Studies Find Probiotics Effective for Weight Loss and Type 2 Diabetes

Supplementing with certain specific strains of bacteria has been shown in research to improve metabolic health and foster fat loss. 

Studies are finding specific probiotic treatments can help with both weight loss and symptoms associated with Type 2 diabetes. Shutterstock

Probiotics can be useful for assisting with fat loss, and new research shows certain bacterial strains even lower health risks associated with Type 2 diabetes.

Two new studies have pinpointed specific bacterial connections that look promising for addressing obesity—and related metabolic diseases—with probiotics. It’s the sort of evidence-based clarity needed to navigate the confusing, cluttered, and sometimes contradicting claims of the probiotic marketplace.

Each person’s gut microbial community is made up of trillions of bacteria, viruses, and fungi that aid in digestion, among other tasks. Probiotics are live microorganisms consumed with the intent to improve the balance of microbes in the gut microbiota.

Probiotics include foods, often fermented, as well as oral supplements. Generally speaking, probiotics can keep pathogenic bacteria in check and provide enhanced immunity against viruses and fungi.

Targeting the health of the microbial community offers little risk and may offer profound benefits—even as a complement to medical remedies. That said, some people do react to probiotics and may take too many of certain strains, which can create problems.

Probiotic treatment may be particularly good news for those who don’t want to or are unable to pursue bariatric surgery or medications, as well as those who have plateaued in losing weight with diet and exercise. Both diet and exercise have proven valuable for altering the microbiome for the better.

The Gut’s Role in Diabetes

A causal mechanism that links gut microbiota to obesity hasn’t been found, despite some promising leads. Still, it makes sense that the gut microbial community could offer treatment options for obesity-related risks, due to its connection to metabolic disorders like diabetes and heart disease.

Obesity can cause a chronic inflammatory state—an immune system in overdrive—which can lead to insulin resistance. Insulin is a hormone that regulates glucose in the body, allowing cells to sop up glucose and use it for energy. Glucose will build it up in the body without proper insulin and lead to Type 2 diabetes, which is a risk factor for many other health conditions.

A healthy gut microbiome plays an essential role in regulating blood glucose levels. Certain strains of bacteria ferment fiber that produces short-chain fatty acids, which are metabolites beneficial for improving insulin sensitivity, reducing inflammation, and enhancing glucose metabolism. Certain bacteria may also affect the function of leptin and ghrelin, appetite-regulating hormones, as well as orchestrating other digestive-related tasks that can impact obesity and Type 2 diabetes.

In a randomized trial of patients with Type 2 diabetes in Greece, a multi-strain probiotic taken for six months was shown to have positive effects on glycemic and lipid parameters while also improving adiposity and leading to a decrease in waist circumference. Results were published Nov. 3 in Nutrients. 

Glycemic parameters were measured through hemoglobin A1c (HbA1c) values that show the average blood sugar, or glucose, level over the past two to three months. Lipid tests measure cholesterol and triglycerides and can detect vascular complications in patients with Type 2 diabetes. Adiposopathy is associated with both Type 2 diabetes and obesity. This is an inflammatory change to a type of fat known as adipose tissue, some of which is visceral fat that surrounds the organs and can lead to insulin resistance.

Power in Probiotics

The recent findings indicated that a probiotic blend of Lactobacillus acidophilus, Lactobacillus plantarum (L. plantarum), Bifidobacterium lactis, and Saccharomyces boulardii improved insulin sensitivity, allowing the body to more effectively make and use insulin. Taking the probiotic could theoretically reduce reliance on medication.

“These statistically significant improvements in glycemic control and waist circumference values can bring about clinically meaningful benefits for people with diabetes, including reduced risk of diabetes-related complications (such as cardiovascular disease, neuropathy, retinopathy, and kidney disease), leading to an enhanced quality of life,” according to the study.

The findings come on the heels of a review of studies that measured beneficial microbial therapies targeting obesity, published Sept. 28 in The FASEB.  It categorized specific prebiotics and probiotics found useful for obesity.

One study it highlighted included six strains of probiotics used for obese women, which reduced body mass index (BMI), body weight, and waist circumference, while improving appetite regulating hormones and eating behavior.

