The Hidden Connection
Are your gut bacteria helping or hurting your weight loss efforts?
Amazingly, and perhaps frustratingly, you and your friend can eat the exact same diet, but she may lose five pounds while your weight doesn’t budge. Why is that? The answer may have to do with your gut bacteria.
There is a whole universe of microbes living inside your gut — some good, some bad. But yours is likely quite different than your friend’s, because there is a lot of variation in the composition of gut bacteria from person to person. While any two people share 99% of the same genes, chances are their gut bacteria are only 50% similar(1). And what do the trillions of tiny guests in your gut have to do with your weight? A lot.
Bacterial Influences on Weight
Which Bacteria Are in Your Gut?
The first step toward a healthy population of gut bacteria is diversity. A study from Denmark found that people with more species of gut bacteria were likely to be leaner than their counterparts with fewer species. They also had better blood sugar control and cholesterol levels.(2)
The second step is having the right bacteria. You don’t invite just anyone to pull up a chair in your home. It’s the same with gut bacteria; some visitors are more welcome than others. When it comes to your gut, species in the Bacteroidetes phylum are good to have around. A study of 61 Ukrainian adults showed that people with more of these strains of gut bacteria and fewer strains from the Firmicutes phylum were slimmer on average.(3) This result echoed earlier findings in mice.(4)
However, just as with people, you can’t judge bacteria solely by their families. While some members of the Clostridia genus (which belong to the Firmicutes phylum) can cause infection, others are beneficial. Research in mice suggests the good kind may help keep off extra pounds.(5) Christensenellaceae is another helpful type of Firmicutes bacteria. A study published in the scientific journal Cell found folks with more of these bacteria had healthier BMIs.(6)(7)
How Do Gut Bacteria Influence Your Weight?
There are two main mechanisms at work here: appetite and metabolism. Your appetite is the big determinant in how much food you eat. Your metabolism governs how much energy from that food is burned and how much is stored as fat. Your gut bacteria have a hand in both factors.
Your gut is basically a restaurant for the microbes that live there, because they eat some of what you eat. Scientists are starting to think that when you feel hungry it’s not just because your body needs energy, but because your gut bacteria do too.(8) When they want to place a takeout order, they can stimulate the release of hormones, like ghrelin, which makes you feel hungry. When they’ve had enough, they can help your body release leptin, which makes you feel full.(9) Or they can just slow the production of ghrelin, so you stop eating. That’s what H. pylori (a species of ulcer-causing bacteria) does.(10)
On the metabolism side, gut bacteria help you extract nutrition from the food you eat. They even regulate what time of day you absorb the most nutrients, fat, and protein from your meals by helping program your circadian rhythms. Scientists speculate that anything that disrupts your circadian clock, such as working night shifts, or frequent travel across time zones, could contribute to weight gain.(11)
Gut Bacteria and Weight Loss
Your gut microbiota’s favorite eats are the indigestible fibers found in whole grains and many fruits and vegetables, like apples, bananas, artichokes, garlic, leeks, onions, and asparagus. When they ferment these fibers in your gut, they produce short-chain fatty acids like propionate that seem to reduce appetite, food intake, and weight gain in folks who are already overweight.(12)(13) That’s probably why high-fiber diets are linked to leaner physiques.(14)(15)(16)
A meta-analysis of 21 studies published in the scientific journal Genes offers more proof that the composition and health of the bacterial colonies in your gut affect how much you weigh. Researchers looked at what happened when people took probiotics, prebiotics, or synbiotics (a combination of the two).
Probiotics: Supplements of live beneficial bacteria
Prebiotics: Food for beneficial bacteria
Synbiotics: A combination of probiotics and prebiotics
The result? They lost weight, decreased their fat mass, and lowered their BMIs.(17) Similarly, another review of studies in the European Review for Medical and Pharmacological Sciences found synbiotics helped people lose weight and keep inflammation in check.(18) (Inflammation is another factor linked to obesity.)
The role of Antibiotics
So if gut bacteria play such an important role in appetite, metabolism, and weight, what happens when we kill them?
When you take an antibiotic for an infection or illness, it doesn’t just wipe out the bacteria that are causing the problem. It kills the good guys, too, leaving an empty neighborhood behind. And as bacteria begin to recolonize your depopulated gut, sometimes the new arrivals aren’t the ones you want. That’s why many people experience stomach upset and digestive problems during or after a round of antibiotics.
But even if you’re not taking antibiotics, the animals whose meat and milk you consume probably are, and what’s in their systems can end up in yours. Many farm animals are routinely given antibiotics, even when they’re not sick, because they promote growth. (In fact, it’s estimated that 70 percent of the antibiotics sold in the U.S. are given to livestock.(19) And if these medications promote growth in farm animals, it’s not a far stretch to assume they will cause it in people, too.
Scientists have tested the idea in mice by giving them antibiotics. Sure enough, those germ killers changed the composition of their gut bacteria and caused them to put on weight.(20) Another study found that children who had taken antibiotics in the first six months of life were more likely to be overweight by the time they were three years old than those who had not.(21)
How to Support Your Gut Bacteria and Manage Your Weight
If you want to keep your gut populated with healthy bacteria, there are some practical steps you can take:
Avoid unnecessary antibiotics. Sometimes antibiotics are medically necessary, but they are overprescribed. Ask your doctor if a wait-and-see approach is appropriate, and don’t request antibiotics for a viral infection like a cold or flu (which they can’t treat).
Eat organic food. Organic meat and milk come from animals that aren’t treated with antibiotics, so you can reduce your exposure to these medications by buying organic.
Eat less sugar. Beneficial bacteria don’t like sugar. They need complex carbohydrates instead. If you’re chowing down on refined carbohydrates, your good guys aren’t getting enough to eat. They will either die off, or start feeding on the mucus in your intestines, which can lead to inflammation.(22)(23)
Get enough fiber. Gut bacteria love fiber, so make sure you’re getting an adequate amount. Whole grains, fruits, vegetables, nuts, and seeds are all good sources of the kind of fiber gut bacteria like best. Prebiotic fiber is also available in supplements.
Eat fermented foods. Foods like yogurt, kefir, sauerkraut, miso, tempeh, and kombucha contain helpful species of microbes that can replenish gut bacteria populations if they start to dip.
Strengthen your gut. Beneficial bacteria can’t thrive in your gut unless its structure is habitable. (They like a house in good repair, just like us.) A number of supplement ingredients can help build gut architecture:
Immunell™ Nucleotides: These plant molecules provide building blocks for the fast-renewing tissues of your gut and immune system.
Rhyotrace™: This organic trace mineral complex improves the length of your microvilli, tiny gut structures that aid nutrient absorption.
Advanced Plant Peptides: These protein building blocks help maintain, reinforce, and repair the tight junctions of your gut barrier.
Zinc & Selenium: These essential minerals are needed for gut health; deficiencies in either mineral can increase your gut permeability.
Vitamin A: This essential vitamin is necessary for manufacturing mucin, which covers the cells of your gut barrier in a gooey film that’s like a fly trap for germs and toxins.
If you’re having difficulty losing weight, attending to your gut could flip the switch on your metabolism.
This article is provided by Previlli™, a new approach to gut health with long term benefits.