Are There Any Probiotic-Based Vaccines Available?
Are There Any Probiotic-Based Vaccines Available?
Some people have various immunological reactions to vaccinations. A vaccine’s reduced ability to prevent disease can happen for a variety of factors, with potentially fatal or hazardous results. One aspect linked to vaccine failures is the correlations between the microbiota and immunological response after immunization. Sadly, there is conflicting research demonstrating the value of probiotics in modifying vaccination response (most likely due to the heterogeneity of probiotic strains, dosages, and routes of administration). The use of probiotics as vaccine adjuvants, however, is a different potential field of research.
We shall examine the supporting evidence in this piece.
An individual is protected from disease by a vaccine because it encourages the immune system to produce immunity to that disease. 4-5 million lives from diseases like measles, diphtheria, tetanus, pertussis, influenza, and COVID-19 are currently prevented each year thanks to vaccination.
A vaccination is made up of adjuvants and antigens
- Proteins or carbohydrates produced from the pathogen that an adaptive immune response is intended to combat are the typical components of antigens. With mRNA vaccinations, the antigen is created by the body.
- Adjuvants are chemicals added to vaccinations to boost the humoral and/or cellular response to an antigen that has been administered.
When the right antigen and adjuvant are used together, immune responses can be induced more quickly, powerfully, and persistently. Less antigens may also be required to produce protection. For the next 70 years after its introduction in the 1920s, alum was the only adjuvant that was authorized for use in humans. Five more adjuvants have been added to licensed vaccines since the 1990s, although the molecular mechanisms by which they function are still poorly understood.
Mucosal sites are where most infections enter the body. Due to its simplicity of administration and the common-mucosal immune system, mucosal vaccine delivery is appealing given that the defense of these barrier tissues is mediated by innate and adaptive immune responses.
LAB are potential candidates for mucosal vaccine delivery vectors due to their many benefits.
These benefits include easy, painless delivery through the oral or nasal mucosa, as well as affordability. LAB typically only evoke weak immunological reactions against themselves, instead producing large amounts of systemic and mucosal antibodies in response to the absorption of the produced foreign antigen by the mucosal immune system. Moreover, some orally delivered LAB may be used to generate specific immunity in the respiratory tract as well as the intestinal mucosa. This property may be employed to develop SARS-CoV2 vaccines.
For more than 30 years, the potential of LAB as a mucosal vaccine adjuvant has been known. Streptococcus gordonii, Lactococcus lactis, and several lactobacilli species are frequently used as vaccine vectors.
A graphic from a 2019 analysis shows the probiotic and commensal bacteria that have been shown to have vaccine adjuvant characteristics in both animal and human trials.
There are sadly not many vaccines accessible for use worldwide since the attenuated pathogen could revert to virulence.
New kinds of mucosal vaccine vectors, such as recombinant LAB as next-generation mucosal vaccine vectors, are required as a result of these safety concerns because of their inherent acid and bile resistance, stability at room temperature, and capacity to advantageously modulate mucosal innate and adaptive immune responses.
Do probiotics have a place in preterm birth?
Do probiotics have a place in preterm birth?
Unexpected early arrival is never a good thing, no matter how excited you are to meet a new baby. A serious problem around the world is preterm birth (PTB), which happens when a child is born before 37 weeks of pregnancy. The estimated 15 million instances of spontaneous preterm birth (SPTB) per year are the leading cause of infant death under the age of five. Ascending bacterial infections of the uterine cavity, one of the several risk factors for PTB, are responsible for the majority of spontaneous preterm births. Hence, the cervicovaginal microbiome has received greater attention recently.
Many risk factors can have an impact on foetal developmental plasticity, gestational age, or birth outcome even though the pathophysiology of PTB is poorly known.
Toxins, a high-fat diet, a family history of PTB, a lack of education, low socioeconomic status, a short pregnancy interval, an early or late pregnancy (before the age of 16 or after the age of 36), the use of tobacco or alcohol, high stress levels, hypertension, obesity or underweight, an infection, a short cervix, uterine anomalies, and previous miscarriages are some of the environmental and clinical factors included in this list.
The host cervicovaginal microbiota and quantities of produced metabolites can now be added to the list as regulators of the interaction between the maternal and foetal immune systems as well as the outcome of childbirth.
