We all knew that our digestive system is essential for good nutrition, but it seems it affects our immune system, as well. And fruits like elderberry can protect us from the flu.

This may not be a surprise to some, as groundbreaking new facts about digestive health are making headlines every week. It seems that our digestive microbes affect more than just our ability to absorb nutrients and remove toxins. The balance of microorganisms in our digestive system affects mood, weight, and now, apparently, our immune system too.

A study from the Washington University School of Medicine in St. Louis recently revealed that gut microbes could help prevent the flu. But only, however, if they get the right fuel for the job.

What the Study Uncovered

Researchers discovered that a key microbe, called DAT (desaminotyrosine) protects test mice when they have influenza. This microbe is the byproduct of breaking down flavonoids, contained in fruits like elderberries, blueberries, and raspberries.

Following up on previous evidence that the gut microbiome affects response to flu infections, researchers at Washington University sought to figure out which microbes provided the protection.

Senior author of the study and Conan Professor of Pathology & Immunology, Thaddeus S. Stappenbeck, MD, Ph.D., said that the bacteria aided immune response by boosting interferon. Once they identified the bacteria, Clostridium orbiscindens, they identified the byproduct of its breakdown of flavonoids: DAT.

“(T)his prevented influenza-related lung damage in the mice. It is this kind of damage that often causes significant complications such as pneumonia in people.”

After testing their theory on mice, they found far less lung damage, even though the infection level was equal to control subjects.

“(T)he mice still had the virus. But the DAT kept the immune system from harming the lung tissue.”

Study co-author Ashley L. Steed, MD, Ph.D., a pediatrics instructor who also treats intensive care patients at St. Louis Children’s Hospital, also commented on the remarkable discovery:

“For years, flavonoids have been thought to have protective properties that help regulate the immune system to fight infections.”

You can read the final paper as submitted at Science.

Elderberry and digestive bacteria: UBiome - Microbiome Sequencing Gut Bacteria Sample Kit

UBiome – Microbiome Sequencing Gut Bacteria Sample Kit
Image: CC by A 2.0, by Tony Webster, via Wikimedia

An Intriguing Twist to the Flu Shot Controversy

What’s really exciting is this completely new approach for managing flu outbreaks after so many controversies surrounding the effectiveness of flu vaccines.

There seems to be some debate about vaccines in recent public conversation. The statistics are very clear that vaccines prevent illness and death and has reduced child mortality by revolutionary numbers in the last 100 years. However, despite the evidence, there are still a few people who have their suspicions.

Whether you’re pro-vaccine or anti-vax, you may neglect to get a flu shot altogether, whatever strain is in fashion this season. There are both real and quirky reasons to avoid your flu shot. Modern medicine has made us all a bit spoiled. It’s hard to believe that only 100 years ago, the 1918 Influenza Epidemic killed 20 million people worldwide. Surprisingly, more people died in the 1918 outbreak than died in World War I.

The flu shot dilemma

In this century, many people don’t bother to get their flu shot unless they work or deal with children or the elderly in their daily lives. It probably wouldn’t hurt to remind those that take such of cavalier attitude of the China/Russia H1N1 Influenza A Flu epidemic of 1977. Most noteworthy, the disease outbreak only affected those under the age of 25. That’s because older people had immunity from an earlier outbreak during the 1950s. The problem with neglecting your vaccines for infection illness is that it’s not a very socially responsible thing to do.

But, whether you’re pro-shot or anti-shot, the Centers for Disease Control is pretty clear that everyone over the age of 6 months who can get the shot, should. But they also define cautions before doing so:

  • They caution that people with severe, life-threatening allergies to ingredients in the vaccine or the vaccine itself refrain. Ingredients can include eggs or gelatin.
  • Patients who have ever had Guillain-Barré Syndrome, a severe illness, should also refrain.
  • Those who are currently ill or feeling unwell should discuss their condition with their doctor before receiving the vaccine.

Meanwhile, there are people who simply aren’t convinced of the shot’s effectiveness. Some claim they feel worse after the shot than they would by actually getting the flu. Others still claim that all vaccines cause developmental delays in children, like autism. Still others are simply lazy and can’t be bothered. For for a rare unfortunate few, a severe reaction to this year’s formula can have devastating effects.

Getting a flu shot: those who miss their annual flu shot may want to include elderberry in their diet.

