Is there a link between gut health and weight loss? While we’ve long known that the key to weight loss is a constant calorie deficit, the latest research shows that there may indeed be a link between gut health and weight loss. So can improving our digestion help us shed unwanted pounds?
A study published in the Gastroenterology (opens in new tab) magazine suggests that the makeup of our gut microbiome could predict how successful we are in achieving our goals. However, scientists are just beginning to explore this new concept of gut weight. And it is not an easy task.
Our metabolism is a very complex mechanism. If you’ve ever embarked on a weight loss journey, you may know that it’s not as simple as “energy in versus energy out.” How efficiently our body uses calories and regulates appetite depends on many factors. Some of them cannot be changed, such as our genetic makeup or age. But others, such as our gut flora, can be modified.
If there’s a link between gut health and weight loss, it could open up new possibilities. For example, probiotics and prebiotics could be used in the fight against obesity. But how do these ideas relate to science?
Here we discuss what we know so far about the role of gut bacteria in weight management and explore ways to improve our gut health. And if you’re looking to boost your gut bacteria, be sure to check out our guide to the best probiotics for helpful tips and advice.
What is the gut-weight connection?
The constant communication between our nervous and digestive systems is central to regulating our metabolism and appetite. Gut hormones play a critical role in this exchange of information, relaying nutritional status signals from our gut to the brain so that the brain can interpret the body’s energy needs and respond accordingly.
Our gastrointestinal system releases over 20 different hormones that are involved in maintaining energy balance. The levels of these gut hormones depend on a number of factors, including the foods we eat, health conditions, and the compounds produced by gut bacteria.
Some of these hormones have a direct influence on our eating behaviour. According to the Diary of Obesity (opens in new tab)cholecystokinin, peptide YY, pancreatic polypeptide, glucagon-like peptide-1 and oxyntomodulin suppress your appetite, while ghrelin makes you hungrier.
studies (opens in new tab) the use of advanced neuroimaging techniques have shown how powerful these hormones are in altering our brain activity. Interestingly, one of the goals of a vertical sleeve gastrectomy — a procedure in which part of the stomach is removed to limit the amount of food people can consume — is to affect this endocrine appetite control. According to the Annals of surgery (opens in new tab)this type of surgery leads to a marked decrease in the levels of hunger-boosting ghrelin.
Gut hormones are crucial for weight loss. Low-calorie diets will inevitably alter their levels to promote appetite and a less efficient metabolism, as reported in the Hormone and Metabolism Research log. That’s why so many dieters have trouble controlling their appetite and the dreaded yo-yo effect.
Gut bacteria and obesity
Is there a link between gut health and obesity? There is growing evidence that overweight individuals tend to have a different composition of gut microbes compared to lean individuals. According to a review published in the nutrients (opens in new tab) journal, the gut flora of obese people may be less diverse and contain fewer beneficial strains of bacteria.
however, the Genes and nutrition (opens in new tab) journal reports that certain strains linked to obesity and metabolic disorders in western populations may not have the same effect on eastern populations. For example, Prevotella and ruminococcus were obesity-associated genders in studies from the West – but lean-associated in the East. roseburia and Bifidobacterium were lean-associated lineages only in the East, while Lactobacillus was an obesity-associated tribe in the West. It is therefore unclear whether these differences are a cause or consequence of obesity. More studies are needed to fully understand this issue — and what it might mean for weight loss interventions.
There is also mixed evidence when it comes to the use of fecal transplants as a treatment for obesity, as noted in the nutrients (opens in new tab) log. Fecal microbiota transplantation (FMT) is a procedure in which fecal bacteria are transferred from one individual to another. The idea is that the lean person’s microbiota will help balance an obese person’s microbiome, causing weight loss in the process. However, no significant changes in blood sugar, BMI, or cholesterol were detected in those who underwent this procedure.
Anyway, studies (opens in new tab) have shown that certain microbial byproducts tend to be constantly elevated in obese individuals. Overweight people tend to test more for metabolites such as amino acids, lipids and lipid-like metabolites, bile acid derivatives and other compounds that have been shown to increase the risk of insulin resistance, hyperglycemia and dyslipidemia.
Gut bacteria and weight loss
What does the science say about gut health and weight loss interventions? According to a meta-analysis published in the gut microbes (opens in new tab) journal, losing weight usually leads to an increase in the diversity of gut microbes. It also promotes the growth of more beneficial species.
There is also some evidence that your gut health may determine how quickly you can shed unwanted pounds. As mentioned in the Gastroenterology (opens in new tab) journal, the baseline gut microbiota — the composition of gut microbes at the start of a weight loss program — may be one of the most important predictors of successful end-results.
At the same time, researchers from The American Journal of Clinical Nutrition (opens in new tab) point out that gut microbes can be quite resistant to change. The extent of these changes may also depend on the type of weight loss diet. A study published in the Magazine for personalized medicine (opens in new tab) points to the Mediterranean diet as potentially the most beneficial.
Physical activity can also change the makeup of our gut bacteria. According to a review published in the Nutrition, metabolism and cardiovascular disease (opens in new tab) journal, exercise can promote the growth of the beneficial strains, while reducing obesity-related Proteobacteria.
So there is definitely a strong link between gut health and weight loss, but we still don’t know what really works and what doesn’t. That said, we have a good understanding of which individual foods can benefit our gut health — and taking care of our small gut residents can benefit our bodies nonetheless.
What are the best foods for gut health?
Foods rich in dietary fiber:
- Whole grain
Foods rich in probiotics:
- Fermented dairy products, such as yogurt and kefir
- Fermented soy products, such as tempeh and natto
- Miso soup
Foods rich in prebiotics:
- chicory root
Do probiotics help with weight loss?
Can you use probiotics for weight loss? It is difficult to answer this question with certainty. The science investigating the links between probiotic supplementation and weight loss is still in its infancy.
It can largely depend on the type of bacterial strains used. According to a review published in the International Journal of Obesity (opens in new tab)among which Lactobacillus plantarum, Lactobacillus rhamnosus, Lactobacillus curvatus, Lactobacillus gasseri, Lactobacillus amylovorus, Lactobacillus acidophilus and Lactobacillus casei. However, it may be necessary to combine them with a low-calorie diet to achieve the best results. Scientists are also exploring the potential of lesser-known akkermansia tribes. As stated in a review published in the Archives of Physiology and Biochemistry (opens in new tab)they may help manage obesity and associated metabolic complications.
This article is for informational purposes only and is not intended as medical advice.