How Imbalanced Digestive Bacteria Cause Obesity & Heart Disease
by Byron Richards, CCN
_http://www.wellnessresources.com/weight/articles/how_imbalanced_digestive_b
acteria_cause_obesity_heart_disease/_
(http://www.wellnessresources.com/weight/articles/how_imbalanced_digestive_bacteria_cause_obesity_heart_disease/)


Science now reveals that the foreign contents within your digestive tract
play a dramatic role in your energy level, metabolic function, body weight,
and cardiovascular health. While it is not the only causative factor
involved in obesity and the metabolic syndrome it is a significant contributing
factor for virtually any overweight person – especially someone who has
difficulty losing weight and keeping it off.


This past week the national media attempted to cover the breaking news
story that obesity was linked to the wrong type of bacteria in your stomach.
The inability of each station’s supposed health expert to properly explain
what the study meant is a testament to the poor training physicians have in
actually understanding how the human body functions. As soon as a story
isn’t involved with a surgery, diagnostic procedure, or drug to be given
they are at a loss.


The widely reported story was based on animal research performed at _Emory
University School of Medicine_
(http://www.wellnessresources.com/studies/entry/altered_gut_bacteria_associated_with_obesity) . Lead author, Matam
Vijay-Kumar, PhD, has been studying a mouse engineered to lack an important
gene signal that helps to recognize bacteria propelling themselves around,
Toll-like receptor 5 (TLR5). This one change causes the mouse to have an
excessive appetite (eating 10% more than normal), develop insulin resistance,
have high blood pressure, have elevated levels of cholesterol and
triglycerides, develop fatty liver disease, and become 20% heavier than normal
mice. In short, the mouse develops the condition known as metabolic syndrome
that is an epidemic in America. The mouse also tends to develop ulcerative
colitis and Crohn’s disease.


The researchers determined that it is the flora content, or microbiota of
the intestinal tract that is the source of the problem. Because the mouse
lacks TLR5 the wrong type of bacteria overgrow in the stomach.
Interestingly, when the researchers transferred the overgrown bacteria to normal mice
they also developed metabolic syndrome abnormalities. This overgrowth of
bacteria fueled obesity and it was found that the bacteria actually made the
mice have inappropriate food cravings. If food was restricted the mice
did not get fat but insulin resistance persisted, which of course leads to
type II diabetes.


While there are over a thousand different kinds of bacteria that naturally
live within your digestive tract, there are two main classes: Firmicutes
and Bacteroidetes. TLR5 mice have abnormal Firmicute populations causing
the problem.


“It has been assumed that the obesity epidemic in the developed world is
driven by an increasingly sedentary lifestyle and the abundance of low-cost
high-calorie foods,” says senior author Andrew Gewirtz, PhD, associate
professor of pathology and laboratory medicine at Emory University School of
Medicine. “However, our results suggest that excess caloric consumption is
not only a result of undisciplined eating but that intestinal bacteria
contribute to changes in appetite and metabolism.”


Earlier Research on Firmicutes and Bacteroidetes

The famous mouse that makes no leptin, the ob/ob mouse, eats endlessly and
becomes extremely obese. This mouse has a _50% reduction in
Bacteroidetes_
(http://www.wellnessresources.com/studies/entry/obesity_changes_gut_microbial_ecology) and a proportional increase in Firmicutes. This means that
the condition of obesity itself is causing there to be excess numbers of
Firmicutes.


Through a variety of experiments with genetically altered mice scientists
now believe that excessive populations of the wrong type of Firmicutes
activate enzymes that promote the storage of fat in fat cells (adipocytes).
This means that what is going on in your gut can have a direct impact on
where calories go in your body.


Firmicutes are gram positive bacteria, many of which are friendly and
essential to human digestion, such as Lactobacillus. On the other side of the
Firmicute coin are members in the Streptococcus and Clostridium families,
responsible for many infections.


What Does All This Mean to Your Health?

The short answer is plenty. A bit more explaining is required.

Also this past week _Chinese researchers_
(http://www.wellnessresources.com/studies/entry/the_gut_microbial_gene_frontier) released a report on 3.3
million microbial genes obtained from the fecal samples of 124 individuals
from Denmark and Spain. The gene set is 150 times larger than the entire
human genome. Over 99% of the genes are bacterial, indicating between 1,000
and 1,150 prevalent bacterial species. Each individual has at least 160
species, which are also largely shared. This is the first catalog of
organisms found in the human digestive tract.


