil war between the army and the police, while insurgents happily plundered.

        It is likelier that the different outcomes are due to differences between a virus and a bacterium and that at least a bacterium has two phenotypes or reversible variants, one mild and one virulent. This may even be true of most or all creatures, including viruses, since all have had to cope with cycles of night and day, winter and summer, ice ages and green ages.

        Indeed, Fred Hoyle and Chandra Wickramasinghe pointed out that ‘the lethal wave of influenza in 1918-19 … was first detected on the same day in Boston and Bombay. Yet in spreading within the United States it took three weeks to go from Boston to New York,’ so the one epidemic can hardly have caused the other.

        Both were likelier to have been caused by a third factor, and they found a correlation with solar cycles. Longer cycles are the main causes of ice ages and green ages, and solar activity may be sensed by our bodies in various ways, as shown for instance by Hans Baumer and Walter Sönning.

        Called on by a printing works in Munich, to find out why the quality of print was varying with the weather, they found that a key ingredient was collagen, common in our bodies and akin to bacterial proteins. The size of its pores is regulated by certain atmospherics, consisting not of static electricity but of regular sine waves.

        Hans Cousto, pointed out that they are based on a cycle of 24 hours, except in the case of a series of harmonics, which I have shown to be based on a cycle of 36 hours. The earth spins once in 24 hours but only relative to something elsewhere, be it the sun, a planet or a star.

        In other words, the coronavirus may not be unusual in having two reversible ‘strains’, adapted to ice ages and green ages, but not all creatures may react to the same cues. The bacterium which nearly wiped out all saiga antelope in 2015 was prompted to switch into its green age variant by unusually warm and moist years.

        For billions of years, such a rise in humidity has followed a rise in solar activity, so by reacting beforehand to solar activity, the antelope could lower their thresholds for an immune reaction in time, but while temperatures have been rising in the wake of industrialization, the level of solar activity has been falling in recent decades, so in 2015 the antelope catastrophically did the opposite.

        On all levels of life, coupled systems are being decoupled by global warming, so this is the age of industrial growth and epidemics. Governments take credit for the former and blame nature for the latter, but they are sides of the same coin. This may lead to a world of sophisticated toys without anyone left to enjoy them …

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