How Probiotics Can Help You Lose Weight Faster

How to use Probiotics for Weight Loss: How Much You Need & Which Work Best

Are bad bugs in your gut making weight loss impossible?

It turns out that the type of bacteria in your GI tract has a strong influence on both your weight and your ability to lose weight. 

This means that putting in the “right” type of bugs in your gut can actually help with weight loss. 

But how do you do this?

By using ultra-potent, targeted, and specific probiotics. 

This isn’t just opinion either, studies have shown that certain species found within specific probiotics (1) promote weight loss through multiple mechanisms which we will discuss in this article. 

The catch?

You have to use the right type of probiotics and at the right dose. 

Let’s talk about how probiotics help with weight loss, but more important, which ones to use: 

Do Probiotics Help with Weight Loss?

To start, we know that people who are overweight have certain changes to the bacteria in their GI tract. 

Broadly this change is manifested as an imbalance between two major bacterial forces: Firmicutes and bacteroidetes. 

How exactly this change in bacterial concentration results in weight gain is not completely understood but we do know for sure that changes in bacterial species in your gut result in weight gain. 

For instance: ​

It has been shown that dairy products may increase the growth of certain bacteria in your gut (2) (lactobacillus species) which then alter hormones and food absorption potentially leading to weight gain in susceptible people. 

Meanwhile, other studies have shown that diets including fruits (and other high polyphenol-based foods) like apples, pears, grapefruit, and green tea can actually help with weight loss by promoting the growth of beneficial bacteria in the gut.

This may explain why so many people do poorly on heavily processed foods and why patients who remove dairy and adopt a plant-based, whole-food diet tend to rapidly lose weight (3).

How probiotics help with weight loss

We obviously know that food can help with weight loss, but what about probiotics?

Well, just like food, probiotics have been shown to help with weight loss through a variety of mechanisms.

But are all probiotics created equal?

Not by a long shot.

For starters, only certain strains and species of probiotics have been shown to be effective. 

For reference please see this list of probiotics that have been clinically shown to help with weight loss: 

You can find more information about my recommended probiotic designed for weight loss that includes these species here

The fact that these probiotics help with weight loss provides you with a very valuable opportunity to use them to your advantage and assist with weight loss. 

Taking probiotics for weight loss may seem very attractive to many people but in order to get results, you need to make sure you follow several rules. 

Rules for achieving weight loss with probiotics:

#1. Always use multiple species -> studies show that patients lose more weight (9) when they use probiotics that contain multiple species. 

You need to realize that there are hundreds of bacterial species in your gut RIGHT now. 

Taking 1 (or a few) probiotics does not allow for the kind of diversity that exists in your gut which means that people don’t usually respond well to these types of probiotics. 

When it comes to weight loss you will want to use a probiotic that contains at least 10+ different strains or species of probiotics. 

#2. Use a high enough dose (> 300 billion CFUs).

Beyond taking 10+ species you will also want to make sure that your probiotic has a high enough concentration of bacteria in each serving. 

It’s easy to get a probiotic with multiple species but it’s difficult to find a probiotic with multiple species AND with a high concentration. 

If you aren’t aware the concentration of probiotic bacterial concentrations is represented as CFU which stands for colony-forming units. 

For weight loss, you will want a probiotic that has several hundred billion CFUs in EACH serving (I recommend > 300 billion CFU per serving).

#3. Use probiotics daily and combine them with other weight loss therapies (never use probiotics by themselves)

Lastly, you want to remember that losing weight will always be more complex than simply taking a single probiotic and hoping for a miracle. 

Instead of thinking of probiotics as a miracle weight loss pill, you want to think of them as a perfect complementary treatment that synergizes with dietary changes, lifestyle changes, and other supplements to help promote weight loss at multiple levels. 

probiotics as a complementary treatment for weight loss

Probiotics will help modulate the number of calories that you absorb, and how much energy you burn, and reduce systemic inflammation but all of these benefits are multiplied when combined with something like high-intensity exercise or a whole food-based diet. 

