There’s a lot of research focusing on the microbiome - the population of microorganisms that live on and inside of us. It’s becoming increasingly apparent that these bugs can influence everything from obesity to the effectiveness of cancer treatments. So rather than start an endless number of threads on the topic, I’ll try to concentrate whatever interesting finds I come across here.
NIH mouse study finds gut microorganisms may determine cancer treatment outcome
An intact population of microorganisms that derive food and benefit from other organisms living in the intestine is required for optimal response to cancer therapy, according to a mouse study by scientists at the National Cancer Institute (NCI), part of the National Institutes of Health, and their collaborators.
Gut Microbes Linked to Rheumatoid Arthritis
The researchers found that 75% of people with new-onset, untreated rheumatoid arthritis had the bacterium Prevotella copri in their intestinal microbiome. In comparison, it was present in 12% of people with chronic, treated rheumatoid arthritis, 38% of people with psoriatic arthritis, and 21% of those in the control group. Increased levels of P. copri correlated with reductions in several groups of beneficial microbes, such as Bacteroides . The researchers performed more complete DNA sequencing on a subset of samples and identified unique Prevotella genes that correlated with rheumatoid arthritis.P. copri in inflammation.
Declaring a Truce With Our Microbiological Frenemies
Researchers have historically focused on microbes in the body as primarily pathogens that must be fought, said Eric Harvill, professor of microbiology and infectious disease.
However, he said that recent evidence of the complex interaction of the body with microbes suggests a new interpretation of the relationship.
“Now we are beginning to understand that the immune system interacts with far more beneficial bacteria than pathogens,” said Harvill. “We need to re-envision what the true immune system really is.”
Harvill said that this reinterpretation leads to a more flexible approach to understanding how the immune system interacts with microbes. This approach should balance between defending against pathogens and enlisting the help of beneficial microbes.
While the role that some bacteria play in aiding digestion is better known, microbes assist in improving body functions, including strengthening the immune system and responding to injuries.
In some cases, attacking pathogens can harm the beneficial effects microbes have on immune system, according to Harvill. For example, patients on antibiotics have an increased risk of contracting yeast infections and MRSA.
After the Human Genome Project: The Human Microbiome Project
Earth Day may be more than a month away, but another, more personal, ecosystem has been shown to also be worth protecting – within our bodies are communities of microbes that affect the behavior of human cells hosting them. These communities, called the “microbiome,” is so crucial to our health that some consider it to be a complex “second genome.” Understanding the interaction of these microbes among one another and their human hosts has the potential to yield insights into numerous diseases and complex human disorders from obesity to susceptibility to infection.
In a new report appearing in the March 2013 issue of The FASEB Journal, scientists take an important step toward designing a uniform protocol for microbiome research that ensures proper controls and considerations for variations among people. By doing this, future researchers should be able to better assess how what we ingest, whether drugs or food, affects our bodies.
“While historically pre and probiotics have dominated the microbiome landscape, emerging data from numerous labs as to the impact of dietary interventions and antibiotic exposure will play formative roles in tailoring therapy,” said Kjersti M. Aagaard, M.D., Ph.D., from the Department of Obstetrics and Gynecology at Baylor College of Medicine in Houston, Texas. “We may find that the answers to our most common and prevalent health and disease states lies not in manipulating the human genome, but rather, in utilizing subtle shifts in diet and components of the diet, efficacy trials in prophylactic or preventative antibiotic therapies, and care attention to the over prescription of steroids and antibiotics.”
It looks like we might soon get the first pill targeted at the microbiome for treating disease:
Seres Health hopes to develop the first regulated, clinically approved bacteria-filled pill to treat diseases associated with disruptions to the microbes inside the human body. The company launched last month with $10.5 million in investments; its founders have been working on the bacteria pill for two years and say they’re already testing one candidate treatment in patients.
A new understanding of the microbiome—the collection of microbes inhabiting a body—has led a wave of companies, from startups to large pharmaceutical companies, to look at bacteria as a new area of focus. While some companies plan to develop drugs to “reset” the microbiomes of sick people, Seres is one of a few planning to use live bacteria to do the same job.
In recent years, large-scale studies by the National Institutes of Health and others have shown that the healthy human body is home to 10,000 or so species of microbes—outnumbering human cells 10 to one (see “Researchers Catalogue Your Microbial Zoo ”). At the same time, medical researchers have shown that the microbiome can affect health, and that swapping bacteria can cure gastrointestinal infections and potentially treat conditions such as inflammation and obesity (see “Transplanting Gut Microbes to Treat Disease ”). Bacteria have even been shown to protect against diabetes in mice (see “Transplanted Gut Bugs Protect Mice from Diabetes ”).
Decreased diversity of bacteria microbiome in the gut is associated with risk of colorectal cancer
Decreased diversity in the microbial community found in the human gut is associated with colorectal cancer, according to a new study published December 6 in the Journal of the National Cancer Institute .
Previous studies suggest a role for the gut microbiota in colorectal cancer (CRC), but comprehensive epidemiological studies comparing samples from case and control subjects that also consider potential confounders and adjust for multiple comparisons inherently involved in microbiome analysis have not been reported.
