By now, virtually everyone has heard of probiotics, the beneficial bacteria that you can get from yogurt and other fermented foods—or from the many probiotic supplements that are now widely available.
Probiotics can, of course, ease the diarrhea that may occur when taking antibiotics, which kill both “bad” and “good” bacteria. They can also help digestive problems unrelated to antibiotics, such as bloating, gas and constipation. But that doesn’t scratch the surface of what probiotics can do.
What’s new: Researchers are now finding that the bacterial populations in the intestine, known as gut microbiome or intestinal flora, can profoundly affect weight gain. Here’s what you need to know about gut bacteria and weight gain…
Ideally, the bacteria that inhabit the intestine are in equilibrium—with a preponderance of beneficial organisms that keep the harmful bugs in check. But if you’re overweight, there is a good chance that you have a bacterial imbalance of the digestive tract, known as dysbiosis.
This is caused in part by the overuse of antibiotics, both from the medicine we take and from the drugs that are given to farm animals and later end up in our food supply. On top of that, about 13% of calories in the average diet now come from added sugar (including refined cane sugar and honey)—and harmful bacteria love sugar.
Important recent finding: People who are overweight or obese tend to have larger populations of Firmicutes, organisms known as “fat bugs” because they are involved in weight gain. Lean people, on the other hand, have larger populations of Bifidobacteria, beneficial organisms that fight the inflammatory intestinal environment that triggers weight gain.
The traditional American diet—heavy on inflammation-promoting processed foods with not nearly enough anti-inflammatory plant foods—seems to promote the production of fat-forming Firmicutes.
Research shows that adopting a Mediterranean-style diet (see below for more on this) is the best way to maintain a healthier bacterial balance. But other steps can also be taken to achieve a better balance of bacteria.
There’s only preliminary evidence that probiotic supplements prevent weight gain or help with weight loss. What you need are probiotic fermented foods that have live bacteria and prebiotic foods that supply the raw ingredients that feed the beneficial bacteria.
Research in Belgium shows that people who get as little as 16 g (less than one ounce) of prebiotic foods daily can shift their microbial balance…reduce their appetite…experience greater degrees of fullness after eating…and have a reduced body mass. Even if you’re not concerned about weight gain, prebiotic foods feed the intestinal flora. This helps strengthen gut health, which can increase immunity.
Gut-balancing foods worth trying…
• Fermented milk. Fermented products (such as yogurt, kefir and buttermilk) create an intestinal environment that promotes the production of beneficial bacteria. Plus, these foods are rich in Lactobacillus gasseri, a microbe that reduces subcutaneous (under the skin) and visceral (around the organs) fat.
Studies have shown that people who eat at least three servings of yogurt a week tend to have decreased hunger and a lower waist-to-hip circumference as well as improvements in blood lipids and better preservation of muscle mass.
Helpful: I recommend White Mountain Bulgarian yogurt, available at WhiteMountainFoods.com.
• Kimchi, a Korean side dish that’s a potent prebiotic. It’s made of pickled cabbage and spices and also contains kochukaru, crushed red chili pepper, which has fat-burning effects. It’s best to have kimchi (available in Asian markets and online) at least three to four times a week.
• Berries. All types of berries, including blueberries, strawberries and raspberries, have been linked to weight loss. Why? Because beneficial bacteria love them. People who eat berries tend to accumulate less fat and have an improved insulin response—important in preventing diabetes. I recommend having two ounces of berries three or more times a week.
• Green tea. Two to three cups of green tea daily are enough to support the growth of fat-burning bacteria. When researchers analyzed the results of 15 previous studies, they concluded that green tea with caffeine is associated with weight loss, reduced waist circumference and a lower body mass index.
• Cinnamon. This all-around great spice lowers blood sugar after meals and delays the time that it takes the stomach to empty—crucial for feeling full after eating.
It’s best to use Ceylon cinnamon, which can be found in specialty stores, rather than the more common cassia cinnamon found in supermarkets. Ceylon cinnamon is more potent. Sprinkle about one-quarter teaspoon in your morning coffee or on cereal or yogurt daily.
• Asparagus. It contains the prebiotic inulin, which increases populations of Bifidobacteria, Lactobacillus and other beneficial bacteria. Asparagus is one of the few foods (beside cruciferous vegetables) that provides a lot of glutathione, an antioxidant that reduces inflammation-related weight gain. Eat asparagus once or twice weekly.
A Mediterranean-style diet has been shown to greatly reduce the risk for heart disease, diabetes and other chronic diseases.
More recently, scientists have discovered that the same style of eating—lots of fish, olive oil, whole grains, fresh fruits and vegetables and modest amounts of wine—is probably ideal for the microbiome, the bacterial populations in the body.
Recent finding: A study of overweight and obese men and women found that those who ate a Mediterranean-type diet for just two weeks had an increase in microbial diversity, along with impressive 13% average reductions in triglycerides and LDL “bad” cholesterol.
