Do Probiotics Help With Bad Breath? The Gut Health Connection

Bad breath isn’t just a minor inconvenience—it’s a widespread issue affecting millions.

According to the National Institute of Dental Research, around 65 million Americans experience halitosis at some point in their lives, while 50% of adults struggle with it occasionally.

Even more concerning, research suggests that over 80 million Americans suffer from chronic halitosis, a persistent condition that mouthwash and mints can’t simply fix.

Traditional solutions like mouthwashes, gum, and breath fresheners only offer temporary relief, but recent research is pointing to a deeper cause—your gut and oral microbiome. Could probiotics, commonly known for supporting digestive health, also be the key to combating bad breath at its source?

Let’s explore the science behind probiotics and their potential role in fighting halitosis—and whether they’re the game-changer you’ve been looking for.

What Causes Bad Breath?

Bad breath, or halitosis, isn’t just a minor inconvenience—it can impact confidence, social interactions, and even indicate underlying health issues. While diet and oral hygiene play a role, the root cause often lies in bacterial imbalances. Here are the most common culprits behind persistent bad breath:

• Poor Oral Hygiene – Inadequate brushing and flossing allow plaque and food particles to accumulate, creating the perfect environment for bacteria to thrive and release foul-smelling compounds.
• Oral Bacterial Overgrowth – Certain bacteria on the tongue, gums, and between teeth produce volatile sulfur compounds (VSCs) like hydrogen sulfide and methyl mercaptan, causing odors resembling rotten eggs or decayed food.
• Dietary Choices – Foods like garlic, onions, and coffee contain strong-smelling compounds that linger in the mouth and bloodstream, leading to persistent bad breath.
• Tobacco & Alcohol Use – Both contribute to dry mouth, reducing saliva production. Since saliva naturally washes away bacteria, a lack of it intensifies odor.
• Gut Imbalances – A disrupted gut microbiome can encourage the overgrowth of harmful bacteria, releasing unpleasant-smelling gases that may travel from the digestive tract to the mouth.

According to Dr. Michael Ruscio, DC, DNM, adjunct professor and clinical researcher, a recent study revealed that gut-related halitosis can be effectively treated by addressing digestive imbalances. In fact, 99% of participants who resolved their underlying gut issues also eliminated bad breath. This groundbreaking insight highlights the strong connection between gut microbiota and oral health. [9]

While brushing, flossing, and mouthwash are essential for managing bad breath, they only address surface-level issues. The key to long-term fresh breath lies in balancing both oral and gut microbiota.

So, how can probiotics play a role in eliminating bad breath at its source? Let’s explore the science behind their effectiveness.

Do Probiotics Help With Bad Breath​?

Probiotics—beneficial bacteria that support digestive and immune health—may also play a role in managing bad breath. Research suggests that an imbalanced oral microbiome, where harmful bacteria outcompete beneficial species, is a major contributor to halitosis.

A systematic review of seven studies concluded:

"It seems that probiotics (e.g., Lactobacillus salivarius, Lactobacillus reuteri, Streptococcus salivarius, and Weissella cibaria) may relieve halitosis in the short term (≤4 weeks)." (Huang et al., 2022) [1].

This suggests that probiotics may help by restoring microbial balance in the mouth and gut. But what other benefits do they offer for oral health?

Benefits of Oral Probiotics

May Prevent Plaque

One of the lesser-known but important benefits of oral probiotics is their potential to inhibit plaque formation. Certain strains, including Lactobacillus and Bifidobacterium, have been shown to combat bacteria responsible for plaque buildup.

A study conducted by the National Research Institute of Romania examined dogs with varying degrees of dental disease. Researchers found that probiotics effectively suppressed the growth of Staphylococcus, Streptococcus, Pasteurella, and Neisseria—bacteria known to contribute to plaque (Csilla Zambori et al., 2016) [2].

While human studies are still needed, these findings suggest that probiotics may play a similar role in reducing plaque formation in people.

Fight Bad Breath

As discussed earlier, probiotics can help restore microbial balance in the mouth, which is key to controlling bad breath. A study on Streptococcus salivarius K12 found that this probiotic significantly reduced volatile sulfur compounds (VSCs)—the gases responsible for foul-smelling breath.

Thirteen participants with high VSC levels first rinsed with chlorhexidine for three days, then took probiotic lozenges for two weeks. The results showed that:

• Eight subjects had significantly lower VSC levels after one and two weeks of probiotic use.
• Three subjects saw improvement after the first week.
• Two subjects showed no change.

Further analysis revealed that S. salivarius K12 actively inhibited odor-causing bacteria, confirming its potential as a long-term solution for halitosis (Burton et al., 2005) [3].

Manage Symptoms Of Gingivitis

Probiotics have also been explored as a natural approach to managing gingivitis. A clinical review analyzing probiotic efficacy found reductions in key markers of gum inflammation, including:

• Bleeding on probing (BOP)
• Gingival index (GI) (a measure of gum redness and swelling)
• Plaque index (PI)

These findings indicate that probiotics may help alleviate gum disease symptoms by supporting a healthier balance of bacteria in the mouth (Akram et al., 2019) [4].

Reduce Inflammation From Gum Disease

Scientific evidence also suggests that probiotics can help combat gum inflammation, which is a major factor in periodontal disease.

In one study, participants with plaque-induced gingivitis consumed probiotic yogurt daily for 28 days. After four weeks, researchers observed significant reductions in inflammation markers, leading them to conclude that probiotic yogurt may help mitigate gingivitis (Slawik et al., 2011) [5].

These results highlight how probiotics can serve as an accessible and natural way to support overall gum health.

Oral probiotics do more than just freshen breath—they help restore balance to the oral microbiome, preventing the overgrowth of odor-causing bacteria. By promoting healthy bacterial strains, probiotics support gum health, reduce plaque buildup, and even combat inflammation. But not all probiotics are created equal.

