The human gut microbiome represents the microorganisms in the human digestive tract. Scientists know having a healthy gut microbiome impacts things like a person’s immune system, their metabolism and even their mood. Babies first get exposed to the microbes by passing through their mother’s birth canal. Also, as a person matures, they tend to get more diverse microbiomes. Generally, a varied microbiome is a sign of good health [1].
Could Ginger Help the Gut Microbiome?
Researchers
are also aware a person’s diet could have a tremendous impact on the
characteristics of their gut microbiomes. A researcher from Kentucky’s
University of Louisville named Huang-Ge Zhang was curious about how ginger and
other edible plants affected the microbiome. He recalled how, when he was ill
as a child, his mother often gave him ginger tea to drink. The beverage is still
a popular choice when people want to calm their stomachs or ease nausea.
Within
his work as a microbiologist, Zhang recently studied how ginger and other
plant-based edibles could link to microbiome health. He knew scientists still
have a lot to learn about how specific foods affect the gut microbiome’s
characteristics. Zhang believed he could to contribute to ongoing knowledge
growth about how ginger
heals the gut microbiome.
Taking Inspiration from Earlier Research
Researchers previously concluded gut microbes get their primary energy from food. Zhang wanted to study a related topic. Previous research he did with colleagues focused on the effects of exosome-like nanoparticles (ELNs). These are tiny vesicles that aid in animal cell communication [2] by safeguarding the contents from external degradation. The ELNs also contain messenger RNA and microRNA (mRNA).
Some of Zhang’s earlier research with fellow scientists involved mice. The researchers found that ELNs from foods like ginger and broccoli had a preventive effect on both artificially induced colitis — inflammation of the colon — and liver damage caused by alcohol in the animals. In a study published in 2016 [3], scientists confirmed mRNA regulated the gut microbiome.
More
specifically, they synthesized mRNA and administrated it orally to mice. The
results showed mRNA affected the growth of E.
coli bacteria in the microbiome and improved the outcomes of
colitis in the animals. Thus, the scientists concluded manipulating the gut
microbiome in targeted ways might aid patients with specific disorders.
How Ginger Heals the Gut Microbiome
As
Zhang focused on ELNs found in ginger (GELNs), he wondered if gut bacteria
could take them so the GELNs would promote bacterial gene expression. First, he
sequenced GELNs and saw how they have many microRNAs. That conclusion was one
of the foundations of this research.
The
first stage of his experimentation involved purifying GELNs and feeding them to
mice. Next, the researchers investigated the gut microbe makeup in the critters
by sequencing the 16S ribosomal RNA (rRNA) gene. Every microorganism has one,
and 16S rRNA is common to bacteria.
When
the team checked to see if the GELNs affected the mice, the rodents that
received them had a substantial increase in a family of beneficial bacteria
called Lactobacillaceae. Some
manufacturers use bacteria from that group when formulating probiotic
supplements for humans.
Interestingly,
the conclusions showed GELNs, in particular, were exceptional at fostering the
growth of several types of bacteria from Lactobacillaceae.
When the researchers tried the same experiment with ELNs from grapefruits, they
observed the opposite effect by studying cultures under a microscope.
Thus,
their work showed people should not merely assume all ELNs help gut health in
uniform ways. Rather, something about ginger triggers desirable effects.
The Effect of GELNs on Colitis Symptoms
The
next goal was to see how GELNs might affect health. Patients with colitis often
get lesions and ulcers in the lining of their gut. The research team mimicked
that effect by giving mice a chemical called dextran sulfate sodium. It harms
the stomach in a similar way to what happens in patients with colitis.
The
control group of mice received particles of scrambled RNA inside a GELN-derived
lipid. The other group got GELN RNAs. The colitis symptoms in the second group
of mice got better, but the control group did not.
That
finding confirmed the researchers needed to dig deeper to figure out what might
be happening when the mice received GELN RNAs. So, they set up other experiments
to find out. Further investigations indicated that the microRNAs inside of
GELNs activate numerous bacterial genes. One was an enzyme in the L. rhamnosus bacteria. The tests suggested it
turns on a pathway to cause the expression of a cytokine in colon mucus called
IL-22.
Earlier research from other groups showed IL-22 is instrumental in regulating intestinal health [4]. Similar to the work Zhang and his team carried out, scientists previously demonstrated IL-22 had an anti-inflammatory effect in mice with colitis symptoms and helped repair tissue damage in the gut lining. They hoped it would benefit humans in the same way, but recognized the need for further time to study that possibility.
The findings of Zhang’s team back up those previous conclusions. Zhang views his work as a proof of concept that illuminates the need for more studies about how the ELNs from plants affect the gut microbiome. Although this study involved ginger [5], Zhang is working on building a library of all plant-derived ELNs. He wants to see how more of them may affect the gut.
Could Ginger Prevent Colorectal Cancer?
Ongoing research may forever change how doctors treat gastrointestinal problems and increase the attention they pay to the gut microbiome in general. Also, the full-text version of the study [6] goes into much greater details of the scientists’ methods and their findings. This work is undoubtedly fascinating and necessary. Other researchers followed suit with their investigations about the gut microbiome and ginger.
