By Jereme’ Gallier, graduate student in nutrition coordinated program
What are Synbiotics?
Synbiotics are classified as a combination of prebiotics and probiotics. Prebiotics act as fertilizers that stimulate the growth of healthy bacteria and can be found in various fruits and vegetables. A common example of a prebiotic is fiber, which Is also beneficial in digesting food and overall health. Probiotics are live, healthy bacteria that are similar to the good bacteria found in the body and are intended to provide benefits like destroying disease-causing cells. Examples of foods containing probiotics include yogurt, kombucha, and dietary supplements.
A 2016 research study involving mice suggested an association between the probiotic, Lactobacillus rhamnosus, and lessened weight gain in the presence of a high-fat diet. Additional animal and human studies have suggested that probiotics within the Lactobacillus family have varying effects involving both weight gain and weight loss, indicating some variability in effects depending on the probiotic being consumed. To date, there is no consensus on how effective synbiotics are for weight loss purposes; however, previous studies have shown positive associations with synbiotics and improvement of irritable bowel syndrome symptoms.
Why is the gut so popular?
Within the gut (digestive tract), there exists a microbiota, which is the combination of microorganisms in a specific area including bacteria and fungi, for example. The microbiota of the gut has been suggested to play a role in the occurrence of obesity and various diseases. However, the gut microbiota can also play a role in the reduction of low-grade chronic inflammation associated with obesity and metabolic syndrome, and improve weight loss outcomes.
Can Synbiotics Help You Lose Weight?
A group of researchers in South Dakota developed a placebo-controlled intervention clinical trial to determine the effects related to using a synbiotic supplement containing Bifidobacterium and Lactobacillus probiotic strains on the human gut microbiota with respect to changes in body composition and indicators of obesity. In this study, 20 participants comprising of men and women were enrolled into a weight loss program and randomly assigned to a placebo or control group and the synbiotic or treatment group. At enrollment, participants were overweight/obese with an average body mass index (BMI) of 33.5. Each group followed a low-carbohydrate high-protein diet including 104 grams of protein, 68-80 grams of carbohydrate, 36.5-39.0 grams of fat, and 26-30 grams of fiber amounting to 980 – 994 calories. Within the synbiotic supplement, the probiotic component contained a combination of Lactobacillus acidophilus, Bifidobacterium lactis, Bifidobacterium longum, and Bifidobacterium bifidum, and the prebiotic component was trans-galactooligosaccharide.
Now let’s see what they found!
Results of the study showed no differences between the groups at the end of the clinical trial; however, the researchers did notice an increase in the number and diversity of healthy gut bacteria. In particular, they found that an increase in the Lactobacillus species over time led to a decrease in blood glucose. To the contrary, a decrease in body mass, BMI, waist circumference, and body fat was associated with decreased numbers of the Bifidobacterium species.
What does it all mean?
In the study described above, researchers concluded that the synbiotic supplement increased the abundance of healthy bacteria in the gut microbiota but did not influence weight loss or body composition. However, the authors also noted that the increase in microbiota abundance may be beneficial when consuming a high protein diet by protecting colon cells through fermentation.
Overall, this revealed that the chosen synbioitic mixture may be useful when engaging in a high-protein diet. Whether there exists a synbiotic that would promote weight loss or improve body composition has yet to be discovered. That being said, the gut microbioita field is relatively new and is continuously evolving, and future studies may soon discover the perfect combination to support weight loss, as well as body composition.