Maintaining a healthy weight can get increasingly challenging with age. Starting in the late 30s, the body undergoes changes such as a slower basal metabolic rate and hormonal shifts, which can make losing weight more difficult. While drugs such as Wegovy, Ozempic and Mounjaro have dominated headlines with their dramatic results, there’s growing interest in gut-based solutions, like synbiotics, that may support weight management and overall metabolism with fewer side effects. ¹
Recent research suggests synbiotics, targeted combinations of prebiotics and probiotics, can positively influence body composition, metabolic markers and inflammatory processes linked to weight regulation and metabolic disease. ¹
What Are Synbiotics and How Do They Work?
Synbiotics combine probiotics (beneficial bacteria) with prebiotics (the fibres that feed them) to help good bacteria survive and thrive in the gut. This enhances gut microbiome balance, a key player in digestion, immune function, hormone signalling and metabolism.2
A balanced microbiome increases production of substances like short-chain fatty acids (SCFAs), which can help regulate appetite, reduce inflammation and support efficient energy use, all of which are important for weight control.
Synbiotics & Weight-Related Outcomes: What the Evidence Shows
Systematic reviews and meta-analyses have found that probiotic and synbiotic supplementation is linked with statistically significant reductions in:
- Body weight
- Body mass index (BMI)
- Waist circumference
- Fat mass and body fat percentage
compared to controls.
This suggests that synbiotics can support improvements in physical measures used to assess weight and fat distribution, including BMI, waist size and body fat, all of which are closely linked to obesity and central fat accumulation in adults. 3
Faster Weight Loss Through Better Gut Health
The study found that a combination of synbiotic supplementation and a fibre-rich diet was effective in reducing obesity and its related metabolic traits. It also identified that a specific gut bacteria (Megamonas) linked to obesity markers was reduced. Their results showed that synbiotics could even lead to faster weight loss, with participants losing 5% of their body weight 1 month quicker than those on weight loss drugs like Ozempic. By comparison, trials of semaglutide, the main ingredient behind weight loss drugs, found that users lost a similar amount of body weight in 3 months, instead of 2. 4
Here’s why this matters:
A balanced gut microbiome supports more efficient digestion and nutrient absorption, helping your body use calories better.
GRNS
Improved metabolism from a healthier gut can help regulate fats and sugars naturally.
Gutbiome
Synbiotics may also influence hormones like leptin and ghrelin, helping control hunger and reduce cravings.
New Clinical Evidence: Synbiotics & Metabolic Markers in Adults
A 2025 triple-blind, placebo-controlled Randomised Controlled Trial¹ in elderly adults found that taking a multi-species synbiotic over several weeks led to:
- Greater weight loss vs placebo
- Reduced BMI and body fat mass
- Lower fasting glucose and improved insulin resistance
- Lower LDL (“bad”) cholesterol
- Reduced markers of vascular inflammation
compared with placebo.
These metabolic improvements, including better glucose control and lipid profiles, highlight that synbiotics may help reduce cardiometabolic risk alongside weight changes.
The Gut Weight Reaction
The two-fold action of prebiotics and probiotics helps with weight loss by improving gut health. Prebiotics act as fuel for the beneficial bacteria (probiotics) in your gut, helping to build a healthy balance in the gut microbiome. A balanced gut microbiome can help regulate metabolism, reduce inflammation, and improve nutrient absorption. Nurturing a healthy balance of good bacteria in the gut can help regulate hunger hormones and improve digestion, making it easier for the body to absorb nutrients and burn calories efficiently. Helping to reduce fat storage and naturally promote weight loss. Additionally, a healthy gut microbiome can help curb cravings and promote feelings of fullness, making it easier to stick to a healthy diet.
Start with your Gut
Trying to get your weight back on track? Nourishing the healthy bacteria in your gut can play a key role by boosting GLP-1, a hormone that helps control appetite. Naturally produced in the gut, GLP-1 not only regulates hunger but also plays a vital role in managing blood sugar levels, an important factor in both digestion and weight management. An easy way to boost GLP-1 production is to have a daily serving of P3 Gut Builder. This powerful triple-action postbiotic tonic is slow-fermented with a specialised blend of prebiotics, probiotics and postbiotics to deliver beneficial metabolites straight to your gut. It is deliciously easy to enjoy daily as a health shot or can be added to water, juice and smoothies.