6 Ways Probiotics can Help you Lose Weight

We know that weight gain is much more complex than simple “energy balance” or the calorie in minus calorie out model. 

If that were the case then why would taking certain supplements like fish oil, alpha lipoic acid, probiotics, or berberine result in weight loss without any changes to appetite or food intake? ​

I’ve explained in previous posts how those supplements help with weight loss but what about probiotics?

Well, for starters, we know that certain bacteria alter the absorption of food in your GI tract but they also create byproducts that may contribute to weight gain: 

Studies have indicated that certain bacteria produce something called short-chain fatty acid and these SCFs promote low-grade inflammation (10) which causes insulin resistance and increased leptin resistance downstream: 

production of short chain fatty acids and weight gain

These factors collide and result in hormone imbalances like leptin resistance and insulin resistance which make you gain weight. 

Believe it or not, this is just ONE of the ways that bacteria may cause weight gain in your body.

But instead of focusing on how they cause weight gain, let’s discuss how they can cause weight loss: 

#1. Reduce Caloric Absorption and Influence Food/Nutrient Breakdown

The first way that bacteria contribute to weight loss is through their unique ability to break down food and contribute to the absorption of calories. 

Studies have shown (11) that the number of calories (known as “energy extraction”) that you absorb from your food is based (at least in part) on the concentration of certain bacteria in your gut. 

how probiotics alter food absorption for weight loss

Let’s break this down:

Let’s say you have two people who both consume 100 calories of food.

Person A has a “healthy” microbiome (existing concentration of bacteria in their gut) because this person takes probiotics, exercises regularly, and tries to eat as healthy as possible.

When person A consumes 100 calories they absorb 70 calories of the 100 that they consumed

Person B, on the other hand, has a different microbiome that is the result of eating processed foods, not eating enough fruits and vegetables, and not exercising regularly. 

When ​person B consumes 100 calories they absorb 90 of the 100 calories that they consumed

This concept shows us that two completely different people can consume the exact same TYPE and AMOUNT of food but do completely different things with that energy.

Person B will obviously end up gaining more weight over time even if we fed both person A and person B the exact same diet. ​

This concept helps illustrate the importance of a healthy microbiome and its influence on both nutrient AND caloric absorption of food. 

The difference between the calories absorbed by both individuals results from a variety of factors including the fact that certain bacteria may actually feed off of some of the food that we consume which results in less absorption.

In addition, bacterial concentrations may result in increased movement (through serotonin) of the intestinal tract which may also reduce the absorption of food as it is lost through bowel movements. 

Regardless of the mechanism, we know that this difference does indeed exist and may be playing a role in obesity in many people.

By the way, this connection may explain the phenomenon seen when two people consume the same food, and yet one continues to gain weight while the other stays the same. 

Does this sound familiar to any of you? ​

  • Bottom line: Restoring the right type of bacteria in your gut may reduce the number of calories and energy that you consume without reducing the total amount of food that you eat. 

#2. Influence Appetite, Mood and Reduce Food Cravings

The bacteria in your gut also influence the number of calories that you consume. 

It has been shown that the bacteria in your gut (12) influence host behavior including host appetite and food preferences. 

This influence is mediated through a mechanism known as a positive feedback loop and it makes perfect sense. 

Bacteria in your gut secrete certain molecules and enzymes that trigger cravings for the type of food that sustains THAT bacteria and allows that bacteria to grow and survive.

Let’s break this down:

When you eat processed foods or when you eat out you are promoting the growth of certain bacteria in your gut.

As this bacteria grows and becomes the dominant force in your gut it secretes enzymes that make you crave the types of foods that it needs to grow.

​So you start to crave processed foods, sugars, bread, pasta, etc. 


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Because that’s the type of food that the bacteria in your gut need to survive.