In this preliminary work the researchers identified gene signals
associated with obesity and Crohn’s disease. “Apart from helping you digest, these
bacteria may also play a very important role in ... diseases like Crohn’s
disease, cancer, obesity,” said lead author Jun Wang, executive director of
the Beijing Genomics Institute.


Wang and colleagues in China are working on a similar 120-sample study in
Chinese hospitals. “There are four groups: obese diabetics, obese
non-diabetics, lean diabetics and lean non-diabetics. And we found some interesting
bugs related to each type of diabetes,” Wang said.


In other words, gene signals arising from populations of gut bacteria have
a direct interaction with human metabolism – a dramatic finding.


Another angle to this problem is that bacteria produce endotoxin from the
shedding of their cell wall called lipopolysaccharide (LPS). LPS is
commonly studied compound as it reliably induces inflammation. Researchers have
found that gut-derived bacterial LPS enters the bloodstream and directly
triggers _insulin resistance_
(http://www.wellnessresources.com/studies/entry/gut_bacterias_toxic_trigger_for_metabolic_problems) , especially
liver-related insulin resistance that is typically accompanies type II diabetes.
Furthermore, a chronic high-fat diet for four weeks raises LPS two-three
times normal levels. It is also documented in _obese women_
(http://www.wellnessresources.com/studies/entry/obesity_associated_with_increased_lps_toxicity)
that LPS activates inflammation that sets the stage for metabolic
disease.


Of great importance is the fact that LPS is another factor that _inhibits
leptin from entering your brain_
(http://www.wellnessresources.com/studies/entry/lps_toxicity_inhibits_leptin_entry_into_brain) correctly. LPS has
been shown to cause a rise in blood levels of leptin, meaning that it
directly induces leptin resistance. It also raises blood levels of
triglycerides, which are the main known cause of leptin resistance at the blood-brain
barrier.


It has been demonstrated in _overweight and obese children_
(http://www.wellnessresources.com/studies/entry/poor_digestive_flora_linked_to_obesity)
that a lack of friendly flora and an excess number of the Firmicute
Staphylococcus aureus are common findings.


Overweight women are known to have imbalanced microbiota with _excess
numbers of Firmicutes_
(http://www.wellnessresources.com/studies/entry/friendly_flora_is_important_for_weight_management) in the Clostridium and
Staphylococcus families. This problem is aggravated during pregnancy when the
mother’s immune system is down-regulated so as not to reject the fetus,
leading to excessive weight gain during pregnancy. Furthermore, the mother’s
microbiota pattern is typically passed to the child. Interestingly, women
given friendly flora probiotic supplements in the _first trimester of
pregnancy_ (http://www.wellnessresources.com/studies/entry/prob
iotics_pregnancy_and_obesity_reduction) had less abdominal fat 1 year after pregnancy.


Another study shows that the gram negative bacteria _H. pylori_
(http://www.wellnessresources.com/studies/entry/lactobacilli_helicobacter_pylori_and_im
munity) and stop it from producing the toxic LPS that interferes with
human metabolism.


Collectively, all of these studies show a clear path from the overgrowth
of the wrong digestive bacteria to the creation of leptin-resistant and
insulin-resistant obesity which eventually leads to higher risk for type II
diabetes and heart disease.


While killing Firmicutes with antibiotics does lessen the metabolic
problems of TLR5-lacking mice, that remedy in humans would be of no value as it
would encourage regrowth of equally bad if not worse Firmicutes, encourage
the overgrowth of another anti-metabolic population – Candida albicans, and
make the societal problem of antibiotic resistance and new superbugs even
worse than it already is.

Rather, it appears that natural remedies are the front line of defense
against this problem. This begins with diets that do not promote imbalanced
digestion; i.e., diets too high in fat, refined sugar, alcohol, and junk
food. Encouraging the growth of friendly flora with probiotic supplements
(acidophilus) and prebiotic supplements (various types of fiber) is another
very workable solution.


There are also many natural compounds known to kill inappropriate gram
positive bacteria in the digestive tract. Oregano oil, medium chain fatty
acids, bovine colostrum, and bovine lactoferrin are but a few examples of
nature’s toolbox. These all have significant advantages over antibiotics as
they do not breed germ resistance or disturb the good flora. While helping
to reduce the surplus population of unwanted bacteria they also reduce any
surplus population of Candida albicans – unlike antibiotic drugs that
encourage Candida albicans overgrowth.


It has always been important to your health to correct any type of
digestive problem – actually solving it and not just covering it over with
antacids that further induce the spreading of undesirable bacteria in your stomach
by reducing your front line of defense (stomach acid). Now we see that
improving your digestive tract can also have a significant impact on your
metabolism, weight management, and cardiovascular health.



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