Gut Health and Weight Loss: What’s the Connection?

A healthy gut is about much more than proper digestion. Gut health boosts your immune system and contributes to heart and brain health. Gut health also plays a role in weight management.

The key to a healthy gut is a diverse microbiome. Your gut microbiome includes the population of bacteria, viruses, and fungi that live in your gastrointestinal tract.

The makeup of your gut microbiome can affect your ability to lose weight (or make you more likely to put on extra pounds). A healthy microbiome may help support weight loss. In fact, weight loss helps improve your microbiome's diversity. Weight gain, on the other hand, may reduce the diversity of healthy microorganisms in your body.

Below we’ll take a closer look at what gut health really means and how weight loss and weight management can contribute to a healthy gut.

Your gut microbiome, also known as gut microbiota, contains trillions of tiny microbes. Most of them live in your intestines, but they can be found throughout the gastrointestinal tract. The makeup of this sprawling population changes over time and in response to your diet and lifestyle.

Of the many types of microbes in your body, bacteria receive the most attention from researchers and health experts. There are hundreds of different species of bacteria in your gut microbiome. Some of them have the potential to be harmful, but most play a role in keeping you healthy.

For example, several types of gut bacteria help you digest fiber, a nutrient that helps with weight management. Your gut microbiome also communicates with your immune cells, helping you fight off infections. A diverse microbiome is also associated with better brain function.

While losing weight can help improve the makeup of your gut microbiome, research suggests that elements within your microbiome may even be helpful in predicting how well you might maintain your weight loss. A small 2022 study of people with obesity found that certain changes in microbiota patterns occurring while those individuals were in non-surgical weight loss programs can be analyzed to predict long-term weight loss success.

The gut microbiome plays a role in digestion, nutrient absorption, and metabolism.

The countless microorganisms in your body can impact your overall body weight in ways that we still don’t understand completely. A 2023 review of studies notes that your gut microbiota can affect fat storage, blood sugar levels, and the production of cholesterol and triglycerides.

Certain bacteria are better than others at breaking down food in a way that uses calories for energy most efficiently. Some bacteria may break down food in a way that encourages fat accumulation.

 Obesity is associated with a less diverse microbiome and poorer gut health. But a 2022 study suggests that when people lose excess weight, their gut microbiome diversity improves. So, if you live with overweight or obesity, you may be able to boost your gut health through weight loss.

A 2022 study suggests that GLP-1 agonists (like Ozempic^® and Wegovy^®) may promote a healthier, more diverse gut microbiome.

Fortunately, you don’t need a microscope and a PhD in biology to take steps to improve gut health for weight loss. Improving microbiome diversity often comes down to what you eat and how much you move.

Not surprisingly, a well-balanced diet can improve your gut health. A 2020 study suggests that the best diet for gut health and weight loss is a high-fiber diet emphasizing fruits, vegetables, whole grains, and legumes (beans and peas). When you digest fiber, your body creates short-chain fatty acids, which help prevent the growth of “bad” bacteria in your intestines and improve the body’s ability to absorb important minerals, such as calcium.

If you’re unsure how to shift your diet to an eating plan that supports microbiome diversity and weight loss, consider a Mediterranean-style diet. The Mediterranean diet focuses on healthy, high-fiber foods and healthy fats, such as olive oil, while keeping red meat and added sugars to a minimum.

Probiotics and Prebiotics

In addition to fiber-rich foods, some of the best foods for gut health are those containing probiotics. Probiotics are microorganisms that boost your health. Probiotic-rich foods include yogurt, sauerkraut, kombucha, and kefir. Including these foods, along with other healthy snacks, can increase the population of helpful bacteria in your gut.

It’s also helpful to consume foods with prebiotics, which are carbs that healthy bacteria feed on. Foods rich in prebiotics include:

• Apples

• Bananas

• Berries

• Legumes

• Oats

A 2020 study found that consuming probiotics, prebiotics, and synbiotics (foods or supplements containing both probiotics and prebiotics) are among the best foods for gut health and weight loss, as well as sustained weight management.

Inflammatory Foods

Eating unhealthy foods, especially those that tend to increase inflammation in the body, can work against your best efforts to diversify your gut microbiota and lose weight.

Unhealthy microbes can produce chemicals such as lipopolysaccharide, which increase inflammation as they circulate throughout your body.

Chronic inflammation has several damaging effects, such as impacting insulin sensitivity. It also increases liver fat levels and contributes to overall weight gain.

There are many foods that contribute to inflammation. These include:

• Alcohol

• Red meat

• Processed meats

• Snack foods, such as cookies and chips

• Soda and other beverages high in added sugars

• Fried foods

Limiting pro-inflammatory foods and making other positive dietary changes will benefit your gut health and help you lose weight.

Physical Activity

Increased physical activity is another way to aid weight loss and improve your gut microbiota. A 2017 study suggests that physical activity improves the diversity of your microbiome and contributes to gut health. The researchers also note that exercise can help reduce inflammation, a condition that works against greater gut microbiome diversity.

Aerobic exercise is especially good at burning calories, but you don’t need to start out with an intense exercise program. Simply taking a walk every day can help with your weight loss journey. If a 30-minute walk seems like too much right now, break it down into two 15-minute walks.

The key is to keep moving, and as your fitness level and stamina improve, make small, but steady efforts to move more every week.

Gut health and microbiome diversity may seem difficult to understand because you can’t see all those trillions of microbes inside you. But your gut health is an important factor to be aware of when you’re on a weight loss journey.  A few things to keep in mind:

• Your gut microbiome can improve with lifestyle interventions such as a healthy diet and more exercise.

• Foods high in probiotics and prebiotics can help with both weight loss and gut health.

• Weight loss can also lead to greater gut microbiome diversity.