Does gut health affect weight? The answer is yes. Your gut microbiome is critical to how your body performs. Here’s how it all works…

*This is a modified transcript of an episode from my podcast, The Nourished & Thriving show. This episode is titled “ 3 ways your microbiome is impacting your weight ” (published April 2024), which you can find on your favorite listening platform here.

*This is not medical advice.

Does gut health affect weight?

First things first, I’m a registered dietitian on a mission to help you increase your impact and legacy on the world while healing your gut and reducing your IBS and digestive symptoms. My goal is to inspire you to live vibrantly and provide valuable resources and information that empowers you to take bold action towards your health goals.

Let me answer this question: Does gut health affect weight? Yes, gut health can impact your weight.

And before anyone jumps in with “all sizes matter” and “healthy at every size”, let me lay down a few disclosures… I’m addressing the things beyond the way our bodies look. I think there’s been way too much emphasis put on this topic as women, especially as pressure for us to live up to some sort of stereotype or image. I think that the BMI charts we’ve been taught forever are not helpful. And I say frequently that your weight is maybe the least interesting fact about you. I don’t put a ton of emphasis on body weight in my practice.

That being said, body weight is not completely irrelevant either. Everyone wants to lose weight or gain weight. Weight is very top of mind for most people, so I really wanted to address it. If you’ve been around for a hot minute, you probably know at least one person who’s been taking semaglutide, Ozempic, Xenical, etc. to try and help reduce insulin resistance and lose weight. It’s so common. You might also get targeted ads for supplements on Instagram and Facebook, featuring products like Nature’s GLP-1. This is why it’s important to talk about gut health and weight loss or weight gain. Let’s first take a look at the numbers:

The State of American Bodies, Disease, and Obesity

78% of adult Americans are overweight or obese. What’s really scary is that we’re seeing this number rise in our kiddos, too.

50% of adult Americans have at least one chronic disease, like heart disease, diabetes, etc.

As estimated by CDC, the U.S. spent 3.7. trillion—trillion with a ‘T’—per year in healthcare costs related to these chronic illnesses.

Those numbers are staggering. If you are one of these Americans who is struggling with this chronic diseases, then you know, your quality of life is diminished. You are probably in pain. You’re probably tired. You’re dealing with medication. You’re dealing with financial struggles.

It’s expensive to be sick. People always complain about how expensive it is to be healthy and to eat healthy food. I would argue that it’s a lot more expensive to be sick. And I think the cost is much greater than financial cost too. You’re missing out on memories and adventures and all of those things by being sick. So let’s get into it…

Does gut health affect weight? Yes, gut health impacts everything in the body. Simply addressing gut health can fix so many other issues! If you’re wanting to tear down this structure of chronic disease, fixing your gut health is like taking a wrecking ball and knocking down most of that structure in one fell swoop. Then you can go in with a chisel and hammer, fine tune, and adjust anything that’s left standing.

Did you know: 2/3 of Americans are burdened with chronic digestive symptoms?! The numbers are shocking! And there definitely is some overlap between people who are overweight or obese and those who are dealing with chronic digestive symptoms. There are ways we can change that and shift that. Let me be clear: the answer is NOT to take a medication and then continue to add new medications to better manage your condition and then take additional medications to offset the side effects of those other medications and all of that. There are other ways (like focusing on better gut health and lifestyle!)

How does gut health affect weight?

There is emerging research covering gut health and obesity and weight. We don’t have all the answers, but we do have some answers. Let’s dive into three ways your gut health affects your weight:

Different Types of Gut Bacteria Impact Nutrient Absorption

First of all, we know that different types of bacteria impact people differently. There have been studies that have looked at identical twins, where one was obese or overweight and one was normal weight. So researchers looked at their gut microbiome. Consistently, the obese or overweight people have a microbiome that looks different than people who are at a normal weight. Bacteria impact how we’re digesting and absorbing different nutrients, carbohydrates, fats, all of that, so if you have different types of bacteria, you may have an increase in the types of foods you are able to absorb. So you may be actually absorbing more fat and more carbohydrates, even though you’re eating the same amount as somebody else who has a microbiome with a healthier profile than what you have. So you see what I’m saying here: even though you’re eating the same amount or foods as somebody else, you will gain or lose weight differently. But we can fix your microbiome!

Inflammation Affects Body Weight

Second of all, there’s a lot of inflammation associated with gut health. Any time someone has inflammation in their body, I always expect them to also have inflammation in their gut. This can happen for a variety of reasons, but a lot of the time it’s going to come from an imbalance in the microbiome or not having enough diversity in their diet. Whenever you don’t have enough good bacteria or your microbiome is imbalanced, it’s called dysbiosis. When you’re in dysbiosis, it reduces how many short chain fatty acids (SCFA) are produced in your gut. SCFA are the building blocks for a healthy gut lining. This is important because a healthy gut lining acts similarly to a bouncer at a club. The gut lining decides who gets into your body and who doesn’t. So if the SCFA aren’t there and your gut lining becomes weak, the bouncers at the club are essentially off duty and bad things can then get into your body that should not be there.