In addition, these bacteria also cause changes to your mood through their mediation of neurotransmitters such as serotonin (13).

Changes to serotonin then feedback to your brain to increase your appetite. 

So now you are not only craving poor food choices but you want more than is necessary (you overeat).

So taking high-quality probiotics may reduce food cravings and reduce the total amount of food that you eat resulting in weight loss. 

  • Bottom line: Probiotics may reduce the concentration of negative bacteria in your gut and promote healthier food choices. 

#3. Improve Metabolic Function and Reduce “Fat Storing” Hormones

Probiotics seem to also have a direct impact on certain “fat storage” hormones. 

Hormones such as leptin and insulin directly result in increased fat storage and high levels are seen of both hormones in patients who are overweight. 

Taking probiotics may help reduce these hormones which may help with weight loss. 

Beyond the effects that probiotics have on leptin and insulin, they also seem to have at least some influence on sex hormones such as testosterone, estrogen, and progesterone. 

In particular, probiotics have been shown to help women with PCOS. 

Studies have shown (14) that 12-week use of daily probiotics helped reduce weight, improve cholesterol markers, and reduce insulin and triglyceride levels. 

Connection between intesitnal dysbiosis and metabolic syndrome

The exact way that probiotics help reduce these fat storage hormones is not well known but appears to be through a combination of reducing bacterial cytokine release, lowering inflammation, and reducing fat liver storage (hepatic steatosis). 

​A point worth mentioning:

Reversing fat storage hormones can be a complex problem so make sure you use much more than just probiotics if you suffer from existing hormone imbalances such as leptin resistance and insulin resistance. ​

  • Bottom line: Probiotics may help reduce fat-storing hormones such as leptin and insulin by reducing bacteria inflammatory markers. 

#4. Lower Local and Systemic Inflammation

​Inflammation has always been implicated as a key component in weight gain. 

Inflammation can result on a systemic level (which means it’s in the entire body) and on a local level (which means it’s just in the gut).

What you may not realize is that certain bacteria promote inflammation both at the systemic and local levels.

This low-grade inflammation triggers a cascade of changes that promotes hormone imbalance, changes to bacterial concentration, and therefore weight gain.

​Intestinal syndromes such as small intestinal bacterial overgrowth occur when certain bacteria (even good bacteria) grow and overpopulate the GI tract. 

SIBO results in local inflammation which may reduce thyroid function and metabolism leading directly to weight gain.

Reversing this condition is possible through a combination of changes including taking probiotics and prebiotics. ​

In addition to reducing local gut inflammation, probiotics have also been shown to reduce systemic levels of inflammation (15), even in patients with autoimmune conditions. 

  • Bottom line: Probiotics can be used to outcompete both good and bad bacteria and reduce local and systemic inflammation. 

#5. Promote Regular Bowel Movements

Probiotics have been shown to help regulate and normalize bowel movements (16) which are a serious problem for many people. 

Constipation defined as less than 1 healthy bowel movement per day may result in the retention of bacterial byproducts and bacterial load in general.

Constipation also results in symptoms such as bloating and water retention which cause an increase in total body water and therefore in weight.

Taking probiotics may help reduce constipation and improve bowel movements which may reduce weight by limiting excessive water retention, bloating, and constipation. ​

So while promoting regular bowel movements doesn’t directly result in fat loss, it can result in weight loss.

Just realize that this loss in weight is not true fat loss like the other mechanisms listed above. ​

  • Bottom line: Probiotics help regulate bowel movements which may reduce total body water and weight. 

#6. ​Increase Metabolism & Basal Metabolic Rate

​Your metabolism helps to control the total amount of calories that you burn AT rest throughout the entire day. 

This amount of calories is one of the most important factors that determine if your body is able to lose weight.

In addition, your basal metabolic rate is responsible for determining if your body will maintain weight loss.

