In "The Big Lie of Obesity" I showed weight gain was not from laziness or indulgence, but from your body reacting to stressors. In response to stress, your body will store food to prepare for famine, thus causing weight gain. Some stressors are obvious, but many are as silent and invisible as the bacteria in our intestines.
In a startling study, Dr. Gewirtz at Cornell University showed that the weight of mice could be changed by over 15 percent just by shifting their intestinal bacteria. Along with weight changes, the bacteria present changed the mice's chemistry in ways that could predict heart disease, high blood pressure and risks for diabetes. Related work has shown this same link also exists in humans. In fact, transplanting bacteria from the intestinal tracts of obese humans has been shown to trigger obesity in normal-weight mice.
How can bacteria cause weight gain, and how can you make sure your bacteria do not?
First it is important to realize that 99 percent of our intestinal bacteria are unable to use oxygen. These are called anaerobes. This is important because all the foods with bacteria (like sauerkraut and yogurt), as well as all probiotic pills, only contain bacteria that live in oxygen. They have little or no effect on the anaerobes that run the show.
Of the many types of anaerobes, the two that have gained the most attention related to obesity are the Bacteroidetes and Firmicutes. Most studies have shown that the more Bacteroidetes you have compared to your Firmicutes, the leaner you will be. So, if you want to be firm and cute, you want fewer Firmicutes and more Bacteroidetes.
The reason these bacteria affect our weight is because they regulate how much fat we absorb. Imagine two identical twins eating exactly 2,000 calories, but they have different ratios of Bacteroidetes to Firmicutes. One will absorb more calories than the other and be more apt to gain weight on the exact same food.
In light of the growing rates of obesity, what would cause these bacteria to shift in ways that would lead to weight gain?
Over the course of the last few decades, we now:
• Use more antimicrobial soaps and hand sanitizers.
• Are exposed to more environmental pollutants.
• Live under higher amounts of stress.
The antimicrobial soaps and hand sanitizers are problems because they kill good bacteria as well as bad ones. Environmental pollutants are toxic to good bacteria just as they are to us. The last one may not seem to fit. How could stress affect bacteria? Mental/emotional stress starts with the release of adrenal stress hormones, like cortisol and adrenaline. These stress hormones act on the brain and stimulate the vagus nerve. The connection between your brain and your intestines is this same vagus nerve that is involved with stress. Stress reduces the blood supply needed to properly digest foods and manage the balance of bacteria. This tie between your brain and intestines is a two-way street. Stress hurts your digestion, and poor digestion makes you feel more stressed. When this vicious cycle gets rolling, your Bacteroidetes are reduced, and you gain weight more easily.
What can you do to help yourself?
Even though many things that are hard to avoid (like stress) hurt your bacterial ratios, and probiotics do not help, here are some things you can do:
1. Eat a high-fiber diet with good carbs. Because Firmicutes are needed to absorb fats, higher fat diets cause you to have more of them, leading to weight gain.
2. Avoid sugars and processed carbs. Firmicutes are so well-suited to grow on sugars that they're known to grow rampantly in factories that process sugar-cane into table sugar.
3. Raise your intake of beans since they are among the very best foods to raise your Bacteroidetes. What if you cannot digest beans? Along with being a nuisance, that symptom can be a strong sign you have too few Bacteroidetes. Rather than avoid them completely, studies have shown that if you add beans into your diet slowly, and stick with them, the symptoms will go away. To train your bacteria to digest beans well, I encourage you to add just 1 tablespoon of pinto beans daily to the evening meal for two weeks. After two weeks, most people are able to digest more typical amounts.
4. Sleep and eat on regular schedules. Cutting-edge data have shown that our intestinal bacteria have a rhythm that changes throughout the day just like our sleep-wake cycle. Shift work, jet lag and erratic meal times can hurt our good bacteria just like antibiotics can.
The old idea of health was that it was the result of strenuous effort and deprivation. Not only was that not fun, it did not work. The new revolution is that being healthy, lean and energized is a product of being at peace and in sync with the world around you.