This whole process will put your body into an “alert” mode, which will make the security inside the club go crazy trying to find the bad guys. In turn, your immune system gets turned on and you have increased inflammation in your gut and also the rest of your body. This can then increase risk of chronic disease, general inflammation, and weight gain. Then your whole body is inflamed and irritated and angry and in pain. Therefore, having enough good organisms in your gut to produce those SCFA building blocks keeps your gut lining happy, and all of your “bouncers” are on staff, ready to report for duty, and do a great job at keeping things where they need to be.

A healthy gut microbiome can also reduce inflammation by helping to digest phytonutrients. Phytonutrients are special nutrients from plants that gives different plants their colors (for example, blue in blueberries, orange in carrots, green in kale or lettuce). It’s these phytonutrients that are really, really powerful antioxidants which help reduce inflammation in our body. But we need our good tummy bugs to help us break them down so that we can then absorb them. So if you don’t have the right type of organisms in your gut, you won’t break down these nutrients. That means even if you’re eating healthy foods, you won’t be able to utilize them all the way or it might take more time to see benefits. This, of course, can change over time.

Gut Bacteria Can Control Your Calorie Burn and Hunger Levels

How does gut health affect weight? The third point I want to mention is about bad or good gut bacterias and how they can affect your hunger levels. There’s something called LPS or lipopolysaccharide. This is actually a toxin that is in certain types of bacteria which are not helpful. These bad bacteria can actually break down your gut lining and impact your mitochondria and how you produce energy. These bad bacterias can cause something called “metabolic endotoxemia”, where your mitochondria are not producing energy correctly and affects how many calories you burn. It’s kind of like a one-two punch here… If you have too many of these bad bacteria, your gut lining is weakened and isn’t able to repair itself AND your body’s energy consumption is malfunctioning.

On the other hand, certain bacteria directly impact insulin resistance positively—Akkermansia and bifido bacteria specifically. In emerging studies on cancer patients receiving immunotherapy, it is shown that they respond much better to their treatment if they have abundant levels of the good bacteria, Akkermansia.

Similarly, bacteria in your gut can control your hunger hormones. The ones that are beneficial tend to help you feel more satisfied faster and not get as hungry as fast. The ones that are more inflammatory and “bad” bacteria will make you feel not as full and not as satisfied after eating.

Recap: How does gut health affect weight?

So you can see here, there’s a few different ways that your microbiome can impact your gut and weight.

(1) You’ve got different types of bacteria effecting how many nutrients you are absorbing and digesting.

(2) You’ve got inflammation, either increased or reduced, depending on what your microbiome looks like.

(3) Your hunger hormones are controlled by good and bad bacterias.

Those are three different ways your microbiome and gut health affects your weight—for better or for worse. If you’re not convinced by now that you need to go take a close look at your gut health, especially if you’re dealing with unwanted weight loss or weight gain, I encourage you to do further research. Don’t just ever take my word for it. I want you to use discernment and wisdom. I want to start a spark in you to go research and learn more and take control of your health. So, what should you do next?

How Your Gut Health Impacts YOU

What do you need to do with this information to consider and take care of your gut health and gut microbiome?

1. Make a plan.

First, sit down and have heart to heart with yourself. Write out:

• What are your goals?
• What do you want your life to look like?
• Are you satisfied with how things are right now or do you really want to change?

This is going to keep you motivated as you continue to make changes in your lifestyle.

 

2. Make small adjustments to your lifestyle and diet.

The second thing that you can do is make small lifestyle changes.

• Eat a diet that is going to help those good tummy bugs thrive (rich in fiber, rich in phytonutrients, etc.).
• Focus on good, consistent, and adequate sleep.
• Incorporate some sort of movement or exercise throughout your day.
• Manage your stress with relaxation techniques and mindset work.
• Take a look at your environmental toxins (personal care products, cleaning products, air quality, etc.)

3. Own the process and enjoy the journey of transformation.

Don’t be so focused on the end goal that you lose motivation. You won’t see results in two days. Try to fall in love with the transformation of becoming this new and improved version of yourself—a more vibrant and more healthy you. Go back to that first step where you’re really envisioning what you want your life to look like, and hold on to that. That is how you really get the lasting results.

 

4. Set strong boundaries.

Set some boundaries. Manage your time. Say no more often. Recognize if something is getting worse. Go back and refocus to get you back on track.

If all of that feels sounds great, but it feels overwhelming, this is exactly what I help my clients with in my signature six-month program, Gut Rehab. Check it out if you feel like you need support, guidance, and external motivation to make these changes. Remember, being sick is more costly over time than investing in your health now.

I hope you are feeling inspired and empowered to take bold action towards your health goals.