Probiotic supplementation has been shown in certain individuals to increase basal metabolic rate.

This doesn’t mean that taking probiotics will help increase your metabolism if it’s normal, but it does mean that some people with already damaged metabolisms may find a “normalization” of their metabolism with probiotic supplementation.

This effect is mediated through the influence of carbohydrate and fat metabolism at the cellular level.

Bifidobacteria and lactobacilli strains (17) have both been shown to regulate metabolism in people. 

  • Bottom line: Taking probiotics may help improve the metabolism in certain people who have a lower-than-normal metabolism, to begin with. Probiotics may not increase your metabolism if it’s already normal. 

The Best Probiotic for Weight Loss + How to Use Them

​Does this mean that you should start taking the next probiotic that you see at the grocery store to help with weight loss?

Not by a long shot.

I’ve gone over the rules on how to pick the best probiotic in previous posts so we won’t spend a lot of time on it here.

You should know that if you want to lose weight you will need to use a very high-quality, multispecies, and multi-strain probiotic. 

Tips for using probiotics to help with weight loss:

In addition to using the RIGHT probiotic, you will also want to make sure that you follow these basic rules to help promote more weight loss to get the best results: 

#1. Use probiotics consistently

It’s important ​that you remain consistent with your probiotic usage. 

Forgetting to take your probiotic consistently will reduce your results long term. 

When it comes to high-potency probiotics you don’t necessarily need to take them every single day, but you should start out with a strict regimen for the first 1-2 months and then reduce the frequency over time. 

If you use my recommended probiotic you should use 1 packet per day x15 days then 1 packet every other day x30 days. 

From that point on you should be okay to use 1 packet every 2-3 days. 

#2. Combine the use of probiotics with regular exercise

You will always get better results if you combine probiotic usage with exercise.

Exercising helps promote the growth of healthy bacteria in your gut and also helps naturally regulate your bowel movements.

#3. Change your diet to include nutrient-dense, real whole foods

Putting the right type of bacteria in your gut is helpful but in order to promote the growth of healthy bacteria, you will also need to consume healthy foods.

Healthy bacteria in your gut will feed off of the undigestable remnants of whole foods.

This promotes their growth and will also directly help them feel better and lose weight in the process. ​

#4. Take other supplements in addition to probiotics

While probiotics can help you lose weight they certainly aren’t the only supplement that has this property.

You should consider adding other highly effective supplements such as alpha lipoic acid, berberine, and fish oil to your probiotic regimen.

#5. ​Give yourself time (at least 6 months)

Losing weight is a process and it can sometimes take time. 

Don’t be discouraged if you don’t lose 5-10 pounds within 1-2 weeks! 

If you want to lose weight and keep it off you should focus on losing only about 5-10 pounds per month.

This is a healthy amount of weight to lose and if you follow the instructions above you will lose weight AND keep it off long-term. ​

Back to you 

​Probiotics can help you lose weight in a variety of ways. 

Does this mean that they are a miracle weight loss pill?

No, but they can be very effective for certain people with GI-related issues or hormone imbalances.

If you decide to take a probiotic for weight loss make sure that you use more than 10+ strains/species at a dose of more than 300 billion CFU per serving and use it in combination with other weight loss therapies.

​Now I want to hear from you:

Have you tried taking probiotics for weight loss?

Did it work for you?

Why or why not?

Leave your comments below! ​

Scientific References


















how probiotics can help you lose weight faster

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About Dr. Westin Childs

Hey! I'm Westin Childs D.O. (former Osteopathic Physician). I don't practice medicine anymore and instead specialize in helping people like YOU who have thyroid problems, hormone imbalances, and weight loss resistance. I love to write and share what I've learned over the years. I also happen to formulate the best supplements on the market (well, at least in my opinion!) and I'm proud to say that over 80,000+ people have used them over the last 7 years. You can read more about my own personal health journey and why I am so passionate about what I do.

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