Our intestines house trillions of bacteria that make up the gut microbiome. There are good and bad bacteria in the gut, and maintaining a balance between them is critical to maintaining good health.
While good bacteria maintain gut barrier and prevent bad bacteria from entering the intestines, bad bacteria produce harmful chemicals such as lipopolysaccharides (LPS) that increase gut inflammation and associated problems.
Obesity is a very common but very complex disease. We have seen people lose weight in the short term by improving their dietary quality and exercising regularly but maintaining that weight is very difficult. The reason for this is that your body’s biology is resisting the decline in your body weight through powerful physiological mechanisms.
How can bacteria in the gut affect your body weight?
Research has indicated that an imbalance in the gut microflora (dysbiosis) with a resultant decrease in gut microbial diversity can contribute to obesity in the following ways:
- The gut microbiome (particularly Helicobacter pylori) could make long-term weight loss easier by increasing the feeling of fullness/satiety and decreasing hunger in the brain by impacting the release of as ghrelin, the hunger-stimulating hormone.
- The bacterial community in the intestines influence how food is digested and absorbed and how dietary fats are stored in the body.
- An unhealthy gut can increase gut inflammation, which may result in obesity and metabolic disease.
- Gut bacteria alter the way we store fat, and how we balance levels of glucose in the blood.
- Certain bacterial genes appeared to be associated with the ability to lose weight and others were likely associated with a strong resistance to losing weight.
- Researchers have found that people whose gut bacteria reproduce quickly dropped weight more successfully. Hence, some people have a harder time losing weight than others.
- The gut microbiome can influence our eating habits and shape food preferences. In an animal study, mice that received bacterial transplants from mice on plant-based diets preferred a high-protein diet over a high-carbohydrate, low-protein one, a preference that differed from the other groups. This seems to indicate that the composition of bacteria in the gut may somehow shape food preferences, at least in mice.
- Humans can’t digest fibre, but certain gut bacteria can. By digesting fibre, gut bacteria produce several chemicals that benefit gut health and possibly promote weight loss. Studies have reported that people with high fibre intake have a lower weight, which may be due to the role that gut bacteria play in digesting fibre.
Which bacteria affect weight? Research has shown that people with more Prevotella in their gut lost 2.3 kg more body fat than those with more Bacteroidetes species.
Manipulate your gut microbiome for weight loss
It is possible to alter the gut microbiome composition to maintain weight in the long term and stave off obesity.
What we eat affects the type of bacteria that reside in the gut.
Limit the intake of processed foods, as research has shown possible links between the Western diets (high in fat and sugar and low in fruits, vegetables and fibre) and gut microbial imbalance. Western diets prevent the good bacteria from moving in and flourishing, which would allow the pathogenic ones to thrive and contribute to weight gain and obesity.
- Switch to plant-based diets (fruits, vegetables, seeds, legumes, avocado, and nuts) that are high in fibre to feed good bacteria, increase microbial diversity in your intestines and increase the production of short-chain fatty acids (SCFA), which are important for health and weight control.
- SCFAs such as propionate are chemicals that are produced when certain species of gut bacteria break down fibre, lower food intake and prevent weight gain.
- Consume polyphenol-rich foods: These include dark chocolate, green tea and red wine. The polyphenols promote the growth of good bacteria.
- Avoid artificial sweeteners such as aspartame and saccharin that reduce good bacteria.
- Consume healthy facts such as omega-3 fatty acids to support beneficial bacteria in the intestines.
- Exercise regularly: Physical activity may change the composition of our gut bacteria. According to a review published in the Nutrition, Metabolism & Cardiovascular Diseases journal, exercise can promote the growth of the beneficial strains, while decreasing the obesity-related Proteobacteria.
- Limit alcohol consumption: Alcohol can promote gut dysbiosis, metabolic dysregulation, and other consequences that drive weight gain and poor health.
- Prioritize sleep and stress management: Less sleep and higher stress levels can decrease gut diversity. Aim for seven to nine hours of shut-eye per night and make time for moments of calm or stress relief throughout the day—whether that’s a quick five-minute walk every hour, a guided meditation at lunch, or taking a break to read.
- Consider personalized testing: You can get personalized testing to really see what your own biological makeup looks like. You can learn a lot about your gut through stool testing, measuring inflammatory markers in the blood, and getting clear on food sensitivities. Consult a functional dietitian or physician specializing in gut health to see what tests might be right for you, which can get you closer to your weight loss goals.
Consider Supplements: Prebiotics and probiotics
- Supplements such as probiotics and prebiotics could help by increasing good bacteria such as Bifidobacteria and Akkermansia that reduce insulin resistance and body weight.
- Probiotics are live microorganisms found in fermented foods such as yogurt, kimchi, kefir, cheese, fermented soya products, such as natto and tempeh, miso, sauerkraut, and kombucha.
- Probiotics include Lactobacillus plantarum, Lactobacillus rhamnosus, Lactobacillus curvatus, Lactobacillus gasseri, Lactobacillus amylovorus, Lactobacillus acidophilus and Lactobacillus casei.
- Prebiotics act as fuel for good bacteria and reduce body fat. Prebiotic foods include garlic, asparagus, onions, and bananas, chicory root, chickpeas, artichokes, beans, leeks, almonds, and oats.
Final thoughts
Gut bacteria affect our eating habits, cravings, even our ability to put on or take-off weight by influencing the secretion of appetite-suppressing hormones. The wrong mix of gut microbes can help set the stage for obesity and related diseases such as diabetes and heart diseases.
A microbially diverse gut may help counter gain of weight, whereas a leaky gut drives inflammation, promoting fat storage and preventing weight loss. Good bacteria may extract more calories from food and influence blood sugar responses.
