The good news is that you can reset your gut bacteria, swapping bad flora for good.STORY HIGHLIGHTSY...

1. Bacteria in your gut: 4 healthy habits
The good news is that you can reset your gut bacteria, swapping bad flora for good.
STORY HIGHLIGHTS
Your digestive system is home to 70 to 80% of your immune cells
Bad gut bacteria can cause gas, discomfort, bloating and inflammation
Some gut bacteria might even make you fat
(CNN) -- They are terms previously not part of polite conversation -- let alone TV commercials:
Intestinal distress. Irregularity. Irritable bowel syndrome.
Where food goes after it's eaten, however, has become a hot topic. Indeed, emerging research is
linking the health of the gut -- the entire digestive system, particularly the stomach, intestines and
colon -- to general wellness.
"New data shows that the gut is critical to our well-being," says Dr. Mark Liponis, medical director
of the Canyon Ranch health resorts.
Essentially, the gut is your body's gatekeeper, letting in helpful compounds and evicting harmful
ones. It's home to 70 to 80% of our immune cells. When the gut is in good shape, our systems run
efficiently, but when it's not, we may experience upset stomach, be at risk for weight gain or
digestive problems like heartburn and constipation, or just feel vaguely out of sorts.
For many people, that run-down feeling has lasted so long that it's mistaken for the norm, says New
York cardiologist Alejandro Junger, author of "Clean Gut."
"We could feel so much better -- we just don't know it."
The bacteria that rule your body
The gut is swarming with about 100 trillion bacteria, or flora, which outnumber human cells in our
body 10 to 1. Bacteria are often considered "good" or "bad."
"These bacteria and the compounds they excrete can have positive and negative effects on a
person's health," says Dr. Stanley Hazen, chair of cellular and molecular medicine at the Cleveland
Clinic. "To have a healthy gut, one must avoid eating foods that foster the growth of bacteria that
create unhealthy metabolites."
Martha Stewart: How to drink more water, delightfully
Friendly bacteria aid the metabolism of nutrients and help certain compounds get into the
bloodstream. A diverse population of health-promoting flora protects the gut from the less helpful
strains.

2. In contrast, an outsize number of less-beneficial flora -- which proliferate with a diet high in sugar,
fat, and processed food -- can cause gas, discomfort, bloating and inflammation. The flora can also
emit chemicals that compromise the intestinal lining, says Lita Proctor, of the Human Microbiome
Project at the National Institutes of Health.
"This so-called 'leaky gut' allows nonnutritive materials to slip into our bodies and affect how we
feel."
Incredibly, some bacteria might even make you fat: A recent study of twins, published in "Nature,"
found that when bacteria from an obese human twin were introduced into the digestive systems of
lean mice, the mice turned fat; when bacteria from the thin sibling were introduced into lean mice,
the mice stayed lean. Studies also suggest that diabetic and obese patients tend to lack a diversity of
bacteria, and the Cleveland Clinic found that some bacteria metabolize components of egg and meat
to produce a compound that aids in the clogging of arteries.
"This might explain why some unhealthy eaters get heart disease while others don't," says Hazen.
The good news is that you can reset your gut bacteria, swapping bad flora for good.
"Get the right type in your gut and, depending on your condition, you may begin to see
improvements in a matter of days or weeks," says Edmond Huang, a metabolic biologist at the
University of California, Berkeley.
Martha Stewart: Garden-to-table recipes
To cultivate healthful microflora, you want to nourish the desirable species while killing off the bad.
Beware of antibiotics, however, which decimate the flora keeping our bodies healthy along with
those causing illness and infection.
"Every course of antibiotics has a chance for such complications as yeast infections, skin rashes, and
allergic reactions," says Liponis.
Use these drugs only when needed, and always supplement with probiotics to repopulate the
healthful flora.
Choose food-based probiotics first
Probiotics -- the good bacteria in fermented foods and supplements -- bolster the number of friendly
bacteria in the gut. For relatively healthy people, it's always a good idea to start with real food
before taking supplements.
Bifidobacteria, found in most yogurt, release chemicals that create an acidic environment in which
many harmful bacteria can't thrive. And yogurt with the common strain Lactobacillus rhamnosus
may improve your mood: A 2013 study published in "Gastroenterology" found that when healthy
women ate 125 grams of yogurt twice daily for four weeks, their brain scans showed a less intense
response when exposed to negative images.
Eat plenty of prebiotics
You can nourish healthful flora with prebiotics, which contain nondigestible carbohydrates -- found
in whole grains, onions, garlic, leeks, artichokes, asparagus, and chicory root.

3. Regular intake has been associated with decreases in irritable bowel syndrome and fat storage (and
may reduce allergic reactions like skin rashes) -- as well as an increase in an overall feeling of well-
being, according to a 2010 issue of the "British Journal of Nutrition."
Martha Stewart: 30 healthy, tasty snacks
Avoid fatty foods
According to studies done in mice, dietary fats can damage the gut lining, thus allowing the
undesirable chemicals released by certain bacteria to leak into the bloodstream and inflame the
tissues surrounding it.
What's more, some fats "raise the population of unfriendly bacteria," says Rob Knight, a professor of
chemistry and biochemistry at the University of Colorado, Boulder.
Martha Stewart: Curb your food cravings with yoga
Control your stress
Stress may change the makeup of your gut flora. A 2011 "Brain, Behavior, and Immunity" study
reported that stressed-out mice (which had been left in a cage with aggressive mice!) experienced a
plunge in beneficial bacteria and an increase in inflammatory chemicals in the blood serum.
Stress "alters the functioning of the immune system -- either by suppressing or enhancing its
response to foreign invaders," says Ohio State University associate professor of oral biology Michael
Bailey, the paper's author.
For the good of your gut -- and health -- figure out why you're anxious, and take measures to
eliminate those stressors.