The Dangerous Relationship Between Salmonella and Yeast in Your Gut

• Candida colonization is actually common — This yeast is found in the guts of more than 60% of healthy people. Alone, Candida does not usually trigger disease, but under the right conditions, it becomes pathogenic. In people with inflammatory bowel diseases like Crohn’s disease, Candida levels are often higher and tied to flare-ups.

• The researchers used two main groups of mice — In one group, the mice were first given antibiotics to change their gut environment. In the other group, the mice were colonized with Candida albicans without antibiotics. Both groups were then infected with Salmonella, using a setup where there were 10 Salmonella cells for every one Candida cell.

The scientists checked the mice at 24, 48, and 72 hours to measure how much Salmonella was in the gut, whether it spread to the liver and spleen, and how much weight the mice lost.

• The scientists also worked with human colon cells — These cells were exposed to Salmonella alone or with Candida, again using a 10:1 ratio. To make sure results were accurate, they also ran controls using dead Candida or other compounds.

• To measure the results, the scientists looked at many different markers — They ran sequencing to see which genes were turned on, measured amino acid levels in the gut, checked inflammation signals in the blood, and examined tissue samples to see how the body responded.

• The findings clearly show that Candida tips the balance in Salmonella’s favor — When Candida was present, Salmonella grew more in the large intestine, spread more often to the liver and spleen, and caused more weight loss in the mice. In human cell tests, Candida made it easier for Salmonella to invade. Gene studies showed that Salmonella’s invasion systems switched on whenever Candida was nearby.

• One of the most striking details uncovered was the role of a Salmonella protein called SopB — This protein essentially acts like a signal flare, prompting Candida to start releasing the amino acid arginine. Arginine is usually harmless, but here it plays a dangerous role. Once released, it flips on Salmonella’s invasion machinery while at the same time reducing your body’s inflammation signals. Simply put, it suppresses your immune system, while allowing the bacteria to proliferate.

On the other hand, adding lysine, another amino acid, partially reversed the changes. This suggests that the balance of nutrients in your gut directly shapes how aggressive an infection becomes.

• This Candida-Salmonella relationship can be dangerous for vulnerable groups — These include people who are undergoing antibiotic treatment. Antibiotics lead to the proliferation of fungi, including Candida, in the gut. As a result, these drugs make Salmonella infections much worse. Ironically, antibiotics are sometimes prescribed for severe Salmonella cases, such as when bacteria have already spread to the bloodstream or if the patient is immunocompromised.⁵

• The team used several models, including the tiny worm Caenorhabditis elegans as a living host — They also used lab cultures of fungi and bacteria grown together. What they discovered was surprising — instead of helping each other, Salmonella actually worked against Candida, weakening its ability to grow and survive.

• When worms were infected with both Candida and Salmonella, Candida lost filamentation, one of its strongest weapons — Filamentation is when Candida shifts from a round yeast form into long, branching filaments that help it stick to tissues and invade. Without this ability, the yeast is less able to cause damage.

The study showed that Salmonella released a secret substance that stopped Candida from making these filaments, suppressing some of its harmful traits and reducing its invasive power.

• The researchers also tested what happened in liquid culture at two different temperatures — At 86 degrees F (30 degrees C), Candida survived longer, but at 98.6 degrees F (37 degrees C), which is the normal temperature of the human body, Salmonella eliminated Candida much more quickly. By 48 hours at body temperature, Candida levels had dropped dramatically.

• Further tests explored whether Candida’s shape made a difference — They used special Candida strains — one that stayed mostly in yeast form and another that grew almost entirely as filaments. Salmonella was able to kill both, but it killed the filament-forming strain faster. Since filamentous Candida is usually the more dangerous form, this finding suggests that Salmonella targets the form of Candida that poses the greatest risk to your health.

• Salmonella also altered Candida biofilms — These are thick layers of microbes that stick together and protect themselves with a slimy coating. Candida is well-known for forming strong biofilms on medical devices and tissues, making infections very hard to treat.

When researchers placed Candida on silicone pads to grow biofilms, adding Salmonella sharply reduced the thickness and strength of these films. What’s even more interesting is that the culture fluid taken from Salmonella, without live bacteria present, was enough to weaken the biofilms.

• The antifungal activity depended on the growth stage of Salmonella — Culture fluid taken from Salmonella that had been growing for 16 to 24 hours had the strongest effect on killing Candida. This suggests that as Salmonella grows and matures, it begins releasing chemical signals or waste products that specifically harm Candida.

Scientists suspect this involves a type of “quorum sensing,” where bacteria release and detect chemical signals as their population grows, but the exact substance Salmonella uses has not yet been identified.

1. Cook your food properly to stop Salmonella at the source — Salmonella often hides in undercooked meat, eggs, or poultry, especially those from confined animal feeding operations (CAFO). Heat destroys Salmonella before it ever reaches your gut, removing the chance for it to team up with Candida.

Take the extra time to make sure your food is safely cooked — it’s one of the most powerful tools you have to block this dangerous partnership before it begins. Salmonella can also lurk in some raw fruits and vegetables, so always make sure to wash your fresh produce thoroughly.

2. Reduce your use of antibiotics unless absolutely needed — Antibiotics wipe out healthy gut bacteria, leaving empty space that Candida quickly fills. If you are someone who has needed repeated antibiotic courses, your gut balance is already tilted toward fungal overgrowth.

I recommend focusing on foods and habits that rebuild your microbiome after any necessary treatment — such as eating fresh fruits with pulp instead of packaged fiber or using dextrose water in small sips if your gut is sensitive. Restoring the right bacteria is the first step in keeping Candida from giving Salmonella an advantage.

3. Limit gut fuel that feeds harmful yeast — Candida thrives on certain gut environments, especially when diets are heavy in seed oils and processed foods that damage the gut lining. If your meals regularly include ultraprocessed foods, restaurant foods, and seed oils, swap them out for safer fats like grass fed butter, ghee, or tallow. This reduces the conditions that allow Candida to expand.

4. Balance your gut nutrients — The featured study highlighted that arginine released by Candida is what flips Salmonella into attack mode, while lysine helps counteract that shift. If you’re prone to gut problems, consider optimizing your nutrient sources. Whole food sources of lysine — such as eggs, raw dairy, or pasture-raised, organic meats — help you restore that balance. By tilting your diet toward foods rich in lysine, you make it harder for Candida to give Salmonella the upper hand.

5. Support your gut’s natural defenses — Your body already has defenses built in — like stomach acid and bile — that keep pathogens in check. If you often struggle with bloating, reflux, or digestive sluggishness, those defenses are probably weaker than they should be.

Simple steps like eating enough high-quality protein, avoiding alcohol, and getting daily movement all help restore stomach acid and bile flow. When those systems are strong, Salmonella and Candida both struggle to gain ground inside you.

6. Strengthen your gut environment with sun and rhythm — Your gut microbes work in harmony with your circadian rhythm. Spending most of your day indoors or staying up late under artificial light keeps your body from setting that natural rhythm.

I recommend getting daily morning sun exposure and following a regular sleep schedule to optimize your circadian rhythm and improve your gut immunity, so you can resist Candida overgrowth and prevent Salmonella from spreading deeper into your body.