For example, research shows that ginger can significantly decrease the nausea that can arise from common cancer treatments like chemotherapy [7]. Scientists also want to know more about the potential impact of ginger on the gut microbiome in people with colon polyps. As mentioned earlier, people with colitis have inflammation of the colon. Sometimes, that condition presents as ulcerative colitis. People with that illness experience swelling, as well as sores on the colon’s lining.
Those with ulcerative colitis are at a higher risk than the general population [8] for developing colorectal cancer. Their doctors often recommend they get annual screenings called colonoscopies to check for the presence of polyps. Most colon polyps don’t cause symptoms and are harmless. However, some become cancerous. During a colonoscopy, doctors who find polyps perform biopsies on them to monitor for that complication.
The researchers studying how ginger might affect the gut of patients with previous colon polyps are looking for people whose colonoscopies revealed polyps that subsequently got removed. They intend to determine whether ginger might positively affect the gut microbiome by preventing colorectal cancer [9].
Besides the control group that receives a placebo, another group will take 1,000 milligrams of ginger twice a day for 12 weeks [10] and provide stool samples throughout that period. Those researchers will use the same approach as Zhang and his team by looking at the gut microbiome’s condition by sequencing 16S rRNA genes. The team expects to finish their research by the end of May 2020.
Turning to Well-Known Spices to Learn More About
Digestive Health
Another recent study that informed how ginger could modify the gut microbiome focused on other popular spices, too. Along with ginger, the scientists used black pepper, long pepper and turmeric. They found all those substances could benefit fecal bacterial communities [11] in ways not seen in the control group.
This study only had 12 subjects [12], but the research team said their next goal is to do another human trial and further explore the effects they saw. For example, they believe it may be possible to amplify the therapeutic effects of the herbs. If so, that achievement would be a decisive step of progress for using plant-based interventions to treat digestive issues.
Another Team Makes a Fascinating Conclusion About
Ginger
Scientists
are interested in how ginger might change the gut microbiome to help people
that don’t have colorectal problems, as well. A group published a study in
March 2019 examining the ties between gut microbiome modulation and obesity.
They also used ginger. Four groups of mice received either a normal or high-fat
diet for 12 weeks. Some meals contained ginger, while others didn’t.
Scientists learned the mice fed high-fat diets with ginger had decreases in body rate, low-grade inflammation, fat deposits in the liver and insulin resistance compared to the mice that did not eat ginger [13]. Moreover, the scientists observed an increase in several groups of helpful bacteria that are part of the gut microbiota.
Going Beyond
Ginger to Enhance the Gut Microbiome
The research above specifically focuses on changing the gut microbiome with ginger. Scientists are also interested in understanding other therapeutic ways to positively alter it. One case involved particular mixtures of food fed to malnourished kids. The children who received a blend of banana, chickpeas, peanuts and soy [14] had gut microbiomes that were closer to their healthy peers compared to the control group.
Another study investigated using walnuts to influence the composition of the gut microbiome. Some test subjects received 42 grams of walnuts per day for two three-week periods, while the control group did not eat walnuts at all. The research team concluded that the nuts caused favorable shifts in the prevalence [15] of healthy gut bacteria while reducing the abundance of less beneficial bacteria. In addition, it cut down on LDL levels associated with “bad” cholesterol.
Many individuals started hearing the saying “an apple a day keeps the doctor away” in childhood. Scientists wanted to see which parts of an apple had the most bacteria and could be most beneficial for gut health. They determined that the core has approximately 100 million bacteria [16], while the fruit’s flesh only has 10 million. They said the bacteria from organic apples was more diverse and balanced. These findings give people a reason to stop discarding the cores.
A professor is also experimenting with how orange peels help the gut microbiome. He received a $1.5 million grant [17] from the National Institutes of Health and is particularly interested in polymethoxyflavones. They’re a class of flavonoids found in citrus fruits — primarily the peels. He hopes to learn how people could alter their diet to help colon inflammation. Using orange peel or zest in recipes may help, as could supplements.
There’s also good news for people who enjoy
drinking red wine and care about gut health. Scientists working at King’s
College London tested the effects of consuming several kinds of alcohol on gut
microbiota diversity. Participants drank red and white wine, beer and spirits.
However, red wine was the only beverage in the group that promoted a more
diverse gut bacteria makeup [18]. The researchers believe the
results are due, in part, to the polyphenols in red wine.
Compelling Results
The
work of Zhang and his colleagues was the first study described in the coverage
here about how ginger heals
the gut microbiome. However, scientists
have plenty of other reasons to continue seeing how ginger and other foods stimulate gut microbiome
remodeling in humans. It may be several years before researchers make
definitive conclusions, though.
Even
so, the studies mentioned here and others could collectively give much-needed
clarity about which plant-based foods help people have a diverse and healthy
gut microbiome. Health-conscious individuals can make strategic dietary choices
that help them live healthier and have more options for disease management.
