Schisandra chinensis fruit modulates microbiome in obese women

Flower from Schisandra chinensis fruit plant

A search for the blog posts on our site about obesity will result in a list of posts discussing correlations between obesity and bacteria in the gut. People have hypothesized that by modulating the microbiome, you may be able to alter obesity levels in humans. Many studies have looked at how probiotics and prebiotics can modulate bacterial structure to control obesity and metabolic diseases, however little has been done to look at how herbs and fruits could modulate bacterial composition.

A recent study from Korea looked at Schisandra chinensis fruit (SCF), a fruit found most commonly in northern China, that has a long history of being used in East Asian culture as a therapeutic for conditions such as diabetes, obesity, cough, and other conditions.  Previous studies of SCF in mice have shown that it modulates the microbiome, however no human trials had been previously conducted. To analyze this in humans, a clinical trial was conducted in Korea to look at the impact that SCF had on gut bacteria, body composition, and blood chemistry.

At the Dongguk University Ilsan Hospital in Korea, scientists recruited women who were obese (BMI over 25) who met other specific medical conditions. 28 women ended up participating in the study, 13 in the SCF treatment group and 15 in the placebo group. The study participants each took either SCF or placebo twice a day for twelve weeks and blood and fecal samples were taken before and after the treatment as well as a physical examination including heart rate, waist circumference, body weight, and blood pressure.

After twelve weeks, both the placebo and experimental group saw a decrease in waist circumference and fat mass, thought the SCF group saw a greater decrease in fat mass, blood glucose and other parameters. An analysis of the fecal samples before and after the twelve weeks saw greater clustering in the SCF group than the placebo group. At the genus level, there was significant differences between the two groups and the SCF group saw a greater abundance of genus levels (both groups saw similar levels of phyla changes). They saw specific clustering between patients in the SCF group despite dissimilar clustering prior to treatment. This showed that SCF had an influence on gut microbiota that was dependent on gut bacteria prior to treatment.

This study found differences between bacterial composition in patients who were given the Schisandra chinensis fruit and those in the placebo group. Many of the bacteria that saw an increase in the SCF group, including Akkaermansia, Roseburia, Prevotella, Bifidobacterium, and Bacteroides, had shown an association with reduced obesity levels in previous studies. While decreased waist circumference, body mass, and other weight loss parameters were seen in the SCF group, the results were not statistically significant. Much research has been done to look at ways of altering the microbiome and this study shows us that we should continue to investigate the effects of herbs and fruits on our microbiome.  

Antibiotic use in livestock is increasing and leading to greater antibiotic resistance

We’ve talked extensively about antibiotic resistance on the blog but we haven’t focused much on the impact that antibiotics given to livestock have on humans. Farmers give low doses of antibiotics to farm animals in order to not only prevent illnesses in their animals, but also to promote growth within their livestock. Animals being produced for food account for about 80% of antimicrobial use in the United States and bacteria in the animals become resistant to these antibiotics in the same fashion that they do in humans. As antibiotic use rises, more bacteria are becoming resistant and these bacteria are passed from animals to humans through the environment, consumption, and direct contact. An international research team from Europe, India, Africa, and the United States mapped the global consumption of antimicrobials in livestock.

The results were published in the Proceedings of the National Academies of Science (PNAS) and compared the use of antibiotics in livestock in 2010 to the projected use in 2030. The authors found that the global use of antibiotics in livestock will increase 67% in the 20 years between 2010 and 2030. This is largely a result of an increase in demand for meat by middle class individuals in countries like Brazil, Russia, India, China, and South Africa (BRICS). These BRICS countries have shifted their livestock production systems to be more cost-effective by increasing the use of antimicrobials to ensure the health of their animals and to promote growth.

This increase in antimicrobial use in animals is a compounded annual growth rate of 2.6% annual which is almost three times the annual growth rate of the human population (.98%) during the same time period. The authors found that in 2030, if new regulations are not put into place, approximately 30% of all antimicrobial use will be accounted for in the livestock industry in China.

Many countries, and specifically those in the developing world, do not regulate the use of antimicrobials in livestock production. While directly linking antibiotic use in animals to drug resistant infections in humans is very complex, it can be inferred that increase in antibiotic use leads to antibiotic resistant bacteria, and we have seen evidence of this in practice. In countries like India, where bacterial diseases are very prevalent and a major public health concern, antibiotics are a key factor in fighting these illnesses.  Increased resistance to bacteria by increased use of antibiotics in farm animals will only increasingly prevent the effectiveness of antibiotics in humans.  

The study authors call for global action to decrease the use of antibiotics used in animals that are raised for meat consumption. While the authors do state that this analysis was based on limited available data, largely in developed nations, the global trends of antibiotic use in livestock is concerning. 

Hand washing dishes may decrease risk of allergies

A study published on Monday by the journal Pediatrics has gotten a lot of press this week because it shows a connection between allergies in children and the method by which parents wash their dishes. Parents, especially new parents, often consider good hygiene as one of the most important factors in raising their new child, but according to the hygiene hypothesis it may be true that too much cleanliness actually negatively affects a young child.  Asthma, eczema, and other autoimmune diseases are becoming more common conditions in children, and each has been linked to the hygiene hypothesis.  Researchers in Sweden reinforced this link when they discovered a possible connection between allergies in children and whether dishes were washed by hand (less clean) or by machine (more clean) in their homes.

 The researchers sent a questionnaire to parents of children aged 7-8 which was filled out by 717 families in Molndal, Sweden and 312 families in Kiruna, Sweden. The questionnaire asked many questions pertaining to the children, including previous symptoms of asthma or eczema, method of washing dishes, and if their food was farm grown or fermented.  When examining the results it is important to remember that all forms of bias cannot be eliminated when doing surveys, because, among other reasons, it is difficult to get a perfectly random sample.

