HUANJIA ZHANG

Science, humanity, and everything in between.

Newsworthy: previous dietary experience and gut microbial exchange with other individuals have implications on affecting a person’s response to new diets. 

EATING HEALTHILY is at the top of the list for many of those setting New Year’s resolutions. However, changing your diet could be more complicated than you think—researchers have found that your previous dining experience could impact your new diet efficiency through gut microbiota. This might explain why so many New Year diets don’t work.

Gut Microbiota: Our Native Flora by Micah Lidberg

But hold on… researchers also found that if there’s another person in your household who already eats healthily, you might have a better chance of
success. The reason might be that their gut microbes are influencing your dietary practices, according to a recent study published in Cell Host & Microbe. The implications suggest possibilities in developing probiotics that simulate a similar healthy gut microbiota community to support your dietary changes.

The study conducted by Dr. Jeffery I. Gordon, director of the Center for Genome Sciences & Systems Biology at Washington University in St. Louis and his team, was interested in if and how, gut microbiota—the tens of trillions of microorganisms in our intestine—affect, and are affected by, our dietary practices. These tiny microbes usually live happily within our gut and pay the “rent” to our body by helping digest food and synthesize essential vitamins such as vitamin B and K. Gut microbiota also function as an armor for our intestine to defend against other aggressive microorganisms.

Previous studies suggest that typical unrestrictive American diets might result in a weakened gut microbiota, which can compromise overall health. To put this idea to the test, Dr. Gordon and his colleagues genetically analyzed fecal samples from 34 adult donors who have maintained healthy diets and 198 donors who have typical unrestrictive American diets. The results indicated that people who practice healthy diets bear a significantly richer and more diverse gut microbiota than people who do not, including many microbes that seem to only be associated with a healthy diet.

Dr. Gordon’s team also found that when transferring the fecal microbiota from the unrestricted-diet individuals to germ-free mice, these mice were not able to adjust to a new diet as easily as their counterparts, who were received healthy-diet microbiota. Based on these results, the researchers suggest that reduced bacterial diversity caused by the prior dietary practice can influence our body’s response to a new diet.

However, there is still hope in the story of gut microbiota. Although each of us has our unique collection of gut microbiota, it is never isolated or static. Instead, we are constantly shedding our microbiota—picture that we are all surrounded by a cloud of our microbes. Our microbiota and other individuals’ microbiota come together and make up a large microbial community called a metacommunity. Within the metacommunity, we continuously exchange our microbes with people who live in close association with us.

In a follow-up experiment, Dr. Gordon and his colleagues created an artificial metacommunity by placing together mice harboring unrestricted-diet microbiota and mice with healthy-diet microbiota to further understand whether promoting bacterial dispersal between these mice could affect their responses to diet change. Interestingly, it turned out that mice with unrestricted-diet microbiota, which previously showed inefficient response to the new diet, have significantly improved their digestive performance by being in close proximity to mice with healthy-diet microbiota.

These findings suggest important implications for how dietary practices can be prescribed for success. However, since this study was primarily on mice, it will take more research to determine the health outcomes of the interpersonal microbiota exchanges for humans. The researchers believe that with a richer understanding of how humans exchange microbiota with other individuals and its effects on health, one day our concept of “social” diseases will be refreshed to incorporate perspectives of metacommunity dynamics in public health.

For many people, switching a diet can be challenging. Therefore, uncovering microbial potentials and ensuring a positive response to new diets for our body have always been a major goal of these studies. The hope in the near future is to be able to identify microbes that are associated with different dietary practices and use these microbes to make probiotic products in order to enhance people’s digestive responses to their new diet.

After all, switching to a healthy diet is always a smart choice for your health!

Related:

It’s Not Yet Clear How to Boost the Microbiome. But Diet Is the Best Bet” – TIME

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“So, what is this General Tso’s Chicken?”

“It’s hard to explain… It’s a sweet, Americanized dish made out of chicken. Americans love it.

Above was the conversation I had with the owner of the first Chinese restaurant I stepped into in the United States. After arriving to a small town in central Pennsylvania for college, I decided to visit one of the few Chinese restaurants in town hoping to get some food that would ease my feelings of being homesick. Unfortunately, not only did I get little comfort from the authenticity of the food, I became even more jumbled by what appeared on the menu. Why on earth does General Tso, this national hero I learned about in high school history books, have anything to do with chicken?

Perhaps, even General Tso himself would not have expected that one day his name would become famous all the way across the Pacific Ocean—but not for his battle achievements, rather for a chicken dish.

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General Zuo Zongtang (1812 – 1885), often known as General Tso, was a famous Chinese military leader and statesmen of the late Qing Dynasty.

Best known as a nineteenth-century general, politician, and national hero to Chinese people, General Tso’s full name is Zuo Zongtang (Tso Tsung-t’ang was the transliteration of his name before the standard Chinese phonetic system came out). He was born in 1812 in Hunan province, a region in southwest China that is famous for its spicy food and its people’s firey military tradition. As a formidable general, Tso led many successful battles to defeat rebel groups on the northwest border. His most famous achievement was recapturing the Xinjiang region from the Uyghur rebellions. After serving the Qing Dynasty for his entire military career, General Tso died in 1885, leaving his legendry stories to be shared and passed down from generation to generation.

So, how did General Tso end up entitling a chicken dish? The roots can be traced back to a famous chef named Peng Chang-kuei, who came from the same region as General Tso. Born in 1919, Peng grew up in a deprived family during the most troubled times in contemporary China. As a teen, Peng served as apprentice to Cao Jingchen, who was a private chef for the Nationalist officials and the owner of a famous restaurant. After years of apprenticeship, Peng became a famous chef himself and his cooking was so exceptional that he became the executive chef for the Nationalist government banquets.