With various strains available, which probiotic is truly the best for bad breath? Let’s explore the most effective options backed by research.

Which Probiotic Is Best For Bad Breath​?

Certain probiotic strains have shown strong potential in reducing bad breath and improving oral health, including:

• Lactobacillus salivarius
• Lactobacillus reuteri
• Streptococcus salivarius
• Weissella cibaria

These strains have been extensively studied for their ability to lower VSC levels, reduce tongue coating scores (TCS), and improve plaque index (PI) (Huang et al., 2022) [6].

You can find these beneficial bacteria in fermented foods, high-quality probiotic supplements, and specialized oral health products designed to promote a healthier microbiome.

Oral Probiotics Foods Source

Before using any method to supplement probiotics, the first thing you should remember is that they are especially rich in our daily food sources. Food sources rich in Probiotics include:

• Yogurt: Rich in Lactobacillus, Bifidobacterium, and other beneficial bacteria.
• Kefir: A fermented milk beverage, abundant in probiotics.
• Miso, Tempeh: Fermented soybean products that also contain probiotics.
• Kimchi, pickles, pickled mustard greens: Fermented vegetables containing lactic acid bacteria that benefit the body.
  

To better understand the probiotic content in these foods, here is an estimated breakdown of their probiotic levels:

Please note that these values are approximate and can vary based on factors such as the type of ingredients, fermentation method, fermentation duration, and storage conditions.

In addition to obtaining probiotics from natural food sources, people can also improve their oral health and combat bad breath through various probiotic-based products.

While fermented foods provide beneficial bacteria that support gut health, targeted probiotic formulations specifically designed for oral care can deliver even more direct benefits.

How to Use Probiotics for Bad Breath and Oral Health

Gum

Probiotic chewing gums and lozenges provide a simple and enjoyable way to introduce beneficial bacteria into your mouth. These products are widely available in pharmacies and online, making them an easy addition to your daily routine.

Some toothpaste and mouthwash formulations now contain probiotics designed to support microbial balance in the oral cavity. Using these as part of your regular oral hygiene routine can help maintain a healthier oral microbiome.

Toothpaste

Nowadays, there are also some toothpastes that contain probiotics that can help you supplement the process of protecting your teeth. With these products, you just need to brush your teeth after breakfast or twice a day as usual to add probiotics to your oral cavity.

This will be a suitable choice for those who do not like sweets/gum and want to save time on health care. However, the amount of information probiotics can add in this way remains uncertain, and the potential for use is much more limited than with other formulations.

Mouthwash

Besides toothpaste, a similar product, probiotic mouthwash, can also be added to your oral health routine to alleviate bad breath. Not only does it help wash away food residue, mouthwash provides additional probiotics to the mouth area.

Regarding usage, dentists recommend that you rinse your mouth after brushing your teeth to avoid toothbrush foam and water washing away the mouthwash solution.

Supplements

For a more targeted approach, probiotic supplements—especially chewable tablets and lozenges—can be a convenient and effective option for improving oral health and reducing bad breath.

Unlike traditional probiotic supplements that focus on gut health, these are specifically formulated to introduce beneficial bacteria directly into the oral microbiome, helping to outcompete odor-causing bacteria.

When choosing a probiotic supplement for oral health, look for strains such as:

• Streptococcus salivarius K12 & M18 – Known for their ability to reduce bad breath, inhibit harmful bacteria, and support gum health.
• Lactobacillus reuteri – Helps control plaque buildup and promotes a healthier oral microbiome.
• Lactobacillus paracasei – Supports enamel protection and reduces cavity-causing bacteria.
• Lactobacillus salivarius – One of the most effective strains for reducing bad breath, L. salivarius helps suppress harmful bacteria like Porphyromonas gingivalis and Fusobacterium nucleatum, both of which are linked to gum disease and halitosis. Studies suggest it can also help with inflammation and overall gum health.

Many users have reported positive results in the probiotics supplement’s review. Johan Van Aarde, for instance, shared his experience:

"I used the whole bottle, and these are definitely effective. Just give it time. The taste is not too bad—I let them dissolve in my mouth." *

A growing number of people struggling with chronic bad breath have turned to probiotic supplements for relief, also sharing their experiences in online discussions. One particularly insightful conversation highlighted how Streptococcus salivarius K12 helped a user overcome five years of persistent halitosis.*

Based on the discussion, 64.3% of the comments expressed positive sentiment toward the effectiveness of probiotic supplements, particularly Streptococcus salivarius K12.

Another individual recounted how no amount of mints or oral hygiene could mask the "poop-like" smell of their breath. They were hesitant to talk close to others and even had a colleague step back during a conversation. After starting probiotic supplements and cutting out sugar, they noticed a dramatic improvement.

However, results aren’t always immediate. One user warned:

"Start with half a pill and see how your stomach feels first. It caused major bloating for me in the first two days, plus constipation. But it got easier afterward. Also, cut down on sweets during this time—bad bacteria feeds on sugar."*

Another key takeaway from the discussion was that timing matters. Some users found that probiotics work best when taken 30 minutes before a meal, particularly with oatmeal and milk, as suggested in related studies.

Side Effects of Oral Supplements

While probiotics are generally safe, a systematic review on their side effects in adults with inflammatory bowel disease noted mild gastrointestinal discomfort, including nausea, bloating, and changes in stool patterns (Dore et al., 2019) [7]. However, these effects were temporary and typically resolved on their own.

Conclusion

Probiotics are a powerful tool for improving oral health and combating bad breath. When combined with proper oral hygiene and regular dental care, they can significantly enhance microbial balance in the mouth, helping to reduce halitosis and support overall wellness.