AP Biology class blog for discussing current research in Biology

Tag: Healthy eating

Can Microbes Create Healthier Food?

A specific human gut microbe is making processed foods healthier. 

Researchers at Washington University School of Medicine in St. Louis wanted to find the chemicals in processed foods that correlate to diabetes and heart disease. In their study, the scientists used a bacteria called Collinsella intestinal (bacteria that contains an enzyme to break down Fructoselysine), which breaks down fructoselysine into small, harmless parts. According to Ashley R. Wolf, a researcher in the lab, “Fructoselysine is common in processed food, including ultra-pasteurized milk, pasta, chocolate and cereals.” This chemical has been linked to the cause of many diseases of aging.

When Wolf and her team tested the effects of feeding fructoselysine to mice that had Collinsella intestinalis, they not only discovered an increase in the amount of microbes in the stomach, but also found that the mice’s gut microbes had a stronger ability to break down fructoselysine.

“The new tools and knowledge gained from this initial study could be used to develop healthier, more nutritious foods as well as design potential strategies to identify and harness certain types of gut bacteria shown to process potentially harmful chemicals into innocuous ones,” says Jeffrey I. Gordon, a researcher of the lab.

Picture of human gut microbes

(“Courtesy of Pacific Northwest National Laboratory”)

Another study by Harvard University and the University of San Francisco, discovered that raw food was healthier than cooked food. They found that “cooked food allows the host to soak up more calories in the small intestine, leaving less for hungry microbes further down the gut; on the other hand, many raw foods contain potent antimicrobial compounds that appear to directly damage certain microbes.”

Although more research still has to be done to determine the effectiveness of the microbe, these discoveries help lead people into a healthier lifestyle. 

Bacteria Not So “Bad”, After All?

Photo Link: Wild Garden of Gut Bacteria, By: Nicola Fawcett

Most of us are used to the common notion that bacteria may not be the most beneficial factor in maintaining your health.  Thats why the results of a recent research study conducted by scientists at Babraham Institute in collaboration with colleagues in Brazil and Italy, yielding evidence that in fact good bacteria in the gut can control gene expression in our cells, is game-changing!

The research team, led by Patrick Varga-Weisz, made this discovery by studying the gut bacterias found within various mice. Their attention was quickly drawn to the mice that had lost most of their gut bacteria. It became apparent that in the mice with a very low amount of the bacteria within their gut, contained increased amounts of the “HDAC2 protein”.  When investigating deeper into HDAC2, it was found that increased amounts of this particular protein are associated with increased risk of colorectal cancer.

This new research also resulted in the finding that the amount of chemical markers on our genes, are increased by short fatty acids. These specific chemical gene markers, known as “crotonylations”, were only recently discovered and are newly classified as genome “epigenetic markers”. The researchers then found that by shutting down the HDAC2 protein, short chain fatty acids increase the number of crotonylations.

Ingestion of fruits and vegetables into ones healthy diet are vital – ultimately determining how chemicals produced by gut bacteria, affect genes in the cells of the gut lining. In other words, the short fatty acids, which come from those dietary elements, have the ability to move from bacteria into our own cells, and from there cause changes in gene activity and cell behavior.

In the end, the scientists were strongly convinced that the ability to turn off and on genes, is determined by changes in crotonylation. This inferred that the existence of crotonylation in the genome of cells is vital to protect the body from cancer. Therefore, the pretense of good bacteria is very important for the prevention of disease and illness in the body!

As someone with a strong passion for the science, and also very influenced and intrigued by medicine, I very much enjoyed this study. As the boundary to curing cancer is still a hurtle doctors and scientists try to transcend everyday, studies like these, are both hopeful and fascinating, to me. Also, as someone curious about how the human diet ultimately affects the functions and inner workings of the body, this research again was very engaging and interesting!

Primary Source Article: How good bacteria controls your genes

Secondary Source: Wikipedia – Gut Flora (Gut Bacterias)


Don’t be a victim of a pHatty diet!


Are you guilty of a pHatty diet?

What is the pH scale?

