do probtioics make your poop stink

Do Probiotics Make Your Poop Stink? (LEARN WHY)

For this read, I have reviewed user stories and scientific studies to find out if probiotics can make your poop stink and, if not, what could possibly be causing it.

It is a well-established fact that probiotics may treat conditions like gut dysbiosis and relieve gastrointestinal symptoms. In fact, I have covered why some probiotics may cause you to poop more than usual.

But still, users have reported getting smellier poop with probiotics which indicates their potential to cause them. However, experts have yet to research the causal relationship between the two.

Key Highlights
  • Gut bacteria play a crucial role in determining how your feces smell.
  • Smelly stools caused due to probiotics are a part of the adjustment phase and may eventually resolve on their own.
  • Some conditions like malabsorption syndrome or infections may cause foul-smelling stools, and probiotics may help in curing them.
  • Probiotics may improve stool frequency, and consistency, and reduce intestinal transit time.
  • Yourbiology’s Gut+ is a probiotic supplement that may help you get rid of smelly feces.

In this article, you will find the actual reason behind noxious stools, what effect probiotic consumption have on poop features, and the top two probiotics with minimal side effects.

Why Does My Poop Smell a Lot? – If Not Probiotics, Then What Could Be The Culprit?

Yes, considering the evidence from user experience, your poop may get smellier after probiotic intake. However, there is a lack of significant studies to justify that probiotic bacteria may be causing it. Nonetheless, gut bacteria majorly colonize the small intestine, and therefore they play crucial roles in determining how your feces smell.

So, in this section, I will share Reddit stories that suggest that probiotics may affect poop odor and also discuss some other possibilities that might be causing it.

Evidence From Reddit Stories

This user had poop with a bad smell that spread fast

Yggdrasil98 created this Reddit post to take people’s advice on whether or not he should be worried by his stinky poop after probiotics. 

He shared that he had taken the PB8 probiotic a day before, and the next morning he had to take a large poop that was mushier and easy to pass but had an awful smell that lingered in his bedroom. 

He didn’t face any pain or other symptoms and did consider the smelly poop to be caused due to his gut adjusting to the supplements.

To this, repliers suggested he check if he is low on fiber or if it was due to something he ate. 

Nonetheless, one of them agreed that this probiotic side effect might resolve after the adjustment period.

This user’s poop started to smell like hell after probiotics

Papercandy22 shared in this Reddit story that she took a probiotic supplement and yogurt to help with her constipation. After a few days, she had more frequent bathroom visits and softer stools, but they reeked like never before.

To this, many repliers recommended she lower her probiotics dose and see if it helps.

In a nutshell, it seems that smelly stools caused due to probiotics are a part of the adjustment phase and may eventually resolve on their own thus, it may not be a major concern.

So, here are other conditions that you need to consider as the cause of this symptom and how probiotics may help in curing them instead.

You May Have A Malabsorption Syndrome

Some conditions may reduce the efficiency of digestion or nutrient absorption from food which may cause foul-smelling stools. 

For instance, according to the MSD manual, when fats are inadequately absorbed in the digestive tract, they get released into the stool, which gives it a pungent odor (such feces are referred to as steatorrhea). 

Therefore, here are some ways in which probiotics may help reduce bad-smelling stools caused by malabsorption syndromes such as celiac disease or irritable bowel syndrome.

Celiac Disease (CD)

Celiac disease is a multifactorial autoimmune disorder that flares up in response to gluten protein intake and may damage the intestines.

According to, CD may cause more than 200 symptoms that vary for each person, but they generally cause diarrhea, constipation, abdominal pain, fatigue, and fatty, discolored, foul-smelling poop.

A comparative study on CD and non-CD children found that the former has a lower number of the Lactobacillus and Bifidobacterium genera in the gut.

It was also found that certain probiotics improve the digestion of gluten peptides and exert a protective effect on the intestine’s epithelial cells, which may reduce the symptoms.

Irritable bowel syndrome (IBS)

According to NHS, IBS is a disorder of the digestive system that does not have any defined cause but can be managed with certain strategies.

This disorder may cause symptoms like stomach cramps, diarrhea, constipation, or both, and smelly stools of altered consistency.