Image: CC0 Creative Commons, by huntlh, via Pixabay

Elderberry could complement immunization

But for those who cannot get the shot because of age or allergy, or just weren’t able to get their flu shot in time, the results of the study could be a real boon. Dr. Steed added:

“But with DAT, it may be possible to keep people from getting quite as sick if they do become infected. This strategy doesn’t target the virus. Instead, it targets the immune response to the virus. That could be valuable because there are challenges with therapies and vaccines that target the virus due to changes in the influenza virus that occur over time.”

So, for those who are unable to get their annual vaccine for whatever reason, leveraging the flavonoids in your diet by eating right could put you in a better position to ward off the infection.

Details of the Study

Researchers tested 84 different metabolites and identified DAT as the relevant one. Test mice were pre-treated one week before being infected and then were treated with the microbe for 14 days. As a result, control groups sometimes died or lost vital body weight as compared to those treated with DAT.

In some cases, the addition of antibiotic treatment exacerbated the illness, as it killed off important gut microbes. As researchers noted, Clostridium orbiscindens is particularly sensitive to two antibiotics: metronidazole and vancomycin. Treatment with either of these increased mortality rates in test mice.

One other interesting note the researchers added to their paper was that pre-treating with DAT and then stopping on the day of infection afforded the same kind of immune protection as continuing treatment. However, starting the DAT treatment two days after infection did not improve outcomes for the test mice at all. Therefore, we can assume that “that innate, not adaptive, immunity is crucial.” This tells us it’s important to eat well for prevention, not just when we feel ill. It’s far more effective in this case.

How it works to protect you

When the gut bacteria Clostridium orbiscindens breaks down flavonoids, it releases a tiny metabolite that enters the circulation. These metabolites, DAT, enhance interferon signaling to the immune system. Interferon is a protein released by cells that inhibit a virus’s ability to replicate itself.

What Are Flavonoids?

Flavonoids are one of the groups of phytochemicals found in plant source foods. They’re the source of the some of the vivid colors in fruits and vegetables. Researchers have further broken down flavonoids into five categories: flavonols, flavan-3-ols, flavones, flavonones, and anthocyanidins. You’ll find these vital nutrients in fresh fruits and vegetables.

Flavanols: Apples, Romaine lettuce, tomatoes, sweet potatoes
Flavan-3-ols: Blueberries, strawberries, black and green tea
Flavones: Bell peppers, celery, cantaloupe, lettuce
Flavonones: orangs, grapefruit, tomatoes
Anthocyanidins: Elderberries, Blueberries, cherries, pears, cranberries, raspberries,

Dried elderberry tea with other flavonoid-rich ingredients is great for your immune health.

Image: Creative Commons Attribution 2.0 Generic license, by Selena N.B.H., via Flickr

Why Choose Elderberry?

Although there are plenty of fruits and veggies that are rich in phytonutrients, black elderberries (Sambucus nigra) are one of the top choices for ensuring you get a good supply. Black elderberries contain one of the highest levels of anthocyanidins, at 1 percent of anthocyanidins and other polyphenols.

According to the United States Department of Agriculture (USDA) in its 2015 Comparison of Flavonoids, black elderberry simply kicked all the other dark fruits to the curb when it came to anthocyanidins content:

Anthocyanidins mg. per 100 grams of Edible Fruit

Elderberry: 485.28 mg/100 grams
Blueberries 163.3mg/100 grams
Cranberries 104.02mg/100 grams
Red Grapes 48.04mg/100 grams

Finally, the vitamin C contained in elderberries preserves the vital anthocyanidins and its antioxidant properties. This means that even after processing and storage, the flavonoids are preserved.

Previous Study Results

In a 2009 study published in the Journal of Phytochemistry, researchers found that elderberry flavonoids bound to the H1N1 infection (Influenza A) and inhibited the infection. According to the study, when the flavonoids from the elderberry extract bound to the virions, they would:

“(B)lock the ability of the viruses to infect host cells.”

Previous studies also show they reduce the severity and duration of colds in travelers.  Researchers have also discovered that elderberry extract reduces insulin resistance.

In Conclusion

There doesn’t seem to be any doubt that this is just one more very good reason to get plenty of antioxidants and flavonoid-rich foods into your diet pronto. And to make them a regular part of your diet.

Elderberries make a delicious syrup to add to any smoothie or beverage. And who knew you could make candy with them too?


Featured Image: CC by 0, by Anemone123, via Pixabay