Specific bacteria highlighted in additional studies included:

• Bifidobacterium breve in a 12-week trial of overweight people found to lower fat mass.
• Bifidobacterium animalis and Lactis CECT 8145 used for three months in obese adults resulted in decreased BMI, and waist circumference.
• Latilactobacillus curvatus and L. plantarum strains used for 12 weeks in overweight subjects led to weight loss and a decrease in adiposity.
• Lactobacillus sakei CJLS03 used for 12 weeks in adults with a BMI of 25 and up who had a decrease in body fat mass and waist circumference.
• B. breve and L. plantarum strains used for 12 weeks in obese adults led to reduced waist circumference, as well as reductions in total and visceral fat.
• B. breve B-3 in pre-obese adults decreased body fat mass after 12 weeks.
• Lactobacillus gasseri BNR17 given to obese adults for 12 weeks decreased visceral adipose tissue and waist circumference.
• L. plantarum Dad-13 given to overweight adults for three months decreased body weight and BMI, as well as decreasing Firmicutes and increasing Bacteroidetes bacteria levels.

Microbiome Myth Busting

At one point, research settled on the idea that obesity is associated with an altered ratio of Firmicutes and Bacteroidetes. A July 2023 perspective article on microbiome misconceptions, however, said the connection is premature, as data is poor and hasn’t replicated a so-called obesity microbial profile.

Dr. Erika La Vella, a bariatric surgeon and gut health specialist with the Art of Bariatrics, said honing in on specific microbial species ignores the total interaction of the microbial community, not to mention the host’s behavior and genetics.

“I personally have a very lean phenotype of health, but I have an obesogenic [obesity-promoting] microbiome profile, so it doesn’t really paint the whole picture,” Dr. La Vella told The Epoch Times. “If you look at all the basic science stuff, they’re pumping out obesogenic mice studies, and the Bacteroidetes-Firmicutes ratio is something everybody is kind of holding their attention to.”

She suspects the ratio may have more to do with diet, particularly the amount of saturated fat someone consumes. A 2020 study in Nutrients came to a similar conclusion: the Firmicutes and Bacteroidetes ratio likely has to do with behavior and not body mass.

It concluded that discrepancies are “probably due to many lifestyle-associated factors including diet, physical activity, food additives and contaminants, antibiotic consumption, physical activity, among others that influence the composition of the microbiota in the gastrointestinal tract.”

Another association often made that is premature and perhaps erroneous is that obese people have a less diverse microbial profile. This connection was popularized after a 2013 study published in Science where the microbes from four sets of human twins with one obese twin and one lean were introduced into germ-free mice. Not only did the obese twins have less diverse microbial species, the mice groups mimicked the same weight and metabolic behavior of the humans.

It turns out there was no statistically significant increase in diversity among those who took probiotics for six months in the new Nutrients study. It did note that, in general, those who are obese or have Type 2 diabetes have a decrease in specific genera of Ruminoccoccus, Akkermansia, or Haemophilus.

“You really can’t pinpoint obesity being caused by one type of bacteria. Bacteria evolve at a rate much higher than we can even comprehend, which is why you keep seeing them be reclassified,” said Dr. La Vella.

On the other hand, trying to enhance a bacterial species may be useful. She noted that Akkermansia tends to be higher in leaner individuals and those with lower stress. Akkermansia plays an anti-inflammatory role in the gut.

While it isn’t found in foods, Akkermansia proliferates in diets rich in polyphenols. Polyphenols are found in fruits and vegetables, and are particularly noted in berries, grapes, and green tea.

Lifestyle: Proven Intervention

Dr. La Vella suggested lifestyle changes, particularly diet, to improve the commensal bacterial population in the gut. That includes eating more fiber and plants, and decreasing high-fat, processed, and fast foods.

This approach worked for Kimberly Kull. She was clinically obese, and she knew her gut health was involved based on inconsistent bowel movements. She also associated her joint inflammation with her diet. At first she tried probiotics, which bothered her gut, and yogurt, though she didn’t take into account the added sugars were negating any potential benefits.

“You buy into the marketing and think things are healthy when they are not,” Ms. Kull said. “I did notice a correlation in the processed foods and the way I felt.”

So she upgraded her diet with some basics and ultimately lost 80 pounds. Specifically, she increased her protein, gave up fast food and processed food, and eliminated all sugar (and artificial sweeteners) except fruit. When she did an elimination diet for a couple weeks and practiced intermittent fasting, her results were even more noticeable.

Ms. Kull regained some of the weight after her husband lost his job of 36 years earlier this year. She blames it on stress and inability to afford organic foods. But now that he’s found a new job, Ms. Kull has recommitted to eating better quality foods and is working with a functional doctor to address nutritional deficiencies.

“I always lose weight when I’m eating cleaner, even when I’m eating more calories,” she said. “I feel like it just kind of melts off when I’m eating better.”