When the bacteria in the intestinal tract (i.e., your gut microbiota) lack in volume or diversity, or the wrong types of microorganisms start to flourish, it not only can affect your health, but it can also make healthy weight maintenance more difficult. A probiotic supplement that contains science-backed strains of good bacteria can help maintain or restore a healthy microbial balance to your digestive system.* These supplements deliver certain probiotic strains, such as those from genera Lactobacillus and Bifidobacterium, and when taken regularly, they lay down the good bugs you want in your gut, and over time, your health will thank you for it.* But it presents a chicken-or-the-egg question—does the microbial imbalance cause weight gain or does the extra weight somehow change the balance of bacteria? Renowned integrative physician Robert Rountree, M.D., thinks the evidence is clear, “There is no question that the bacteria in our gut can affect our weight.”* He first cites animal studies, in which obese mice are given a fecal transplant2 from lean mice and, consequently, lose weight and body fat.* This might be due to how gut bacteria interact with our cells and digestive process. One study found that simply overeating can tip the balance in favor of bad bacteria3. The problem? As Rountree explains it, “Certain bacteria are better at extracting energy from food than others.” This means these bacteria can harvest even more calories4 from the increased intake of food, to be turned into energy and body fat.* A double weight-gain whammy, if you will. In addition, gut bacteria play a role in appetite regulation and satiety (the feeling you get after eating a huge, delicious meal).* When the “good” bacteria outnumber the “bad,” the levels of short-chain fatty acids increase in the gut, triggering the production of hormones5 that regulate appetite.* So, if these hormones are out of balance, then you might not get the signal that you are full. The result is a weight-gain cycle—you overeat and the bad bacteria increases in your gut, possibly increasing body fat and lowering levels of short-chain fatty acids that would otherwise help control your appetite, causing you to eat more, which increases the bad bacteria, which…well, you get the idea. In contrast, mbg’s director of scientific affairs Ashley Jordan Ferira, Ph.D., R.D.N. explains that, “high-quality and transparent supplement brands will absolutely identify the probiotic at the strain level (genus, species, and strain). Look for those three pieces of info, because that’s how probiotics are clinically researched, by strain.” Exciting research continues to emerge for this specific area of probiotic evidence. For your weight-maintenance efforts, we’ve compiled the top contender probiotic strains rooted in science; the most well-researched strains to support a healthy weight include:* In a study of 125 men and women with obesity, published in the British Journal of Nutrition, it was found that probiotic supplementation helped women lose weight and maintain their weight loss11 over a 24-week period while following a reduced-calorie diet.* The women taking the probiotic supplement lost significantly more weight than women in the control group, who also followed a reduced-calorie diet but did not take the probiotic supplement.* Another study, this one of 90 adults with overweight and obesity, found that taking a probiotic supplement for 12 weeks had a favorable effect on participants’ visceral fat12—the fat that accumulates near the liver, stomach, and intestines and increases the risk for many diseases.* These and other studies have used individual strains and combinations of probiotic bacteria, with beneficial outcomes for weight maintenance.* In fact a comprehensive 2018 systematic review and meta-analysis13 of over 20 probiotic studies on weight concluded that probiotics are “essential tools [for] obesity and can lead to significant decreases in BMI, weight, and fat mass.”* That’s compelling science. Eating a nutrient-dense, colorful dietary pattern, moving often, and quality sleep are still the pillars of long-term weight success. These strains, like Bifidobacterium lactis B420, have been found to have favorable effects on weight, body fat, waist circumference, visceral fat, and blood sugar.* She has worked with media, health professionals, and the scientific community, attending and reporting on scientific meetings, researching topics, tracking trends, and assisting in the preparation of manuscripts for publication in scientific journals. She has also been the author or editor of seven health and nutrition books for consumers and is currently a freelance writer and editor of articles on health and nutrition. She is also an author of two published novels, with a third under contract.
