Obesity and Diabetes – Is Your Gut in Control?

Aug. 21, 2015

By Medical Discovery News

Your body is like a forest, providing a home to microscopic flora and fauna. In fact, your body is home to up to 100 times more microbes than your own cells, which make up your microbiome. While we provide them residence, these microbes help us out by providing a first line of defense against disease trying to invade our bodies, even breaking down food during digestion and producing vitamins. Now, the microbes that live in the digestive tract are helping us understand diabetes better.

According to the Human Microbiome Project sponsored by the National Institutes of Health, the microbiome plays a huge role in human health. When the microbiome is altered or imbalanced, it can cause conditions like obesity, irritable bowel syndrome, skin disease, urogenital infection, allergy, and can even affect emotion and behavior.

Recently, scientists from Israel discovered another surprising effect of the microbiome while investigating the use of artificial sweeteners in relation to glucose intolerance and diabetes. Artificial sweeteners such as saccharin, sucralose, and aspartame are commonly used in weight loss strategies because they do not add calories while still satisfying sweet cravings. However, artificial sweeteners are not always effective in managing weight and glucose, and scientists at the Weizmann Institute of Science may have figured out why.

Through experimentation they observed that adding artificial sweeteners to the diets of mice caused significant metabolic changes, including increasing blood sugar levels more than mice fed regular sugar. It didn’t matter whether the mouse was obese or at a normal weight, they all reacted the same. Dietary changes can alter the populations of bacteria in our guts, so the study addressed whether those changes affected blood glucose levels as well. After being treated with saccharin for nine days, the populations of gut bacteria in the mice shifted dramatically and corresponded with an increase in their glycemic index. Specifically, the bacterial group Bacteroidetes increased while the group Clostridiales decreased. These changes in bacterial populations is associated with obesity in mice and people.

When they administered antibiotics to reverse this and return the bacterial populations to a healthy state, it also countered the effects of saccharin, returning glucose levels to normal. To take it a step further, researchers took feces from saccharin-consuming mice showing glucose intolerance and transplanted them into other mice that had never consumed saccharin. Remarkably, those mice started showing signs of glucose intolerance.

In a study of 400 people, those who consumed artificial sweeteners had a gut microbiome that was vastly different from those who did not. They had a group of people consume high levels of artificial sweeteners for seven days, and like the rats their glucose levels increased and their microbiomes changed.

Overall, these studies show that artificial sweeteners may induce glucose intolerance instead of preventing it due to the intimate connection between the bacteria that live in our digestive systems and our metabolic state. In the future, expect to see diagnostic and therapeutic procedures that utilize our microbial friends.

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The Irresistible Rise of Genomic Medicine

Feb. 6, 2015

By Medical Discovery News


It’s only been 150 years since scientists discovered what we now call DNA. Today, it’s a household word, the basis for the field genomics, and an integral part to multitudes of scientific studies. It’s remarkable how relatively quickly our understanding of genes has progressed.

DNA was first thought to represent the genetic material of living organisms in the 1940s. Doctors Francis Crick and James Watson revealed the double helix structure of DNA in 1953, which is widely considered to be the first revolution in modern biology. In 1977, we first decoded the entire genome of a living organism, a tiny virus that infects bacteria called ФX174. This was the first time we understood all the DNA required to produce a life form. The term genomics was first coined in 1987 to describe the structure and functions of an organism’s entire genetic blueprint.  In 1995, we determined the genome of a free-living organism, a bacterium called Haemophilus influenza, for the first time. The genome of a eukaryotic organism, Baker’s yeast, was first completed in 1996. These early studies provided the novel approaches and advanced technologies that were later used to sequence the human genome, which consists of 3 billion base pairs. The human genome project, the second revolution in modern biology, began in 1990, and was completed in 2003. Since then, the genomes of more than 4,000 other organisms, including the ancient human species Neanderthal and the coffee plant, have been completely determined.

Genomics continues to be a part of the third revolution, convergence, which merges the rigors of computational science and engineering with modern biology. It cost $1 billion and took eight years to complete the sequence of the first human genome. Now, the cost of sequencing a human genome is a fraction of that at $2,000-$4,000 and takes a mere 1-3 days to complete. More than 2,500 human genomes have been sequenced from 26 distinct populations, and 100 million genetic variations have been discovered from these human samples so far. These variations are part of what make us each unique as people, but they can also reveal why we might be experiencing or have susceptibility to disease.

This is where genomic medicine comes in. Dr. Eric Green, the director of the National Human Genome Research Institute at the National Institutes of Health, says there are multiple studies with great promise in this emerging field. For example, cancer genomics has been used to determine the DNA sequence of tumor cells, which can help identify the type of cancer cells in a tumor and the cause of the cancer. That information can then be used to direct the type of treatment that would be the most effective for each individual, creating a personalized approach to medicine. A person’s DNA sequence may also disclose what pharmaceuticals will work most effectively.

The human genome project advanced our understanding of genetics and heredity. Much research is now focused on genomes and their relation to disease. More recently, scientists are using this newfound knowledge to further the science of medicine.

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Putting Your Bacteria to Work

April 4, 2014

By Medical Discovery News

A biotech startup company called uBiome has adopted the concept of crowd sourcing, using the Internet to rally people around a cause, for research on the human microbiome. The microbiome is all the microscopic flora and fauna that live in and on the human body. Humans have 10 times as many bacterial cells as human cells. But science is just beginning to understand the populations of the microbiome and how they affect a person’s health for good or bad.

What science already knows about the microbiome comes from the $173 million government-funded Human Microbiome Project (HMP). This project took five years and collected and sequenced the microbiome of 250 healthy people. It proved there are at least 1,000 different types of bacteria present on every person. The National Institutes of Health (NIH) has made the four terabytes of data from this project available to all researchers via the Microbiome Cloud Project.

Different anatomical sites of the body have different microbial populations. Additionally, the microbial populations that inhabit our bodies vary from person to person, but are very stable within an individual. Each person has their own distinct microbial signature that is unique to them. Most of these microbial species are actually helpful and protect against invading microbes that can cause disease. Some, like certain E. coli in the gut, actually produce essential vitamins that keep us healthy. Alterations in the human microbiome have been associated with diseases like autism, obesity, irritable bowel syndrome, and asthma. In some cases, correcting microbial populations associated with disease states may cure or help manage the disease.

A startup company called uMicrobiome is looking to sequence the microbiomes of at least 1,000 more people from all over the world, and they are trying to find volunteers using crowd sourcing. Anyone interested can go to the company’s Web site (ubiome.com), make a pledge, and request a sampling kit, which contains a swab for gently brushing areas of the ears, mouth, genitalia, or gastrointestinal tract. The swabs are placed into a solution that preserves and stabilizes the bacteria for transport back to the lab.

uMicrobiome examines samples for their 16S RNA sequences. These sequences are present in all microbes, but part of the sequence is unique to each different bacterium. This technology of DNA sequencing can determine the different types of bacteria present and their proportions in each sample.

The company puts the results on their Web site for individuals to access and analyze their microbiome. There are also software tools to help users interpret what they are seeing. uMicrobiome secures the data so that it cannot released in an identifiable form. A person can choose to share their data with other citizen scientists for scientific studies or compare their microbiome to others’.

So science to the citizens has arrived! Anyone can learn about their own microbial world and advance this field of science as well. 

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