One question we frequently get asked is whether the Lactobacillus sakei in Lanto Sinus colonizes in the sinuses. What happens after a person stops taking probiotic Lactobacillus sakei? Does it stay there permanently to live and multiply?

This is a good question, but one with a complex answer. The short answer is that the Lactobacillus sakei can live in the sinuses for a while (weeks or months), dominate over harmful (pathogenic) bacteria, and cause beneficial changes in the sinuses. This appears to be short-term colonization. But whether permanent colonization of the Lactobacillus sakei can occur in the sinuses of people who suffer from sinus infections is unclear.

The good news is that even if Lactobacillus sakei doesn’t colonize long-term, the beneficial changes in the sinuses and improved sinus health are long-lasting, even months after last using the probiotic.

Lactobacillus sakei is a beneficial bacteria found in the sinuses of healthy individuals, and diminished or absent in those with chronic sinusitis. One reason Lactobacillus sakei is so important to sinus health is because it dominates over and suppresses harmful bacteria (e.g. Staphylococcus aureus).

Continuous Sinus Improvement

Even in someone who has been sick with chronic sinusitis for many years, there typically is rapid improvement of sinus health after first introducing Lactobacillus sakei into the respiratory system. How long one initially needs to use Lanto Sinus varies – it can be under a week or longer. Variation occurs because everyone’s sinus microbiome (microbial community of bacteria, viruses, fungi) is different. Our personal microbiomes are unique!

What people typically experience is that over time the sinuses keep improving, even when Lactobacillus sakei is rarely used. When the sinuses feel healthy it feels as if there is microbial balance - with the microbes coexisting in harmony. Perhaps this can be viewed as long-term colonization, with the sinuses just needing an occasional boost (e.g. after a virus). It is interesting that people (ourselves included) find that another effect of Lactobacillus sakei is that once there is sinus improvement, the person also has fewer upper respiratory infections.

Unfortunately, studies examining how the sinus microbial community changes after using Lactobacillus sakei have not been done. At this point we have our own and user experiences (citizen science), sinus microbiome research, and evidence from gut probiotic studies guiding us.

Gut Probiotic Research Shows Colonization Can Occur

A few studies have specifically looked at whether probiotics permanently colonize in the gut (small intestines) and this may offer some clues about what is going on in the sinuses. Probiotics are beneficial bacteria that are used in supplements and foods. The typical finding from gut research has been that there is no colonization from probiotics, and the bacteria leave the body within a week.

Researchers determine what bacteria are in a person’s gut by analyzing the bacteria in the person’s stool. The assumption is that the bacteria in the feces is what is in the intestines. Once a bacterial species is no longer found in the feces, that means it has passed through the gut and left the body.

There is agreement that health benefits can occur from probiotics, even though the probiotics are in the gut a relatively short time. Probiotics may exert their effects on human health a number of ways without colonizing -  such as changing the function of the person’s resident microbes, interacting with immune cells, inhibiting pathogens, and promoting stability of the microbial community (microbiome).

Several recent studies examined this issue in greater depth and found that probiotics don’t always just pass through the intestines - sometimes there actually is colonization of some probiotics.

In 2016 University of Nebraska researchers decided to see if they could deliberately get a beneficial bacteria to colonize in the gut of humans. They decided on one particular strain of Bifidobacterium longum that is found naturally in the human intestines, and which is found in many probiotics. Every day for two weeks 23 volunteers consumed 10 billion live Bifidobacterium longum in a drink. The researchers found that most people had excreted the B. longum soon after stopping the probiotic drink.

A surprising finding was that in 7 people the B. longum levels were still elevated 5 months after stopping the probiotic drink. It turned out that the people in which the probiotic B. longum persisted were those people who had lower levels of this bacteria when the study started. In other words, they had a vacancy in their gut microbial community that the probiotic filled. They also had fewer of certain bacterial genes in the gut which are involved in breaking down nutrients and carbohydrates.

A 2018 study by Weizmann Institute of Science researchers went even further in investigating the presence of probiotic supplement bacteria in the human gut. They took samples from the intestinal walls (endoscopies and colonoscopies!) and stool samples of volunteers before the start of the study, and again 2 months later. The volunteers ingested probiotics with 11 strains of bacteria for 4 weeks. The researchers found that in some people the probiotics didn’t colonize – the gut microbial community of these people rejected or resisted the probiotic bacterial species, so that the probiotics just passed through.

However, in several other people some of the probiotic species stayed or persisted in the guts, multiplied, and actually became part of the person’s gut microbiome by the end of the study. When the researchers examined the data further, they realized that people who had low initial levels of a probiotic species were more likely to accept that probiotic species into their gut microbial community and allow it to stay and multiply. But the amounts persisting varied among these people. Unfortunately, it is unknown how long the bacteria continued living in the gut after the study ended.

A different line of research shows that fecal microbiota transplantation (FMT) results in good colonization of a donor’s bacteria in another person’s gut. FMT is when healthy donor feces (which contains an entire microbial community of bacteria, fungi, viruses) are transplanted into a sick person (the host). The concept for doing this is to repopulate a sick person’s gut with an entire healthy microbiome – to correct the microbial imbalance (dysbiosis). Studies find that people incredibly sick with a Clostridium difficile infection may have miraculous improvement within hours of the transplant, and that gut microbial changes are still occurring many months later.

Gut Probiotic Research Findings That Apply to Sinuses

It appears that some of the gut research findings may also apply to Lactobacillus sakei and the sinuses.

One finding that applies is if a person has a lower amount of a naturally occurring bacteria, then adding that bacteria may result in the bacteria staying around and colonizing. The key seems to be using a species of bacteria found normally in the microbiome. Since Lactobacillus sakei occurs naturally in the sinuses and levels are diminished in people with chronic sinusitis, then the probiotic Lactobacillus sakei has a good chance of short-term and possibly long-term colonization.

A second conclusion from the studies is that because everyone’s microbiome is different and unique, the microbiome of some people will accept a specific probiotic and allow it to join the resident microbial community. But the microbiome of others may resist accepting the bacteria and so the bacteria will leave. The people more likely to accept a certain bacterial species are those who have low levels of that bacteria, and also if the bacteria fits in well with the person’s existing microbial community.

The FMT research shows that bacterial changes keep occurring many months after microbes are introduced into a person (the host). Perhaps the same occurs in the sinuses. While a person may feel sinusitis symptom improvement within hours of using Lactobacillus sakei, the bacteria may somehow still be influencing the sinus microbial community months later - even when probiotic Lactobacillus sakei hasn’t been used in months.

Summary: The Lactobacillus sakei found in Lanto Sinus can have positive effects on the sinuses even without permanent colonization. It appears that it can live and multiply successfully in the sinuses for weeks and months (short-term colonization). People reporting continual sinus health over a several year period may have long-term colonization. Future research will be very exciting!