Women of reproductive age often have a cervicovaginal microbiota that is dominated by Lactobacillus species. In contrast, an aberrant microbiota is characterized by an excess of anaerobic bacteria such Mollicutes, Prevotella spp., Gardnerella vaginalis, and Bacteroides spp., as well as a low concentration of lactobacilli. By using a variety of processes, including the creation of lactate and hydrogen peroxide, lactobacilli inhibit the growth of infections, lowering the pH of the vagina.
It is commonly acknowledged that inflammation and intrauterine infection play a significant role in the development of spontaneous PTB, which is assumed to result from pathogen ascent from the vagina.
For instance, a rise in the pathogenic microbiota during the first trimester of pregnancy allows for the metabolic fingerprints of bacterial vaginosis (BV), which is closely associated with the risk of PTB. A reduction in lactobacilli, an increase in pathogens, and the production of pro-inflammatory cytokines are the hallmarks of bacterial vaginosis (BV).
The connection between the cervicovaginal microbiota and spontaneous PTB has been the subject of numerous investigations. Nevertheless, a 2022 analysis of the data revealed that the outcomes vary according to ethnicity. Importantly, one study discovered that Black American women had more species diversity and lactobacilli depletion than white women. Compared to white women, African American women had a higher prevalence of BV-related microbiota. Yet, it’s interesting to note that higher species diversity and a lack of Lactobacillus were regarded as PTB risk factors exclusively in white women, not in African American women.
Here are just a few of the important discoveries made during the review
- In a 2020 study, Lactobacillus crispatus was highly connected with full-term pregnancies, whereas other microbial communities were linked to PTB.
- There were larger concentrations of Lactobacillus crispatus, Lactobacillus gasseri, or Lactobacillus jensenii DNA in the vaginal swabs of an Australian cohort (mainly white women) who went on to deliver at term.
- L. crispatus and L. gasseri were found to play a protective effect in lowering the risk of PTB in a study from India.
- When compared to women who gave birth at term in a different study, the microbiota of women who underwent PTB exhibited higher richness and variety and higher Mollicutes predominance.
The predominance of Lactobacillus spp. in the healthy vaginal tract is well known to support vaginal homeostasis and prevent the colonization and proliferation of harmful microbes.
A number of methods are used by Lactobacillus species to exercise their protective effects, including the generation of bioactive substances, the competition for nutrients and adhesion sites, the lowering of vaginal pH through the production of lactate, and the modulation of host immunity.
A microbiota dysbiosis, for instance, has a direct impact on the production of microbial metabolites, and the presence of metabolites at higher or lower levels alters PTB metabolism. Short-chain fatty acids, polyamines, polyphosphates, and peptides are some of these metabolites. The other accepted pathways mentioned above may help explain why Lactobacillus spp. is protective in PTB.
It is currently unclear if altering the microbiota of the mother and the newborn by probiotic supplementation influences the risk of preterm birth and associated consequences, despite several clinical trials and meta-analyses.
The idea that maternal dysbiosis might act as a catalyst for preterm birth is supported by evidence. According to one study, probiotic therapy in late pregnancy may alter the vaginal microbiota by reversing the dysbiosis associated with more than 70% of cases of bacterial vaginosis and the rise in Atopobium. This dysbiosis can also result in preterm birth. Additional probiotics can also lower the vaginal pH to an ideal level after antibiotic therapy, encouraging the repair of the vaginal microbiota and moderating the inflammatory cascade frequently seen in preterm birth.
The use of probiotics to stop premature births has had conflicting outcomes, nevertheless.
Probiotic use during pregnancy did neither reduce or increase the risk of preterm birth before 34 weeks or before 37 weeks, according to a 2019 review.
There is still no clear evidence that using probiotics or prebiotics during pregnancy either raises or lowers the risk of preterm birth, according to another systematic review and meta-analysis conducted in 2018. The authors came to the conclusion that there is still insufficient data to justify the use of probiotics or prebiotics during pregnancy in order to avoid premature birth, bad pregnancy outcomes for the mother, or babies.
Colon cancer and probiotic short chain fatty acid production
Colon cancer and probiotic short chain fatty acid production
A significant factor in the development of colorectal cancer (CRC), which claimed 935,000 lives in 2020, is the colon microbiota (the second most deadly cancer worldwide).
