By Dr. Mercola
Recent studies have repeatedly demonstrated that the makeup of your intestinal flora can have an impact on your weight, and your propensity to gain or lose weight.
Most recently, research1 also suggests that as much as 20 percent of the substantial weight loss achieved from gastric bypass, a popular weight loss surgery, is actually due to shifts in the balance of bacteria in your digestive tract. According to co-author Dr. Lee M. Kaplan:2
“The findings mean that eventually, treatments that adjust the microbe levels, or 'microbiota,' in the gut may be developed to help people lose weight without surgery.”
Gut Microbes May Be Behind Weight Loss After Gastric Bypass
To investigate the potential link between gastric bypass surgery and alterations in gut flora, fattened-up mice were divided into two groups. The test group underwent gastric bypass surgery while the control group received sham surgery. After the sham surgery, the controls were further divided into two groups: One received a fatty diet; the other a weight-loss diet.
In the test group, the microbial populations quickly changed following surgery, and the mice lost weight. In the control group, the gut flora didn’t change much, regardless of their diet. After the bypass surgery, the test group was found to have more of certain types of microbes,3 including:
- Gammaproteobacteria, particularly Escherichia species, which can help prevent inflammation and maintain intestinal health, although some species of Escherichia are pathogenic
- Akkermansia bacteria, which can feed on mucus found in your intestines
According to the featured article:4
“Next, the researchers transferred intestinal contents from each of the groups into other mice, which lacked their own intestinal bacteria. The animals that received material from the bypass mice rapidly lost weight; stool from mice that had the sham operations had no effect.”
More Research Shows Your Gut Bacteria Impacts Your Weight
Previous research has also shown that lean people tend to have higher amounts of various healthy bacteria compared to obese people. For example, one 2011 study5 found that daily intake of a specific form of lactic acid bacteria could help prevent obesity and reduce low-level inflammation.
In this study, rats given the bacterium while in utero through adulthood put on significantly less weight than the control group, even though both groups of rats ate a similar high-calorie diet. They also had lower levels of minor inflammation, which has been associated with obesity.
Similarly, gut bacteria have also been shown to impact weight in human babies. One study6 found babies with high numbers of bifidobacteria and low numbers of Staphylococcus aureus -- which may cause low-grade inflammation in your body, contributing to obesity -- appeared to be protected from excess weight gain.
This may be one reason why breast-fed babies have a lower risk of obesity, as bifidobacteria flourish in the gut of breast-fed babies. Probiotics also appear beneficial in helping women lose weight after childbirth when taken from the first trimester through breastfeeding.
Two other studies found that obese individuals had about 20 percent more of a family of bacteria known as firmicutes, and almost 90 percent less of a bacteria called bacteroidetes than lean people. Firmicutes help your body to extract calories from complex sugars and deposit those calories in fat. When these microbes were transplanted into normal-weight mice, those mice started to gain twice as much fat. This is one explanation for how the microflora in your gut may affect your weight.
Yet another study from 20107 showed that obese people were able to reduce their abdominal fat by nearly five percent, and their subcutaneous fat by over three percent, just by drinking a probiotic-rich fermented milk beverage for 12 weeks. Given that the control group experienced no significant fat reductions at all during the study period, this is one more gold star for probiotics.
Probiotics have also been found to benefit metabolic syndrome, which often goes hand-in-hand with obesity. This makes sense since both are caused by a diet high in sugars, which leads to insulin resistance, fuels the growth of unhealthy bacteria, and packs on excess weight.
Diet and Environmental Factors Affect Your Gut Flora
I have long stated that it's generally a wise choice to "reseed" your body with good bacteria from time to time by taking a high-quality probiotic supplement or eating non-pasteurized, traditionally fermented foods such as:
- Fermented vegetables
- Lassi (an Indian yoghurt drink, traditionally enjoyed before dinner)
- Fermented milk, such as kefir
- Natto (fermented soy)
One of the reasons why fermented foods are so beneficial is because they contain lactic acid bacteria, which of course has health benefits over and beyond any weight-loss benefits, as well as a wide variety of other beneficial bacteria. Ideally, you want to eat a variety of fermented foods to maximize the variety of bacteria. But eating fermented foods may not be enough if the rest of your diet is really poor. Your gut bacteria are an active and integrated part of your body, and as such are vulnerable to your lifestyle. If you eat a lot of processed foods, for instance, your gut bacteria are going to be compromised because processed foods in general will destroy healthy microflora and feed bad bacteria and yeast. Your gut bacteria are also very sensitive to:
- Chlorinated water
- Antibacterial soap
- Agricultural chemicals
The Hidden Health Hazards of Antibiotics in Meat
A related news story highlights one hidden source of antibiotics that can have a significant and long-term impact on your gut flora and overall health. Writing for the New York Times,8 David A. Kessler, former commissioner of the Food and Drug Administration (FDA) from 1990 to 1997, warns that antibiotic-resistant pathogens in livestock are on the rise as a result of the fact that, in the US, antibiotics are routinely fed to livestock not only to fight infection, but to promote unhealthy (though profitable) weight gain.
“While the F.D.A. can see what kinds of antibiotic-resistant bacteria are coming out of livestock facilities, the agency doesn’t know enough about the antibiotics that are being fed to these animals,” he writes. “This is a major public health problem, because giving healthy livestock these drugs breeds superbugs that can infect people. We need to know more about the use of antibiotics in the production of our meat and poultry. The results could be a matter of life and death. ... It may sound counterintuitive, but feeding antibiotics to livestock at low levels may do the most harm.