In 1949, the Chinese civil war broke out, during which the Communist army defeated the Nationalist government. When the Nationalist party fled to Taiwan, many service people were brought with them, and among them was Peng. In Taiwan, Peng continued serving the Nationalist government as a chef and soon opened his own restaurant “Peng’s Huanan Yuan”—the most famous Hunan-style restaurant at the time. In his restaurant, Peng created many dishes that were inspired by his much-missed hometown and reflected Human cuisine. One of them includes General Tso’s chicken—a heavily sour, salty, and spicy chicken named after one of Hunanese favorite historical figures General Tso.

The “General” did not arrive in the U. S. until the early 1970s when America’s first Hunanese restaurant, “Hunan,” opened in Manhattan, New York. Inspired by Peng’s General Tso’s chicken in Taiwan, chef T. T. Wang, of the Hunan restaurant, also devised a dish called General Tso’s chicken with more American flavor and introduced this dish on the menu. With the huge success of Hunan restaurant, General Tso’s chicken—this fried, buttery and sweet chicken dish that fits American people’s tastes all around—soon got its own reputation. Shortly afterwards, it was copied by other Chinese restaurants all over the country, making General Tso’s chicken one of America’s favorite Chinese dishes.

Today, you can find General Tso’s chicken almost anywhere in this country. In fact, because of this dish, General Tso has become one of the most famous Chinese people known by the American public, of similar fame to Yao Ming or Jackie Chen. Ironically, although most American people have ordered meals in his name countless times, few of them know who General Tso really was, and why this dish was named after him. People always joke that General Tso to Americans is like Colonel Harland Sanders to Chinese—people know them because of the chicken, but not so much as military officers.

Meanwhile, on the other side of the world, despite the fact that General Tso’s chicken was first invented in Taiwan, it never become as popular as it in the U.S.. In fact, most Chinese people have never heard of it or tasted it. General Tso is still commemorated by the Chinese people as the celebrated Qing general. Even though General Tso’s chicken is as exotic to the Chinese as it to Americans, it is still widely considered to be a Chinese dish. After all, it embodies the history of civil war, the sentimental attachment of homeland, and the struggle of early Chinese immigrants to adapt to American society. Just like how General Tso’s Chicken is rich in flavor, this dish is also rich in its cultural connotations.

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R.V., Chemicals, science equipment, blue gloves, and a busy lab crew…, for many “Breaking Bad” fans, this scene sounds oddly familiar. Believe or not, this was how Kerney lab as well as Kerney lab’s collaborator  spent their 2015 spring break. Unlike the characters of “Breaking Bad”, we were not making drugs, but participating in our “west meats the east” co-culture research experiment.

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Walking through the ancient forest is like Alice exploring her wonderland – so much unknown excitement!

Launched by Dr. Ryan Kerney and Jasper Leavitt ’15, this co-culture experiment aims to study what will happen if we swap the algae from Northwest salamander (Ambystoma gracile) embryo with the algae from the Northeast salamander (Ambystoma maculatum) embryo during their early embryonic development. Therefore, one of the major purposes of this trip is to collect adequate Northwest salamander embryos for the experiment.

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Ambystoma gracile (AKA: the northwestern salamander) mainly inhabits the northwest coast of North America, hence the name northwestern salamander.
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Egg mass of the northwest salamander. The salamander eggs usually form a egg clutch that is coated with clear-looking, firm jelly on the outside to protect them. Did it ever occur to you that these beautiful eggs look like the bubbles in the bubble tea?

Of course Kerney lab has our own ways of doing trips! We rented a R.V., which not only was our living space at night, but also our lab space during the day. The R.V. also functioned as our mobile vehicle when we needed to travel as well as our kitchen and dining space when we needed to eat – it was as convenient as you want it to be. If you are wondering how much of a lab can be made from a R.V., you would be very surprised. Fluorescent microscope, dissecting microscope, full range of chemicals, pH meter, salinity meter, dissecting tools, centrifuge tubes, and even waste disposal were all equipped in this tiny R.V, crazy… isn’t it?

Busy crew inside the “mobile lab”.
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Similar to when doctors take out water samples from pregnant mother to test the living conditions of the babe, here we also take out the fluid surrounding the salamander baby inside the egg capsule to to chemically analysis the aquatic environment in which the embryo lives in.

You might be curious about how this trip itself went. I would say, the trip was absolutely incredible! During the seven-day trip, the crew have traveled across the entirety of Oregon state and Washington state and the furthest place we reached North was Bellingham, WA. Under states permits we collected and fixed salamander embryos from seven sites, including natural parks, local ponds, and the backyard of a few newfound friends.

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Grandma, grandpa, mom, dad, and the little young boy were all working hard to find help us find salamander eggs in their backyard!
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To express our gratitude to the family for helping us for the salamander egg hunt and offering us the delicious dinner, we invited the family into our “mobile lab” and fired up the florescent microscope to show them some cool stuff about science.

What was the most unforgettable memory for me from this trip? I would definitely say the amazing scenery and the friendly people we’ve met. Not only did we cold hike through the ancient temperate rain forests, but we also saw snow-capped volcanoes, coasts, and some old train trails in northwest. Thanks to this amazing trip, the Pacific Northwest was, is, and will always be a true wonderland from the bottom of my heart. In a simple phrase, the trip was truly “breaking good”!

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Picture of our Pacific Northwest collection crew. From left to right: Jasper Leavitt ’15, Huanjia Zhang (myself), Kyle Weis, Ryan Kerney, and John Burns.

Read more about the spotted salamander (Ambystoma maculatum) and its symbiosis relationship with green algae.

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