The human body can only function correctly with a pH level around 7.4. Foods such as fruits, vegetables, beans, and spices all can negatively contribute to poor health conditions because, due to their low pH levels, they are more acidic. If something is acidic, it is a substance that donates hydrogen ions; when an acid is dissolved in water, the balance between hydrogen ions and hydroxide ions is shifted and now there are more hydrogen ions than hydroxide ions in the solution. However if the substance is not acidic. it is considered a base. A base is is a substance that accepts hydrogen ions so when it is dissolved in water, the balance between hydrogen ions and hydroxide ions shifts the opposite way. Because the base “soaks up” hydrogen ions, there are more hydroxide ions than hydrogen ions. This kind of solution is alkaline.

pH Affects Health and Wellness

According to FoodandNutrition, because the kidneys and liver work to control the acidity levels but when big amounts of acidic food is consumed, it’s difficult for the body to accustom to the acidity which could be detrimental. It is important to understand that ” Lemon juice and tomatoes, for example, are acidic. But when ingested, they promote alkalinity. The pH of the actual food does not dictate the net effect on the body. Rather, it’s the “potential renal acid load” which measures acid in excretion/urine.

Even though there are parts of the body that can handle highly acidic materials, such as the stomach, it is important not to consume too much acid food because effects can be long term: : kidney stones, increased chance of cancer, liver problems and heart disease. A person is also at risk of acidosis which is a disease where your body fluids contain too much acid because the kidneys and liver are not functioning properly.  Symptoms of this are…

  • rapid and shallow breathing.
  • confusion.
  • fatigue.
  • headache.
  • sleepiness.
  • lack of appetite.
  • jaundice.
  • increased heart rate.

Here shows examples of liquids and where they fall on the pH scale. As you look down the scale, the liquids become more acidic but if you look up the scale, the liquids become less acidic.

What can you do?

To get away from a high acidic diet, you could try a plant-heavy diet with reduced refined sugar.  An example of a healthy meal with low levels of pH would be mushrooms, corn, beef and collard greens. It is really important to make sure you have a balanced diet, based on acidity, because the riscks are quite dangerous.


What do you think makes the human body not capable of consuming and maintaining large amounts of material with pH levels below 7.4?

Vegan diet found to have the best health benefits



Many people have recently been trying a gluten-free diet in an attempt to be healthier, or for other personal reasons. Gluten is the basic protein found in wheat, rye, barley, and triticale so those on that diet must avoid foods like bread, pasta, cereal, cake, essentially any carb. Carbohydrates seem to have a bad rep in our society and people often try very hard to keep them out of their diet. Some researchers even say that: “We’ve gotten somewhat carb-phobic here in the U.S. when it comes to weight loss”. 

A recent study led by researchers at the University of Southern California have found that a vegan diet even while consuming carbohydrates is best for “weight loss, decreased levels of saturated and unsaturated fat, lower BMI’s and improved macro nutrients.” This study showed that maybe people should be avoiding meat instead of carbs to improve their diet. While a vegan diet is not healthy for everyone, the study still introduced a new look on dieting and healthy eating.

The study randomly assigned one of five diets to several participants that were then followed for six months throughout the study. The five diets included vegan which bans all animal products, vegetarian which bans meat and seafood but allows animal products such as cheese and eggs, pesco-vegetarian which excludes all meat except seafood, semi-vegetarian with some meat intake, and omnivorous which excludes no foods. The participants were invited to weekly support groups throughout the study to make sure they followed their diet and also remained healthy.  At the end of the six months, the participants on the vegan diet lost more weight than the other groups by an average of 4.3%, or 16.5 lb. 

The leader of the study, Gabrielle Turner-McGrievy, was surprised by the outcome of the research. She thought the outcome of the pesco-diet would have been significantly higher than that of the meat-diet but it was not. The vegan diet was also high in carbohydrates. Turner-McGrievy was proud to say that “This study might help alleviate the fears of people who enjoy pasta, rice, and other grains but want to lose weight.”

I found this article to be very interesting because I have been following a pescetarian diet for about 11 months. I exclude meat in my diet but I still eat seafood and other animal products. My diet is also very high in carbohydrates because carbs are easy snacks. I am surprised yet pleased to see how little the effect of carb consumption had on the vegan diet.


Original Article:


Related Articles & Additional Information

Dieting: Where Did We Go Wrong?