Short-chain fatty acids (SCFAs), which have anti-cancer properties, cannot be produced when there is dysbiosis in the colon microbiota, which occurs during carcinogenesis. Certain probiotic strains produce SCFAs that target colon cancer cells in addition to having other anticancer capabilities, making them a promising new treatment option. In this essay, the most effective probiotics for the job will be discussed in light of recent studies.
Cancer of the colon and SCFAs
The fermentation of dietary fibers by gut bacteria results in the production of SCFAs, which are tiny molecules. Most of the colon’s SCFA content is made up of acetic, propionic, and butyric acid.
The regulation of inflammation, carcinogenesis, and intestinal barrier function are all impacted by SCFAs, according to numerous studies.
Butyrate, one of the primary sources of energy for colon cells, is one of the SCFA metabolites that has been shown to be essential for the prevention and treatment of colon cancer by encouraging the cell-cycle arrest and cell apoptosis (programmed death) of cancer cells and enhancing immunomodulation. Normal colon cells use butyrate as their main source of energy, whereas malignant colonocytes use glucose, which has been suggested as one way by which butyrate prevents the growth of cancer cells.
In fact, butyrate-producing bacteria have significantly decreased in CRC patients while the pathogens linked to the disease, particularly Fusobacterium nucleatum, have increased.
The three main fecal SCFAs were shown to be considerably less concentrated in those at risk of developing CRC than in healthy persons, according to a recent systematic review and meta-analysis of 23 research. Another study discovered an inverse relationship between fecal butyrate and CRC tumor growth.
Consequently, changes in SCFA levels may have an effect on colonic health and colonocytes’ propensity for abnormal proliferation and tumor development.
One method for enhancing CRC prevention and/or results is to modify the composition of the gut microbiota towards species that are more advantageous for the production of SCFA. Because of its putrid smell and terrible taste, butyrate administration by oral means is not considered to be ideal. Dietary fibers and partially digested proteins can potentially produce modulation, but only probiotics will be covered in this article.
Probiotics and Colon Cancer
Some probiotic strains have been shown in studies to create SCFAs, however the levels produced vary depending on the strain.
Several strains of Lacticaseibacillus paracasei, Lacticaseibacillus rhamnosus, Lacticaseibacillus rhamnosus, and Lacticaseibacillus rhamnosus were the subject of a recent study that aimed to describe the relative SCFA synthesis by these bacteria.
The results revealed that all of the examined strains produced butyrate at varying levels, but L. paracasei and L. rhamnosus strains produced butyrate at higher levels than the others. The results showed that butyrate production was influenced by strain type, temperature, and incubation time during cultivation.
The functions of the SCFAs were further defined: the SCFAs had a positive anti-cancer effect in the colon through a variety of mechanisms, including suppressing the growth of cancer cells, preventing the growth of pathogens linked to colon cancer, promoting the production of anti-inflammatory cytokines, and squelching the pathogen-stimulated pro-inflammatory cytokines.
Additional probiotic strains will probably also demonstrate promise as pertinent SCFA producers for utilization in conceivable CRC therapeutics.
What’s inside your yogurt?
What's inside your yogurt?
A popular fermented dairy product with many health advantages is yogurt. It not only gives us beneficial proteins and immune-stimulating compounds, but it also has the ability to transport probiotic microbes. Here, we’ll examine the benefits of including yogurt in your diet and how bacteria contribute to the creation of this dreamy, creamy white substance.
If you enjoy yogurt as much as I do, you might enjoy a serving of this white fantasy every day. probably for breakfast. But have you ever wondered how yogurt is manufactured from milk and where it comes from? Do you know why yogurt has such a lovely yet tart flavor? What if I told you that the superpowers of bacteria are the only reason yogurt tastes the way it does?
Sure, microbes generate great bread, wine, beer, and chocolate. But, yogurt is also produced from milk by bacteria. Here, we’ll examine the microorganisms that manufacture yogurt and the components that give it its creamy, sour, and healthful qualities.
How is your yogurt made?
Without our bacterial pals, yogurt would not exist. It’s interesting to note that only two bacterial species are required to produce this creamy white fantasy that is yogurt. Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus are the two microorganisms in question.
