by Karen Foster
PreventDisease.com
Bacteria constitute one of the largest domains of microorganisms in the world. They were among the first life forms to appear on Earth and have been critical members of human metabolism since our existence. They are not our enemies. Managing bacteria and other microorganisms in the body, rather than just fighting them, may be lead to better health and a stronger immune system, according to a Penn State biologist.
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.
Normal fat absorption is dependent upon normal metabolism of bile salts and normal bile acid metabolism is, in turn, strongly influenced by intestinal bacteria. Altering bacterial growth in the digestive system alters interrelations between intestinal bacteria, bile acids, and ingested fats which can have significant physiological consequences.
Changing Microbes In The Gut Can Lead to Rapid Weight Loss
Regulation of intestinal dietary fat absorption is critical to maintaining energy balance. While intestinal microbiota clearly impact the host’s energy balance, their role in intestinal absorption and extraintestinal metabolism of dietary fat is less clear.
Research in Science Translational Medicine conducted in collaboration with scientists at Massachusetts General Hospital, has found that the gut microbes of mice undergo drastic changes following gastric bypass surgery.
“Simply by colonizing mice with the altered microbial community, the mice were able to maintain a lower body fat, and lose weight — about 20% as much as they would if they underwent surgery,” said Peter Turnbaugh, a Bauer Fellow at Harvard’s Faculty of Arts and Sciences (FAS) Center for Systems Biology.
“It may not be that we will have a magic pill that will work for everyone who’s slightly overweight,” he said. “But if we can, at a minimum, provide some alternative to gastric bypass surgery that produces similar effects, it would be a major advance.” The benefits of microbes are no longer debated by scientists. In some cases, attacking pathogens can harm the beneficial effects microbes have on immune system. For example, patients on antibiotics have an increased risk of contracting yeast infections and MRSA.
“Viewing everything currently considered immunity, including both resistance and tolerance, as aspects of a complex microbiome management system that mediates interactions with the sea of microbes that surround us, many of which are beneficial, can provide a much more positive outlook and different valuable perspectives,” Harvill said.
The system that includes bacteria and other microbes in the human body, or the microbiome, is much larger and more integrated into human health than most people suspect, according to Harvill.
“The human body has ten times more bacterial cells than human cells,” said Harvill. Adding to the complexity is the adaptive capacity of the human immune system. The immune system can develop antibodies against certain pathogens, which it can reuse when threatened by future attacks from the same pathogen.
Harvill, who described his alternative viewpoint in the latest issue of mBio, said that some researchers have not yet accepted this broader approach to the immune system.
“Among immunologists or microbiologists this is an alien concept,” said Harvill. “It’s not part of how we have historically looked at the immune system, but it’s a useful viewpoint.”
Other researchers who study plant and nonhuman biology are already starting to embrace the concept. For example, plant biologists are beginning to recognize that viruses can help plants resist drought and heat.
“Within nonhuman immunology, this is not an alien concept because they have seen many examples of beneficial relationships between the host and its microbial commensals,” Harvill said. Harvill said adopting this new perspective could be the first step toward new medical treatments.
“This new viewpoint suggests new experiments and results will published,” said Harvill. “And, hopefully, the concept becomes more and more mainstream as supporting evidence accumulates.”
Diverse Bacteria On Fresh Fruits and Vegetables
Fresh fruit and vegetables carry an abundance of bacteria on their surfaces and most do not cause disease. Scientists report that these surface bacteria vary depending on the type of produce and cultivation practices.
The results are published in the open access journal PLOS ONE by Jonathan Leff and Noah Fierer at the University of Colorado, Boulder.
The study focused on eleven produce types that are often consumed raw, and found that certain species like spinach, tomatoes and strawberries have similar surface bacteria, with the majority of these microbes belonging to one family. Fruit like apples, peaches and grapes have more variable surface bacterial communities from three or four different groups. The authors also found differences in surface bacteria between produce grown using different farming practices.
The authors suggest several factors that may contribute to the differences they observed, including farm locations, storage temperature or time, and transport conditions. These surface bacteria on produce can impact the rate at which food spoils, and may be the source of typical microbes on kitchen surfaces. Previous studies have shown that although such microbes don’t necessarily cause disease, they may still interact with, and perhaps inhibit the growth of disease-causing microbes. The results of this new research suggest that people may be exposed to substantially different bacteria depending on the types of produce they consume.
Read the full article here: http://preventdisease.com/news/13/032913_Bacteria-In-The-Body-Are-Your-Friends-Not-Enemies.shtml
Sources:
ajcn.nutrition.org
sciencedaily.com
ncbi.nlm.nih.gov
Karen Foster is a holistic nutritionist, avid blogger, with five kids and an active lifestyle that keeps her in pursuit of the healthiest path towards a life of balance.