Dieting is like Apple technology: the faster you discover the newest edition, it immediately becomes obsolete and a more efficient and useful model is hot on the market. However, unlike technology, an improper diet can cause long-term repercussions, such as disease and obesity. But, with so many different diets and foods available to us, how do we know which one to try?




In the September 2011 Special Nutrition Issue of Time Magazine, Dr. Oz cuts through all the food hype by comparing and contrasting food choices, diets and other crazy ways American people try to lose weight. Stating the classic phrase, “everything in moderation,”  Dr. Oz takes us through a journey beginning in a time before manufacturers learned that putting the words “fat free” on the side of a cookie box could make them into billionaires and where all natural was the way to go. Dr. Oz explains that whole milk, salt, fat, nuts, wine, chocolate and coffee are the way to go to lose weight and live longer. Right now, I bet you are all thinking the same thing I did when I began reading this article: we have been taught to shun foods that are high in fat, calories, sodium and cholesterol, so how can these foods possibly be good for you? Well, let’s break these delicious foods down while remembering that overindulging in them can be as problematic as you’ve always been led to believe!




Before reading further, just think to yourself, “Have I ever not ordered, made or ate something, no matter how healthy it is supposed to be, because it is known to contain a lot of fat?” Most likely, the answer is YES! I have too; it’s how our generation is being raised. We are scared of the lipid monster! However, fats are by no means universally bad. Monounsaturated and polyunsaturated fats (mono meaning one, poly meaning many, and unsaturated referring to the fact that the carbon backbone is double bonded, making it so less hydrogen molecules bond with the lipid) are actually recommended for good health. Dr. Oz gives specific examples, such as canola oil and olive oil, which have been found to lower LDL cholesterol (the bad cholesterol) and raise HDL cholesterol (the good kind), thus reducing the risk of atherosclerosis and heart disease. The fats we should be watching out for are saturated fats (found in animal products) and trans fats (found in hydrogenated products such as peanut butter). Don’t let this scare you, for even this general grouping can be misleading due to recent findings that some saturated fats may actually be good for you and that dietary cholesterol may not affect blood cholesterol as much as past generations thought.


Now, about the egg…


I have grown up eating strictly egg whites because high cholesterol runs in my family. Even when I was little and my parents would take us out to breakfast, egg whites were my go-to food. But, Dr. Oz, a practicing heart surgeon, explains that most physicians recommend one egg with the yolk per day as an “inexpensive source of high-quality protein” .  So, parents, as well as children, let’s try to stop criticizing and breaking apart the most wholesome animal product available to mankind and enjoy every last bit of it!

A healthy breakfast option!




Don’t dial that number quite yet! Salt is another example of a demonized compound. Repeating his opening statement about moderation, Dr. Oz does point out that too much sodium can increase blood pressure to dangerous levels, increase our appetite (causing us to gain weight), and overindulgence can cause us to lose five years of our lives. But, our hearts cannot, and will not, beat without it! Just remember that a little sodium goes a long way and everything will be a-okay!


A new and true fad that has come around recently is the allowance of red wine and chocolate in our diets. Why the sudden change in heart? Well, Dr. Oz says that both red wine and chocolate are sources of antioxidants, which reduce the impact of bad cholesterol, which in turn reduces the risk of cardiovascular disease. But, it seems to be coffee in the lead for the number one antioxidant in the Western world and in some studies has been associated with lower incidences of dementia, Parkinson’s disease and Type 2 diabetes. So, that cup of coffee in the morning isn’t just waking you up, but also lowers your risk of disease.




Nowadays, there are programs that take large chunks or whole food groups out of our diets in order to lose weight (Atkins takes out all carbohydrates, the Grapefruit diet only allows grapefruit…). These fads do get dieters results, and fast ones too. But, Dr. Oz points out the ultimate issue: once you reach the weight or healthy place you want to maintain and stop whatever one-food-group diet you have been on, all the weight can and will come back. All those weeks of torturing yourself by not having a little bit of chocolate or a scoop of ice cream are worthless if the minute you decide to indulge all your hard work disappears. So, when dieting or when trying to create a healthier lifestyle, remember Dr. Oz’s motto: “The key in life is moderation.” With this advice, nothing can go wrong!

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