The research found that the Lactobacillus species are reduced in IBS type C, which may be one reason why these symptoms occur.

Correspondingly, a meta-analysis of more than 30 studies revealed that Lactobacillus and Bifidobacterium probiotics might improve IBS symptoms by strengthening the intestinal barrier, removing pathogens, and aiding the digestion process.

You Might be Infected

Infections like those caused by Clostridium difficile indicate gut dysbiosis. This may cause symptoms like diarrhea, fever, stomach pain, or smelly stools.

According to a systematic review of 19 articles, using probiotics based on Saccharomyces boulardii, Lactobacillus GG (LGG), or other Lactobacilli species as an adjunct therapy to C. difficile treatments, such as antibiotics, may improve their effectiveness.

What Happens To Your Poop When You Take Probiotics?


Scientific studies and user reviews suggest that taking probiotics may improve stool frequency and consistency.

Let me explain how this happens.

Probiotics May Affect Stool Frequency and Intestinal Transit Time

Studies have found that probiotics increase stool Frequency and decrease Intestinal Transit Time (ITT).

A review of 21 studies concluded that probiotics based on Lactobacillus or Bifidobacterium species might increase bowel frequency by 0.8 times per week in constipated adults as compared to the control. 

Although on the basis of comparative analysis, these are positive findings, other meta-analyses have even reported an improvement of 1.3-1.5 bowel movements per week.

Furthermore, probiotics may reduce intestinal transit time by up to 15 hours in constipated adults.

This finding is significant because if the food takes longer to pass through the intestine, it may cause harder stools and constipation.

With reference to the stats compiled by, the average intestinal transit time of a non-constipated person is 30 to 40 hours.

However, an intestinal transit time of greater than 72 hours would still be considered normal, and it may reach up to 100 hours in women.

So, if you are pooping less than three times per week, then it indicates constipation and a higher intestinal transit time, and this is your sign of taking probiotics.

Probiotics Improve Stool Consistency

Probiotics may positively impact stool consistency due to two main reasons.

One of them is that in a clinical trial, participants who were fed the probiotic Lactobacillus plantarum had a higher fatty acid concentration in their feces.

These fatty acids prevent the growth of pathogens, increase stool volume, and make it softer.

The other reason is the same that I mentioned above, their ability to shorten the intestinal transit time.

Probiotics – Ultimate Solution To Nasty Smelling Poop & Farts.

Probiotics are good bacteria that help to establish a healthier microbial diversity in the gut, which may aid nutrient absorption from food and cure gut dysbiosis, the two main causes of foul-smelling stool.

So, if you want to cure smelly poop caused by certain conditions, these are the two best probiotic supplements that you can try.

1. Yourbiology’s Gut+

Yourbiology Gut+ bottle

The Yourbiology probiotics have a gut-centered formula based on clinically proven bacterial strains and prebiotics. This supplement also stabilizes the vaginal microflora.

Its probiotic blend contains three Lactobacillus and one Bifidobacterium specie that have better tolerability and safety and may also help you get rid of stinky feces.

First is the L. acidophilus strain, which is proven by research to improve the digestion of food by breaking down sugars such as lactose into lactic acid and improving nutrient absorption.

Furthermore, it also prevents vaginal infections in women.

The next strain L. paracasei, improves immune function as studies have found that children who are supplemented with this probiotic are less likely to pick up on infections.

Moving forward, clinical trials suggest that the L. plantarum strain may alleviate IBS and other metabolic disorders.

A review of studies concluded that B.lactis reduce the frequency of gastrointestinal symptoms like flatulence, diarrhea, or stomach pain.

Apart from probiotics, it also contains the prebiotic fructooligosaccharide, which supports the survival and colonization of good bacteria in the gut.

On top of this, these supplements are based on the MAKtrek Bipass Technology that ensures that live bacteria are delivered to the intestine.


You can buy its one-month supply of 60 capsules for a retail price of $74.99 without shipping costs.


  • Helps improve IBS symptoms.
  • 40 billion CFU of four probiotic strains.
  • Contains prebiotics & delivers live bacteria.
  • Does not require refrigeration.
  • Preservative-free.
  • Doesn’t have gluten or soy allergens & GMP certified.
  • Offers a 60-day money-back guarantee.