When he accepted the Nobel Prize in 1945 for his discovery of penicillin, Alexander Fleming warned that 'there is the danger that the ignorant man may easily underdose himself and by exposing his microbes to nonlethal quantities of the drug make them resistant.' He probably could not have imagined that, one day, we would be doing this to billions of animals in factory-like facilities.”
The link between antibiotic use in livestock and antibiotic-resistant disease is so clear that the use of antibiotics as growth promoters in animal feed has been banned in Europe since 2006.9 In sharp contrast, according to the first-ever report by the FDA10 on the topic, confined animal feeding operations (CAFOs) used a whopping 29 million pounds of antibiotics in 2009, and according to Kessler, that number had further risen to nearly 30 million pounds in 2011, which represents about 80 percent of all reported antibiotic sales that year.
What’s more, on December 22, 2011, the FDA quietly posted a notice in the Federal Register11 that it was effectively reneging on its plan to reduce the use of antibiotics in agricultural animal feed – a plan it has been touting since 1977.
Instead, the agency decided it will continue to allow livestock producers to use the drugs in feed unabated. Only one class of antibiotics, cephalosporin, has been restricted from use in livestock.12 This class of antibiotics, which are regularly prescribed to humans, are implicated in the development and spread of drug-resistant bacteria among humans that work with, and/or eat, the animals. As of April 5, 2012, the antibiotics are no longer be allowed for use in preventing diseases in livestock, although they are still allowed for treatment of illness in livestock.
The Food and Drug Industries Don’t Want You to Know the Facts
As stated by Kessler, we have more than enough evidence that using antibiotics as growth promoters is threatening human health. Yet the drug and food industries are doing everything they can to block proposed legislation that would limit this practice, and both the FDA and the Senate Committee on Health, Education, Labor and Pensions aid and abet them. For example, the Committee took no action on a proposal from Senators Kirsten E. Gillibrand (D-NY) and Dianne Feinstein (D-CA), which would require the FDA to report data on agricultural antibiotics that it already collects but does not disclose. According to Kessler:
“'In the House, Representatives Henry A. Waxman of California and Louise M. Slaughter of New York, also Democrats, have introduced a more comprehensive measure. It would not only authorize the FDA to collect more detailed data from drug companies, but would also require food producers to disclose how often they fed antibiotics to animals at low levels to make them grow faster and to offset poor conditions.
This information would be particularly valuable to the F.D.A., which asked drugmakers last April to voluntarily stop selling antibiotics for these purposes. The agency has said it would mandate such action if those practices persisted, but it has no data to determine whether the voluntary policy is working. The House bill would remedy this situation, though there are no Republican sponsors.' ...Lawmakers must let the public know how the drugs they need to stay well are being used to produce cheaper meat.”
How to Avoid Hidden Antibiotics in Your Food
This is one of the many reasons why I always recommend buying your meat, whether beef or poultry, from a local organic farmer rather than your local supermarket. The only way to avoid this hidden source of antibiotics is to make sure you’re only buying organic, grass-fed, free-range meats and organic pasture-raised chickens, as non-medical use of antibiotics is not permitted in organic farming.
If you live in an urban area, there are increasing numbers of community-supported agriculture programs available that offer access to healthy, locally grown foods even if you live in the heart of the city. Being able to find high-quality meat is such an important issue for me personally that I've made connections with sources I know provide high-quality organic grass-fed beef and bison, free-range chicken and ostrich, all of which you can find in my online store. The farms our supplier uses have three USDA inspectors on hand that regularly inspect the packaging facility. Additionally, all of the cattle are grass-fed on open pastures, and E. coli 0157 testing is performed daily. You can eliminate the shipping charges though if you find a trusted farmer right in your area.
The Weston Price Foundation has chapters all over the world and many of them are connected with buying clubs in which you can easily purchase these types of foods locally. Another resource you can try is Local Harvest, which you can use to find farmers' markets, family farms, and other sources of safe, sustainably grown food in your area.
For Optimal Health, Tend to Your Gut
The micro-organisms living in your digestive tract form a very important "inner ecosystem" that influences countless aspects of health, including your weight. More specifically, the type and quantity of organisms in your gut interact with your body in ways that can either prevent or encourage the development of many diseases, including heart disease and diabetes, and may help dictate the ease with which you’re able to shed unwanted pounds.
Since virtually all of us are exposed to factors that destroy beneficial bacteria in the gut, such as antibiotics (whether you take them for an illness or get them from contaminated animal products), chlorinated water, antibacterial soap, agricultural chemicals and pollution, ensuring your gut bacteria remain balanced should be considered an ongoing process.
Cultured foods like raw milk yogurt and kefir, some cheeses, and fermented vegetables are good sources of natural, healthy bacteria. So my strong recommendation would be to make cultured or fermented foods a regular part of your diet; this can be your primary strategy to optimize your body's good bacteria. If you do not eat fermented foods frequently, taking a high-quality probiotic supplement is definitely a wise move. In fact, this is one of the few supplements recommended for everyone. A probiotic supplement can be incredibly useful to help maintain a well-functioning digestive system when you stray from your healthy diet and consume excess grains or sugar, or if you have to take antibiotics.