Results of the study showed that there were lower instances of allergies in children whose families washed their dishes mainly by hand rather than by machine. In addition, this effect was amplified if the children ate food that was either fermented or purchased from a farm (both of which should introduce diverse bacteria to the children).  Of course, there were other variables that were not inquired in the questionnaire that are also known to decrease rates of allergies in children, and which may be related to washing dishes by hand, for example a lower socioeconomic status.  Then again, the authors suggest that hand washing dishes may reasonably be responsible for these lower rates of allergies in children of lower socioeconomic status.

So, you may be wondering how exactly this pertains to the microbiome. Hand washing dishes cleans less thoroughly than highly efficient machines, which sounds gross, but the exposure to more microbes when you are young may help develop the microbiome and immune system.  While this study is not perfect, it still shows us that exposure to bacteria is potentially a good thing for the new and developing microbiome. 

What microbes are in the food we eat?

There is a common saying “You are what you eat.” But is this actually true? A lot of attention has been paid to the microbes in our gut and the effects they have on disease and nutrition, but little has been reported on what microbes are in the food that we eat on a daily basis and the impact that this has on our microbiome and the microbial communities in our body.  A team of three scientists at the University of California, Davis set out to characterize the microbes that are in three different dietary patterns.

Published in the journal PeerJ, the scientists described the microbial communities in a typical American diet, a USDA recommended diet, and a vegan diet. The American diet consisted of convenience foods like Starbucks, McDonalds, and Stouffer’s frozen food. The USDA recommended diet consisted of foods such as fruits and vegetables, lean meat, dairy, and whole grains. The vegan diet excluded all animal products (at the bottom I have included what exactly was in each diet). 

The USDA diet contained by far the most microbes at approximately 1.3 billion per day, while the vegan diet came in second with about 6 million microbes, and the American diet last at 1.4 million microbes. The USDA diet consisted of many live active cultures such as yogurt and cottage cheese which was most likely the reason for the higher number of microbes.  

This study did not answer the important question of what happens when we ingest these foods and what impact does diet have on our microbiome.  But it opens up the door to many further questions about the impact that our diet has on our microbiome. This study was only a small study and while previous studies have shown that microbial shifts have been seen after a large change in diet, we still do not know how readily the microbes in our food colonize in our gut. While this study suggests that different diets vary in terms of the number and composition of microbes we consume, further studies need to be conducted to better understand its impact as well as other factors such as cooking techniques and processing have on our microbiome. 

As a side note, one of the authors of this study, Dr. Jonathan Eisen, writes a very interesting blog himself and if you are interested in the microbiome, I recommend you take a look. Here is his post about this recently published work.

And if you are interested in exactly what was in diets that they studied, here it is:

The American diet consisted of a “large Starbucks Mocha Frapuccino for breakfast, a McDonald’s Big Mac, French fries, and Coca Cola for lunch, Stouffer’s lasagna for dinner, and Oreo cookies for a snack.”   

The USDA recommended diet consisted of “cereal with milk and raspberries for breakfast, an apple and yogurt for a morning snack, a turkey sandwich on whole wheat bread with salad (including a hard-boiled egg, grapes, parmesan cheese, and Ceasar dressing) for lunch, carrots, cottage cheese and chocolate chips for an afternoon snack, and chicken, asparagus, peas and spinach on quinoa for dinner.”

And the vegan diet consisted of “oatmeal with banana, peanut butter, and almond milk for breakfast, a protein shake (including vegetable-based protein powder, soy milk, banana and blueberries) for a morning snack, a vegetable and tofu soup (including soba noodles, spinach, carrots, celery and onions in vegetable broth) for lunch, an apple and almonds with tea for an afternoon snack, a Portobello mushroom burger (including Portobello mushroom, avocado, tomato, lettuce, and a whole wheat bun) with steamed broccoli for dinner, and popcorn, hazelnuts and fig bars for an evening snack.”

Promoting your dog’s microbiome through functional food

Dogs are man’s best friend, but did you know that they can suffer from digestive diseases and inflammatory bowel diseases too?  A new study published in the British Journal of Nutrition aimed to investigate how dog foods could be ‘functionalized’ by the addition of potato fiber.  This prebiotic promoted the production of many important molecules and shifted the microbiome in ways that may be critical to gut health.

In the study, numerous dogs had their feces sampled for their microbiome in addition to metabolites.  A control group was fed a normal diet and an experimental group was fed the normal diet with the different amounts of potato fiber.  All of the dogs’ microbiomes were richest in Firmicutes, regardless of diet.  However, dogs given potato fiber had an increase in Firmicute abundance, as well as Bifidobacterium spp. and Lactobacillus spp.   Both Bifodobacterium and Lactobacillus are common probiotics that are shown to promote gut health in humans.  In addition, one particular bacterium, Faecalibacterium prausnitzii, was shown to proliferate after the potato fiber was added to the diet.  This bacterium has also been related to decreases in IBD in humans.  Finally, the dogs that ate potato fiber had an increase in butyrate, short chained fatty acids (SCFAs), and an overall decrease feces pH.  Each of these has been implicated with lower incidence of IBD.

This study was one of the first to investigate prebiotics in dog food.  The simple addition of potato fiber, a complex carbohydrate, had important changes on the microbiome, including the production of SCFAs which we have blogged about in the past.  Potato fiber may be an easy, inexpensive dog chow additive for all dog owners and lovers to help their pets lead happier, healthier lives.