  • Not available at physical stores.
  • Contains maltodextrin.
  • Has to be taken twice per day.

 2. Biotics 8

Bauer Nutrition Biotics 8

The Biotics 8 is not a regular probiotic supplement as it contains additional ingredients like vitamins and enzymes to promote digestive health and overall well-being. Plus it also supports the reproductive health of men.

The probiotic blend comprises six Lactobacillus, three Bifidobacterium, and a Saccharomyces cerevisiae species.

Both the Lactobacillus and Bifidobacterium species support immunity and gut health.

Out of all other strains, the L. plantarum specie is worth mentioning as it controls symptoms of IBS and promotes prostate health.

And Saccharomyces cerevisiae inhibits the proliferation of pathogens that cause diarrhea and helps to preserve the diversity of intestinal microflora.

Furthermore, a 2019 control trial performed on yeast probiotics showed that they improve the stool characteristics and symptoms of IBS. 

The prebiotic fiber in the formula is derived from chicory root and fructooligosaccharide, which nourishes the gut microbiome.

Last but not least, the digestive enzyme blend promotes digestion and minimizes the risk of gastrointestinal side effects such as bloating or indigestion.


You can purchase one bottle that contains 60 capsules for $74.99 and get it delivered for free.


  • Boosts digestion, immunity, and mood.
  • May help relieve IBS symptoms.
  • Contains 20 billion CFU of ten probiotic strains.
  • Free of gluten, dairy, and soy.
  • No preservatives & GMP certified.
  • Stored at room temperature.
  • 60-day money-back guarantee.


  • 3 capsules have to be taken every day.
  • Available on the official website only.
  • Proprietary probiotic blend.

Also read: Does Probiotics Change Your Poop Color?


Do Probiotics Make You Poop A Lot?

Yes, as mentioned above, probiotics may increase stool frequency. This may occur because, during the transitioning process, the small intestine may get overpopulated with bacteria which may carry out faster digestion and cause you to defecate more.

Do Probiotics Make Your Poop Weird?

Yes, probiotics may change your stool characteristics. In fact, it is a sign that your probiotic is working. 

Although many users suffer from diarrhea or constipation in the start (since your gut is establishing a healthier microbiome), the differences you see may eventually settle towards a more normal appearance.

Can Probiotics Make Stool Dark?

There is no solid evidence that may justify that probiotics’ stool color may be darker. However, research found that the stool color of infants who took probiotics changed to mustard yellow, whereas those who were formula fed had feces in the brown color spectrum. 

Therefore, getting a yellow stool after probiotics has a greater possibility than dark-colored stools.

Can Probiotics Cause Mucus In Stool?

Yes, users have reported getting mucus in stool after probiotic intake. In this regard, scientific studies have reported that probiotics alter mucus production to strengthen the gut barrier. Consequently, the mucus may get released in the stool as well.

Can Probiotics Cause Diarrhea?

Yes, diarrhea is a common side effect of taking probiotics and is suffered by many users.

Do Probiotics Make You Fart A Lot?

Yes, probiotics may cause gassiness while your gut is adjusting to them. 

Normally, when the undigested food enters the intestines, the bacteria breaks it down, releasing hydrogen, carbon dioxide, and methane as a by-product. But taking probiotic supplements may oversaturate the gut with bacteria, and when they rush to digest the food, causing excessive flatulence.

Why Do Probiotics Cause Smelly Gas?

Smelly farts with probiotics may occur if your supplements have prebiotics in them because they will feed both the good and bad bacteria in the gut. 

Or you might be taking lactose-containing probiotics while being lactose intolerant (knowing or unknowingly), which could make another reason.

Bottom Line

To conclude, probiotics basically regularize bowel movements and improve their consistency in constipated adults.

Their correlation with a smellier stool has not been established yet, but such an incidence cannot be disregarded since users have faced it. Besides this, if you have just started taking probiotics and suffer from this symptom, then it may resolve in a few weeks after your gut has finally accommodated the new bacteria.

However, if your symptoms seem more concerning, then consult your doctor as soon as possible.

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