These two bacteria coexist in milk in a mutually beneficial interaction. Hence, they support one another’s development and survival. And they create amazing yogurt together. Many chemicals produced by these two bacteria give yogurt its distinctive flavor. Lactic acid is one of them, along with other acids including acetoin, acetate, and acetaldehyde. Yogurt has a strong acidic flavor as a result of all these acids. Exopolysaccharides are also produced by our two bacteria. They are typically used by bacteria to form biofilms. But, in this instance, the lengthy sugar chains of the exopolysaccharides give the yogurt its creamy, thick texture. Yogurt also contains a lot of beneficial compounds because of the bacteria and milk content, including proteins high in energy, calcium, and vitamins B2, B6, and B12.
How is yogurt made?
It would appear that all we require to make wonderful yogurt is milk, our two bacterial species, Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus, as well as the appropriate temperature. These two bacterial species are referred to as yogurt starter cultures.
But milk must first be processed before their superpowers can use it to make yogurt. Basically, this is to get rid of everything else that we don’t need. Hence, the milk is heated to 95 °C in order to eradicate any further germs that can ruin our yogurt. This procedure may be familiar to you as pasteurization. Our two starting bacteria are added when the milk has cooled to about 40 °C. The mixture is then poured into cups and sealed. The cups are then kept in a warm environment, a process known to scientists as incubation. The bacteria can get to work and utilize their superpowers throughout this incubation period. This indicates that the microbial fermentation process is initiated by our two bacteria. They make lactic acid and other acids as they digest lactose, the milk sugar. Because of the many acids, the pH of the milk decreases and it turns sour. Now, the acids denature the milk proteins; this is the same process that happens to eggs when they are heated, making them tougher and less fluid. The milk thickens and becomes creamier and more gel-like in consistency.
What makes yogurt healthy for you?
As we’ve already seen, yogurt has a number of beneficial ingredients, and research has shown that these molecules make yogurt healthy for us. However, how do these proteins, short-chain fatty acids, and vitamins affect our health?
Yogurt, for instance, stimulates the immune cells in our gut. This strengthens our immune system, enabling us to better fend off harmful invaders. Certain milk proteins are also broken down by our two starter bacteria, which results in the creation of so-called bioactive peptides. These peptides are well-liked by our digestive systems. Thus, it delivers them to our bodies where they help our health. Yogurt also contains prebiotic carbohydrates. This indicates that other bacteria in our guts that keep us healthy need them as sustenance. Yogurt also contains a lot of the protein our bodies require to maintain and build muscle. Surprisingly, casein and whey protein are two essential parts of yogurt protein.
Whey protein is referred to as a “fast protein”. In other words, because our bodies absorb this sort of protein more quickly, yogurt gives us energy right away. The other component, known as the “slow protein,” is casein. The acids in our stomach trigger this type of protein to coagulate. Yet, this protein clot can only be slowly digested by our body. As a result, the casein protein keeps us going for up to 7 hours after consuming yogurt. In this way, yogurt promotes fullness, allowing us to eat less overall. Last but not least, yogurt’s short-chain fatty acids are loaded with advantages for our health. They control insulin resistance, blood sugar levels, and appetite suppression.
What is yogurt with probiotics?
Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus, the two starting bacteria, were discovered to not survive the stomach’s acidity. They therefore do not enter our digestive tracts and have no effect on the bacteria there.
Yogurt, on the other hand, is a fantastic carrier for other probiotic microbes to enter our bodies. Organisms are known as probiotics “confer a health advantage on the host when delivered in suitable levels,” according to the definition. Probiotics must also be secure, well-defined, and stable while the yogurt is sitting on the shelf, waiting to be consumed. As a result, many yogurt manufacturers now add healthy microorganisms to yogurt. These microorganisms include Bifidobacterium, Lactobacillus acidophilus, and Lactobacillus casei. These bacteria benefit our immune system and digestive system. They maintain the health of our gut microbiota by promoting the growth of the beneficial bacteria there. For instance, in one trial, yogurt with a Lactobacillus casei species added was given to kids who had severe diarrhea. The yogurt mixture helped these kids’ symptoms and gastrointestinal ache subside after a few days.